Order Cart | Contact Us | Home | SIGs | Login
Spread Spectrum:

1994-1999 Spread Spectrum Rules and Changes

The 1990's saw large changes in the way spread spectrum communication was conducted in the US amateur radio service. TAPR, the ARRL, and others particpated activly in the process to change the rules and enable spread spectrum communications to enter the 21st centruy as a normal amateur radio mode. What follows is an archives of the proceedings and comments that happened between 1995 and 1999. While the rules that were finally adopted are not perfect, they have enabled a much wider range of applications within the amateur radio service.

Report Order WT 97-12
Amendment of the Amateur Service Rules to Provide For Greater Use of Spread Spectrum Communication Technologies
Adopted: August 31, 1999
Released: September 3, 1999


Petition for Partial Reconsideration

Clearwire Technologies, files Petition for Partial Reconsideration (October 25, 1997). (pdf, 867K)

Comments on Reconsideration

Clearwire Technologies withdraws Petition (pdf, 89k)


WT Docket No. 97-12

WT Docket No. 97-12, released March 3, 1997. (WP, 67K)
WT Docket No. 97-12, released March 3, 1997. (txt, 19K)
WT Docket No. 97-12, released March 3, 1997. (pdf, 1482K)


Comments to WT Docket No. 97-1 Reply Comments to WT Docket No. 97-1


The Initial Filing, assigned as RM-8737

ARRL Petition for Rulemaking, filed December 12th, 1995.


Comments to RM-8737


Reply Comments to RM-8737


Additional Notes and Comments


Page note: Correction of spelling or other errors in the above documents were not made so that they may reflect the exact wording submitted to the FCC. If the author of any the above comments finds a mistake with data entry, please let us know so that we might correct the error. These documents are made available for the general amateur community and are being made available as accurate as possible.
Tucson Amateur Packet Radio Corp, comments to Docket rm8737 May 5th, 1997


                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.rm8737
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 

To: The Commission


                        COMMENTS OF
           TUCSON AMATEUR PACKET RADIO CORPORATION

The Tucson Amateur Packet Radio Corporation ("TAPR") 
submits these comments in response to the above-referenced 
notice of proposed rule making (the "NPRM") released by the 
Commission on March 3, 1997.  

BACKGROUND AND STATEMENT OF INTEREST

TAPR is a non-profit (501(c)(3)) scientific and educational 
organization with more than 2,500 members worldwide.  It is 
chartered to engage in three principal activities:  scientific testing 
and research into the development and improvement of 
technological systems for use in the amateur radio service 
including, but not limited to, digital packet radio 
communications; research and testing of systems, hardware, and 
software for packet radio local area networks and computer 
network systems; and disseminating to the public the 
information obtained as a result of such research and testing.

TAPR was founded in 1982 as a national organization 
with interests in the areas of packet and digital communications.  
It grew out of a 1981 effort to design a packet radio Terminal 
Node Controller, or "TNC," that would be available to amateurs 
at a modest cost.  From these initial designs emerged what is 
now the de facto standard in amateur and many commercial 
packet radio operations. 

Today, TAPR continues as an international, membership-
supported research and development organization for the 
amateur radio community.  TAPR continues to develop new 
communications technology, provide kits for the amateur 
community, and promote the advancement of the amateur art 
through publications, meetings, and communications standards.  
TAPR also maintains a web site (http://www.tapr.org), which 
includes a page specifically addressing current amateur spread 
spectrum issues (http://www.tapr.org/ss).

DISCUSSION

TAPR generally supports the proposed rule changes the 
Commission makes in its NPRM.  Spread Spectrum ("SS") 
technology has not made great advances in the amateur radio 
service since it was first permitted in 1985, in part due to the fact 
that, by today's standards, the Part 97 regulations on amateur SS 
are extremely restrictive.  In particular, the small number of 
fixed spreading codes permitted under Section 97.311(d)(1) 
inhibits the use and development of SS by amateur radio 
stations.  TAPR believes that it is in the public interest, and in 
the interest of the amateur radio service , to change the rules for 
SS in order to accelerate the adoption of SS by the general 
amateur community.

TAPR in general supports many of specific rule change 
recommendations made by the Commission.

First, TAPR supports the Commission's proposal to 
modify Part 97.311(b) as it pertains to the unintentional 
triggering of repeater inputs.  This provision is redundant when 
considered in relation to the existing sections in Part 97 which 
deal with how interference should be treated and handled.  This 
single provision alone has been a subject of concern for some 
time to members of the repeater operator/owners community 
and rightly so.

However, for this same reason TAPR feels that the 
proposed wording of this section puts an unnecessary burden on 
those who choose to utilize SS emissions.  After being 
authorized as a legal emission mode in the service for over 
fifteen years now, it now seems inappropriate to continue to 
single out SS to be considered secondary to all other allowable 
emission modes authorized in the service.  We therefore ask the 
Commission to strike the proposed section 97.311(b) in its 
entirety.  The Commission's rules in this area should go no 
further than to set a maximum transmitter power output level 
and to set limits on spurious emissions outside the amateur 
radio bands.

Second, TAPR supports the Commission's decision to 
delete sections 97.311(c) and (d), in order to permit SS emissions 
and spreading codes that are not currently authorized.  
Elimination of the rule that dictates specific spreading codes in 
necessary to facilitate further experimentation and deployment 
of SS technology in the amateur radio service.  In particular the 
removal of the provision that restricted the use of  hybrid SS 
emissions will open up potentially new areas of interesting 
experimentation that have not been allowed for over fifteen 
years now.

While, as noted above, TAPR agrees with many of the 
Commission's proposed rule changes, it disagrees with a few of 
the proposed changes contained in the rulemaking.

First, TAPR does not agree with the proposed automatic 
power control provision of section 97.311(g).  Although TAPR 
supported the ARRL proposal for this provision in the 
comments and reply comments that it filed in RM-8737, it no 
longer feels that this provision should become a part of the rules 
governing SS emissions.  Further discussion and 
experimentation that has taken place since the petition phase of 
this proceeding has convinced TAPR that the implementation of 
this provision would impose a serious handicap on the future 
development of this emission mode.  While TAPR agrees that 
technically it is simple to control the output power of a 
transmitter, it is quite another matter to make this control 
automatic and foolproof over the wide range of applications and 
uses that are common today in the service.  For instance, the 
implementation of this provision would make it impossible to 
use SS emissions in the point-to-multipoint packet radio 
networks that are common in the service today because it would 
be difficult to transmit a single packet which would not exceed 
the Eb/N0 level at the nearest station.  TAPR therefore asks the 
Commission to strike the proposed automatic power control 
language of this section.  TAPR feels that the provisions of 
section 97.313(a), which limits the power level to the minimum 
required to maintain communications is all that is necessary to 
cover the concerns which prompted this proposed rule change.

Further, TAPR would like to see the limit on transmit 
power to 100 watts of this section also deleted.  While TAPR does 
feel that 100 watts of power is more than enough for most 
terrestrial SS operations, this limit may present problems for 
some of the more interesting applications in the service today 
such as EME (Earth-Moon-Earth) operations.  It would appear 
that the 100 watt limit was imposed back in 1985 out of a concern 
for limiting the range of possible SS interference, this concern 
appears groundless in the operating environment that we now 
face today.  TAPR therefore asks the Commission to strike this 
provision and allow SS emissions that same transmitter power 
levels allowed for the other emission modes authorized for the 
service.

Second, TAPR does not agree with the Commission's 
decision to allow sections 97.311(e) and (f) to stand as written.  
Both sections place a significant record-keeping burden on any 
operator who wishes to make use of the SS emission mode. 
 While these sections may have made sense back in 1985, twelve 
years later all they serve to do is to present a serious impediment 
to any amateur operator who wishes to experiment and deploy 
this mode.  TAPR therefore asks the Commission to now 
establish parity between SS and all of the other emission modes 
(including pulse) and delete the burdensome provisions and 
requirements of these sections.

In addition to the rule changes proposed in the NPRM, 
TAPR would also like the Commission to consider the making 
additional changes in the rules affecting SS emissions.

First, TAPR would ask that the Commission allow SS 
emissions on all amateur radio bands above 50 MHz.  As we 
have stated earlier, TAPR feels that the Commission's rules for 
SS should go no further than to set a maximum transmitter 
output power level and to set reasonable limits on spurious 
emissions outside the amateur radio bands.  Conventions for all 
other parameters of operation such as operating frequencies, 
modulation method, bandwidths, protocols, etc. are best left to 
the development of the amateur radio community itself.  Such 
an approach would be in line with the stated policy of the 
Commission itself in the NPRM to develop rule changes which 
are "...consistent with our policy of encouraging greater 
spectrum flexibility by enabling licensees to introduce 
innovative technologies and to respond quickly to demands for 
new and different services and applications, without 
administrative delays".  TAPR feels that SS technology will 
provide for such innovation in the service and has great 
applicability to amateur bands below 70 cm (SS now only being 
allowed on bands 70 cm and above).

Second, TAPR feels that the station identification 
requirements of section 97.119(b)(5) should be deleted.  The 
interference and harm to the band in which an SS station is 
operating that would be caused by a requirement to use a CW 
identification far outweighs the benefits that would accrue for 
monitoring purposes from the use of such an ID.  Further, it is 
vital to avoid an ID requirement that would in itself cause 
interference even when the associated SS emission does not.  
TAPR feels that it would be better for the amateur radio 
community to develop approaches for handling the necessary 
functions of monitoring and identification of SS emissions.

CONCLUSION SS technology can provide many useful benefits to the amateur radio community if its use becomes more widespread and mainstream. In order to accomplish this however, certain changes must be made to the Commission's rules governing the use of SS in the amateur radio service. By making these changes, the Commission will create a regulatory environment that will give members of the amateur radio service enough flexibility to develop innovative equipment and hardware employing SS technology. For these reasons, TAPR urges the Commission to promptly issue a report and order in this rulemaking as soon as possible to facilitate the development and deployment of SS communications in the amateur radio service, as proposed in the NPRM and as modified herein. Respectfully submitted, THE TUCSON AMATEUR PACKET RADIO CORPORATION By: Dewayne Hendricks Tucson Amateur Packet Radio Corporation 8987-309 E Tanque Verde Rd #337 Tucson, Arizona 85749-9399 (940) 383-0000


AMERICAN RADIO RELAY LEAGUE INCORPORATED, comments to Docket rm8737 May 5th, 1997

Before the
FEDERAL COMMUNICATION COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of the Amateur Service   )  WT Docket No. rm8737
Rules to Provide For Greater Use   )
of Spread Spectrum Communications  )
Technologies                       )
                                   )

To: The Commission

COMMENTS OF THE
AMERICAN RADIO RELAY LEAGUE INCORPORATED

The American Radio Relay League, Incorporated (the League), the national association of amateur radio operators in the United States, by counsel and pursuant to Section 1.415 of the Commission's Rules (47 C.F.R. paragraph 1.415) hereby respectfully submits its Comments in response to the Notice of Proposed Rule Making (the Notice), FCC 97-10, released March 3, 1997. The Notice proposes to amend the Amateur Service Rules, Part 97, to facilitate Spread Spectrum (SS) communications by means of additional spreading codes, and to cause the incorporation of automatic power limiting circuitry to limit power to that actually necessary to carry out the communications. The Notice is based on the League's petition RM-8737, filed in December of 1995. For its comments on the proposals contained in the Notice, the League states as follows:

1. The Notice proposal is essentially a deregulatory plan to encourage and facilitate experimentation with SS communications in the Amateur Service. The League wholeheartedly supports each of the proposals. The rule changes offer the opportunity to experiment with SS modes, thus to develop practical applications in addition to those already known.

2. In amateur applications, the bands above 420 MHz are presently used principally for narrowband modes. The proposed new rules for SS systems in those same bands will allow experimentation and maximized compatibility between wideband and narrowband communications. The Notice would at once permit experimentation with SS spreading codes that will minimize potential [1] interaction with narrow band communications modes, and also limit power automatically to the absolute minimum necessary to establish and continue the communications. This combination of benefits from the proposed rule changes should be sufficient to minimize any interaction between amateur emission modes. The effect of the automatic power limitation on interference potential is obvious. The relief of restrictions on spreading codes will permit experimentation with a wide variety of spreading codes, thus to determine which are least likely to cause interaction with narrowband amateur emission modes. In any case, amateurs are called upon to cooperate in the use of shared frequency bands regardless of emission type. As has always been the case, advance planning and coordination will facilitate harmonious use of both SS and narrowband communications modes. Any fear of interference to voice repeaters or weak-signal communications can and should be avoided by intraservice cooperation in the selection of frequencies, rather than by restricting emissions types for SS communications The latter has served to restrict the ability to experiment with SS communications. The Commission has established the correct presumption in favor of encouraging experimentation while at the same time proposing mechanisms to limit interference potential.

3. That there is interest in experimentation with SS communications is indisputable. However, the bulk of SS experimentation over the past few years has been conducted pursuant to extended Special Temporary Authorizations granted by the Commission. That fact evidences both the overly restrictive nature of the current SS rules, and the effect thereof on SS experimentation and utilization in the Amateur Service. The Notice suggests a modest deregulatory effort, and is properly aimed at increasing the flexibility of spread spectrum users in order to allow the development of compatible system which maximize spectrum efficiency. The amendment of the rules to permit experimentation is a proper course of action for the Amateur Service, which is a fundamentally self-regulating service that makes its own efficient accommodations for the varied uses of its frequency allocations.

4. The Commission properly had proposed no restrictions on amateur SS operation in order to protect Part 15 devices, which operate at sufferance to licensed services in certain bands. No such restrictions exist relative to other emission modes, and there is no justification for any restrictions on any licensed service's use of its own allocations in order to protect SS Part 15 devices.

5. Comments on the League's Petition, RM -8737, variously supported even greater flexibility for amateur spread spectrum operations, or reduced flexibility in order to protect other narrowband amateur operations or certain kinds of unlicensed, Part 15 intentional radiators. In its proposal, the Commission has recognized that these competing objectives have been carefully balanced in the rules proposed therein. The League commends the Commission for its balanced approach and urges that the rules be adopted as proposed at the earliest opportunity.

Therefore, the forgoing considered, the American Radio Relay League, Incorporated supports the Notice proposal, and respectfully requests that the Commission move quickly to implement the rules in the Appendix B thereto.

Respectfully submitted,

THE AMERICAN RADIO RELAY
LEAGUE, INCORPORATED
225 Main Street
Newington, CT 06111

By Christopher D. Imlay
Its General Counsel

BOOTH FRERET, IMLAY & TEPPER, P.C.
1233 20th Street, N.W., Suite 204
Washington, D.C. 20036
(202) 296-9100

May 5, 1997


[1] The League, as stated in its petition, PM-3787, is unaware of any instances of interference to amateur narrowband communications from amateur SS communications using the saem or adjacent frequencies.


LYLE V. JOHNSON WA7GXD, comments to Docket 97-12 May 5th, 1997


                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.97-12
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 


COMMENTS OF LYLE V. JOHNSON WA7GXD

Introduction

I have been a licensed radio Amateur since 1964 (WN6JLR) at age 13 and have held my present station callsign since 1967. My operator license is Extra Class.

I am cofounder of Tucson Amateur Packet Radio, and served on its Board and as its President for many years, including the time of the TNC and TNC-2 projects. I was also a leading member of the project teams that created those devices. Since 1983, I have been a volunteer engineer for AMSAT. I was a principal designer of the Digital Communications Experiment aboard the UO-11 amateur spacecraft, and I was responsible for much of the design of the computer systems aboard the MicroSats (AO-16, DO-17, WO-18, LO-19, AO-27). I currently am heavily involved in the technical design of many of the systems aboard the upcoming Phase 3 D satellite (control computer, digital communications system, etc.).

It is from the perspective of one who has been a direct participant at the forefront of some of the more sweeping technical developments within the amateur radio community over the past several years, and without commercial interest, that I offer the following comments.

Overview

The proposed new rules will in general be conducive to increased experimentation and development of SS techniques within the Amateur community. However, I perceive three impediments in the proposed rules that may serve to defeat much of the stated purpose of the rulemaking.

Specifically, I request that part 97.119(b)(5) be changed to allow identification of an SS station by means of SS techniques, that part 97.311(e) be simplified or eliminated, and that part 97.311(g) be retained in its present form.

Discussion

Station Identification

The original ARRL petition for rulemaking specifically avoided requesting a change to SS station ID requirements, but did question the practicality of narrowband identification for SS operation (footnote 7 of the petition of 12 December 1995).

There are three purposes that come to mind when considering ID requirements. The first is to facilitate communications between stations; the second is to allow monitoring by other stations; the third is to more easily identify a station causing harmful interference.

Part 97.119(b)(5) presently requires that a narrowband ID be sent, or that the SS emission be altered so that a narrowband CW or phone receiver can determine the station callsign.

I suggest that this requirement is at odds with a stated purpose of this rulemaking, "to develop more effective and efficient uses of the radio spectrum."

Many commenters to the original proposal expressed concerns about potential interference to narrowband users. Others pointed out that many SS stations could coexist with many narrowband stations over the same overall spectrum without mutual interference. To allay the fears of the former, and allow demonstration of the benefits of the latter, SS emissions must necessarily be "invisible" to a narrowband station's receiver.

But, we have in place a rule that requires the SS station to operate in a way that guarantees the emission will be heard by narrowband receivers!

Consider that, if the ID is not to cause harmful interference, the SS station operator must listen on the chosen narrowband frequency before sending the ID since the normal operation of the SS station would have correctly led a narrowband user to conclude the spectrum was available for him to occupy. The normal method employed by amateur operators to determine if a channel is available for use is to listen for a brief period of time, perhaps several seconds. If no activity is detected, the operator usually sends a brief transmission inquiring if the frequency is occupied. If this does not elicit a response, he or she concludes the channel is available and commences operation.

If, several minutes into operation the receiver at the narrowband station is trampled by an SS station's sudden narrowband-compatible ID, the narrowband operator will be subjected to annoying, and perhaps harmful, interference. Such operation can only strengthen fears that SS operation will lead to interference with narrowband operation. This type of problem can easily be avoided if SS stations are allowed to send their ID in the same manner as they are sending other information by narrowband-invisible SS!

It seems reasonable, then, that in order to comply with the present rule, the SS station operator has two choices, neither of which are good:

1) The SS operator must have in operation simultaneously a narrowband radio and an SS radio to reasonably meet the station identification requirement and not cause potentially harmful interference to the narrowband user. The narrowband transmitter must operate any time the SS one does, to preclude a narrowband station from occupying the ID frequency the SS operator has chosen.

2) The SS station must operate in a manner such that its signal is always detectable by a narrowband receiver in order to preclude the narrowband user from occupying the identification frequency the SS operator has chosen.

Both of these scenarios are clearly in direct opposition to an important stated reason for SS operation and experimentation in the Amateur Radio Service: that of more efficient spectrum utilization. It also forces the SS station to add to narrowband channel congestion, which precisely feeds the fears expressed in the arguments of many of the commenters to this proceeding.

For SS to be practical, casual listening must be possible or the SS station operator will never be able to communicate with anyone else. Thus, it seems reasonable that SS station operators will publicly disseminate information about their transmission format and frequencies so that others can communicate with them. If this is not done, SS is unlikely to ever achieve widespread use, in which case this mode will not be responsible for causing much interference to anyone.

This dissemination could be on a narrowband channel giving callsign and other details of operation. This is analogous to early packet operation, where stations would coordinate on a local VHF FM repeater, then change frequency to operate on packet. Later, as packet gear became more widespread, it was no longer necessary to coordinate using other modes, packet-only operations commenced and have become ubiquitous.

It seems reasonable that SS operation, if it in fact becomes popular, will follow a similar path. Early on, station information will be easily available by non-SS means, including station ID, because it is the only way the SS station operator can attract other station operators with which to communicate.

Later, if SS operation evolves into a practical mode, equipment will be widely available to anyone who cares to purchase it in a competitive marketplace. Such equipment will necessarily be able to operate on the then-popular SS modes and monitor such transmissions at will. It seems unreasonable to assume that SS will be widespread enough to cause harmful interference to narrowband users, yet remain unidentifiable by easily available means.

Thus, practical concerns will make it easy for a narrowband user to be able to reasonably identify an SS station early on. As the SS modes become popular, the narrowband user can obtain an SS radio, or ask an SS-equipped station to monitor for a particular transmission if he wishes to identify it. Regulatory monitoring facilities will have access to the same information and equipment on the same widely-available basis.

This has been the historic pattern when new modes are developed and then adopted. It seems reasonable that SS will follow the same pattern.

Since virtually every other authorized mode in the Amateur Service is allowed by 97.119 to ID by the communications method being employed for the primary communications, it is reasonable that SS stations have this same freedom. If the SS station is sending voice, then the ID is in SS-voice in the English language - this is already covered by 97.119(b)(2). If the SS station is sending data, then the ID should use a standard data format (e.g., ASCII callsign information) - this is already covered by 97.119(b)(3). If images, then 97.119(b)(4) already covers the ID requirement.

If the ideal of efficient spectrum utilization is indeed a goal of these proceedings, the requirement of a narrowband ID is contrary and should be eliminated.

If a malicious individual wants to use an SS transmitter to cause harmful interference, he or she will likely have to be discovered via direction-finding (DF) techniques, just as the few malicious interferers are tracked today. In spite of requirements that they identify themselves, such operators are unlikely to comply with the rule that they provide a narrowband-compatible station ID.

My point is that it is in the SS station operator's self-interest to promulgate information about his station in a manner that is easily discovered or he cannot communicate with other stations. If the only means employed to do this is SS, then the implication is that SS is sufficiently entrenched that monitoring receivers are readily available at inexpensive prices.

For these reasons and others, I respectfully submit that it is logical and compelling for the Commission to rescind Part 97.119(5) as a part of this rulemaking.

Station Record Keeping

Part 97.311(e) places a significant record-keeping burden on any station operator who wishes to use an SS radio. This level of record-keeping presents a serious impediment to an amateur who wishes to experiment with this mode. There is no similar record-keeping requirement for any other mode of operation within amateur radio, so it only seems rational to ask the question:

How does this detailed level of record keeping assist in the Commission's stated purpose of this proceeding to, among others, "encourage the amateur service community to expand its experimental activities with SS" and to allow "licensees flexibility to develop more effective and efficient uses of the radio spectrum"?

A person performing technical investigation and experimentation will, as a normal part of that process, keep such records as he or she deems appropriate to document the phenomenon or feature being investigated. The fact that the information being sent may represent a voice, a picture, or text may be irrelevant. If the methods employed are generally known to practitioners of the art and well-understood, a requirement to keep a detailed technical description of a circuit's operation seems superfluous.

Further, if the experimenter is using a subset of available packaged integrated circuits to perform a function, detailed information regarding the internal operation of the chip may not be easily available for him or her to provide the documentation required by this rule. This may preclude the use of readily available, proven technology for portions of an experimental SS radio design.

In order for SS to become generally useful in the Amateur Radio Service, it must necessarily be used by communicators as well as technical developers.

A person whose pursuit of SS within amateur radio is simply to utilize a more interference-resistant mode in, say, a local emergency (flood, fire, etc.) may not have the technical expertise or know-how to comply with this rule. This doesn't limit their ability to effectively use the SS radio as a practical matter.

I suggest that technical investigators will create records pertinent to the investigation as a natural course of their investigation, and that potential communicators will often not be in a position to comply with the present rule due to a lack of information and understanding.

Thus, I request the Commission:

1) drop the present requirement and mark 97.311(e) as "reserved" or

2) rewrite 97.311(e) to read in its entirety "Logs and notebooks pertaining to technical investigations in SS on amateur radio frequencies be retained by the licensee for a period of one year following the date of the last entry."

Power Control

Part 97.311(g) currently allows SS emissions with a maximum power output of 100 watts. This seems a reasonable limit, and it is very simple to construct a transmitter which falls within this rule.

The proposed rule modifies this considerably, requiring a measurement of received energy per bit, spectral power density of noise and interference. Then a computation must be performed and a limit of the received signal strength be enforced by the local station commanding the distant transmitter to adjust its power output level.

Implementation of this rule might be feasible (technically and economically) in point-to-point communications between two Amateur stations. It is being done in commercial CDMA cellular telephones because it is technically necessary in a system of numerous mobiles "connected" to a central cell site using DSSS modulation techniques.

Unfortunately, to allow cooperative operation of SS radios from multiple sources, control protocols must be designed, agreed upon and implemented. It is one thing for an innovative cellular manufacturer to promulgate such protocols under the umbrella of its various patents; it is quite another for multiple, parallel and independent developers, such as amateurs, to define, agree upon and implement such a scheme as a practical matter. This requirement effectively places a significant barrier to be overcome and a barrier which in itself constrains traditional amateur communications practice.

Amateur operation is frequently quite different than commercial cell phone operation, and often uses multipoint-to-multipoint and point-to- multipoint topologies.

For example, it is common practice to engage in "roundtable" discussions among several amateur stations in varying geographic relationships. This is a case of multipoint-to-multipoint operation. If station A is 1 mile from station B but 20 miles from station C, how does station A set its transmitter to comply with the proposed regulation? If the signal is in compliance at intended receiver B, it may be weak or unusable at intended receiver C. If set to be useable at intended receiver C, station A's transmissions will very likely be non- compliant with the new proposed rule at simultaneously intended receiver B.

If a station is transmitting through a linear translator (e.g., a spacecraft) this becomes even more of an issue as the capability of amateur stations receiving such transmissions vary dramatically with antenna size, location (urban versus rural) and other factors for a transmission with many intended recipients. How would one set a telemetry downlink from a spacecraft using SS techniques to ensure no ground station ever had a signal which exceeded the threshold in the new rule? This is an example of point-to-multipoint communications.

While many more examples could easily be cited, my point is that automatic power control as specified in the proposed regulations will render unfeasible one of the traditional, and popular, styles of Amateur radio communications, and preclude the use of SS in technically advanced projects such as amateur spacecraft.

Finally, Part 97.313(a) already requires that Amateur stations use the minimum power necessary for the intended communication, regardless of mode. Thus, SS operation is already reasonably constrained. Singling out SS operators as being inherently more likely to flaunt this rule, and thus requiring some sort of "silicon cop" to achieve compliance, seems unreasonable.

The new rule is more restrictive than the old, and in the absence of evidence in the record that the existing SS power rule has led to difficulties, I request the Commission retain Part 97.311(g) in its present form. Conclusion

Amateur spread spectrum communications will be greatly facilitated by the present proposed rules changes if Parts 97.119(b)(5) , 97.311(e), and 97.311(g) are amended as suggested in this comment. The retention of 97.119(b)(5) will necessarily cause SS stations to interfere with narrowband users, severely curtailing the development and use of SS as a viable means of amateur communications and diluting the mode's potential for spectrum efficiency. The retention of 97.311(e) unnecessarily burdens the potential SS communicator and technical investigator, reducing their incentive to contribute to the development and deployment of SS modes within the Amateur Radio Service. The proposed 97.311(g) rule, if adopted, will prevent traditional amateur multipoint-to-multipoint operation and inhibit the use of SS in point- to-multpoint applications, such as spacecraft telemetry.

Thank you for your consideration of these comments in this proceeding.

Respectfully Submitted,

Lyle V. Johnson 02 May 1997

Page 5 of 6

RM-8737 Comments of Lyle V. Johnson


Philip R. Karn, Jr, KA9Q, comments to Docket 97-12 May 5th, 1997

Before the Federal Communications Commission
Washington, DC
In The Matter of				)
Amendment of the Amateur Service		)
Rules to Provide For				) WT Docket No. rm8737
Greater Use of Spread				)
Spectrum Communication				) RM-8737
Technologies					)
Comments of Philip R. Karn, Jr, KA9Q

Introduction
I respectfully offer these comments to the Commission in support of the proposed liberalization of the existing rules to permit expanded use of spread spectrum (SS) communications in the Amateur Radio Service. While I am a member of the ARRL Future Services Committee and an employee of Qualcomm Incorporated, a major developer and manufacturer of commercial digital spread spectrum cellular telephone equipment, the opinions expressed here are strictly my own.

Spread spectrum has become an important communication technology. The many advantages of this technique include:

  • improved resistance to multipath propagation, especially in urban environments;
  • increased resistance to interference, both intentional and unintentional;
  • reduced average transmitter power requirements, when combined with error control coding and automatic transmitter power control;
  • increased spectrum capacity, especially when carrying intermittent traffic;
  • special features, such as accurate ranging

But spread spectrum is, so far, almost entirely a non-amateur phenomenon. While many license-free devices incorporating spread spectrum have been used under Part 15.247 rules, and while the large scale deployment of CDMA (spread spectrum) digital cellular telephones is now underway, use of spread spectrum under the existing amateur rules remains almost nonexistent.

Why Amateur SS Has Failed

The reasons for this include restrictive rules, the lack of suitable equipment and resistance from certain elements of the amateur community. Also, the ready availability of Part 15.247 equipment to amateurs has significantly diluted potential interest in spread spectrum operations under Part 97 rules. Not only are the Part 15 rules far more liberal in the allowed modulation methods and spreading codes, but Part 15 operation also permits encryption and commercial use -- two practices prohibited under amateur rules -- yet, ironically, the Part 15.247 bands are shared with the amateur service. In any event, it is safe to say that far more amateurs are presently conducting spread spectrum operations under Part 15.247 than under Part 97 rules.

But Part 15.247 devices are invariably proprietary "black boxes" designed for ease of use by a nontechnical consumer. While they are quite useful to amateurs (and others) in a "utility" mode (e.g., as Internet access links) Part 15 was not intended to further the basis and purposes of the Amateur Service.

The Amateur Service Needs Maximum Rule Flexibility
The amateur service needs its own spread spectrum rules specifically designed to promote the basis and purposes of the service, particularly technical experimentation, development and self-training. This is best accomplished with an absolute minimum of restrictive regulation, deferring as much as possible to the amateur community to produce its own operating standards and practices to minimize harmful intra-service interference.

The FCC's rules should therefore go no further than to set a maximum transmitter power level and to set limits on spurious emissions outside the amateur bands. In the context of the present proceeding, therefore, the Commission should permit spread spectrum operations on all amateur bands, including HF, not just those above 50 MHz or 219 MHz.

Conventions regarding all other parameters, including operating frequencies, modulation type, bandwidths, protocols, etc, are best left to the amateur community, as it can react to changing needs and local conditions far more rapidly than the Commission.

HF spread spectrum is particularly interesting, given its inherent ability to deal with interference and ionospheric multipath. Even without full-blown spreading, relaxing the existing bandwidth limits on HF digital modes would permit the use of more power-efficient modulation and coding schemes that could easily permit transmitter power reductions of 10-15 dB or more for a given data rate. Such gains have already been demonstrated by lab and field tests published in QEX that compared military standard HF digital modems operating in 3 KHz channels with those designed within the amateur community for the arbitrarily narrow 500 Hz data channel. A general reduction in average amateur HF transmitter power levels is clearly a desirable goal.

Intra-Amateur Interference Issues
The complete deregulation of amateur spread spectrum may seem like a radical suggestion that would lead to anarchy on the ham bands. Yet the existing FCC rules technically permit many things that, if widely practiced, would also lead to anarchy on the ham bands. For example, there are no specific prohibitions in the rules against

  • Operating local FM simplex on the input of a repeater;
  • Conducting high power terrestrial DX operations on the downlink of an amateur satellite;
  • Conducting local operations on the various EME and DX calling frequencies;
  • Operating 100 KHz bandwidth digital links on the 432.1 MHz weak signal calling frequency;
And so on. Despite some well-publicized exceptions, interference of this kind is actually quite rare. There is still a strong sense of community within the amateur service and a willingness to work together to avoid interfering with one's fellow ham.

Even if the rules were amended to permit spread spectrum on all amateur bands, other rules would continue to apply with full force, such as 97.313 (no more power than required to maintain communications), 97.101(c) (priority given to emergency operations) and 97.101(d) (no malicious interference). And the present rules would make spread spectrum operations secondary to other operations.

It is impossible to say that under absolutely no circumstances could spread spectrum operations interfere with traditional narrow band operations. But it is wholly inappropriate to demand such guarantees in the first place. Yes, amateur frequencies are still occasionally involved in emergency communications despite being almost completely eclipsed in recent years by cellular phones, portable satellite links and the like. But the amateur service has always been primarily an experimental, technically-oriented service. It is not a critical operational safety-of-life service like public safety or aviation, nor is it a common carrier utility like cellular telephones. Some level of unintentional interference is therefore to be expected and tolerated.

Discussion of the Proposed Rules
I generally support the rules proposed by the Commission with the following exceptions and additions:

Increase the maximum power allowed for SS emissions directed to space
100W is probably enough for any conceivable terrestrial spread spectrum operation, particularly if strong error-control-coding techniques are incorporated to improve the power efficiency of the communication over traditional narrow band signal formats.

But the 100W limit may present a problem for certain promising deep-space applications of spread spectrum, particularly EME (Earth-Moon-Earth) operation with the moon as a passive reflector. The EME link is characterized by severe multipath, making spread spectrum a highly promising technique. The high antenna gains and skyward-pointing antennas generally used with EME clearly make the 100W limit unnecessary to protect terrestrial operations.

Another promising use for high power SS transmissions is communications with interplanetary spacecraft. Discussions are already underway within AMSAT for an amateur-built spacecraft to be flown to Mars, and it would be beneficial to use high power SS transmissions for accurate ranging measurements over interplanetary distances.

I therefore suggest a waiver on the 100W SS power limit for space communications. If the Commission feels it necessary, it could use language similar to that of existing section 97.313(f) to allow use of the waiver only above a certain antenna elevation. (That section specifies that the -3dB point of antenna main lobe be above 10 degree elevation.)

Eliminate the automatic power control requirement
I originally conceived and devised the proposed requirement for automatic transmitter power control with a received Eb/N0 limit. My proposal was adopted by the ARRL Future Systems Committee, of which I am a member, and then by the League in its RM-8737 filing.

I no longer believe this provision should be codified in the FCC rules. It is possible to conceive of situations where it would be difficult or impossible to meet this requirement. The best example is in a multicast situation (one transmitter sending to several receivers simultaneously), where one cannot reach all stations with an acceptable signal without exceeding the Eb/N0 at the nearest station. In any event, the provisions of 97.313, particularly paragraph (a) limiting power to the minimum required to maintain communications would still apply, as it does to all amateur communications.

Ways The Amateur Service Can Mitigate SS Interference
The present proceeding addresses the rules the Commission should establish regarding spread spectrum operation, and in my opinion these rules should be kept to an absolute minimum to promote flexibility and self-regulation within the amateur community. Nevertheless, I believe it would be useful to put into the record some of the approaches that could (and should) be used on a voluntary basis to minimize interference.

This is only a partial list, based on my own ideas and experience. Nonetheless, I believe it shows the potential of the amateur service to devise its own effective and novel solutions to mutual interference problems. I'm sure that other amateurs can add substantially to this list.

Automatic power control

Although I no longer feel it should be a mandatory rule, I still firmly believe in the value of automatic transmitter power control and the minimization of receiver Eb/N0 ratios with the strongest available error control coding. Analysis and field tests of SS-CDMA channel capacity performed at Qualcomm and elsewhere conclusively show the close inverse relationship between receiver Eb/N0 and overall system capacity: every 3dB reduction in Eb/N0 ratio translates directly into a 3dB increase (a doubling) of the number of users that can simultaneously share the channel.

I will certainly endeavor to incorporate power control and strong coding into any system I design, and I will strongly encourage other designers to do likewise.

Directional antennas
It almost goes without saying that when a point-to-point link is desired, directional antennas are always helpful in minimizing the amount of energy radiated in directions other than the intended receiver.

Min-power relaying
It is now well established in studies and experiments with self-organizing distributed packet radio networks (e.g., DARPA SURAN) that it is far more efficient, spectrally speaking, to cover significant distances by relaying data across a series of relatively short links at low power than to send it at high power over long links. This approach is straightforward to implement in existing packet network routing algorithms if the "link cost metric" used in the calculations is simply the estimated transmitter energy required to reach the next station. The routing algorithm will then work to minimize the total transmitted energy, summed over all of the nodes in the path, needed to reach a specified destination.

Alternatively, the link metric can be an automatic estimate of the number of neighboring stations that will have to be "jammed" by the present transmitter using whatever power is needed to reach the next hop. I presented a talk on this specific topic at the 1991 ARRL Digital Communications Conference.

Modifications of these techniques can be used to implement multicasting by relaying relatively low power transmissions to each intended receiver across a spanning tree instead of "blasting" the transmission at high power to all the receivers simultaneously.

These techniques clearly work toward minimizing the total interference potential of a spread spectrum packet radio network.

Geographical Bandplans
Amateur bandplans have already established band segments on the basis of geographical region of use rather than modulation mode. This is especially true in the VHF and UHF bands, where segments are set aside for satellite, local utility and terrestrial weak signal DX operations. The local utility segments are further subdivided into repeater input, repeater output and simplex segments. In mountainous areas such as California, the repeater channels are further divided into "high altitude" (wide area) and "low altitude" (local area) coverage. Even on the HF bands, subbands are frequently set aside by convention for "DX windows" to keep them clear of strong local interference.

Geographical bandplans are a highly effective way to mitigate the "near-far problem". Although usually associated with spread spectrum signals, the near-far problem also exists with conventional narrowband methods, because no receiver is perfect at rejecting strong unwanted signals. This is precisely why these plans evolved in the first place.

Much of the interference potential of, say, a local utility SS link to weak signal DX operations can be completely avoided by such plans. Moreover, the DX operators would be free to use wideband SS-like techniques (such as strong error control coding) within the DX segments for their own purposes.

Narrowband Identification of Spread Spectrum Signals
There has been much discussion within the amateur community of the need to identify interfering signals, especially experimental spread spectrum signals for which the necessary demodulation equipment may not be widely available.

It is my opinion that no special ID rules are really needed here. If a spread spectrum signal does interfere with a traditional narrowband user, then by definition it can be heard by that user. Conventional "fox hunting" (direction finding) techniques can then be used to locate the source of the SS interference, just as they have long been used to identify other interference sources, both narrowband and broadband (e.g., power line interference).

It would be possible in some (but not all) SS systems to incorporate a CW ID that could be demodulated by a conventional receiver. There are many ways to do this, including:

  • Gating the entire spread emission on and off with Morse Code;
  • Injecting a weak discrete spectral component somewhere in the SS emission and gating it with a Morse identifier;
  • "Notching" part of the spread emission with a filter that is gated in and out with the Morse ID
Other possibilities exist. Some are much more practical than others with a given type of signal; for example, it's very simple in a Direct Sequence SS signal to inject a small unspread carrier component by unbalancing the spreading mixer. The notching approach could be implemented in a fast frequency hopping system by simply gating the transmitter off whenever it would otherwise transmit in the notch during a "key up" interval of the ID. And so forth.

While such an ID scheme would clearly be desirable, I argue against making it mandatory. I can easily conceive of situations where it would be difficult or impossible to implement, and the chances of causing harmful interference are nonetheless low. The best example would be a very high speed packet radio modem using spread spectrum, where the transmissions are very much shorter than a Morse ID at a reasonable speed.

Furthermore it is vital to avoid an ID requirement that would itself cause interference even when the associated SS emission does not. To this end, if other commenters persuade the Commission to adopt a narrowband CW ID requirement, then the power spectral density of the ID (as measured in a typical narrowband receiver bandwidth, e.g., 3 KHz) should not be any greater than the power spectral density of the spread emission that it identifies.

Local Coordination
A highly effective interference mitigation technique is to simply announce one's intentions to the local amateur community. There are now many ways that local amateurs can communicate on a regular basis, ranging from traditional meetings and newsletters to packet bulletin boards and Internet newsgroups and web pages.

If it were customary to give notice of spread spectrum operations, including transmitter location, modulation type, bandwidth, power levels, antenna patterns, etc, to the local amateur community, then anyone experiencing interference from an unidentified source would know who to ask.

I have conceived of a more automatic and general technique for dynamic local spectrum management based on packet radio. It is a generalization of the "Busy Tone Multiple Access" scheme that has been in the literature for years. Imagine a local community of radio amateurs who, by convention, all monitor a fixed packet radio channel in addition to an operational radio frequency (e.g., a DX channel on HF). The stations could announce their receive frequencies on the local packet channel, asking others to stay clear. Such a feature could easily be automated, perhaps integrated with the existing APRS (Amateur Packet Reporting System) that displays GPS station location information. Such a system could work to prevent inadvertent local interference between all types of amateur operations, not just those involving spread spectrum.

Conclusion
I again state my very strong support for the Commissions' proposal to liberalize the spread spectrum rules. Spread spectrum operations should be permitted on as many amateur bands as possible, on a secondary basis, subject only to a total power limit (100W, waived for space operations) and to all the other rules governing the use of minimum necessary power, avoidance of intentional interference, and the like.

Concerns about interference to narrowband operations, while not entirely unfounded, are greatly overblown. The amateur service is fundamentally experimental in nature, and interference has long been a fact of life in the amateur service. These issues are best resolved by the good will and cooperation of the amateurs themselves, not inflexible and detailed rules established by the Commission.

Indeed, given the overall industry trend toward more flexible, dynamic and efficient usage of radio spectrum, the creation of effective cooperative procedures for interference mitigation is itself an opportunity for the amateur service to contribute significantly to the state of the radio art.

Respectfully submitted

Philip R. Karn, Jr., KA9Q


ROBERT A. BUAAS, K6KGS, comments to Docket rm8737 May 5th, 1997


                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.rm8737
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 


To: The Commission


                      COMMENTS OF ROBERT A. BUAAS, K6KGS
Background

I have been licensed in the Amateur Radio Service since 1953. I earned my Amateur Extra Class license in 1961, when I was age 17. For most of my lifetime, I have enjoyed the privilege of experimenting with radio communications, a pasttime I truly love. In addition, I hold a Special Temporary Authorization (STA) dated December 27, 1994, that permits experimentation with any Spread Spectrum (SS) technology in all Amateur spectrum above 50 Megahertz. My involvement with Amateur SS dates back to its original contemplation by AMRAD, in whose STA I participated. I have contributed to the development of successful commercial Part-15 SS systems, and I am a charter member in IEEE P802.11 (the Wireless LAN Ethernet Standard development project).

Introduction

I view the adoption of the Rules Change contained in the proceeding with considerable dismay. While its claimed goal is to simplify and encourage SS, it in fact would contribute to the reduction or elimination of its use.

Precious few of the commenters in this proceeding have any personal practical experience with SS. I find it curious that the spokespeople for the weak-signal interests, particulary Tynan of AMSAT, continue to present their conjectures of doom as fact, without bothering to conduct any realistic tests to validate their claims. Recently, I was invited to speak at the NASA Jet Propulsion Laboratory to Amateurs interested in the current state of affairs in Amateur SS. That opportunity was particularly rewarding, in that some of those same members are responsible for the SS technology used in NASA's deep space weak-signal communications. The concerns of the FM/repeater community are also unfounded, and I address their situation in the Discussion below.

That Commercial interests, particulary Part-15 promoters, seek parity with Amateur operators in the context of this proceeding seems to me to be entirely inappropriate. Metrocom and Symbol Technologies wish to advance their business interests at the expense of Amateur Radio operators opportunity and earned privilege at advancing the State of the Art in Radio Communication. Such is one of the Purposes of the Amateur Radio Service. Part-15 proponents knew and continue to know the Rules and relative priorities of the two Services when they chose to enter the business. Such are the risks of business, and they deserve to abide by their decisions.

Summary

I urge that Commission turn aside this proposal in favor on one which implements the spirit of the environment provided for participants of the STA(s), to wit, (a) operation in any Amateur bands at 50 MHz and above without restriction, (b) use of any coding and/or modulation technology imaginable, (c) permit "in-mode" identification, and (d) eliminate restrictions, thus providing encouragement for designs that reduce interference. I made the same recommendation in my filings on RM-8737. To date, no one has come forward with any evidence that Amateur SS emissions have interfered with anyone.

While I admire the elegance of Phil Karn's proposal for Automatic Power Control (I enjoyed the several discussions we had during its gestation), and I encourage its use, I cannot agree that the specifics of this proposal belong in the Rules. We already have a provision that says: "Use Minimum Power." Rules should apply to ALL systems, not just new ones. There are so many violations of this Rule now, I find it entirely inappropriate that only SS should be saddled with a proposal this specific. After all, it is the very nature of the specificity of the current Part 97 Rules for SS that have all but prevented its use.

Spectral Partitioning, of the variety practiced currently, also is without merit. What will happen when the day comes that a novel weak- signal application wishes to use the very SS technology now proven for deep space, yet the Rules prevent it use in spectrum reserved for weak- signals? Such Rules have proven to be short sighted. The results of this proceeding will affect Amateur Radio for at least a decade. Few of us have sufficient vision to see that distance into the future. Let history be our guide.

Discussion

In this section, I wish to turn some illumination on the subject of conjectured INTERFERENCE to existing operations. This a popular topic, to say the least. I have been the subject of some criticism from those who dispute my claims that properly designed SS system have minimum liklihood of causing interference. Most vocal has been the Repeater Coordination community, yet they have to conduct any independent studies or come forward with documented cases of interference. They certainly have the means and expertise to do their own tests, yet they refuse, and complain all the while.

Having once been a Frequency Coordinator, I understand their position, and their frustrations. They have only one degree of freedom, the Frequency Domain, in which to operate. Perhaps they have two, if one considers the Spatial Domain (stations that would otherwise interfere unacceptably, were it not for the distance or terrain that separates them). The degree of freedom they don't command is the Time Domain. Dealing in the Time Domain requires systems complexity that is currently beyond current Amateur practice. The consequence that Amateur repeaters cannot handle frequency agility has lead to the operational mentality that a Coordinated Repeater "owns" the frequency on which it operates, whether it is IN USE or NOT. Alternative use of its input frequency could mean denial-of-service to authorized repeater users, and thus is defined as INTERFERENCE. Notwithstanding, the Rules are very specific, saying that no Amateur station has any title to any particular frequency. Repeater Owners believe the contrary, and they act like it. Repeater Wars have been fought over single frequencies.

What is fundamentally interesting is the NOT part of the notion above. The prevailing attitudes have lead to particularly low levels of spectral utilization in the Amateur VHF and UHF bands. This is obvious to anyone who looks casually but critically at consecutive scans on the face of a spectrum analyzer. On any one scan, there are very few spectral lines representing current usage. The situation is very dynamic, as repeater transmitters activate and deactive at essentially random times in response to the needs of their respective users. Several years ago, when I began designing STA experiments for assessing the coexistance potential in "densely populated" repeater spectrum, I began collecting real-time utilization data, principally for use in simulations, testing the merits of a variety of frequency and time hopping patterns. This data validated my operational experiences that the interference to existing system was negligable.

Consider for a moment the age-old question: "Is there sound when a tree falls in the forest, if no one is around to hear it?" The following charts show that very little of the popular repeater spectrum is actually in use at any one instant. Conversely, much is available to time-agile systems on a minimum/non-interference basis. The vertical axis is percentage of total spectrum in use; the horizontal axis are the hours in a day. Predictably, certain times see more activity than others. What is not obvious is the low level of simultaneous demand. These charts show, even for the allegedly densely-populated Los Angeles area (for the most part, each of the 133 146-MHz and the 200 445-MHz repeater channels have multiple coordinations per channel), in the TIME domain, the spectrum utilization is well below ten percent (10%).

              146010-147990                        445000-449975
    10 +                                  10 +                        
       |                                     |                *       
    08 +                  **              08 +                        
 %     |                               %     |               * *      
    06 +      *       *     *             06 +      **   *      *     
 U     |       *  **   *               U     |        *   *      **   
 S  04 +            *                  S  04 +     *   **  **         
 E     |    **   *   *  *    *         E     |                     *  
    02 +        *        *    **          02 +    *                   
       |*                                    |*                     * 
    00 +----+----+----+----+----+         00 +----+----+----+----+----+
       0    5   10   15   20   25            0    5   10   15   20   25
              HOUR OF DAY                           HOUR OF DAY

The charts contained in Appendix-A further elaborate on these findings. The first set of 24 charts show the contiguous part of the 2-Meter repeater band hour by hour. The presentation is useful in seeing the probability of collision FHSS systems would experience. The vertical axis shows the frequency of occurance; the horizontal axis shows the number of possible collisions. The second set of 24 charts show data taken simultaneously with the 2-meter data, but for the 445-MHz band. These data conclusively show why our experimental systems achieved no measurable impact. THERE WASN'T ANY IMPACT TO BE HAD.

Further, this situation is little different elsewhere.

It is easy to see why various Commercial interests have launched efforts to reallocate Amateur spectrum to their Service(s).

There is some good news here: given that Amateurs would embrace this technology, and rise to the technical challenges it poses (which are not minor), there need never again be denial of service for Amateurs needing to communicate. FH is one of the simplest and easiest SS systems in operation today. Most Amateur VHF/UHF transceivers contain all the elements needed to do FHSS. By design, they are not configured properly, and the software needed to acquire and maintain synchronization is missing. Most also require slight modifications to the Frequency Synthesizer.

Of course, if this mode catches on, there will be little need for Frequency Coordinators -- their power and prestige will be gone. Simple public databases on the Internet will serve to negotiate and declare code sequences and timebase references.

The examples given here are but few of the many possibilites for coding technology, SS representing a small piece along that continuum. My view is that the Amateur Rules should permit the widest possible interpretation and latitude.

Writing Rules requires VISION; we seem to lack the very thing we most need now.

Conclusion

Spread Spectrum is a complicated art. Even the simplest SS system designs have been, to date, beyond the technical reach of all but the most advanced Amateurs. Yet, it offers considerable promise, not the least of which is much better spectral utilization than is the current practice. Perhaps more importantly, Amateur Radio is one of few vehicles for encouraging young people into taking up a professional careers in Radio Engineering. Without the freedom to try new ideas, those individuals will turn elsewhere. The Internet is currently a powerful draw. Fewer and fewer radio engineers are entering the field from college. I believe that it is the Commission's responsibility to nurture this Service, not limit it or contribute to its demise. I urge you to see the detractors in their true light, and adopt the proposal I make in the Summary above.

RESPECTFULLY SUBMITTED,

By_______________________ Robert A. Buaas, K6KGS

May 2, 1997

Mailing Address: 10044 Adams Ave. #108 Huntington Beach, CA 92646

E-Mail: buaas@wireless.net

-----------------------------------------------------------------------------

APPENDIX-A

146010-147990 hour-24 146010-147990 hour-01 30 + 30 + | | | * | * | * | % | % | 20 + * 20 +* S | S | A | A | M | M | P | * P | L 10 +* L 10 + * E | E | S | S | | * | | * | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-02 146010-147990 hour-03 30 + * 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | P | P | * L 10 + L 10 + E | E | S | S | | * | | | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-04 146010-147990 hour-05 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | * A | ** M | M | * P | * P | * * L 10 + L 10 + E | E |** S | * S | * | | | * | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-06 146010-147990 hour-07 30 + 30 + | | | | | | % | % | 20 + * 20 + S | * S | * A | * A | * M | M | P | P | ** L 10 + * * L 10 + E | * E | * S |* S | *** | * * | * * | * ** | * ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-08 146010-147990 hour-09 30 + 30 + | | | | | | * % | % | 20 + 20 + * S | S | A | A | * M | * * M |* P | P | L 10 + * *** L 10 + E | * * E | * S | * S | | * | ** | ** ** | ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-10 146010-147990 hour-11 30 + 30 + | | | | | | % | % | 20 + * 20 + S | S | * A | A | * M | * M | * P | * P | L 10 + ** L 10 + ** * E | * E | * S |* * * S | * | | * | ** | * * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-12 146010-147990 hour-13 30 + 30 + | | | | | | % | % | 20 + 20 + * S | * S | * * A | * A | M | ** M | * P | P | L 10 + * * L 10 + * E | E | * S | * S | | * | * | * ** |** *** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-14 146010-147990 hour-15 30 + 30 + | | | | | | % | * % | 20 + * 20 + S | S | A | * A | * M | M | * P | * P | * * * L 10 + * L 10 + E | E | * S | * * S | ** | | * *** | *** | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-16 146010-147990 hour-17 30 + 30 + | | | | | | % | % | 20 + 20 + S | * S | A | * A | * M | M | * P | * P | * * * L 10 + * * L 10 + * E | * E | * S | * ** S | * | * |* * | * * | ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-18 146010-147990 hour-19 30 + 30 + | | | | | * | % | * % | 20 + 20 + S | * S | A | A | * M | M | * * P | * P | * L 10 + L 10 + * * E |* * E | S | S | * | * | ** * | * | * * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-20 146010-147990 hour-21 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | * A | M | * M | ** P | ** * P | * L 10 + * L 10 + * * E | E | * * * S | * S | * | ** * | * | * * | ** * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

146010-147990 hour-22 146010-147990 hour-23 30 + 30 + | | * | | * | | % | % | 20 + ** 20 + S | * S | * A | * A | M | M |* P | P | * L 10 + * * L 10 + E | E | S | S | | * | |* * | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-24 445000-449975 hour-01 30 + 30 + | * | | |* | | % | % | 20 + 20 + * S | S | A | * A | M | M | P | P | ** L 10 + L 10 + * * E | E | S | * S | | | * | ** | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-02 445000-449975 hour-03 30 + 30 + |* | | | | | % | % | 20 + 20 +* S | S | A | A | M | M | P | P | L 10 + L 10 + E | E | S | S | * | * | * | * * | *** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-04 445000-449975 hour-05 30 + 30 + | | | | | | % | % | 20 + 20 + S | S |* A | A | * M | M | * P | P | L 10 + L 10 + E | * E | ** * S | S | * | * * | *** | * | * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-06 445000-449975 hour-07 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | P | P | * L 10 + ** L 10 + * * * E | * * E | * * S | * S | * * * | ** * ***** ** * | * ** |* ** * *** | ** *** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-08 445000-449975 hour-09 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | * P | * * * P | ** L 10 + * * * L 10 + * E | * E | * ** S | * S | | ** * * | * *** | * *** | ** **** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-10 445000-449975 hour-11 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | ** P | P | L 10 + * * L 10 + * E | * * ** * E | * ** S | * S | ** * ** | ** * ** | |* **** * | * *** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-12 445000-449975 hour-13 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | P | * P | * L 10 + * ** *** L 10 + * * E | * E | * * S | S | *** | ***** | * ** * *** | **** | * * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-14 445000-449975 hour-15 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | * M | P | P | L 10 + *** L 10 + * * ** E | * * E | * * * * S | * *** S | * * | ** | * * | * ** | * ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-16 445000-449975 hour-17 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | P | P | * L 10 + * * * L 10 + * E | * * * E | * ** S | * ** * S | *** ** | * ** * | * *** | * ** | * ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-18 445000-449975 hour-19 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | * M | M | P | P | ** L 10 + * * L 10 + * * E | * * * * E | ** * S | * * * S | | **** * | * ** | *** **** * | ** ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-20 445000-449975 hour-21 30 + 30 + | | | | | | % | % | 20 + 20 + S | S | A | A | M | M | * P | * * P | ** L 10 + * * L 10 + * E | ** * E | ** * S | ** * S | * * | * * | * * | * * * | ** * 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT

445000-449975 hour-22 445000-449975 hour-23 30 + 30 + | | | | * | | % | % |* 20 + 20 + S | S | A | A | ** M | * * M | P | ** P | L 10 + * L 10 + E | ** E | S | * S | * | * * | ** | ** | ** 00 +----+----+----+----+----+----+ 00 +----+----+----+----+----+----+ 0 5 10 15 20 25 30 0 5 10 15 20 25 30 CARRIERS PRESENT CARRIERS PRESENT


Central States VHF Society, comments to Docket rm8737 May 5th, 1997

                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.rm8737
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 
 
 To: The Commission
 
COMMENTS Of The Central States VHF Society

Background

The Central Sates VHF Society (CSVHFS) was founded in 1967 to promote the use of the VHF, UHF and microwave amateur bands. One of our principal activities is to hold an annual conference in which those interested in the higher amateur frequencies can meet and exchange ideas and information as well as test antennas and other equipment. We invite leaders in the field of higher frequency operation to present papers, which for a number of years have been published in Proceedings form by the American Radio Relay League. Although our membership is not large, compared with some amateur organization, several hundred, they are some of the leaders in the field of amateur VHF, UHF and microwave techniques. Despite the fact the CSVHFS primarily targets those in the Central portion of the U.S., amateurs from all over this country and many overseas countries have attended and participated in our annual Conferences. It should be noted that the facet of Amateur Radio, to which CSVHFS members devote much of their time, is what has been termed "weak signal" work. Those following this endeavor constantly strive for greater and greater distances on all of the amateur bands from 50 MHz through the higher microwave frequencies. This effort has, over the years, led to many contributions to the radio art, including improved performance receiving, and transmitting equipment and more efficient and better antenna systems. Weak signal operators have also learned how to take advantage of various types of anomalous propagation, often missed or ignored by the professionals. These include long haul tropospheric ducting, tropospheric scatter, reflections from ionized meteor trails, the aurora, ionospheric scatter, Sporadic E Layer propagation and various F Layer phenomena. Many have also been very active in developing techniques and equipment needed to reflect their signals off the moon. This is called Earth-Moon-Earth or EME, and requires very exacting station construction and superior operating skills. These activities have led to many advances in the radio art that have found their way into a number of non-amateur applications. It is anticipated that additional advancements will be made by weak signal operators if they are able to continue their activities.

It should be apparent that many weak signal activities require a very low noise level in the receiver, and most amateurs who seriously work the bands above 50 MHz employ receivers with noise figures of 1 dB or less.. This, coupled with the high gain antennas commonly used, make their stations particularly vulnerable to any increase in the noise level. Thus, any significant increase in noise level will render their work impossible, and their continuing contributions to radio communications will, therefore, cease..

Introduction

On behalf of its members and others involved in weak signal work on all of the bands above 50 MHz, CSVHFS wishes to file comments in the Subject Docket, which proposes to liberalize the Amateur Service Rules relative to spread spectrum operation. After reviewing the NPRM and many of the comments filed under RM-8737, we have become concerned that widespread use of spread spectrum may pose a serious threat to weak signal work, when it is operated on the frequencies customarily used for that work.

Summary

CSVHFS understands, and is sympathetic to, the intent of the Commission's Proposed Rule Making to liberalize, and thereby encourage, the development of spread spectrum in the Amateur Service. We feel that various types of spread spectrum may have an application in the kind of work our members, and other weak signal operators, engage in. As noted, our organization has, since its inception, wholeheartedly supported the development of new technologies in and for the Amateur Service, in particular better exploitation of the amateur VHF, UHF and microwave assignments. Although, spread spectrum may represent a significant vehicle for facilitating improved communication between licensed amateurs, we are concerned that it may also present a significant threat to current weak signal activities under the proposed rules. We understand the Commission's desire to provide rules aimed at providing the maximum degree of flexibility for accomplishing the increased use and development of spread spectrum, however, we contend that such rules must be consistent with preserving the viability of current communications capabilities, especially including those associated with various kinds of weak signal work. We will suggest certain provisions which we believe must be included in any new rules the Commission my adopt to promote the development of spread spectrum techniques which will allow its development without materially impacting existing weak signal amateur activities. These provisions will be outlined in these comments.

CSVHFS believes that, to maximize the flexibility for developing spread spectrum techniques for uses other than its apparent advantages in local communication applications, two classes of spread spectrum should be defined by the Commission and implemented in any new Rules. These will be defined and certain frequency bands suggested for each.

Discussion

While some feel that spread spectrum promises improvement in amateur communication, CSVHFS contends that its unbridled authorization and widespread use, on frequencies customarily used for weak signal work has the potential of rendering useless many of the current communications techniques practiced on the VHF, UHF and microwave amateur bands particularly the weak signal long-haul applications employed by our members..

Some may contend that the fact that spread spectrum has been authorized on 420 MHz and above for over ten years, demonstrates that it poses minimal interference threat to other modes. CSVHFS believes that this argument is fallacious. Even those supporting more flexible rules for spread spectrum have agreed that the number of amateurs using it during this period has been extremely small. Furthermore, CSVHFS is not aware of any tests that have been conducted between the spread spectrum operators, who were active, and weak signal VHF/UHF operators. No such tests have ever been reported in the amateur press or in papers presented at our annual Conferences. What tests that reportedly did take place, were poorly advertised in advance; and involved only SS operation in the presence of FM voice repeaters, not weak signal stations. As part of their argument that spread spectrum offers little or no interference to other modes, its proponents cite only occasional short lived signals on a specific channel as characteristic of the type of interference that spread spectrum might present to other modes. Of note is the fact that these illustrations deal only with FM repeaters, not weak signal work such as long haul tropospheric propagation or EME). While this interference scenario may be valid for FM repeaters and a single SS station, or even a few such stations; it is unrealistic if spread spectrum should become a popular mode. It is also invalid for almost all weak signal modes. If spread spectrum does become a popular mode, these short bursts of interference will be repeated by each spread spectrum station on the air at the time. Thus, spread spectrum interference, instead of being an occasional "pip", will take the form of continuous "hash". We have seen calculations that indicate that spread spectrum operation has the potential for raising the noise floor by as much as 50 dB, or even more, over existing levels. With an activity that cannot tolerate a noise floor increase of even a few dB, this will have the effect of eliminating all possibility of weak signal - long-haul work. .

CSVHFS further believes that, if significant interference does result from spread spectrum operation, it will only serve to divide the amateur community and result in impeding the growth and development of spread spectrum, as well as the cessation of weak signal activity. We are certain that no such eventualities represent the Commission's intent in proposing these rule changes.

CSVHFS feels that a way must be found to foster the development of spread spectrum techniques and still prevent potential serious harm being caused to existing weak signal activities. We believe that these, seemingly contradictory, objectives can be met with the establishment, in any new rules which the Commission may invoke, of provisions prescribing certain frequency segments, in which the kinds of spread spectrum being addressed in the NPRM, shall not be allowed. We will outline our recommendation for these prescribed frequency limits later in these comments.

Automatic Power Control

The NPRM includes a requirement for automatic power control for spread spectrum stations running more than 1 Watt. While CSVHFS applauds the apparent Commission intent of minimizing interference to other amateur operation, we believe that automatic power control will be ineffective in materially reducing spread spectrum interference. We believe that much of the time the spread spectrum stations will be running as much power as they have available, especially if they are sharing spectrum with other stations using other modes - particularly if those stations are running considerable power, as many weak signal operators do.

Two Kinds of Spread Spectrum

In a paper given at the our 1996 Conference, Tom Clark W3IWI and Phil Karn KA9Q presented a case for the use of spread spectrum-like techniques for enhancing weak signal communication such as EME and long haul terrestrial. CSVHFS believes that the types of techniques discussed in this paper may have potential for the kind of work our members, and other weak signal operators, do. We would like to see the rules written so as to permit experimentation with these kinds of spread spectrum. We feel that this can be accomplished while not allowing spread spectrum operation to materially impact other operation. To do this, we suggest that the Commission define two types of spread spectrum. One type might be called "Broad Band" and the other "Narrow Band".

The bandwidth of spread spectrum being proposed in this NPRM appears to be undefined but CSVHFS believes what the Commission is proposing would occupy bandwidths considerably greater than that of "conventional" modes such as voice FM, AM and SSB. Hence, we would proposed it be termed "Broad Band". The "Narrow Band" type of spread spectrum such as that discussed by Clark and Karn in their paper, might occupy a bandwidth of perhaps 10 kHz. Since it would occupy such a relatively narrow band of frequencies, it is reasonable to believe that it can be accommodated on the VHF, UHF and microwave amateur bands without materially impacting existing weak signal operation.

CSVHFS Proposal

In light of the above, the CSVHFS proposes that a "Narrow Band" version of spread spectrum be defined and authorized on all of the amateur bands above 50 MHz presently open to SSB and AM, so long as the bandwidth of the transmitted signal does not exceed that of an AM voice signal, e.g. 10 kHz or less. We also propose that, until more data on the impact of "broad band spread spectrum operation on other modes becomes available, spread spectrum should be prevented form causing potentially harmful interference to existing weak signal operations. Therefore, we propose that the rules state that no Broad Band spread spectrum emissions shall take place in the following segments.

          50.0 -    50.5  MHz*
         144.0 -   144.5  MHz*  
         222.0 -   222.15 MHz*
         431.5 -   432.5  MHz  
         902.0 -   903.5  MHz
        1295.5 -  1296.5  MHz
        2303.5 -  2304.5  MHz
        3455   -  3457    MHz
        5759   -  5761    MHz
       10367   - 10369    MHz

* These segments are included in case the Commission should decide to authorize spread spectrum on frequencies below 420 MHz.

Conclusion

CSVHFS believes that spread spectrum operation should be encouraged. It may eventually prove valuable for a variety amateur applications. However, we contend that, until more information is available on its impact on existing amateur activities, spread spectrum operation should be allowed only on band segments that will not significantly impact weak signal operation and perhaps render such operation untenable.

CSVHFS contends that, provisions limiting the frequency segments on which spread spectrum is authorized, is consistent with existing Commission policy in the Amateur Service, and cite, as examples, the fact that voice operation has been limited to certain segments in the HF and VHF amateur bands for many years. In addition, unattended digital operation is restricted to certain small segments of the HF bands and Unattended Beacon Operation is allowed only in small segments of the 10 meter, 6 meter, 2 meter, 1-1/4 meter and 70 cm bands. Also, repeaters are allowed only in certain band segments.

It is recommended that the Commission incorporate these suggestions in formulating new Rules designed to foster widespread use of spread spectrum among amateur radio operators. In addition CSVHFS proposes that the Commission authorize two types of spread spectrum. One that could be termed, "Narrow Band", would be authorized anywhere above 50 MHz where SSB and AM are allowed, as long as the transmitted bandwidth does not exceed 10 kHz. The other, that could be called "Broad Band", would be authorized anywhere, except in the segments listed above. We believe that this course will allow amateurs to develop spread spectrum technology and continue to do other notable work to further develop all facets of the radio art.

RESPECTFULLY SUBMITTED,

Gerald Handley WA5DBY Board Chairman

May 2, 1997


Appendix A

Part 97 of Chapter 1 of Title 47 of the Code of Federal Regulations is proposed to be amended as follows:

Part 97 Amateur Radio Service

All other provisions contained in NPRM rm8737 are retained except as noted:

97.305 Authorized emission types

SS (spread spectrum) emission with bandwiths wider than 10 kHz are prohibited from the following frequency segments:

          50.0 - 50.5 MHz*
          144.0 -144.5 MHz*  
          222.0 - 222.15 MHz*
         431.5- 432.5 MHz  
         902.0 - 903.5 MHz
         1295.5 - 1296.5 MHz
         2303.5 - 2304.5 MHz
         3455 - 3457 MHz
         5759 - 5761 MHz
       10367 - 10369 MHz

(* These frequencies included only in case the Commission should decide to authorize spread spectrum on bands lower than 420 MHz.)

SS (spread spectrum) emissions with bandwidths of 10 kHz or less are authorized on the following frequencies:

50.1 - 54.0 MHz 144.1 - 148.0 MHz All frequencies above 222.0 MHz subject of other existing limitations.

Emission Types.

***

(b) A station may transmit test emissions on a frequency authorized to the operator for brief periods for experimental purposes, except that no pulse or SS modulated signals with bandwidths greater than 10 kHz may be transmitted on any frequency where pulse or SS are not specifically Authorized.


WILLIAM A. TYNAN W3XO, comments to Docket rm8737 May 5th, 1997

                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.rm8737
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 


                 COMMENTS OF WILLIAM A. TYNAN W3XO

Background

I have been a licensed amateur since 1945, obtaining the call sign W3KMV early 
1946.  I upgraded to Class A (later called Advanced) in the fall of 1946 and to 
Extra in the early 1970s.  I obtained my present call sign, W3XO in 1976.  
Throughout those 50 years, my principal interest has been in the bands above 50 
MHz. I am currently operational on all bands from 50 to 1296 MHZ.  For 18 years, 
from 1975 through 1992, I served as a Contributing Editor of QST Magazine, 
responsible for the monthly column "The World Above 50 MHz".  I was one of the 
founders of the Radio Amateur Satellite Corporation (AMSAT) and have been 
serving as its President since 1991.  

Summary

I generally support the intent of the Commission's proposed Rule Making 
contained in this Proceeding - namely liberalizing the rules governing the use 
of Spread Spectrum (SS) in the Amateur Service.  I have always wholeheartedly 
supported the development of new technologies in and for the Amateur Service and 
Amateur-satellite Service.  I believe that SS may represent a significant 
vehicle for facilitating improved communication between licensed amateurs.  I 
further believe that the Commission's rules should provide the maximum degree of 
flexibility for accomplishing this objective, consistent with preserving the 
viability of current communications capabilities, especially including those 
associated with various kinds of terrestrial "weak signal" and amateur satellite 
work.  I contend, that, to promote the development of a variety of SS techniques 
and still not materially impact existing amateur activities, certain provisions 
must be included in any rules which the Commission may adopt.  My views with 
respect to such provisions will be outlined in these comments, along with 
supporting technical justification for them.
In addition, I believe that, to maximize the flexibility for developing SS 
techniques for uses other than its apparent advantages in local communication 
applications, two classes of SS should be defined by the Commission and 
implemented in any new rules.  These will be defined and certain frequency bands 
suggested for each type.

Discussion

While SS promises a great deal of benefit for improving amateur and amateur 
satellite communication, I contend that its unbridled authorization and 
widespread use, particularly in a wide bandwidth embodiment, has the potential 
of rendering current techniques, as practiced on the VHF and UHF Amateur bands, 
unusable.  I made this argument in my Reply Comments in RM-8737 and provided 
supporting calculations to show that SS has the potential of raising the noise 
floor for other stations by as much as 50 dB.  (Note 1)

Those promoting greater use of SS in Amateur Radio may claim that these 
calculations are flawed because they do not address their particular concept of 
how SS will be employed by amateurs.  Largely, their concept is based on 
commercial cellular telephone experience, involving quite short path lengths and 
very low power levels.  I acknowledge that, if  this is the approach that 
amateurs take to SS, interference to other modes of operation is likely to be 
quite low.  However, it is not clear that this will be the type of SS operation 
that evolves in the Amateur Service.  It is more likely to be similar to that 
existing today with repeaters and packet nodes.  These applications involve a 
well located central station covering an area of perhaps thirty miles in 
diameter and a number of participating users within that area.  In this kind of 
situation, the powers of SS stations are  likely to be considerably higher than 
in the "small cell" cellular telephone arrangement.  In this case, the 
calculation I presented are quite applicable.  Since no one can accurately 
predict how SS will develop in the Amateur Service, interference calculations 
must be based on permitted power levels, rather than on some imagined 
low-power-short-range model.

As part of their argument that SS offers little or no interference to other 
modes, SS proponents also say that, even if its level does exceed a signal being 
received in a narrowband receiver and captures the receiver, it will produce 
only occasional short lived signals on that specific channel.  This, they say 
will cause very little loss of information. (Note 2)   While I acknowledge that 
this scenario may be valid for the case of a single SS station, or even a few 
such stations; I contend that it is an unrealistic if SS becomes as popular a 
mode as its proponents obviously hope it will. If that comes to pass, short 
bursts of interference will be repeated by each SS station on the air at 
the time.  If there are, for example one-hundred SS stations on the air in a 
major metropolitan area, these short bursts of interference will be repeated 
one-hundred times as often as in the case of a single SS station. Thus, SS 
interference to other modes could eventually take the form of a continuous 
"buzz" rather than a few short "pops".  Some might contend that the potential 
for having one-hundred stations operating in an area at a time is small.  I 
submit that this is not necessarily true.  A reasonable scenario can be 
envisioned which calls for continuous 24 per day operation of amateur SS 
stations.  Such operation is already present in commercial applications of SS 
techniques.  One example is the Internet connectivity offered by  Metricom in 
several cities.  Many, who use this service leave their computers and radio 
transceivers on all the time connected to the Internet through the system.  
Thus, even when they are not actively using the connection their transceivers 
are continuously exchanging signals with the local site.    While I do not share 
their view, a growing number or licensed amateurs today feel that inexpensive 
Internet access should be one of the major applications of Amateur Radio.  If 
such activity gains favor, it is easy to envision local amateur SS links being 
up continuously, connected to a central station which is connected to the 
Internet.  Even if Internet connectivity does not become a common use for 
Amateur Radio, various other amateur-only applications such as DX clusters are 
likely to employ SS and be active continuously.  Many amateurs today maintain 
constant connection with DX clusters via AX-25 packet radio links.  They can 
certainly be expected to do so using SS.

A number of SS proponents participating in RM-8737 claimed that ten years of SS 
authorization have produced little or no complaints of interference to other 
modes, thus presumably supporting their contention that SS operation does not 
cause interference to such modes .  I submit that this claim cannot be 
substantiated for two reasons.  The first, and most compelling, is  that, even 
those proposing further liberalization of SS rules, admit that there has been an 
extremely small number of amateurs using SS during this period.  Second, there 
seems to have been a concerted effort to "hide" any operation that did take 
place.  To my knowledge, there have been no tests conducted by SS operators in 
which non-SS operations were invited to take part.  Indeed, I know of at least 
one prominent weak signal VHF operator in a large West Coast metropolitan area 
who has repeatedly requested that tests be conducted by SS equipped stations so 
that he could assess possible interference.  All such requests were met with 
indifference, or even hostility, on the part of the SS operators he contacted.  
And no such tests were ever conducted.  Another indication of the lack of 
testing during this over-ten-year period, is the fact that no reports of any 
such testing has ever been published in magazines of general amateur 
circulation.  I am unaware of any reports published even in specialty 
periodicals.   So, claims that SS will not affect current amateur operation are 
completely unsubstantiated.

Contained within the Commission's NPRM is an indication that some apparently 
informed people believe that SS does represent a threat, even to other SS 
operation.  The NPRM notes that Metricom has urged the Commission to limit 
amateur SS power in the 900 MHz and 2400 MHz bands to the same levels presently 
authorized for them and other Part 15 users.  While I believe that the 
Commission should reject any such proposal on the basis of an unlicensed service 
claiming that a licensed service should be limited to prevent interference to 
it, I believe the Metricom statement clearly indicates that SS may not be as 
immune to interference, or as unlikely to cause interference, as claimed by 
amateur SS advocates.   

Automatic Power Control

The Commission's proposed rule making includes a provision for automatic power 
control (APC) for SS stations running more than 1 Watt. I believe that this is 
another clear indication that even the Commission is concerned that SS will 
cause interference to other modes.  While amateur Rules have always called for 
stations to use the minimum power necessary to maintain communication, a Rule 
calling for AUTOMATIC POWER CONTROL is unprecedented.  Furthermore, while I 
support the apparent intent of the proposed rule, to minimize the impact of SS 
on other types of operation, I contend that APC is impractical in the Amateur 
Service.  I further contend that requiring its use will have minimal effect on 
the impact of SS on other modes an may well inhibit SS's growth and development. 
 I cite the following scenario to illustrate my case for the minimal protection 
APC will afford: 

Let's assume that two SS stations located 12 miles apart are in contact, and 
that they are spreading their direct sequence signals over one megahertz and 
operating at powers of 0.5 Watts each, with a processing gain of 50.  If a 
single station using 25 W of FM, and operating on a frequency anywhere within 
this 1 MHz band, and located 12 miles from each of the  SS stations, comes on 
the air; the SS stations will automatically increase their powers in order to 
maintain the same level of communication.  This power increase will amount to 
the 23 dB ( a 200 to 1 ratio) or 100 Watts - the maximum permitted for SS 
operation.  Thus, the assertion that APC will reduce interference does not 
appear to be true.

I note that several SS proponents commenting on RM 8737 were not in favor of 
APC.  Both TAPR and the Naval Post Graduate School expressed reservations about 
it.  (Notes 4 & 5)

While APC may provide some marginal benefit in terrestrial point-to-point 
(one-on-one) situations, such as encountered in cellular telephony, it has 
little application to amateur radio.  For example, amateur communication is 
often  from one station to a number of listening stations ("bulletin mode"), 
rather than one-on-one.  In such a case APC breaks down no matter how it is 
implemented.  Even in the "one-on-one situation, mandating APC requires a higher 
degree of standardization than is typical of amateurs.  It may even require that 
all stations participating in the power adjustment must have equipment from a 
single manufacturer.  Does the Commission want to support such a potential 
monopoly situation?  APC is certain to mitigate against "home brewing" of 
equipment.  As already noted, it may be just the "straw" that prevents SS from 
becoming popular with amateurs.  It certainly runs counter to the objective of 
making amateur SS rules as flexible as possible.  In fact, any such requirement 
seems to represent the height of inflexibility.

A Proposed Approach for Peaceful Development of SS in the Amateur Service

How can the development of SS techniques be encouraged and still prevent 
potential serious harm being caused to existing modes and the inevitable bad 
feelings that will result from such harm? 
I contend that the solution to this dilemma lies in the establishment, in any 
Rules which the Commission may invoke, of provisions proscribing certain 
frequency segments for SS operation.

In addition, in order to take advantage of the potential capability of SS 
techniques for long-haul weak signal work, I propose that a Narrow Band versions 
of SS be defined and authorized.  I believe that it should be able to be used 
more generally throughout the spectrum than the "wideband" version apparently 
being addressed in the NPRM.

Two Kinds of SS

The case for the potential utility of a narrowband version of SS was made in a 
paper presented at the Central States VHF Conference held in Minneapolis in July 
1996. (Note 6)  In this paper, Tom Clark W3IWI and Phil Karn KA9Q outlined a 
possible use of SS techniques for enhancing weak signal communication such as 
Earth-Moon-Earth or long haul terrestrial paths.   Their presentation convinced 
me that this application of SS should be accommodated in any new rules which the 
Commission may adopt.  I feel that to accomplish this, while not allowing SS 
operation to materially impact other operation, the Commission should define two 
types of SS. One type might be called Wide Band" and the other "Narrow Band". . 

Proposal

In light of the above, I propose that a "Narrow Band" version of SS be 
authorized on all of the amateur frequencies above 50 MHz on which voice is 
permitted, so long as the bandwidth of the transmitted signal does not exceed 
that of a properly modulated double sideband AM signal, i.e. 10 kHz. I also see 
no reason why stations using this Narrow Band type of SS should not be enabled 
to use as much power as those using existing modes. 

I further propose that the "Wide Band" version of SS should be authorized only 
in the following  
frequency segments:
      219 - 220 MHz
      435 - 438 MHz*
      904 - 928 MHz
     1240 - 1270 MHz*
     2390 - 2450 MHz*
     All Amateur frequencies above 3300 MHz

*  In the segments 435 -438 MHz, 1260 - 1270 MHz  and 2400 - 2410 MHz, SS 
emissions shall, except for short tests to confirm proper operation of 
equipment, be only be for the purpose of work in conjunction  with  amateur 
satellites.

The rationale for stipulating limited use of SS in the segments denoted by * is 
to protect relatively weak amateur satellite downlink signals from being 
interfered with by terrestrial SS stations and also to prevent terrestrial SS 
stations from transmitting signals that might be inadvertently picked up and 
re-transmitted by amateur satellites.  However, permitting the use of SS in 
these segments allows it to be used in conjunction with amateur satellites.  
While there is weak signal experimentation occurring around 3456 MHZ, 5760 MHZ, 
10368 MHz and at specific frequencies in the higher microwave bands, I have 
become convinced that amateur SS operation poses little threat to these 
activities.  The principal reason for reaching this conclusion, is the power 
levels that might be expected to be used in these bands and the effect
antenna directivity characteristically involved.    

Conclusion

I believe that SS operation should be encouraged.  I further believe that it may 
well eventually prove valuable for both terrestrial and satellite applications. 
 However, I contend that the development of SS in the Amateur Service can best 
be encouraged if it is done so as not to result in major conflicts with those 
using existing modes.  I submit that such conflicts are inevitable if SS is 
merely "plopped down on top of everything else.  Such conflicts, in my opinion, 
can only weaken Amateur Radio and inhibit the growth and development of SS.   
Therefore, I urge that  its use should be restricted to particular frequency 
segments outlined above.  These are relatively lightly used segments and SS 
operation there should cause very little difficulty and hence I feel that some 
of the restriction presently placed on SS operation, such as non-interference to 
other modes, should be eliminated .  I submit that such frequency "segregation" 
is consistent with established Commission policy in the Amateur Service. I cite, 
as examples, the fact that voice operation has been limited to certain segments 
in the HF and VHF amateur bands for many years.  Unattended digital operation is 
restricted to certain narrow segments of the HF bands.  Unattended Beacon 
Operation is allowed only in limited segments of the 10 meter, 6 meter, 2 meter, 
1-1/4 meter and 70 cm bands. Also, there are frequency limits placed on repeater 
operation.  All of these limitations have served Amateur Radio well for many 
years.  A similar approach to authorizing  more flexible SS Rules, should serve 
it, and the rest of Amateur Radio, well also.

I recommend that the Commission incorporate these suggestions in formulating new 
rules designed to foster widespread use of SS among amateur radio operators.  I 
further recommend that the Commission place no greater restrictions on SS use, 
such as station identification and authorized spreading codes, than it feels is 
absolutely necessary, and that automatic power control not be required.  
Appendix A contains my attempt at putting these recommendations into Part 97 
Rule form.  

I contend that the  course I have outlined will foster growth of SS among 
amateurs, including those using it in connection with extended range weak signal 
communication as well as through amateur satellites. In addition I propose that 
the Commission authorize two types of SS.  One that could be termed "Narrow 
Band" would be authorized on all frequencies above 50 MHz, presently open to 
voice operation, as well as a satellite downlink in the 10 Meter band above 29 
MHz.  The transmitted bandwidth of Narrow Band SS emissions should  not exceed 
that of a properly modulated double sideband AM signal.  The other, form of SS  
could be called "Wide Band", should be authorized anywhere in the segments 
listed above, with the limitations stated.  

I believe that this course will allow amateurs to develop SS technology and 
continue in their historic pursuit of all new technologies as well as their 
march to higher and higher frequencies.  At the same time, other valuable 
amateur operation will be preserved..

RESPECTFULLY SUBMITTED,

By_______________________
     William A. Tynan W3XO

May 2, 1997



Notes: 1. AMSAT said in its Reply Comments, "To obtain a measure of the possible interference that could result from only a single spread spectrum station, the following parameters are assumed: Spread spectrum station with an effective power of 100 W ERP = +20 dBW (The power specified in the Docket) If spread over 10 MHZ -50 dBW/Hz Free-space attenuation at 20 km from the spread spectrum station at 432 MHZ = -110 dB Spread spectrum signal at 20 km = -160 dBW/Hz A receiver with a 1 dB NF (common in satellite & weak signal work) = -210 dBW/Hz So the spread spectrum signal could be as much as 50 dB above the noise floor that would exist without it. One can use these calculations to cite other scenarios: For example, if the spread spectrum station had a power of only 1 W ERP, this is 20 dB less, yet the noise floor would still be as much as 30 dB higher because of its presence. Similar calculations for other distances can also be done. For example, the spread spectrum signal would be 20 dB stronger at a 2 km distance. As another example, a 100 W transmitter and 10 dB gain antenna could create 10 dB more interference. Obviously, if the spread spectrum station is in close proximity to the satellite or terrestrial weak signal station, the degradation from the spread spectrum station's operation would be much greater." 2. Reply Comments of Robert A. Buaas, K6KGS 20271 Bancroft Circle Huntington Beach, CA 92646. Mr. Buaas postulates the following scenario: (His paragraph numbers are included for ease of reference.) (3a)"Use Voice modulation type F3E(conventional NBFM): (3b) Use only Frequency Hopping of the carrier frequency to accomplish the SS function: (3c) Operate within the 450 MHZ repeater spectrum and conventions: receive within the 5 MHZ allocated for repeater receivers and transmit within the 5 MHZ allocated for repeater transmitters: use carrier frequencies aligned with those of current repeaters: this provides 200 discrete receiver and transmitter operating frequencies, each of width 25 Khz (Choosing 20 Khz bandwidths provides an additional 50 hopping channels: this may eventually be operationally desirable, but for the purpose of this model it only complicates the arithmetic for interference assessment. It does not significantly alter the impact of or nature of signal collision): (3d) Dwell on each channel for exactly 10 milliseconds, then hop: (3e) Choose a hopping function which: (3e1) uses every available channel before any reuse. We will call the total time required to use all the channels the "period" of the hopping function (taking (3c) and (3d) together, it is 200- milliseconds) and, (3e2) during one period, selects channels for each use such that the time since the same channels use in the previous period is statistically random: ......." "With the system parameters give above, interference impact evaluation is very straightforward. Parameter 3d is chosen so that SS activity does not activate the noise squelch of NBFM receivers. When the FHSS arrives on an active repeater channel, FM capture rules apply. In the case where the SS station captures the other user, the capture lasts 10 milliseconds in 2000, or for 0.5% of the transmission. This impact is so slight as to be neglected in real operations." 3. Reply Comments of Charles M. (Marty) Albert Jr. KC6UFM Paragraph entitled "Additional General Comments. Mr. Albert says in part "Using the 10 millisecond dwell time cited by Buaas, this means that you will miss only ONE-FIFTH of ONE WORD sent. If we assume that the voice transmission lasts 5 minutes and the SS makes a "hit" as often possible...." 4. In part: "NPS does not agree with the changes proposed to 97.311(g) requiring the addition of "automatic transmitter power control." T Reply Comments submitted by the Naval Post Graduate School state his is clearly counter to making the spread spectrum mode of communication more flexible and is itself superfluous as noted by Mr. Buaas' reference to 97.313(a). The technical hurdles implied by this rule change are not trivial: and as pertains to space-based stations in particular, would pose an unnecessary burden on the design of the space segment of the communications link." 5. In its Comments, TAPR says in part: "Third, TAPR supports the ARRL's proposed change to 97.311(g) which would provide for automatic power control to limit the output power of and SS station to that which is required for communication, when more than one watt of output power is used. TAPR, however differs with ARRL as to just how simple to control the output power of a transmitter, it is quite another matter to make this control automatic and foolproof...." 6. In an unpublished paper presented at the 1996 Central States VHF Conference, Drs. Tomas A. Clark, W3IWI and Phillip Karn, KA9Q outlined the possibility of using SS techniques over a fairly narrow band to enhance the capability for weak signal amateur communication. Appendix A Part 97 of Chapter 1 of Title 47 of the Code of Federal Regulations is proposed to be amended as follows: Part 97 Amateur Radio Service All other provisions contained in NPRM rm8737 are retained except as noted: 97.305 Authorized emission types SS (spread spectrum) emission with bandwiths wider than 10 kHz are authorized on the following frequency segments: 219 - 220 MHz 435 - 438 MHz* 904 - 928 MHz 1240 - 1270 MHz* 2390 - 2450 MHz* All Amateur frequencies above 3300 MHz * In the segments 435 -438 MHz, 1260 - 1270 MHz and 2400 - 2410 MHz, SS emissions shall, except for short tests to confirm proper operation of equipment, be used only in conjunction with amateur satellites. SS (spread spectrum) emissions with bandwidths of 10 kHz or less are authorized on the following frequencies: 50.1 - 54.0 MHz 144.1 - 148.0 MHz 219.0 - 220.0 MHz All frequencies above 222.0 MHz subject of other existing limitations. Emission Types. *** (b) A station may transmit a test emission on any frequency authorized to the operator for brief periods for experimental purposes, except that no pulse or SS modulated signals with bandwidths greater than 10 kHz may be transmitted on any frequency where pulse or SS are not specifically authorized. 97.311 SS Emission types (a) SS emission transmissions by an amateur station are authorized only for communication between points within areas where the amateur service is regulated by the FCC and between points within areas where the amateur service in regulated by the FCC and amateur station(s) located in countries that permit SS by its amateur stations. SS emissions must not be used for the purpose of obscuring the meaning or content of any communication. (b) deleted (g) (1) For spread spectrum emissions with bandwidths greater than 10 KHz, the transmitter output power shall must not exceed 100 Watts under any circumstances. . (g)(2) For spread spectrum emissions with bandwidths of 10 KHz or less, the transmitter output power must not exceed 1.5 KW under any circumstances, subject to other restriction already existing in the particular frequency range and location.


PART 15 COALITION, comments to Docket rm8737 May 5th, 1997


                                Before the
                      Federal Communications Commission
                          Washington, D.C.  20554


In the Matter of                     )    WT Docket No.rm8737
                                     )
Amendment of Amateur Service         )    RM-8737 
Rules to Provide For                 ) 
Greater Use of Spread                )
Spectrum Communication               )
Technologies                         ) 

To: The Commission

COMMENTS OF THE PART 15 COALITION

	The Part 15 Coalition ("the Coalition"), by its attorneys, 
submits these comments in response to the Notice of Proposed 
Rulemaking ("NPRM") in the above-referenced proceeding.  
The Coalition represents a group of companies that manufacture 
and market radio technologies, including many spread spectrum 
technologies, designed to operate in compliance with the 
Commission's Part 15 rules.  

In the NPRM, the Commission has proposed changes to 
its rules that would allow amateur stations to use a wide variety 
of spread spectrum transmission modes, at power levels 
applicable to the amateur radio services (100 watts with 
unlimited antenna gain), in the radio bands used or shared by 
the amateur service over 420 MHz.  The Coalition is concerned 
that the changes could upset the delicate balance that has been 
struck in the heavily-used ISM bands and that the Commission 
has not fully considered the full effects of the proposed change. 

DISCUSSION

In the NPRM, the Commission tentatively has concluded 
that the expanded use of spread spectrum technologies by 
amateur radio stations will increase spectrum efficiency and 
promote technological development.  Nonetheless, to help 
protect against harmful interference, the Commission has 
proposed a requirement that amateur radio stations transmitting 
in spread spectrum mode must use an automatic power control 
("APC") device to reduce radiated power to the minimal level 
necessary.  The Coalition is concerned that the tension between 
these two proposed changes is not fully explored in the NPRM.

In reality, the rule changes proposed in the NPRM could 
have a dramatic effect on the ability of Part 15 users and others to 
share spectrum with the amateur radio service.  Although from 
a purely theoretical standpoint the expanded use of spread 
spectrum transmission technologies by amateur radio operators 
should not substantially increase the interference potential of 
these stations, the rule change could have downstream effects 
that, as a practical matter, could fundamentally alter the delicate 
balance between users of these shared bands.

For instance, by expanding the range of spread spectrum 
transmission modes that may be used by amateur radio stations, 
operators who have little or no technical knowledge will now be 
able simply to purchase and use Part 15 spread spectrum 
equipment that is widely available in the market.  This 
clustering of radio technologies will, in turn, lead to a 
proliferation of operations in the bands of spectrum in which 
the Part 15 equipment has been manufactured to operate the 
ISM bands, especially the 915 MHz and 2.4 GHz bands.  Further, 
those who purchase Part 15 equipment for amateur radio use 
may choose to add power amplifiers and thereby boost the power 
of this equipment out of all proportion to off-the-shelf Part 15 
technologies manufactured to transmit at a maximum power of 
1 watt.  Thus, the proposed rule change may lead to increased 
use by amateur radio operators of shared ISM bands and require 
Part 15 users to coexist with Part 15 equipment being operated at 
output power levels far in excess of that for which they were 
designed.

Although the Commission makes passing reference in the 
NPRM to these potential interference problems, its sole response 
is to propose a requirement that amateur radio stations using 
spread spectrum transmissions employ some form of APC to 
reduce transmitter power below the 100 watt maximum.  It is 
entirely unclear from the NPRM, however, what this device will 
be or how it will work.  Moreover, the addition of an APC does 
not address the more fundamental interference issues posed by 
the proposed rule changes.  However the APC works, it will not 
reduce power levels to anything approaching those applicable to 
unlicensed Part 15 users.  Thus, whether transmitting at 25, 50, 
or 75 watts, an amateur radio station using spread spectrum 
transmission and an APC will still far exceed the transmitter 
power of any unlicensed Part 15 technologies in its vicinity.  

In the end, the interference issues raised by the proposed 
rule change involve more subtle relationships than mere 
transmitter power comparisons.  The expansion of spread 
spectrum transmission by amateur radio operators as proposed 
in the NPRM is an example of a rule change that may upset the 
delicate balance that has been struck between co-users of shared 
spectrum.  This is particularly true in the 915 MHz band, where 
the Commission struggled for years on how to add LMS use to a 
band already crowded with amateur and Part 15 users, and in the 
2.4 GHz band, where the Commission has recently decided not to 
authorize licensed services because of the exisiting use. 

By allowing amateur radio operators unlimited use of 
spread spectrum transmission technologies, the Commission 
will permit the use by these stations of Part 15 equipment and 
thereby increase the use of the ISM bands in which that 
equipment has been designed to operate.  This will, in turn, 
encourage users of that equipment who have the flexibility to do 
so (i.e., amateur stations) to increase output power to maximum 
permitted limits.  The failure of the NPRM to address these 
downstream effects and to focus solely on the immediate 
technical impact of the transmission technology undermines the 
force of the Commission's tentative conclusion.

In general, the Coalition is confident that the Part 15 
community, working with amateur radio interests, can continue 
to resolve technical and interference problems when and where 
they arise.  It cautions, however, that future proposed rule 
changes affecting the Part 15 bands should be subject to careful 
analysis that includes both immediate technical concerns and 
the practical market effects of the change so that the advantages 
of sharing in the ISM bands can continue.


                  Respectfully submitted,
                  THE PART 15 COALITION


               By: Henrietta Wright
                   W. Kenneth Ferree

                   GOLDBERG, GODLES, WIENER & WRIGHT
                  1229 Nineteenth Street, NW
                  Washington, DC  20036
                  (202) 429-4900

                  Its Attorneys


RADIO AMATEUR SATELLITE CORPORATION, comments to Docket rm8737 May 5th, 1997

                           Before the
               Federal Communications Commission
                    Washington, D.C.  20554


In the Matter of                        )
                                        )
Amendment of the Amateur Service        ) 
Rules to Provide For Greater Use of     )    WT Docket No.rm8737 
Spread Spectrum Communication           )
Technologies                            )
 
To: The Commission

      COMMENTS OF THE RADIO AMATEUR SATELLITE CORPORATION
Introduction

The Radio Amateur Satellite Corporation (AMSAT) is a not-for-profit District of Columbia corporation established in 1969. It is the principal membership organization of the amateur satellite community in North America. Our current membership is approximately 7,000. Together with more than 30 of our affiliated organizations throughout the world, we have constructed, launched and operated over two dozen satellites to date in the Amateur-satellite Service, of which many are presently in operation. AMSAT is currently constructing a new satellite presently designated "Phase 3D". Scheduled for launch later this year by the European Space Agency, it is designed to provide wide area amateur communications transmitting on amateur satellite bands from 2 meters to 1.25 cm. Phase 3D will provide approximately 500 kHz of bandwidth on all of the bands on which it will transmit, except for 2 meters where the bandwidth will be limited to 200 kHz by frequency coordination within the amateur community.

It is envisioned that part of Phase 3D's bandwidth will be used for digital transmission up to speeds of about 56 kb/s. The remainder is expected to be used for multiple access by many stations at a time using narrower band modes such as SSB, CW and other relatively narrowband modes, but could also be used for wide bandwidth modes, including SS, that require a linear transponder.

Since its inception, AMSAT has wholeheartedly been in favor of the development of new technologies in and for the Amateur and Amateur-satellite Services.

Summary

1. AMSAT generally supports the intent of the Commission's proposal contained in this NPRM to liberalize the rules governing the use of Spread Spectrum (SS) in the Amateur Service. We believe that SS may be one of those techniques that offers a potential for improved amateur communication, both terrestrially and via amateur satellites. However, we believe that modifications to the Rules as proposed in the NPRM are necessary in order to minimize the potential for destructive interference to satellite operation. We believe our suggested change to the Rules will enable SS and satellite operation to develop together more rapidly and effectively.

Discussion

2. AMSAT believes that SS is a technique that may very well prove a significant vehicle for facilitating improved communication between licensed amateurs, both terrestrially and through amateur satellites. However, our calculations, (see AMSAT's Reply Comments in RM-8737, paragraphs 3, 4 and 5), show that a single terrestrial SS station transmitting in the 435 MHz amateur satellite band, even with a power of only one watt spread over 10 MHz could increase the "noise" level up to 20 dB at a distance of 20 km, resulting in interference to reception of relatively weak amateur satellite signals. The situation worsens as the number of SS stations increases, and with the higher power levels permitted under the proposed Rules. The interference would also be worse at lesser separation distances.

3. We are also concerned that higher power terrestrial SS signals may find their way into satellite-borne transponders and be inadvertently retransmitted, in whole or in part. These concerns are held despite the good faith efforts incorporated in the NPRM to minimize interference from SS, such as the requirement for automatic power control for SS stations running more than 1 watt. At the 100 watt level, there is a significant likelihood of SS signals being unintentionally received by amateur satellites.

4. For these reasons, we respectfully request that the Commission adopt the limitation proposed below in an attempt to prevent such interference situations from developing, and still permit the growth and development of SS for both satellite and terrestrial applications.

AMSAT's Proposal

5. AMSAT contends that there is a feasible way to make SS available for both amateur terrestrial use and amateur satellite communication without the potential of destructive interference caused to existing satellite modes. We believe that this can be done by a clear statement in the Rules, that no SS transmissions shall take place in those ITU designated Amateur-satellite Service allocations below 2410 MHz, unless they are to or from amateur satellites, or short tests to confirm the proper operation of equipment in preparation for such work. 6. We believe that the Part 18 emissions above 2410 MHz make it irrelevant whether SS interference is present or not. In the higher microwave satellite bands antenna directivity should prevent any significant interference.

7. We respectfully request that the Commission add language to Section 97.305:

97.305 Authorized emission types

SS (spread spectrum) emissions are authorized on the following frequency segments:

420 - 450 MHz* 902 - 928 MHz 1240 - 1300 MHz* All Amateur frequencies above 2300 MHz* *In the segments 435 - 438 MHz, 1260 - 1270 MHz and 2400 - 2410 MHz, SS emissions shall be used only for transmissions to or from amateur space stations, except for short tests to confirm proper operation of equipment in preparation for such work.

Conclusion and Recommendations

8. AMSAT recommends that the Commission incorporate the above provision in any new Rules arising out of this proceeding, in order to protect amateur satellite users from interference that could result from terrestrial (non-satellite) SS communication. Such a provision would still permit the use of SS in conjunction with amateur satellite communication.

9. AMSAT believes that the suggested course will foster experimentation by the amateur community and encourage the growth of SS, including its use in connection with amateur satellites. At the same time, it will preserve the capability of using current modes in conjunction with satellite operation, even by satellite users located in close proximity to other stations using SS for terrestrial applications.

RESPECTFULLY SUBMITTED,

Radio Amateur Satellite Corporation P. O. Box 27 Washington, D.C. 20044

By ___________________________________ Dr. Perry I. Klein, W3PK Vice-President, Government Liaison

May 5, 1997


220SMA, comments to Docket rm8737 May 5th, 1997

                           Before the
               Federal Communications Commission
                    Washington, D.C.  20554


In the Matter of                        )
                                        )
Amendment of the Amateur Service        ) 
Rules to Provide For Greater Use of     )    WT Docket No.rm8737 
Spread Spectrum Communication           )
Technologies                            )
 
To: The Commission
_____________________________________________________________

COMMENTS OF

THE 220 MHZ. SPECTRUM MANAGEMENT ASSOCIATION
OF SOUTHERN CALIFORNIA (220SMA)

ON

NOTICE OF PROPOSED RULEMAKING

REGARDING: AMATEUR SPREAD SPECTRUM OPERATIONS

RELEASED: MARCH 3, 1997
____________________________________________________________

220 MHz. Spectrum Management Assn.
21704 Devonshire St. #220
Chatsworth, CA 91311-2903
http://www.220sma.org

Prepared by:
James T. Fortney, K6IYK
President
<Jim@Fortney.org>
May 2, 1997

INDEX

OPENING SUMMARY.. PAGE 2
DISCUSSION.. PAGE 2
CONCLUSION.. PAGE 5


OPENING SUMMARY

The 220 MHz. Spectrum Management Association of Southern California (220SMA) 1 is in general agreement with the Commission that the proposed amendments would allow for increased spectrum efficiency and allow Amateur operators to contribute to technological advances in communications systems and equipment. We do however believe that there are additional concerns not discussed in detail in the NPRM that require consideration before final rulemaking actions are taken. Specifically these have to deal with: a) Spread Spectrum (SS) operations in areas where the Amateur community determines that formal coordination procedures are in the best interest of Amateur Spectrum Management; b) SS operations on frequencies below 420 MHz.; c) identification of SS emitters; and d) the application of Automatic Power Control (APC) techniques to SS. Our detail comments follow.


DISCUSSION

The 220SMA is an Amateur General Membership organization open to all Amateurs interested in the 220 MHz. bands. The leadership and general membership of the organization have actively followed the development of SS operations in Southern California for several years. Members of the existing STA's have helped educate the membership concerning the principals of SS operation by making presentations at our General Meetings. The present Docket was formally discussed at the April 19, 1997, General Meeting and the ideas and concerns discussed herein were formulated at that meeting.

In general the membership supports the proposed amendments to the Amateur Rules relaxing the controls over SS operation. There is, however, concern that this mode, much like dedicated link and repeater operations, may need and benefit from formal coordination processes.

COORDINATION
If Amateur SS operations become half as pervasive as their proponents suggest they will, the potential for severe cross-mode interference at developed communications sites is significant. In the same manner that fixed frequency emitters benefit from coordination of co-channel and adjacent frequency operations, and site location proximity, these same activities will benefit from managing common site mixed mode operations (i.e., Repeaters and SS Hubs) and, in the case of frequency hopping SS, by managing the hopping frequencies so as to minimize on frequency interference.

In reference to Part 97.311(b) proposed language, the current Notice suggests that SS in the Amateur Service should be a subordinate mode and operate much as it does in the unlicensed Part 15 environment. This situation may be appropriate under Part 15 but probably should not apply in the Amateur world of advancing technology. The 220SMA believes that regulatory recognition of the fact that when interference occurs between a coordinated emitter and an uncoordinated emitter, the uncoordinated emitter is responsible for resolving the interference, is as important under SS and mixed mode environments as it is in the fixed frequency world of repeater operations.

We would prefer to see regulatory language which would allow the Amateur community to manage the interference potential between modes, much as it does today where it is allowed to plan the use of its own bands. History has proven that regional characteristics such as population density and geographic considerations make one size fits all' decisions less than optimum for anyone.

OPERATING FREQUENCIES
Although the subject Docket proposes to retain the current restriction of SS operations on 420 MHz. and above, there have been suggestions that SS should be allowed on lower Amateur frequencies. Based upon both theoretical analysis and empirical tests, it appears that heavy SS usage on a band will eventually degrade the noise floor and significantly affect operations that are sensitive to random noise. The 220SMA does not want to close the door to possible future SS operations on the 220 MHz. and below bands, but does believe that because of the population density and weak signal uses of those bands, SS operation should not be authorized at this time. The membership believes that an appropriate period of developmental operation on the higher bands will demonstrate the realistic high density sharing characteristics between SS and other modes. We recommend that the Docket provisions in this area be retained as proposed.

SS EMITTER IDENTIFICATION
The requirement for CW identification of an SS transmitter is considered totally inconsistent with sound technological practice and should be replaced with a technique native to the SS mode being used.

AUTOMATIC POWER CONTROL (APC)
Although operation at the minimum output power required to establish and maintain communications is considered good practice, and APC techniques are a good way to enforce implementation of this practice, we believe that there are significant shortcomings in the proposed APC technique. At a minimum, provisions need to be made for the circumstances where SS emitters are trying to initiate contact with yet to be identified stations, or where they are operating as a central node in a multi-cast environment.


CONCLUSION

The 220SMA endorses the proposal to provide relaxed Spread Spectrum regulation in the Amateur Service. We recommend that the general provisions regarding interference be revised to require a formal emitter coordination process when elected by the local/regional body of Amateurs. We agree with the proposed operating frequencies and suggest that no authorization to use lower frequency bands be granted until there has been an opportunity to evaluate higher density SS operations. We believe that a requirement for identification in a mode other than SS is inappropriate. Lastly, we recommend that the Automatic Power Control provisions be supplemented to provide for implementations beyond the point-to-point environment implied by the proposal.


1 The 220SMA is the Amateur spectrum management coordinator for the 220 MHz. bands in Southern California and serves as the regional coordinator for 219 MHz. Digital Linking and 222-225 MHz. Repeater Coordination. The Association is formally recognized by the five Councils of Radio Clubs representing Amateurs in the 220SMA service area.


Comments of the Manager of the National Communications System

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                 )      WT Docket No. rm8737
                                 )
Amendment of the Amateur Service )
Rules to Provide For             )      RM-8737 
Greater Use of Spread            )
Spectrum Communications          )
Technologies                     )

COMMENTS OF THE MANAGER
OF THE NATIONAL COMMUNICATIONS SYSTEM

The Secretary of Defense, Executive Agent of the National Communications System (NCS)1, through duly authorized counsel, pursuant to Section 201 of the Federal Property and Administrative Services Act of 1949, 40 U.S.C. 481, and the Memorandum of Understanding between the General Services Administration and the Department of Defense dated November 27, 1950, hereby files these comments in response to the Notice of Proposed Rulemaking (NPRM) in the above captioned matter by the Commission on March 3, 1997.

The Secretary of Defense, for the Department of Defense and in his capacity as Executive Agent of the NCS, has historically files comments in Commission proceedings in support of the activities of amateur radio licensees.2 The NCS continues to rely on amateur radio operators as a resource to be utilized by it in carrying out its national Security and Emergency Preparedness (NS/EP) responsibilities. The NCS and the American Radio Relay League (ARRL) continue the cooperative spirit set for on the June 2, 1983 Memorandum of Understanding between the NCS and the ARRL which established a close working relationship with amateur operators for national emergency communications functions.

In the NPRM, the Commission proposes to amend its rules to allow amateur stations greater flexibility in transmitting spread spectrum communications by eliminating rules that have restricted amateur stations to transmitting only frequency hopping and direct sequencing spreading techniques. The Manager fully supports the proposed rule changes.

There are several additional changes that the Manager believes appropriate.

Section 97.311(e) should be eliminated. There appears little reason to impose the specific record keeping obligations set forth in that Section on only spread spectrum transmissions when similar requirements are not imposed on other types of transmissions. Should the Commission feel it necessary to gather the information called for in Section 97.311(e) in specific cases, it has the authority to do so under Section 97.103© of the rules.

Section 97.311(f) should be eliminated. The Commission has ample authority to require a station to cease of restrict transmissions and to maintain records without it being addressed in Section 97.311(f). Restating that authority in rules relating solely to spread spectrum could suggest the Commission does not believe it has that general authority over its other licensees.

Section 97.119(b)(5) should be eliminated. The section contains the CW identification requirement for spread spectrum communications. To the best of the Manger's knowledge, no currently available Commercial Off the Shelf (COTS) spread-spectrum equipment complies with this rule. Deletion of the requirement could lead to increasingly available COTS equipment for amateur use of spread spectrum technology and concurrent increased usage.

CONCLUSION

The Manager fully supports the changes proposed by the Commission and in addition urges Commission consideration of the further changes suggested herein.

Respectfully submitted,

Paul R. Schwedler
Deputy General Counsel, Regulatory Law
(703) 607-6092

Carl Wayne Smith
Acting General Counsel
Code RGC
Defense Information Systems Agency
701 S. Courthouse Road
Arlington, WA. 22204


1 Executive Order No. 12472, "Assignment of National Security and Emergency Preparedness Telecommunications functions," April 3, 1984 (49 Fed. Reg. 13471, 1984), established the National Communications System, which consists of an administrative structure involving the Executive Agent, Committee of Principles, Manager, and the telecommunications assets of the federal organizations which are represented on the Committee of Principles. Section 1(e) of EO 12472 designates the Secretary of Defense as Executive Agent for the NCS. By direction of the Executive Office of the President (EOP), the NCS member organizations (which are Department of Commerce, Department of Defense, Department of Energy, Federal Emergency Management Agency, General Services Administration, Department of Justice, National Aeronautics and Space Administration, the Joint Staff, Department of State, Department of Transportation, Department of the Treasury, U.S. Information Agency, The Department of Veterans Affairs, Department of Health and Human Services, Department of the Interior, National Security Agency, the National Telecommunications Commission, the United States Postal Service and Federal Reserve Board also participate in the activities of the NCS. The vast majority of the telecommunications assets of these 23 organizations are leased from commercial communications carriers and serve the NS/EP needs of the Federal government as well as States and local governments.

2 See, for example, Manager's Comments in Docket 87-14 and in RM-7747.


Comments of Robert Brown, N7STU

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
the Amateur Radio Service to          )
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

COMMENTS OF Robert Brown, N7STU

Introduction

I am Robert Brown, licensed in the Amateur Radio Service as N7STU since 1991. I am very active in "weak signal" activities on the VHF/UHF/uWAVE bands. I am currently equipped for operations on the 6, 2, .7, .33, .23, .05m bands and 670nm laser. I regularly exploit the various terrestrial propagation modes available here on the west coast of the United States. I am the Fresno, CA, Area Representative for the Western States Weak Signal Society, a non-profit organization of amateur radio operators interested in the preservation of the "weak signal" segments of the current VHF/UHF/uWAVE bands.

Comments

I filed technical comments on the issue of spread spectrum in my Reply Comments to RM-8737. I fully support the comments filed by the Central States VHF Society by Gerald Handley, WA5DBY (see attached).

RESPECTFULLY SUBMITTED,

Robert Brown, N7STU
Area Representative, Western States Weak Signal Society

May 4, 1997

Attachment: Central States VHF Society Comments


Comments of Metricom, Inc.

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of

Amendment of the Amateur Service   ) 
Rules to Provide For Greater       )     WT Docket No. rm8737 
Uses of Spread Spectrum            )     RM-8737 
Communications Technologies        )

To: The Commission

COMMENTS
OF
METRICOM, INC.

Metricom, Inc. ("Metricom"), by its attorneys, pursuant to the Notice of Proposed Rule Making released on March 3, 1997 in the above referenced proceeding (the "Notice"), hereby submits these Comments. This proceeding results from a Petition for Rule Making filed by the American Radio Relay League ("ARRL") requesting expanded spread spectrum authorization for amateur operations. Despite the absence of strong record support for such amendment, the Commission nevertheless issued the Notice.

INTRODUCTION AND BACKGROUND

1. Metricom does not oppose the proposal to allow amateurs greater flexibility for spread spectrum operations; however, Metricom must strongly oppose amateur operations with 100 watts output power and unlimited antenna gain in the Industrial, Scientific and Medical ("ISM") bands because these bands are shared with Part 15. If amateurs are to conduct more flexible spread spectrum operations in these bands, they should be limited to Part 15 power levels. Only with such limitations can the Commission assure that no harmful interference exists to other operations in these bands where the Commission has worked diligently to create a delicate balance so that all parties can share, and operate successfully.1 While the Commission's proposal in the Notice for automatic power control is a significant step in limiting amateur spread spectrum power and resultant harmful interference, it does not go far enough in limiting amateur power in the ISM bands.

2. Metricom is a young, rapidly growing, wireless telecommunications company based in California's Silicon Valley. Metricom is a pioneer in the development of state-of-the-art, spread spectrum, unlicensed data communications systems operating under Part 15 of the Commission's Rules and Regulations in the 902-928 MHz frequency band. Metricom's frequency hopping, spread spectrum systems -- at the leading edge of technology -- had their origins in amateur radio, and many of Metricom's engineers are active amateur operators. The experimentation done with spread spectrum amateur radio enabled Metricom to develop an innovative mesh network architecture that permits cost-effective, intelligent and flexible data communications operating at a gross over-the-air transmission rate of 100 kbps - the fastest wide area (regional) wireless data network available today.

THE COMMISSION MUST PRESERVE THE DELICATE BALANCE
ESTABLISHED IN THE ISM BANDS

3. Metricom fully understands, supports and appreciates the need for experimentationin amatuer spread spectrum and other operations. However, this need for experimentation cannot be met at the expense of the delicate balance the Comission has established in various shared bands. Because Amateurs are allowed to operate with 100 watts output power and unlimited antenna gain, Metricom is concerned that if Amateurs commence widely used, unlimited high power spread spectrum operations in the ISM bands, the careful balance which the Commission has developed for sharing in these bands could be destroyed.2

4. A good example of the Commission's efforts to maintain the delicate balance is the proceeding styled: In re Amendment of Part 90 of the Commission's Rules to Adopt Regulations for Automatic Vehicle Monitoring Systems, PR Docket No. 93-61, 10 FCC Rcd 4695 (1995) (the "LMS Proceeding"). The LMS Proceeding, involves, among other things, competing Part 90 and Part 15 interests in the band. One of the major issues in the proceeding was the low power (1 watt) Part 15 operations will interfere with the higher powered Part 90 licensed service. After a voluminous record was developed over a two-year period, the Commission ultimately fashioned a compromise permitting both types of operations to co-exist in the band, subject to the condition that testing be conducted to assure that no harmful interference would be caused to Part 15 operations. The Commission's Order was subject to numerous Petitions For Reconsideration which, to date, have not been resolved.

5. The delicate compromise constructed by the Commission in the LMS Proceeding is jeopardized by spread spectrum Amateur operations in the band with 100 watts output power and unlimited antenna gain. Obviously, Part 90 licensed services could experience significant interference: imagine the impact of wide-spread amateur spread spectrum operation at, for example, 1 kW EIRP (100 watts output and 10 dB antenna gain).

6. Part 15 spread spectrum operations in the 902-928 MHz band would also experience significant interference if wide spread, more flexible amateur spread spectrum operations were allowed in the band. Even though both the Part 15 operations and the amateur operations are spread spectrum, because of the enormous difference in authorized power, Part 15 operations would be severely impacted by significantly higher powered amateur spread spectrum operations.

7. Metricom recognizes that both high powered spread spectrum and non-spread spectrum operations are currently permitted in the ISM bands. However, in the case of spread spectrum operations, amateur operations are limited technically by the rules and there is no "off-the-shelf," commercially available equipment for amateur spread spectrum operations. Therefore, high powered amateur operations are not very likely to occur. The difference between the current situation and the newly proposed, more flexible amateur spread spectrum operations is that is the proposed rules are adopted, then equipment for amateur operations is inexpensive and readily available off-the-shelf from Part 15 suppliers. If amateur operators are permitted to use off-the-shelf equipment designed for low power operations in a shared, congested environment, and modify this equipment by boosting the output power up to as much as 100 watts, with unlimited antenna gain, there would undoubtedly be a severe negative impact on other operations in the band.

8. In the LMS Proceeding, the Commission did not ignore the fact that Part 15 products and services represent American jobs, investment, innovative technology and a significant benefit to the public. Likewise, the Commission must not ignore that fact in this proceeding. Part 15 devices -- such as cordless phones, automatic meter readers, point-to-point data links, local and wide are networking, wireless PBXs and security systems -- provide a plethora of services to the public including NII access for schools, libraries and others. In addition, the Commission cannot ignore the fact that Part 15 low power technology also helps to mitigate the public's increase concern and awareness of exposure to RF radiation. In fact, the Commission's recent RF exposure standards categorically excluded Part 15 devices from their excess of the specified guidelines.3

AUTOMATIC POWER CONTROL WILL NOT SIGNIFICANTLY
LIMIT INTERFERENCE TO PART 15 OPERATIONS

9. The Commission takes a significant and necessary step in the Notice by requiring automatic power control ("APC"). Under the proposal, the signal-to-noise ratio (specified as Eb/(No+Io)) at the "intended receiver" must be automatically adjusted to maintain no more that 23 dB.4 This level still allows a strong signal (especially when compared to a one watt Part 15 signal) and this 23 dB threshold would, in most cases of usual and ordinary amateur operations, allow a much greater power output than one watt. As illustrated in the calculations appended as Attachment 1, based on empirical test data at 915 MHz and assuming a typical RF environment, an amateur path of only 10 miles would, under the Commission's proposal, allow a transmit power of 63 watts (see Attachment 1). This relatively short distance is not at all typical of amateur operations. It is obvious, therefore, that the APC proposed by the Commission will not significantly limit interference to Part 15 operations.

AMATEURS HAVE SEVERAL OTHER BANDS AVAILABLE
FOR HIGH POWER SPREAD SPECTRUM OPERATIONS

10. Limiting the power of amateur spread spectrum operations in shared ISM bands would not work a hardship on amateurs. Precedent exists for limiting power of amateur spread spectrum operations as evidenced by the fact that existing spread spectrum operations are limited to 100 watts output power while non-spread spectrum operations are permitted generally to operate with 1,500 watts output power.5 In addition, there are sufficient frequency bands available for high power amateur spread spectrum operations outside of the shared ISM bands (e.g. 1240-1300 MHz, 3.3-3.5 GHz, 10-10.5 GHz) where higher powered spread spectrum operations could be conducted without affecting the delicate balance established in the ISM bands. Moreover, there is no question that spread spectrum operations work successfully in the 900 MHz, 2.4 GHz and 5.8 GHz bands. Experimentation in bands where spread spectrum operations have not proven successful appears to be much more conductive to amateur operations and to maintaining the success thus far achieved in the 900 MHz, 2.4 and 5.8 GHz bands.

CONCLUSION

11. Because the automatic power control proposal in the notice will not sufficiently limit power in the ISM bands to Part 15 levels, and because there are other suitable frequency bands available for higher powered amateur spread spectrum operations, there are no sound public policy reasons to disturb the delicate balance the Commission has established in the ISM bands. The position advocated by Metricom herein will facilitate the successful situations where conflict is both likely and difficult to resolve. Moreover, limiting amateur spread spectrum operations to Part 15 limits will provide for the continued operation of products and services in which the American public has a significant interest and investment. Accordingly, the Commission should limit amateur spread spectrum operations in the ISM bands to Part 15 power limits, and should adopt the remainder of the Notice as proposed.

Respectfully submitted,
Metricom, INC.

By Henry M. Rivera
Larry E. Solomon
GINSBURG, FELDMAN & BRESS, Chtd.
1250 Connecticut Avenue, N.W.
Washington, D.C. 20036-2600
Telephone: 202-637-9000
Email: lsolomon@gfblaw.com

Dated: May 5, 1997


1 In its Replay Comments on the ARRL Petition, Metricom took the position that more flexible amateur spread spectrum operations should not be authorized in the ISM bands. Reconsidering its position, Metricom believes that more flexible amateur spread spectrum operations should be allowed in the ISM bands, provided operations are limited to Part 15 power levels.

2 It should also be noted that the Commission recently established the UNII service which uses part of the 5.8 GHz ISM band (Report and Order, Amendment of the Commission's Rules to Provide for Operation of Unlicensed NII Devices in the 5 GHz Frequency Range, ET Docket No. 96-102, FCC 97-5 (rel. Jan. 9, 1997). These newly created UNII operations could be severely impacted if the proposals in the Notice are adopted.

3 Report and Order, Guidelines for Evaluating the Environmental Effects of Radiofrequency Radiation, ET Docket No. 93-62, FCC 96-326 (Rel. Aug. 1, 1996).

4 See proposed rule section 97.311(g).

5 See 47 C.F.R. section 97.13.


Attachment 1

To determine the total Lb for a 10 mile range, the path loss at 915 MHz must be determined.

Path Loss (dB) = -10log(c/4*pi*f*d)exp

Where
Path Loss dB
c Speed of Light (1.8697e5 miles/second)
pi 3.14
f Frequency (MHz)
d Distance (miles)
exp Loss Exponent

Path Loss = -10log(c/4*pi*915e6*10)2.4
Path Loss = 139dB

Substitute Path Loss for Link Budget above:

139 = Trpwr + 91
Trpwr = 139 - 91 = +48 dBm = 63 watts


Comments of Raphael Soifer, W2RS

Before the
Federal Communications Commission
Washington, D.C. 20554

In the Matter Of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater Use of   )   WT Docket No.rm8737
Spread Spectrum Communication         )
Technologies                          )

To: The Commission

COMMENTS OF RAPHAEL SOIFER, W2RS

Background

1. I am an Amateur Extra Class licensee and have been an active radio amateur since 1955. My amateur radio operation covers HF, VHF and UHF, including satellite, moonbounce (EME) and digital communications. I hold a B.S. degree in Electrical Engineering from Massachusetts Institute of Technology and an MBA degree from Harvard University.

Discussion

2. I generally support the intent of the Commission's proposal to liberalize the rules governing the use of Spread Spectrum (SS) in the Amateur Service. However, I respectfully request modifications to the Rules as proposed in the NPRM to minimize the potential for destructive interference to satellite and EME operation.

3. With respect to satellite operation, I am in full agreement with the points made by the Radio Amateur Satellite Corporation (AMSAT) in paragraphs 2 and 3 of their comments. However, the rule modifications proposed by AMSAT may not go far enough in minimizing potential interference, in several specific respects:

4. Although the Commission's proposals would affect only amateur bands above 420 MHz, I understand that some commenters are proposing liberalization of SS operation in the amateur VHF bands as well. I do not support such proposals at this time, since I believe that the bands above 420 MHz provide ample spectrum for SS experimentation. Based on the results of such experiments, it may or may not turn out to be appropriate to consider broadening the frequency range in which amateur SS operation may be conducted, in a subsequent rulemaking proceeding.

5. Extension of SS operation to the 50 MHz band would, in my view, be particularly undesirable in view of the frequent ionospheric propagation at this frequency, which would make it highly probable that SS station in the USA could cause interference to amateur and non-amateur stations in other countries.

6. However, should the Commission decide to extend amateur SS operation to the two-meter band (144 - 148 MHz) in the current proceeding, the same persuasive arguments made by AMSAT with respect to the Amateur-satellite Service bands between 435 and 2410 MHz would apply also to the international Amateur-satellite Service allocation at 144 -146 MHz.

7. AMSAT chose to confine its comments to matters specifically affecting the Amateur-satellite Service. However, it must be noted that EME operation involves the reception of signals reflected from the moon that are typically far weaker than those from amateur satellites. Amateur EME signals as weak as -175 dBm have been detected using digital signal processing, and skilled human CW operators are able to complete two-way contacts with received signals in the range of -160 to -165 dBm. Such signals woud be more susceptible to destructive interference caused by the higher apparent noise floor resulting from co-channel SS activity than are satellite signals, by several orders of magnitude.

8. The Commission wishes to foster the development of advanced technology. I can think of no better way to do this than to encourage amateur EME operation, which has already led to major innovations in the fields of antenna design, low-noise receiving amplifiers, transmitter design and radio propagation. More than a few successful high-technology companies active today have been founded by amateur EME operators.

9. Owing to the extremely weak signals involved, the vast majority of amateur EME operation today utilizes narrowband CW. Some SS proponents have argued that SS technology holds the promise of even better results. However, at the present time, these anticipated benefits exist only in theory and hove not been demonstrated in practice. My proposed modifications to the Commission's proposal would encourage the future development and testing of such technology without endangering present EME operation.

10. At present, most amateur EME operation in the 144 MHz band takes place in the band segment 144.0 - 144.1 MHz, which is restricted to CW operation under present FCC rules. Regardless of the Commission's decision with respect to SS in this proceeding, I urge that no change be made in the permitted modes of operation in the band segment.

11. In the amateur bands above 148 MHz and below 2410 MHz, EME operation most commonly takes place at 222.0-222.2, 432.0-432.2, 1296.0-1296.2 and 2304.0-2304.2 MHz. I urge that SS operation not be permitted in these band segments, except for transmissions intended to be reflected from the lunar surface.

12. In addition, I concur with the recommendations made by AMSAT with respect to the international Amateur-satellite Service allocations between 435 MHz and 2410 MHz.

Recommendations

13. My specific proposed modifications, embodying these comments, are as follows. I respectfully request that the Commission add the following language to Section 97.305:

    97.305 Authorized emission types

    SS (spread spectrum) emission are authorized in the following frequency segments:

    420 - 450 MHz*
    902 - 928 MHz
    1240 - 1300 MHz*
    All Amateur frequencies above 2300 MHz*

    *In the segments 435 - 438 MHz, 1260 - 1270 MHz and 2400 - 2410 MHz, SS emissions shall be used only for transmissions to or from amateur space stations, except for short tests to confirm proper operation of equipment. In the segments 432.0 - 432.2 MHz, 1296.0 - 1296.2 MHz and 2304.0 - 2304.2 MHz, SS emissions shall be used only for transmissions intended to be reflected from the lunar surface.

14. In the event that the Commission chooses to permit SS operation in the 144 MHz and/or 222 MHz bands, I respectfully request that language be added to Section 97.305 as follows:

    SS (spread spectrum) emission are authorized in the following frequency segments:

    144.1-148.0 MHz*
    222.0-225.0 MHz*

    *In the segment 144.1-146.0 MHz, SS emissions shall be used only for transmissions to or from amateur space stations of for transmissions intended to be reflected from the lunar surface, except for short tests to confirm proper operation of equipment. In the segment 222.0-222.2 MHz, SS emissions shall be used only for transmission intended to be reflected from the lunar surface.

Conclusion

This suggested course is consistent with the Commission's policy of fostering experimentation among the amateur community and encouraging the growth of SS, including those using it in connection with amateur satellites and EME. At the same time, it would preserve the capability of using current modes in conjunction with satellite and EME operation, even by satellite and EME users located in close proximity to other stations using SS for terrestrial applications.

RESPECTFULLY SUBMITTED,

//signed//

Raphael Soifer, W2RS
60 Waldron Avenue
Glen Rock, New Jersey 07452

May 5, 1997


Reply Comments of John R. Ackermann, AG9V

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF: John R. Ackermann AG9V 4353 Napa Valley Drive Bellbrook, OH 45305 jra@febo.com

June 3, 1997

Introduction

I have been an amateur radio operator since 1974. I have held an Amateur Extra Class license since 1979, and a First Class Radiotelephone Operator╠s License and its successor since 1980. Over the years I have actively pursued many facets of the hobby, including ¤DXing,Ë contest operation, building and using voice repeaters, and weak signal VHF operation, but for the last decade my primary interest has been in using digital communications within Amateur Radio.

Although I am a member of the American Radio Relay League, Tucson Amateur Packet Radio Corporation, and the Radio Amateur Satellite Corporation, I am filing these comments in reference to this Notice of Proposed Rulemaking, solely on my own behalf.

Discussion

I believe that the Commission╠s consideration of the rules relating to spread spectrum (¤SSË) communication is a step forward for the Amateur Radio Service, and I applaud this action. However, I am concerned that certain of the proposed rule changes will unnecessarily hamper the development and implementation of SS techniques in the ARS.

Two proposed provisions cause me particular concern. Although some comments filed in response to this Notice of Proposed Rulemaking support their inclusion, I respectfully disagree and instead suggest that these provisions do not further the Commission╠s intent to encourage technical innovation within the Amateur Radio Service.

First, the requirement in proposed Section 97.119(b)(5) for morse code identification is counterproductive. The narrow-band identification may itself cause interference even though the SS emission does not, and it is likely to be difficult to correlate the CW identification with a particular SS signal. This requirement also precludes the use of currently available commercial SS equipment, as to my knowledge no such unit provides for CW identification.

Second, the automatic power control provision contained in proposed Section 97.311(g) is unnecessarily restrictive. Automatic power control has the potential to improve the channel efficiency of SS signals, but this is as yet unproven in the amateur environment, and it adds unnecessary complexity to the development of experimental hardware. I believe that at this stage of SS development, it would be more appropriate for the rules to encourage, rather than require, the use of automatic power control.

Another concern with proposed Section 97.311(g) is the 100 watt power limitation. This limitation places SS in a second-class position with respect to other modulation methods used in the Amateur Radio Service, and it effectively precludes the use of SS in some unique areas such as moonbounce.

Conclusion

One of the cornerstones of the Amateur Radio Service has been technological innovation. Numerous technologies that are in common commercial use today were first proven on the ham bands. However, amateur work with SS has been hampered by the current rules, and as a result hams have lost the opportunity to experiment with Ď and, based on past experience, likely improve Ď this technology. Therefore, I applaud the Commission╠s decision to consider relaxation of these restrictive rules.

However, as I have noted, the proposed rules still place SS at a disadvantage with respect to other modulation methods and unnecessarily constrain amateur radio operators╠ ability to advance the state of the art. I urge the Commission to remove these restrictions so that SS may develop on an equal footing with other technologies.


RESPECTFULLY SUBMITTED,

John R. Ackermann AG9V


Reply Comments of AMSAT

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF THE RADIO AMATEUR SATELLITE CORPORATION (AMSAT)

1. AMSAT filed Comments in this proceeding on May 5, 1997. We have since reviewed the Comments filed by William A. Tynan (Tynan), Central States VHF Society (CSVHFS), American Radio Relay League (ARRL), Tucson Amateur Packet Radio (TAPR), Raphael Soifer (Soifer), Philip R. Karn, Jr. (Karn), Metricom, Robert J. Carpenter (Carpenter), The Part 15 Coalition (The Coalition), Lyle V. Johnson, Jr. (Johnson), Robert A. Buaas (Buaas) and The 220 MHz Spectrum Management Association of Southern California (220 SMA). The following Reply Comments are provided with respect to the Comments reviewed.

2. To the extent that they are consistent with our comments, we support the views of Tynan, Soifer, Carpenter and CSVHFS with respect to protection of frequencies utilized by the Amateur-satellite Service.

3. TAPR and Karn propose to extend amateur SS operation to all frequencies in the 50, 144 and 222 MHz bands, as well as the bands above 420 MHz as proposed by the Commission. AMSAT will not address the portion of these proposals regarding the 50 MHz band, since it is not an Amateur-satellite Service allocation. However, the 144 to 148 MHz band does contain an Amateur-satellite Service allocation, namely 144 to 146 MHz. If the Commission should favorably consider the TAPR/Karn proposal, consistent with our comments, AMSAT urges that it exclude this segment of the 2 meter band from use by SS stations communicating terrestrially.

4. Most of those commenting in favor of SS use terms like "no restrictions" and "maximum flexibility". RM-8737 and this Docket are absolutely silent on what SS is. No bandwidth limits are specified. Presumably amateur spread spectrum emissions would be limited to the amateur bands, but even that is not stated. The amateur community is being asked to accept this new technology without any information as to what its effect will be. Buaas takes particular exception to Tynan's expressed concerns regarding potential SS interference to weak signal and satellite communications, terming them "conjectures of doom as fact, without bothering to conduct any realistic tests". Neither Tynan nor AMSAT are in a position to conduct SS tests. However, Mr. Buaas presumably is in such a position. Quantitative results of ss tests need to be seen before concluding that terrestrial SS operation poses no threat to relatively weak amateur satellite signals.

5. Much has also been said in comments as well as in informal correspondence between SS proponents and those concerned about its possible impact, with regard to the amateurs working out "band plan" arrangements among themselves. In their comments, TAPR and Karn suggest that amateur SS experimenters will publish information about their activities on the Internet. For one thing, there is no assurance that they will. Certainly, no such requirement is contained in the proposed Rules. In addition, how would this prevent interference? Additionally, there is no definition in the Docket as to how much bandwidth SS will occupy. It might be 1, 2, 10, or perhaps even 30 MHz. Even if a frequency coordinating body were to attempt to coordinate 70 cm SS operation so as to not impact the Amateur-satellite Service allocation from 435 to 438 MHz, how could this be done if the SS operation in question is 30 MHz wide? AMSAT continues to feel that the provisions we proposed in our comments, namely that no terrestrial SS communication be permitted in Amateur-satellite Service allocations, are appropriate and will afford SS ample room in which to develop without impacting amateur satellite activities. We continue to wish to be able to employ SS techniques in the Amateur-satellite Service bands for purposes of communicating with and through amateur satellites. Our proposal contained in our comments does permit this.

6. AMSAT is very disturbed by the comments filed by Metricom and The Coalition. Metricom is an unlicenced user of the radio spectrum, namely 902 to 928 MHz and 2400 to 2450 MHz, and The Coalition represents various companies so engaged. Both urge the Commission to limit the power of amateur SS stations operating in these bands to the same level they, as Part 15 users, are permitted - 1 watt. We contend that, not only would such a limitation represent a very dangerous precedent which could have long term negative consequences for the Amateur and Amateur-satellite services, it might also have an immediate impact on the ability of amateurs to use SS in the 2400 MHz Amateur-satellite Service band for satellite uplinks. The question also arises as to whether it would apply to satellite downlinks. The Phase 3D spacecraft presently being completed in our Orlando, Florida facility for launch later this year will carry a high power 2400 MHz transmitter. Since this satellite is to be licensed in Germany, not the U.S., one wonders how such a power limitation could even be imposed by the Commission.

7. The comments of Metricom and the Coalition are entirely out of order and inappropriate. Essentially, they want some amateur stations and amateur-satellite stations to be limited to emissions and power levels which are similar to the limits on Part 15 devices. Unlicensed operation under Part 15 is on a secondary basis to all licensed services, industrial, scientific, and medical (ISM) devices, and even incidental radiators sharing the relevant frequency allocations:

"Operation of an intentional radiator is subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station, by another intentional radiator, by industrial, scientific and medical (ISM) equipment, or by an incidental radiator."

See 47 CFR 15.5(a).

Making rules to protect Part 15 unlicensed intentional radiators is entirely inconsistent with the intent of Part 15, the purposes of the various services, and the Table of Frequency Allocations. Therefore, the proposals of Metricom and the Coalition should be rejected.

8. Copies of these Reply Comments have been provided to those individuals and organization whose comments are cited herein.

RESPECTFULLY SUBMITTED,

Radio Amateur Satellite Corporation
P.O. Box 27
Washington, D.C. 20044

By: Dr. Perry I. Klein, W3PK
Vice-President, Government Liaison

June 5, 1997


Reply Comments of AMERICAN RADIO RELAY LEAGUE, INCORPORATED

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF THE AMERICAN RADIO RELAY LEAGUE, INCORPORATED
                              The American Radio Relay
                              League, Incorporated


                              Christopher D. Imlay
                              Booth Freret Imlay & Tepper, P.C.
                              1233 20th Street, N.W., Suite 204
                              Washington, D. C.  20036

June 5, 1997


TABLE OF CONTENTS
Summary ................................................................... i

     I.   Overview......................................................... 1

    II.   Supporting Comments.............................................. 3

   III.   Proponents of Further Deregulation..............................  6

    IV.   Repeater Compatibility Issues and Local Coordination............ 10

     V.   Interference Concerns of Weak-Signal and Satellite Operators.... 12

    VI.   Comments of Part 15 Manufacturers............................... 15

   VII.   Conclusions..................................................... 18

Certificate of Service


SUMMARY

The American Radio Relay League, Incorporated (the League), the national association of amateur radio operators in the United States, submits its Reply Comments relative to the Notice of Proposed Rule Making (the Notice), FCC 97-10, released March 3, 1997. The Notice proposes to amend the Amateur Service Rules, Part 97, to facilitate Spread Spectrum (SS) communications by means of additional spreading codes, and to cause the incorporation of automatic power limiting circuitry to limit power to that actually necessary to carry out the communications.

The Comments in this proceeding fall into five reasonably distinct categories: (1) those who support the Notice proposal to liberalize the regulation of SS spreading codes, and to impose automatic power limiting functions, but who offer minor additional regulatory modifications; (2) those who generally support the Notice proposal as far as it goes, but who would suggest significant additional deregulation of amateur SS emissions, including authorization of SS in additional frequency bands; (3) weak-signal experimenters, satellite enthusiasts, and other terrestrial users concerned about interference to sensitive receivers in weak-signal, Earth-moon-Earth, and satellite operations; (4) a single comment which suggests mandatory local coordination of "emitters" in mixed-emission mode bands, to minimize interaction between incompatible modes; and (5) those who object to more liberalized amateur SS operation because of concerns about interference to Part 15 devices in some of the same bands that amateurs would use for SS.

The League suggests, as it did in its comments in this proceeding, that the Commission has arrived at a balanced approach, carefully crafted to accommodate competing interests in this proceeding: greater flexibility for amateur spread spectrum operations, and avoidance of reduced flexibility in other narrowband amateur operations and certain kinds of unlicensed, Part 15 intentional radiators. The comments in this proceeding, variously asserting that lesser or greater regulation of amateur SS operation should be arrived at, itself reflects the Commission's success in having arrived at the proper balance of interests. The League suggests that the comments establish the propriety of the existing rules, and again urges the adoption of the Notice proposal without delay.


     Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554
In the Matter of ) ) Amendment of the Amateur Service ) WT Docket No. rm8737 Rules to Provide For Greater Use ) of Spread Spectrum Communication ) Technologies ) To: The Commission
REPLY COMMENTS OF THE AMERICAN RADIO RELAY LEAGUE, INCORPORATED

The American Radio Relay League, Incorporated (the League), the national association of amateur radio operators in the United States, by counsel and pursuant to Section 1.415 of the Commission's Rules (47 C.F.R. Sec. 71.415) hereby respectfully submits its Reply Comments relative to the Notice of Proposed Rule Making (the Notice), FCC 97-10, released March 3, 1997. The Notice proposes to amend the Amateur Service Rules, Part 97, to facilitate Spread Spectrum (SS) communications by means of additional spreading codes, and to cause the incorporation of automatic power limiting circuitry to limit power to that actually necessary to carry out the communications. In response to the several comments filed in response to the Notice, the League states as follows:

I. Overview

1. The Comments in this proceeding, of which the League was able to locate 14, including those filed by the League, fall into five reasonably distinct categories. The first are those who support the Notice proposal to liberalize the regulation of SS spreading codes, and to impose automatic power limiting functions, but who offer minor additional regulatory modifications, so as to address what they perceive as overregulation of amateur SS operation. The second group are those who generally support the Notice proposal as far as it goes, but who would suggest significant additional deregulation of amateur SS emissions, including authorization of SS in additional frequency bands. The third group consists of weak-signal experimenters, satellite enthusiasts, and other terrestrial users concerned about interference to sensitive receivers in weak-signal, Earth-moon-Earth communications, and satellite operations. The fourth, consisting of only one comment, suggests mandatory local coordination of "emitters" in mixed-emission mode bands, to minimize interaction between incompatible modes. Finally, the fifth group objects to more liberalized amateur SS operation because of concerns about interference to Part 15 devices in some of the same bands that amateurs would use for SS.

2. The League suggests, as it did in its comments in this proceeding, that the Commission has arrived at a balanced approach, carefully crafted to accommodate competing interests in this proceeding: the goal of greater flexibility for amateur spread spectrum operations, and avoidance of reduced flexibility in other narrowband amateur operations and certain kinds of unlicensed Part 15 intentional radiators. The comments in this proceeding, variously asserting that lesser or greater regulation of amateur SS operation should be arrived at, themselves reflect the Commission's success in having arrived at the proper balance of interests. The League suggests that the comments establish the propriety of the proposed rules, and again urges the adoption of the Notice proposal without delay. Each of the comments filed, regardless of position, indicates support for amateur SS experimentation and disclaims any intention to frustrate such. Therefore, the only issue for consideration is how to structure the final rules to permit such, without arriving at unintended adverse consequences. A reading of the comments leads inescapably to two conclusions: 1) that more liberal deregulation of SS emissions is undesirable at this time, until more experience is gained with different types of SS operation, and 2) on the other hand, the present level of Commission regulation of amateur SS emissions is unnecessary for interference avoidance and has choked off SS experimentation in an inherently experimental service. The modest deregulatory proposal in the Notice is entirely proper and should be adopted verbatim.

II. Supporting Comments

3. The Comments of the Manager, National Communications System (NCS), for the Secretary of Defense, support the Notice proposal. NCS has regularly participated in amateur radio rulemaking proceedings in support of the functions of NCS in carrying out its National Security/Emergency Preparedness (NS/EP) functions. NCS "fully supports" the Notice proposal. However, NCS also suggests some additional, relatively minor SS deregulation that might further unburden experimenters. Specifically, NCS asks that the Commission eliminate the narrowband identification requirement for SS emissions (Sec. 97.119(b)(5), as it precludes the use of any commercially available SS equipment, and fulfills no useful purpose. Second, NCS asks that the station recordkeeping requirements (Sec. 97.311(e) be eliminated, as they are not imposed on other types of amateur emissions. Third, NCS asks that the Commission's stated authority to restrict or cause the cessation of amateur SS emissions, or require recordkeeping, (Sec. 97.311(f)) is redundant of other amateur regulations and the Commission's authority generally, and need not be repeated in the SS rules specifically. While the League is somewhat sympathetic to these additional suggestions of NCS, it is suggested that no further deregulation of SS regulations beyond that proposed in the Notice be implemented at this time. It is apparent from the comments that there is a lack of comfort among narrowband users about increased instances of mixing of SS and narrowband modes; there has been a significant absence of SS experiments over the past 10 years since SS was initially authorized in the Amateur Service; there is an inherent lack of "monitorability" of amateur SS emissions; and therefore, it would be prudent to continue the narrowband station identification requirement and station recordkeeping for SS emissions for the near term.

4. The well-stated comments of Lyle V. Johnson, WA7GXD (Johnson), a co-founder of Tucson Amateur Packet Radio (TAPR) and an accomplished amateur satellite and digital communications experimenter, generally support the deregulatory portion of the Notice proposal, but also object to the continuation of the narrowband SS emission identification requirement. Johnson notes that the entire objective of the use of SS is for such communications to relieve narrowband channel congestion, but the identification requirement adds to it. He also notes that SS operators will disseminate information about transmission format and frequencies anyway, so that others can communicate with them. He also suggests that, because all other authorized amateur emissions allow in-mode station identification, the same should be allowed for SS. As does NCS, Johnson also objects to the recordkeeping requirements as inconsistent with other amateur emission modes, and asks that the requirements be eliminated or at least liberalized, limited to a one-year retention period.

5. Finally, Johnson objects to the automatic power limitation requirement proposed in the Notice. He notes that this technology is used currently in CDMA cellular telephones connected to a central cell site using DSSS modulation techniques, because it is necessary in that configuration. However, he claims that amateur operation is different, because the station intercommunication characteristics (such as point-to-multipoint operation, e.g., roundtable-type on-air discussions and spacecraft downlink telemetry) are different. The result, he claims, is that automatic power control circuitry will limit the applications and utility of amateur SS communications. He asserts that Section 97.313(a) of the Rules already requires that Amateur stations use the minimum power necessary for the intended communication for all emissions, and that is a sufficient constraint.

6. The automatic power limiting circuitry requirement is useful both in mixed-mode situations where SS emissions are being added to bands in which narrowband emissions are already established and ongoing, and generally with respect to intra-mode interference avoidance. Amateur SS emission types are in the experimental phase, and until sharing protocols are developed sufficiently to avoid inter-mode interference, automatic power limitation circuitry is desirable. To the extent that this would limit point-to-multipoint amateur communications, that is a matter that should be resolved by technical innovation, not Commission regulation. The wideband characteristics of SS emissions make automatic power limitation highly desirable as a quid pro quo for the authority to use widely varied spreading codes.

III. Proponents of Further Deregulation

7. The next group of comments included those of Robert A. Buaas, K6KGS (Buaas), Philip R. Karn, Jr., KA9Q (Karn), and TAPR. Buaas is perhaps the most prolific of the amateur SS experimenters, and has held Commission Special Temporary Authority (STA) for experiments with SS emissions. The results of his work contributed to the conclusions which led to the League's petition in this proceeding. Buaas, while acknowledging that the intent of the proceeding was to simplify SS regulation and encourage its use, feels that the result is the opposite. Buaas asks for authority to conduct SS operation in any amateur band above 50 Mhz without restriction; to use any coding and/or modulation technology; that in-mode identification be permitted; and to eliminate other restrictions on SS operation. He notes the absence of any complaints of interference from narrowband modes from co-channel SS operation, and offers an analysis of the compatibility between narrowband and SS modes that is largely based on time domain sharing. He concludes that "properly designed SS systems" have "minimum likelihood of causing interference". Buaas is critical of repeater operators and narrowband weak-signal experimenters who are opposed to liberalization of SS rules, having conducted few experiments themselves, and therefore lack an empirical basis for their interference fears.

8. The League is most respectful of the extensive experiments of Buaas, and has assisted his efforts to obtain and extend his STAs for the same. The League is comfortable that increased use of SS emissions as an overlay on established narrowband operation can be done without significant interference potential, but to do so requires informal band planning and informal spectrum management techniques such as amateurs routinely employ. It is not reasonable at this time to completely deregulate SS emissions as Buaas suggests, because to do so without affording the amateur community the opportunity to develop its own protocols for band sharing invites a clash between incompatible modes, rather than the hoped-for assimilation of both narrowband and wideband emissions. Furthermore, as to the suggestion made by Buaas to permit SS emissions on all bands above 50 MHz, the current narrowband occupancy of those bands is sufficiently high that development of SS systems in bands currently authorized for SS operation is prudent. The amateur bands at 50, 144 and 222 MHz are among the most popular bands for numerous narrowband communications, and the higher bands are best suited for additional SS experimentation using varied spreading codes, due to substantially larger bandwidths (and concomitantly decreased power densities), available.

9. The comments of Karn note the distinct benefits of deregulation of SS emissions in the Amateur Service,[1] and the almost complete lack of development of SS technology by amateurs to date. Karn, like Buaas, has extensive experience with SS emissions, and laments that Part 15 regulation of SS emission, often in the same bands in which SS is authorized for amateur use, is far less restrictive than the current amateur rules, and that, because power levels up to one watt are permitted for Part 15 devices, far more amateurs are conducting experiments under the Part 15 rules than they do in the Amateur Service. He contends, and the League agrees, that the current rules offer a significant disincentive to amateurs to experiment or communicate with SS, and that the Notice proposal is a reasonable first step.

10. Karn, however, before announcing certain modifications he would offer to the Notice proposal, admits that it is impossible to say that under no circumstances could SS operations interfere with traditional narrowband operations. He thus concedes that there should be some continued regulatory limitations on its use. On the other hand, he insists that it is wholly inappropriate to demand a guarantee of non-interference in the first place, or to design rules with that expectation. The Amateur Service is, after all, an experimental radio service, albeit with emergency communications and public safety characteristics. All frequencies are shared, and there is no channelization. The flexibility to experiment and develop mixed-mode protocols in the same bands is a necessary characteristic of the Amateur Service. There have never been non-interference guarantees among radio amateurs in the use of shared bands, using differing emission modes. While the goal of the regulations on SS emissions is to minimize interaction on a broad scale, inter-mode interference avoidance largely is dependent on action by the users themselves. In any event, the deregulation of spreading codes and imposition of automatic power control interposes no additional interference concerns or Commission regulatory intervention.

11. Karn reverses his prior position relative to automatic power control. Though he suggests that it is useful as a means of minimizing interference potential, he no longer suggests such as a regulatory requirement. He also asks for elimination of the present 100-watt power limit for SS EME operation, as it is an impediment to SS EME experimentation, and because, he states, the antenna elevations above the horizon necessary for EME operation make the power limit unnecessary for interference prevention. This position is not well-taken, because when the moon is at or near the horizon, there is no significant antenna elevation, and thus that factor cannot serve as a sufficient interference avoidance technique. There are, in fact, certain advantages to EME operation when the moon is at or near the horizon, due to the ground reflection gain derived in that configuration.

12. Finally, Karn discusses non-regulatory means for limiting the interference potential of SS emissions, all of which are worthy of further testing and evaluation. It is precisely because of that relative absence of compatibility testing, however, between narrowband and SS modes that more substantial deregulation of SS emissions is premature. Safeguards such as automatic power control are necessary, as discussed above. It may be that higher power for SS EME operation is justifiable, but it is not necessary to allow such at the present time. The idea of the League's petition for rule making, and of the instant Notice as well, is to permit sufficient deregulation to permit greater SS experimentation, and a determination on a reasonable scale of the aggregate interference potential to narrowband modes. Mr. Karn's interference-limiting concepts are exactly the type of technical development that must occur before complete deregulation of SS emissions is subject to reasonable discussion.

13. The comments of TAPR make essentially the same points as do those = of Buaas. TAPR supports the Notice proposal. TAPR, like Karn, abandons its support for the automatic power control requirement, noting that it would be difficult to utilize SS emissions with APC circuits in the point-to-multipoint packet radio networks. TAPR also asks for elimination of the 100-watt power limit, due to the preclusion of some of the more interesting applications in the Amateur Service, such as EME operation. TAPR also asks for elimination of the narrowband station identification requirement and the recordkeeping requirement, and asks that SS emissions be permitted on all amateur bands above 50 MHz.

14. The time may come when each of these regulations may be eliminated= without concern for compatibility with narrowband modes already existing in the bands where SS is authorized. That concern exists now, however, because of the relative absence of SS experimentation and operation in those bands, and the comments in favor of further deregulation do not make much of a case for the necessity of additional deregulation. The difficulties in application of the APC requirement to point-to-multipoint operation, for example, are hardly a justification for elimination of APC as an interference limiting device generally. The adverse effects of the 100-watt power limit on EME operation have not been shown to be a reason why amateurs have not experimented with SS emissions to date, and no technical justification for the contention is offered. Similarly, the narrowband identification requirement and the station recordkeeping requirement are minimal intrusions indeed, and are designed to permit self-regulation and compatibility determinations involving a mode that is difficult to monitor.

IV. Repeater Compatibility Issues and Local Coordination

15. There were a number of comments filed in response to the League's petition for rule making, RM-8737, by groups of repeater users and local coordinators, expressing concern over what they perceived as a potential for interference from SS emissions to amateur repeaters. Surprisingly, there was but one comment in this category filed in response to the Notice, that being from the 220 MHz Spectrum Management Association of Southern California (220 SMA). The 220 SMA comments carefully identify that organization as a "spectrum management coordinator" rather than a "repeater coordinator", but note that its functions include coordination of digital linking at 219 MHz and repeater coordination at 222-225 MHz. The 220 SMA fears interference from SS operation at "developed communication sites". As the result, the 220SMA argues in favor of regulatory language that would place the burden of interference resolution as between SS and narrowband modes on the "uncoordinated emitter", thus to establish a de facto local coordination requirement on SS operations.

16. There are several problems with this concept. It is based on the = premise that the Notice proposal envisions SS operation to be a "subordinate" emission mode, which is already established as a regulatory matter by virtue of Section 97.311(b), which is unaffected by the Notice proposal. It reads, in relevant part, as follows: "Stations transmitting SS emission must not cause harmful interference to stations employing other authorized emissions, and must accept all interference caused by stations employing other authorized emissions". This rule is sufficient to establish the priority of interference resolution as between a station transmitting SS emissions and one transmitting another narrowband mode. The implicit suggestion of 220 SMA, however, is more than simply to establish a hierarchy of interference resolution obligations; it would in addition place amateur SS experimentation under the watchful jurisdiction of local repeater coordinators, whose membership consists essentially of repeater owners, and whose interest is in repeater and remote base operation and not in SS or other types of amateur operation. It might be presumed under that configuration that interference involving repeaters would be resolved in favor of the repeater, because it is "coordinated", over other types of amateur emission modes. In any case, the formal coordination requirement that is suggested by 220 SMA is unnecessary, and undesirable in the proposed configuration, because the Commission has established the priority of emissions relative to amateur SS.

17. While the League would agree with the 220 SMA that Commission restrictions on SS operation should be reduced, and that the amateur community should be permitted to do its own spectrum management, it is not desirable to mandate any particular frequency coordination mechanism for SS operation at the local level, any more than it is desirable to mandate local coordination of other emission modes. Therefore, the League strongly opposes the proposal for a "formal emitter coordination process when elected by the local/regional body of Amateurs".

V. Interference Concerns of Weak-Signal and Satellite Operators

18. There were several comments from amateur weak-signal and satellite enthusiasts, who were concerned about interference to those types of operation from amateur SS. The Radio Amateur Satellite Corporation (AMSAT) supports liberalization of the Commission's Rules governing SS in the Amateur Service, but is concerned that increased noise levels of up to 20 dB at distances up to 20 km from the SS emitter could result, and that the situation, it claims, is worse in the aggregate. AMSAT therefore asks that SS operation be excluded from the Amateur-Satellite Service bands below 2410 MHz.

19. The comments of Robert J. Carpenter, W3OTC, express a similar concern. He asks that the power level of SS emissions be limited to one watt, and proposes that the APC requirement in the Notice not be adopted. APC, he argues, would increase power of an SS transmitter in response to moderate signals from other modes within the spreading frequency range of the SS transmitter. Mr. Carpenter also suggests that a form of narrowband SS, not more than 10 kHz, be permitted on bands above 50 MHz.

20. The Comments of the Central States VHF Society (CSVS), a substantial group of sophisticated weak-signal VHF, UHF and microwave enthusiasts, notes that weak-signal operation in those bands, and especially EME operation, requires low noise levels. CSVS also suggests that the rules differentiate between "wideband" and "narrowband" SS operation, similar to the comments of Carpenter. CSVS proposes exclusion of "broadband" (i.e. greater than 10 kHz) SS emissions on any segments between 50 MHz and 10.4 GHz that are used for regular weak-signal amateur operation, so as to avoid interference potential that may exist.

21. The comments of William A. Tynan, W3XO, Raphael Soifer, W2RS, and Robert Brown, N7STU, are similar to CSVS and others in this category. The League's response to these individuals, who are properly concerned about interference to their mode of operation, is the same as that offered in response to arguments made in comments on the League's Petition for Rule Making: The Notice does not propose to either increase power for SS emissions, nor expand the frequencies on which SS transmissions may be conducted. Instead, it merely proposes to permit additional spreading codes, so that SS experimenters can have additional flexibility to determine, among many other things, which spreading codes have the least interference potential to narrowband amateur modes. The frequencies on which SS emissions may be transmitted is not at issue in this proceeding, as no change is proposed over existing rules. There are no instances of interference identified in any of the comments, and there is thus no justification for imposition of additional restrictions on SS emissions. The only other change proposed is to limit power by use of APC, for those SS transmissions over one watt. The League is sympathetic to the desirability of limiting interference between SS and narrowband emissions, and the need to avoid interference to satellite and weak-signal communications. However, band planning to accomplish that is best done in this context informally, by amateurs and amateur groups themselves, rather than by Commission regulation which significantly and unnecessarily limits SS experimentation. Cooperation in the use of shared bands, in the standard self-regulatory traditions of the Amateur Service, should be adequate to prevent or resolve unintentional amateur-to-amateur inter-mode interference.[2] Commission regulation is not needed in this case, and none of the Comments offer sufficient justification for increased regulation of SS emissions, or continuation of the current limitations on spreading codes.

VI. Comments of Part 15 Manufacturers

22. The remaining category of comments included those of the Part 15 Coalition and Metricom, Inc., an association of manufacturers and a manufacturer, respectively, of Part 15 SS devices, which operate at sufferance in certain bands allocated to the Amateur Service. The Part 15 Coalition is concerned about the deregulation of SS spreading codes which may be used by amateurs, to the extent that the proposed deregulation would permit amateurs to use and adapt commercial Part 15 devices for amateur use.[3] Metricom states that it has no objection to the deregulation of spreading codes, provided that amateur SS emissions be limited to the power levels of Part 15 devices. Metricom and the Coalition are concerned about the possible addition, by amateurs, of power amplifiers to the devices.

23. This issue has been raised by Metricom and one other manufacturer earlier, and the Notice has already dealt with the arguments.[4] The League has met recently with representatives of the Part 15 Coalition and Metricom, and it was agreed that the League and Metricom would conduct tests of Metricom's devices at the League's laboratory, with the goal of minimizing interaction between Metricom's devices and amateur SS station configurations.

24. It apparently bears reiteration, however, that Part 15 manufacturers generally have no standing to object to Amateur Service rules changes, because Part 15 devices have no allocation status in any Amateur bands. There can be no restrictions, nor any refusal to eliminate unnecessary regulatory barriers, on amateur radio experimentation based on unquantified fears of possible future interference to Part 15 devices. This is especially so where the fear of interference is based on projections of increased amateur band occupancy. The Commission has absolutely no basis for restricting any licensed radio service in the performance of its intended operations in authorized allocations, in order to protect Part 15 devices from anticipated interference. Those devices are allowed to operate only at sufferance.[5]

25. Amateurs can currently operate, using narrowband emissions, at up to 1500 watts, and up to 100 watts PEP output using SS emissions, in the same bands that Metricom wishes to be limited to one watt for SS emissions. Yet, nothing in the Notice proposal increases the interference potential from amateur stations to Part 15 devices. The 100-watt power level for SS emissions has been authorized for twelve years, apparently without interference. The Notice now proposes to limit amateur power output for SS emissions by imposing automatic transmitter power control requirements, limiting the power to those levels necessary to maintain communications. That limitation fits conceptually within the general scheme of amateur regulation. The reduction of power to one watt on a blanket basis does not.

26. The practical result of the Metricom proposal to limit amateur SS power to one watt, ostensibly to protect Part 15 devices from interference (an argument which is totally devoid of technical support, and has not been proven to be necessary at all) would be to elevate the status of Part 15 devices to a protected status relative to licensed services in the subject bands. This would be tantamount to a change in the entire conceptual framework of regulation of Part 15 devices: they would be entitled to the benefits of a licensed radio service but without any of the obligations attendant to shared, licensed users in shared bands. This is inequitable under the circumstances, as well as unjustified and unprecedented.

VII. Conclusions

27. The League's review of the comments in this proceeding leads it to conclude that the Notice proposal constitutes a proper balance between relief of restrictions on an experimental mode of amateur communications, which will permit increased experimentation, and continued protection against any increase in interference potential. As the Notice states, the rule changes proposed "would increase spectrum efficiency and allow amateur operators to contribute to technological advances in communications systems and equipment. Experiments conducted by amateur operators have shown that stations transmitting SS emissions can co-exist with other amateur stations, and in many cases these spread spectrum emissions are undetectable by other amateur stations...We agree that the current rule prohibits amateur stations from using SS emission types that are routinely used in other communication services, and that such a prohibition is inconsistent with the experimental purpose of the amateur service..." (Notice, at 68).

28. There are comments from amateurs that urge greater deregulation, including authorization for SS emissions in additional frequency bands. There are, on the other side, comments from amateurs that urge additional frequency restrictions. These issues largely go beyond the scope of this rulemaking proceeding, which is limited to authorization of additional spreading sequences and APC circuitry. There are those who urge deletion of the 100-watt power limitation, and those who urge greater power limitations for amateur SS emissions. The changes advocated have not been justified technically by any of the comments, however, and the APC requirement appears to be adequate to insure that SS transmissions are made at the minimum power necessary to conduct the SS communications generally. There are those who urge informal notification to narrowband users to further amateur self-regulation, and those who favor mandatory coordination. The League suggests that an informal notification process, such as that suggested by Karn, is desirable, but certainly not something that the Commission should mandate, in the Amateur Service.

29. Overall, it is apparent from the Comments that the Commission has arrived at the proper result in this proceeding and the proposed rules should be enacted verbatim at the earliest possible opportunity.

Therefore, the foregoing considered, the American Radio Relay League, Incorporated reiterates its support of the Notice proposal, and respectfully requests that the Commission move quickly to implement the rules contained in the Appendix B thereto.

                              Respectfully submitted,
                              THE AMERICAN RADIO RELAY
                              LEAGUE, INCORPORATED
225 Main Street
Newington, CT  06111

                              Christopher D. Imlay
                              Its General Counsel


BOOTH FRERET, IMLAY & TEPPER, P.C.
1233 20th Street, N.W., Suite 204
Washington, D.C.  20036
(202) 296-9100
June 5, 1997

Footnotes shown here as Endnotes:

[1] Karn notes the following benefits of SS as a communications technology: improved resistance to multipath propagation, especially in urban environments; increased resistance to interference; reduced average transmitter power requirements, when combined with error control coding and automatic transmitter power control; increased spectrum capacity, especially when carrying intermittent traffic; and other special features, such as accurate ranging.


[2] The League is impressed by the arguments of Karn in this respect. Karn's comments note, in part:

A highly effective interference mitigation technique is to simply announce one's intentions to the local amateur community. There are now many ways that local amateurs can communicate on a regular basis, ranging from traditional meetings and newsletters to packet bulletin boards and Internet newsgroups and web pages.

If it were customary to give notice of spread spectrum operations, including transmitter location, modulation type, bandwidth, power levels, antenna patterns, etc. to the local amateur community, then anyone experiencing interference from an unidentified source would know who to ask.

This is perhaps the simplest solution to SS interference avoidance, though Karn notes numerous others.


[3] The Part 15 Coalition states, in part, as follows:

Although from a purely theoretical standpoint the expanded use of spread spectrum transmission technologies by amateur radio operators should not substantially increase the interference potential of these stations, the rule change could have downstream effects that, as a practical matter, could fundamentally alter the delicate balance between users of these shared bands.

For instance, by expanding the range of spread spectrum transmission modes that may be used by amateur radio stations, operators who have little or no technical knowledge will now be able simply to purchase and use Part 15 spread spectrum equipment that is widely available in the market.

(Part 15 Coalition, at 2).

This statement is absurd; the goal of Part 15 manufacturers is to sell consumer devices to the general public, the majority of whom have absolutely no technical knowledge whatsoever. Amateur licensees have passed examinations in radio theory and operation. They routinely adapt devices, and often refine, modify, and redesign them. If the use of the devices by amateurs reduces the utility of the devices for the general public, then the device has designed into it its own obsolescence.


[4] The Notice, at Paragraph 9, states:

We agree that the current rule prohibits amateur stations from using SS emission types that are routinely used in other communication services, and that such a prohibition is inconsistent with the experimental purpose of the amateur service. As requested by the ARRL and Part 15 equipment providers, we propose to require that automatic control circuitry which reduces the radiated power of an amateur station transmitting an SS emission to the minimum level necessary to conduct communications, be included in SS equipment. Additionally, we solicit comments, regarding other methods that are available to minimize any potential interference between amateur station operations and Part 15 devices.


[5] Part 15 devices have no allocation status, internationally or domestically. They are permitted on an "at-sufferance" basis: they must not cause interference to licensed radio services, and they must tolerate interference received from licensed radio services in the same bands. The Communications Act of 1934 is devoid of any authority to accord Part 15 type devices any allocation status, or interference protection from licensed services, at all; the only authority to permit unlicensed devices under the Act is with respect to radio control and citizen's radio service facilities, and, more recently, marine and aviation services. 47 U.S.C. 307(e). The only provision for Part 15 devices in the Communications Act is for the Commission to regulate the interference potential of such devices by "reasonable regulation". 47 U.S.C. 302. This the Commission has done by permitting operation of such devices in bands allocated, on a primary basis, to one or more licensed radio services, where the operation of the unlicensed devices have been determined to be unlikely to cause interference to the licensed radio services.

The benefits to the manufacturers of such non-licensed devices under the circumstances are several: their products need not be licensed before they can be used by the purchasers thereof; the equipment itself need only be authorized by the Commission by type, pursuant to Part 2 Equipment Authorization requirements; they can operate with some degree of frequency agility and bandwidth variability; and they can be used for an infinite number of purposes, without any eligibility determinations on the part of the user. The devices can be made less expensively, and operated without regulatory effort by the owner. These benefits are realized by manufacturers at the cost of an absence of any priority in the subject bands relative to licensed radio services.

The Commission recently released its Report and Order in ET Docket 94-32, (FCC 96-390, released October 18, 1996) in which it refused to elevate the regulatory status of Part 15 devices in the 2400-2483.5 MHz band, and reaffirmed the primary allocation status of the Amateur Service in the 2390-2400 MHz and 2402-2417 MHz bands. In so doing, at paragraph 34 thereof, the Commission stated:

Further, we note that unlicensed devices enjoy a certain flexibility with their unlicensed status and are being effectively used under existing rules. In this regard, we deny Motorola's proposal to establish an operating parameter under which Part 15 devices would be presumed not to cause interference. Accordingly, we will not grant unlicensed devices additional rights to the spectrum at this time; however, if problems develop, we will consider this issue at that time.


Reply Comments of CENTRAL STATES VHF SOCIETY

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF CENTRAL STATES VHF SOCIETY

1. The Central States VHF Society (CSVHFS) filed Comments in this proceeding on May 5, 1997. We have since reviewed the Comments filed by Radio Amateur Satellite Corporation (AMSAT), William A. Tynan (Tynan), American Radio Relay League (ARRL), Tucson Amateur Packet Radio (TAPR), Raphael Soifer, (Soifer), Philip R. Karn, Jr. (Karn), Metricom, Robert J. Carpenter (Carpenter),The Part 15 Coalition (The Coalition), Lyle V. Johnson, Jr. (Johnson), Robert A. Buaas (Buaas) and The.220 MHz Spectrum Management Association of Southern California (220 SMA). The following Reply Comments are provided with respect to the Comments reviewed.

2. In our comments, filed May 5, 1997, CSVHFS urged that Wide Band SS operation not be allowed in frequency segments customarily use for weak signal communications. The frequency segments which we said should not be open to Wide Band SS are: 50.0 - 50.5 MHz, 144.0 - 144.5 MHz, 222.0 - 222.15 MHz, 431.5 - 432.5 MHz, 902.0 - 903.5 MHz, 1295.5 - 1296.5 MHz, 2303.5 - 2304.5 MHz, 3455 - 3456 MHz, 5759 - 5761 MHz and 10367 - 10369 MHz .

3. CSVHFS also supports the recommendations of AMSAT insofar as providing protection of frequencies utilized by the Amateur-satellite Service. We also support Soifer's comments with respect to protecting amateur earth-moon-earth (EME) communication, as that is completely consistent with our recommendations. We can also accept the proposal, made by Tynan, limiting SS to certain designated frequency segments, except for his allowing SS unrestricted operation above 3300 MHz. We renew our contention that widespread use of any type of Wide Band Spread Spectrum (SS) transmission in the amateur bands used for various types of weak signal work, including long haul terrestrial, satellite or EME, poses a serious threat to the continued viability of these activities.

4. We agree with Carpenter and Tynan, and re-affirm our own recommendation, that a special class of SS (Narrow Band SS with bandwidths less than 10 kHz) be authorized with the same power limits as authorized to other amateur operation. As we recommended in our comments, this Narrow Band SS should be allowed on all amateur frequencies above 50 MHz with the exception of the segments reserved for CW operation - 50.0 to 50.1 MHz and 144.0 to 144.1 MHz..

5. TAPR and Karn propose to extend amateur SS operation to all frequencies in the 50, 144 and 222 MHz bands as well as the bands above 420 MHz as proposed by the Commission. Since they have not recognized a distinction between Wide Band SS and Narrow Band SS, as proposed in our comments, as well as those of Tynan and Carpenter, it can only be assumed that they are referring to Wide Band SS. Therefore, we strongly oppose this proposal for the reasons discussed in our comments.

6. In their comments, Carpenter, Tynan, TAPR, Buaas, Karn, Johnson and 220 SMA take issue with the Commission's proposals to require automatic power control (APC), as we did. We find it particularly interesting that Karn, who takes credit for the inclusion of APC in RM-8737, is now opposing it. In addition, TAPR and Karn oppose the Commission's proposed power limit of 100 W. In his comments filed under RM-8737, Karn contended that SS is a power efficient mode and that it would be expected to utilizes powers of 1 Watt or less in most instances. He is now proposing 1.5 kW! We believe that Karn's change of heart, and the comments of so many knowledgeable people validate our contention that APC is impractical in amateur use; and calls into question the entire proposal to impose SS on the amateur community. Apparently, Buaas is also arguing for higher power for SS, when he says in his comments,"(a) operation in any amateur band above 50 MHz, without restriction". He is unclear as to what he means by "without restriction". Does this mean maximum authorized amateur power? He is also unclear as to whether or not he would include the sub-bands from 50.0 to 50.1 MHz and 144.0 to 144.1 MHz, currently restricted CW operation.

7. In various informal discussions on the Internet, and elsewhere, some have claimed that an "adequate ID scheme" should allay any fears that the weak signal community might have with respect to SS interference. There are several things wrong with this contention. First, it assumes that one, or only a few, SS stations are responsible for the interference. If there are many, it may not be possible to identify any of them. The other major problem with this notion is the "short range/ever present signal" mentality displayed by those proposing it. They think only in terms of local communication. Frequently, in long haul weak signal work, the available propagation exists for only a short time, sometimes measured in minutes or even seconds. The concept of identifying an interfering SS station and notifying the operator so that that operator can take action to reduce or eliminate the interference in time for the weak signal operator to make a fleeting contact, stretches credulity. So, from the standpoint of correcting problems of interference to weak signal operators, the ID question is irrelevant. It may have relevancy with the Commission, but that is a separate issue, which CSVHFS does not feel competent to address. TAPR, Johnson and Buaas take exception to any requirement that would require identification that could be read by non-SS stations. There is much to be said for their position, and we accept it, if Wide Band SS is restricted to frequency segments outside of those used for weak signal work, as we have proposed.

8. The Docket contains no definition of SS in terms of its bandwidth limits. Presumably amateur spread spectrum emissions would be limited to the amateur bands, but even that is not stated. The amateur community is being asked to accept "this new technology" without any information as to what it is, or what its effect on other types of operation will be. Buaas takes particular exception to Tynan's concerns, terming them "conjectures of doom as fact, without bothering to conduct any realistic tests". In CSVHFS's opinion, this is an absolutely ridiculous comment, about on a par with his "tree in the forest" analogy. It is Mr Buaas who, presumably possesses the SS equipment with which to conduct such tests. We are quite certain that Mr. Tynan does not and are not aware of any CSVHF member who has SS equipment which could be used to conduct tests. Furthermore, acquiring SS equipment is probably not one of any of our members' highest priorities. They have other pursuits which are also valuable to development of radio technology. It is Mr. Buaas's responsibility to conduct tests. After all, isn't that the principal reason the STA, he alludes to, was granted him? CSVHFS contends that it is the responsibility of the SS proponents, to run tests to determine its interference potential, not Tynan or any other weak signal operators. SS is the new mode trying to gain access to the amateur bands. It is the responsibility of the new mode to demonstrate that it can coexist, not the responsibility of current inhabitants to prove that it can't. Mr. Buaas has had ample opportunity to test for the potential of SS interference with weak signal operators in his area. One, who has approached him to do so is E.R. (Chip) Angle N6CA, a prominent, and knowledgeable weak signal operator in the Los Angeles area, not far from Mr. Buaas. Mr. Angle has stated that his offer was ignored completely. Why does Mr. Buaas have an STA for SS operation, if it is not being used to gather valuable data which the Commission can use in framing new Rules? The fact that SS interference to weak signal operations is likely, has been proven in simple straightforward calculations made and documented in comments submitted by Carpenter in this proceeding as well as under RM-8737. To date, SS proponents have failed to present anything that disproves these calculations. They have claimed that Carpenter's assumptions were not representative of their concept of what they think amateur SS would be, generally a model based on cellular telephones, with a heavy reliance on APC which they now disavow. But, Mr. Carpenter's assumptions are based on the proposed Rules, not some imaginedsituation. The failure of SS proponents to conduct and document tests or respond sensibly to fundamental radio propagation calculations, should in themselves, make the Commission wonder if proposals contained in this Docket are well founded.

9. Much has also been said in informal correspondence between SS proponents and those concerned about its possible impact, with regard to the amateurs working out "band plan" arrangements among themselves do that SS can be accommodated without disrupting other activities. ARRL is probably the only organization that might be capable of undertaking this thankless task, but it is unclear that even they can accomplish it. Even if a good faith effort were to be made to establish a frequency coordinating body to establish "band plans" to guide SS amateurs in their choice of band segments in which to operate, how could it function to coordinate a mode with undefined bandwidth? SS signals might be 1, 2, 10, or perhaps even 30 MHz wide. No one knows at this time. The proposed Rules do not specify a bandwidth.. The 220 SMA comments elude to regional band planning. Does this mean that it might set up a California SS frequency coordinating organization in competition with ARRL? How many other "regional bodies might there be? The VHF bands are not regional. In many instances they are not even national, but international - again the "short range" mentality. This international characteristic is certainly the case with EME and satellite operation. The same applies, to a somewhat lessor extent, to other types of VHF operation, particularly on the 50 MHz band. Therefore, despite what some may claim, these bands do not lend themselves to local, or even regional, frequency coordination. In their comments, TAPR and Karn suggest that amateur SS experimenters will publish information about their activities on the Internet. For one thing, there is no assurance that they will. Certainly, no such requirement is contained in the proposed Rules. In addition, how would this prevent interference? Many amateurs, including many weak signal operators are not on the Internet. Their interests and priorities may lie elsewhere. As we have noted, many instances of propagation in which weak signal operators engage, are of short duration, so determining the source of interfering signals, from the Internet or elsewhere, and then taking appropriate action to resolve the interference; are likely to be useless in terms of allowing the completion of a rare contact. CSVHFS submits that, if SS Rules are to be liberalized as proposed in this Docket, the only viable approach is for the Commission to specify the frequency segments in which Wide Band SS operation can take place, as proposed by Tynan; or, at least, restrict it from frequencies used by weak signal operators, as proposed by

10. CSVHF is dismayed by the comments filed by Metricom and The Coalition. Metricom is an unlicenced user of the radio spectrum, namely 902 to 928 MHz and 2400 to 2450 MHz, and The Coalition represents various companies so engaged. Both urge the Commission to limit the power of amateur SS stations operating in these bands to the same level they, as Part 15 users, are permitted - 1 Watt. We contend that such a limitation would represent a very dangerous precedent which could have long term negative consequences for the Amateur Service. How long it would be before Metricom, or another Part 15 user, proposes to limit the power of all amateur transmissions, not merely SS, in any bands in which Part 15 operation might experience interference from amateur operations? The Coalition appears to go even farther, expressing concern that increased amateur activity in the 902 MHz and 2400 MHz bands, using equipment manufactured for the Part 15 industry, might "upset the delicate balance that has been struck between co-users of shared spectrum." In other words, The Coalition is saying that, Part 15 devices operate satisfactorily as long as there is little or no amateur activity on the bands they use. The Coalition also refers to "working with the amateur radio interests ... to resolve technical and interference problems when and where they arise". CSVHFS was under the impression that Part 15 of the Commission's Rules makes it clear that unlicenced users are subject to whatever interference they might receive from licensed users. Where is the requirement for amateurs (licensed users) to "resolve" interference complaints from unlicenced users? This is a very important issue which goes far beyond this Docket and, in our opinion, must be addressed on a priority basis. It would appear that, if these unlicenced spectrum users have a service that is as vital as they contend it is, they should compete for spectrum space like any other commercial user.

11. Since our comments were filed, two pieces of information concerning the potential for interference from SS operation to weak signal work, have come to the attention of CSVHFS. David Anderson is a U.K. amateur located in Scotland. His callsign is GM4JJJ. Mr Anderson has informed us that, an apparently U.K. government run spread spectrum communications system, has recently been put into operation about 20 kilometers from his location. This has resulted in about a 10 dB increase in his noise level across a broad range of frequencies around 432 MHz. This noise peaks in an easterly direction. According to Mr. Anderson, this increase in noise level is sufficient to make EME work in that direction all but impossible.. He has supplied us with spectrum analyzer plots of the signal which we attach as Appendix A. Other information we have from weak signal operators in the San Francisco Bay Area is that the 902 MHz band has become essentially useless since Metricom began operation there. This is but one example of the fact that even low power SS (1 W or less) is capable of causing interfere to weak signal operation. We submit that the experience related by Mr. Anderson as well as the information on the effect on weak signal operation by low power Part 15 type operation, should be sufficient to convince the Commission of the falsehood of any and all statements that SS operation is "essentially invisible to other modes". For this reason, we urge that, while its development in the Amateur Service should be encouraged, SS should not be allowed to disrupt other on- going valuable operations. Our recommendations with respect of appropriate frequency restrictions for SS operation will provide it ample room to develop and prove its merit, while preserving weak signal work of various kinds. We would also accept Tynan's recommendations, modified to also protect the weak signal segments above 3300 MHz.

12. Copies of these Reply Comments have been provided to those individuals and organization whose comments are cited herein.

Respectfully submitted,

Gerald Handley WA5DBY
Board Chairman
June 4, 1997


Appendix Spectrum analyzer plots presented by David Anderson GM4JJJ


Reply Comments of Steven S. Dimse, K4HG

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF Steven S. Dimse, K4HG 189 Le Grand Lane Summerland Key, FL 33042 sdimse@bridge.net

June 3, 1997

INTRODUCTION

I have been an amateur radio operator for the last seven years, and have held the extra class license for most of that time. I am very active in the digital, voice and satellite aspects of Amateur Radio. Although I am a member of the American Radio Relay League, Tucson Amateur Packet Radio Corporation, and the Radio Amateur Satellite Corporation, I am speaking only for myself. I submit these comments in response to the above-referenced notice of proposed rule making (the "NPRM") released by the Commission on March 3, 1997, and to the comments filed since.

DISCUSSION

I am pleased that the commission has decided to consider new rulemaking on spread spectrum (SS) communication within the Amateur Radio Service. However, I feel that the proposed changes are too restrictive.

The proposed section 97.311(b) continues to relegate SS communications to second class status. New technologies in the past, such as single sideband and packet radio have not burdened with such rules, and it seems to me unfair to do this with SS. Section 97.101 already covers the requirement for coexistence of various operators and modes within the Amateur Radio Service, and provides adequate protections to current users.

Likewise, the proposed automatic power control provision of section 97.311(g) is needlessly restrictive. I understand the intent of this section, but automatic power control adds another level of complexity to the design of experimental radios. This would serve only to smother experimentation in this new mode of communications. Likewise, the 100 watt limit on total power provides no additional protection to other users, but limits one of the more interesting uses of SS, namely moonbounce communications.

Sections 97.311(e) and (f) place a significant record-keeping burden on any operator who wishes to make use of the SS emission mode. Again this singles out SS communication without providing any specific benefit to amateur radio or the Commission.

I would also ask that the Commission eliminate the requirement of section 97.119(b)(5) for morse code identification. This requirement of a cross-mode identification would be likely to cause interference, and a monitoring station would find it quite difficult to associate the narrow band CW emission with a particular SS signal. It also precludes the use of all commercially available equipment.

CONCLUSION

The Amateur Radio Service has a long tradition of innovation in communications. However, as radios have gotten more complex there has been less opportunity for the ARS to further the state of the art. There are now a significant number of amateurs anxious to explore the exciting possibilities of SS communications. The present rules, and to a lesser extent, the proposed rule changes, impede that experiementation.

The introduction of new communication methods have always brought objections from more entrenched users. As the conficting comments before the Commission indicate, no consensus exists as to how much spread spectrum communications will impact on more traditional means of communication. The results of amateur experimentation could be quite useful to the Commision in addressing questions sure to arise in the coming decade. I ask that the Commission remove these unnecessary restrictions standing in the way of such widespread experimentation.


RESPECTFULLY SUBMITTED,

Steven S. Dimse K4HG


Reply Comments of Robert A. Buaas, K6KGS

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )      WT Docket No.rm8737
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      RM-8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF

    Robert A. Buaas, K6KGS
    10044 Adams Ave. #108
    Huntington Beach, CA 92646
    buaas@wireless.net

June 4, 1997

INTRODUCTION

I listed my credentials in my Comments on this Proceeding, dated May 2, 1997. The most relevant of these is the fact that I am one of but a handful of PRACTITIONERS in the art and science of Spread Spectrum (SS) as it applies to the Amateur Service. Being the holder of the SS Special Temporary Authorization (STA) caused me to be the focus of those interested in moving forward. Over the years I received many, varied levels of inquiry. It became quite clear how limiting the current Rules are, and also how diverse are the levels of expertise and interest. SS is sufficiently complex that only a few stout experimenters were willing to invest the many hours required to build even the simplest SS systems. A common theme for each of us is that we all started at the very beginning, learning from simple modules, building on that learning until we arrived at a critical mass of elements that could be called a working system. Along this path was the gift of insight into SS's strengths (resistance to interference and multipath fading) as well as its weaknesses (complexity, wideband receivers, the near-far problem). Many of us came to conclude that SS systems resulted from special cases of more general digital codes, and that what we require is blanket authorization to pursue additional avenues whose many desirable properties are worth investigating and adopting.

I find it interesting that many commentors refer, in their remarks, to SS as experimental technology. The fact is quite the contrary; only in Amateur Radio is SS experimental!

DISCUSSION

While I am pleased that the Commission has decided to consider new rulemaking on SS communication within the Amateur Radio Service (ARS), after contemplating all the Comments in this Proceeding, I urge that the Commission step back and take the longest possible view into the future. The outcome of this Rule Making will impact Amateur Radio for the next 10-20 years.

I urge that the Commission grant additional weight to the Comments of those who speak from experience. Particularly, I wish to concur with and endorse (a) the Comments of Phil Karn KA9Q, for his willingness to be a light of experience in a sea of darkness, and for the courage in his Comments to advocate SS technology at HF; (b) the Reply Comments of Dick Bingham W7WKR for his pioneering work in very-low-power 80M DSSS; (c) the Reply Comments of Glenn Elmore N6GN, who eloquently shows that the concerns of current weak-signal enthusiasts are technically unfounded; (d) Greg Jones WD5IVD and Dewayne Hendricks WA8DZP of TAPR, for making SS an organizational priority, thereby making current commercial SS more widely available; and (e) the ARRL, for bringing this matter to the current forum.

In my opinion, the ARRL (as an organization) is illustrative of the lack of consensus among Amateurs. It has the pro-SS and the anti-SS factions, and the many other factions/interests that leave it at cross- purposes with the initiative that is the subject of this Proceeding. The ARRL has neither contributed to nor provided leadership in this matter. As for policy, it wishes to see, predominately that the status quo remain in place, since this position best serves the ARRL as a power broker. All the while, technology is advancing, leaving the current practices in Amateur Radio behind. It's one thing to "say" you are "for something," and very much another to give it life by contributing time and resources. I have little use for the ARRL as an organization, as the advocate and representative for advancement of Amateur Radio. On balance, I would like to acknowledge those individuals inside the ARRL who have, over the years, worked very hard on the side of technology, research, and SS. You know who you are.

Repeater operators and users can forget about concerns they voiced of interference from SS systems. The data I included in my Comments provide a sample of the irrefutable evidence showing that interference is, at most, unlikely and infrequent. If there are any lingering doubts, feel free to look at a spectrum analyzer sometime; how does one interfere with something that isn't there?

I find it interesting that the weak-signal community would seek to differentiate narrowband-SS as acceptable practice; yet wideband-SS is unacceptable. This position exposes a fundamental lack of appreciation for the power of the underlying coding technology involved. I understand the motivation and I encourage the experimentation, confident that these folks will learn as we have, that the wider the signal gets, the better the result. It is just that the differentiation they seek should have no place in the Rules.

I remarked about Metricom in my Comments. After all, they are a struggling business, offering guaranteed service performance using spectrum to which they do not have exclusive title. Hmmmm, but they are only offering this service where the population is dense and there is the possibility of profit. In the same breath, they would enjoin an Amateur from using their product modified with a high power transmit amplifier and receive low-noise preamplifier and high-gain directional antenna, to link across a long distance of wilderness or desert, because doing that might benefit the public interest or assist in a time of emergency. Something is wrong with this picture! The Rules have to work for everyone, everywhere, not just for a particular special interest. Sure, occasionally an Amateur will momentarily capture a Metricom transmission; he/she was granted that privilege when he/she earned his/her Amateur Operators License. I believe both TAPR and ARRL will further address this matter.

In my Comments, I recommended that the Commission turn aside the specific proposal made in this proceeding, in favor of a Rules change embodying the spirit of the STA. After careful consideration, I wish to go further: not only should SS be permitted in all Amateur spectrum (including HF), I suggest that the Rules be fundamentally altered so that "any unspecified code" is permitted without restriction anywhere within any Amateur band. This includes, but is not limited to, what we now think of as Frequency-Hopped Spread Spectrum (FHSS) coding, Direct Sequence Spread Spectrum (DSSS) coding, hybrid combinations of these, Forward Error Correction (FEC) codes of varying properties, all inclusive of digital modulation forms. This recommendation might take the form of: (a) removing section 97.311 in its entirety; (b) rewriting section 97.309 (the definition of the data emission) to permit any imaginable digital code (with the sole prohibition that the code is not used to obscure the transmission) and that section 97.309(b)3 be eliminated; (c) editing section 97.307 to remove verbiage that implies bandwidth limitations for the data emission; and (d) adding entries in section 97.305(c) frequency band table giving the data emission access to the entire band.

I would also ask that the Commission eliminate the requirement of section 97.119(b)(5) for morse code identification of the data emission. This requirement of a cross-mode identification would be likely to cause interference, and a monitoring station would find it quite difficult to associate the narrow band CW emission with a particular data emission signal.

CONCLUSION

The ARS has a long tradition of innovation in communications. With the introduction of new communication methods have always come outcries from existing-mode users. Each new method has advanced the state of the communication art, eventually, in an orderly manner, supplanting the prior method. The ARS, unlike all the others, which the FCC manages, also has a history of self-management. It needs, and deserves, considerably less regulation, to allow it to achieve its Purposes, particularly sections 97.1 (b) (c) and (d). In this Proceeding, the Commission could significantly reduce its workload attributed to the ARS by recognizing these facts, and by removing the bandwidth limitations it has attached to each modulation mode and the arbitrary spectrum allocations given to the various modulation modes. Since SS is but one point on the continuum of digital coding technology, allowing any bandwidth provides system designers with the flexibility to determine what works and what doesn't. There are adequate provisions existent in the Rules to prevent undue interference from new modes, as there are Rules about appropriate transmit power levels. Digital Coding technology, whatever its form or emission consequence, should be freely permitted on ALL Amateur bands, not just those about 50 MHz as I proposed in my Comments, or above 420 MHz as is current.

RESPECTFULLY SUBMITTED,

//signed//

Robert A. Buaas K6KGS


Reply Comments of James Barron, Jr, KA5WSS

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

Reply Comments of Robert James Barron, Jr, KA5WSS
P.O. Box 180703
Austin, TX 78718-0703
June 2, 1997

Background

I have been licensed as an Amateur Radio operator since 1985 and currently hold an Advanced class license. As an Amateur I have enjoyed a wide variety of operating activities but Packet Radio has been one of facets of Amateur Radio on which I have spent the most time. I currently am a participant in the Tucson Amateur Packet Radio Spread Spectrum STA.

Summary

I urge the Commission to adopt a set of rules based upon, but slightly different than, the rules currently proposed. While I applaud the the effort to modify the Amateur Radio SS rules to promote greater use, I fear that some aspects of the proposed rule changes may continue to hinder wide-spread adoption of SS in Amateur Radio. I would further urge the Commission to reject any proposals from non-Amateur, commercial groups which seek to subvert the proposed rules changes to serve their own means as a way to chip away at the current Amateur allocations.

Discussion

Section 97.119(b)(5), which mandates the use of CW for identification, should be eliminated. In the near term this requirement would disallow the use of off-the-shelf Spread Spectrum components or systems as few, if any, support such an awkward method of identification.

While completely Amateur based Spread Spectrum systems may be built with CW identification its use in properly identifying an SS station is questionable, at best. Where shall an SS transmitter transmit its narrow-band CW identification stream? Given a transmitter that may be spreading its signal out over 10 MHz or more, a narrow-band receiving station may have as much trouble finding the CW signal as they would the wide-band transmission.

Part 97.311(g), which mandates automatic power control when transmitter output exceeds 1 watt, should be changed. In communications situations where stations are operating in a point-to-point manner power control makes sense, both for the stations involved in the communications and other users who must share the same spectrum. This mode of operation is the norm for services such as cellular, where each user communicates with one single base station at a time.

In Amateur Radio this model gets more complex with the addition of point-to-multipoint situations. Amateur Radio repeaters, satellites and "simplex" operation use this topology. One Amateur station transmits and many listen. With which station should the transmitter coordinate to set the allowable transmitter output power? And if the transmitter adjusts power for proper receive levels at a more distant receiver, does not the transmitter exhibit more than "enough" power at receivers located closer to the transmitter? Is an Amateur transmitter then breaking the rule? The formula for automatic power control as it stands would render common Amateur Radio communications topologies unusable.

The current rules regarding the use of the minimum power necessary, Part 97.313(a), provide ample protection to ensure that excessive power is not used and still provides enough flexibility to allow for complex topologies like point-to-multipoint. The sentence in Part 97.311(g) which limits SS power output to 100 watts does not appear to be a burden at this time.

If the purpose of the proposed rules changes for Spread Spectrum are to allow for greater use by making SS a "first class" mode in the eyes of the Commission then these restrictive rules must be removed or modified.

Conclusion

The proposed rules changes are a step in the right direction. Only a few changes need to be made to the rules to ensure that Spread Spectrum becomes a "first class" mode in the Amateur Radio Service.

Respectfully Submitted,

Robert Barron, KA5WSS


Reply Comments of Guy Story, KC5GOI

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF

Guy Story, KC5GOI
5301 East McKinney # 417
Denton Texas, 76208
gstory@icomply.com

June 8, 1997

Introduction

My name is Guy Story. I am an Amatuer Radio Operator KC5GOI. I have been a licsensed Amatuer Operator for 3 years. In the past six months I have become active in the STA that has been granted to the Tucson Amatuer Radio Packet Corporation (TAPR). The use of Spread Spectrum (SS) as a mode of transmission is new to me. It is my personal belief that the Amatuer Radio Service (ARS) continue to aid in the advancement of technology and that SS is one such technology. This is pursuant to CFR 47 97.1 (a) and (b). I consider myself to be an entry level operator in SS due to lack of experience, but feel that it is important for Amatuers such as myself help contribute to ARS.

Discussion

In reading the commissions Notice Of Proposed Rule Making (NPRM) I would like to submit the following.

After reading the NPRM and comments made by Robert Buaas, K6KGS, and TAPR , the following concerns occurred. In the best interest of the ARS in my opinion SS should not be restricted to just 420 MHz and up. SS should be allowed to operated on all ARS allocated bands. This is an important issue since by nature of SS, SS can coexist with current modes of transmission. This on its own will help relieve "congestion" on ARS bands.

In the NPRM the commission issued in March 3, 1997 includes concerns made by Metricon. Some of the concerns made by Metricom contradict some of the reasons for usage of SS. The chances of an Amatuer Operator properly decoding transmissions made by Metricom customers is very slim.

A concern of Symbol seems to be to limit power of ARS SS transmissions. Since the ARS is requesting the use of unlimited gain antennas, this helps reduce chances of direct interference due to focused RF from on point to another. While I cannot speak for other Amatuers , my plans for operation include the use of directional antennas. Part 97 also includes power to be limited to that required to maintain contact. This also would help reduce the chances of interference.

The issue of station ID has also come up. The use of a narrow band signal to ID is contradictive to the use of SS. While SS is "immune" to narrow band signals, if enough users ID at the same time throughput suffers. Identification of a station should occur in the same mode that the transmission occurs. This is not an attempt to obscure information, just a practical approach.

The maintaining of log books also should not be required. The use of logbooks is no longer in practice and SS should not be made an exception.

Conclusion

As an Amatuer Radio Operator, I support the filing made by TAPR and their efforts. The spirit of Amatuer Radio exists the experimentation of SS and the resultant activities. To actively contribute to technology, Amatuer Radio SS does not need to be hindered by limiting spreading sequences and inaccurate opinions of a few that wish to see ARS fail in their current endeavors.

I apologize for late filling of my comments to the Commission and appreciate the viewing of this document.


Respectfully submitted,

Guy Story, KC5GOI


Reply Comments of Anthony McConnell, N3JLI and Jacob Brodsky, AB3A

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF Jacob Brodsky, AB3A Anthony McConnell, N3JLI 13924 Sunnybrook Rd. Phoenix, MD 21131 e-mail: frussle@erols.com June 5, 1997

Introduction

These are the comments of Jacob Brodsky (AB3A) and Anthony McConnell (N3JLI), a private group of amateur radio experimenters. Mr. Brodsky has been an amateur radio operator for over 20 years. He is a graduate of The Johns Hopkins University with a degree in Electrical Engineering. Mr. McConnell is a business owner and a highly experienced radio technician who has worked on a wide variety of communications systems including race car camera systems, terrestrial microwave networks, radio paging systems, and commercial two way radio, among others.

We are collaborating on an experimental spread spectrum data radio design for 52 MHz. Although this radio is intended for use under the TAPR Spread Spectrum STA, we are planning to modify this design for similar applications such as high speed data communications, weak signal recovery, and spread spectrum linear transponders.

Overview

We support TAPR's position on spread spectrum deregulation. We feel that any proposed or existing regulations regarding power, band, frequency hop rates, direct sequence spread rates, and allowable codes for spread spectrum ought to be dispensed with.

Discussion

Spread Spectrum technology is surprisingly versatile. Until recently, we did not feel any strong motivation to experiment with this technology because the existing regulations were too strict. It was the freedom the TAPR STA offered which got us started building prototypes. While building these prototypes, we have begun to notice many other ways to apply this technology.

We feel that most of the amateur community has a long way to go before applications and standards are established for this technology. Limiting such operations now, before they have even been explored, would severely limit future development of this technology from the amateur community.

Therefore, we concur with TAPR's position, that spread spectrum ought to be deregulated to encourage future development among the amateur community. Spread spectrum technology can be used in many ways that Part 15 equipment manufacturers and other commercial radio interests aren't bothering to explore. Examples of this would be weak-signal recovery in the presence of multi-path distortion, or an orthogonal code spread spectrum transponder.

We think there are more amateur radio experimenters who would be interested in doing what we are, if only the tight regulatory environment now in place were loosened up. Our 52 MHz spread spectrum radio, for example, could not be legally tested on the air without the TAPR STA. If we are to continue experimenting, we need a free hand to try all sorts of different coding schemes, spreading bandwidths, even power levels and antennas. We should not have to resort to an STA permit to do this kind of development.

Conclusion

We feel it is premature to be tightly regulating spread spectrum technology, when so few prototype radios are in service, and when so few potential applications have been explored. We think TAPR's proposal ought to be seriously considered.

Sincerely,

Anthony McConnell, N3JLI
Jacob Brodsky, AB3A


Reply Comments of Thomas C. McDermott, N5EG

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

Reply Comments of Thomas C. McDermott, N5EG

June 4, 1997

Introduction

I respectfully submit these reply comments to the Commission regarding the Notice of Proposed Rulemaking that proposes to change certain rules governing spread spectrum operation in the Amateur Radio Service (ARS). I am a licensed Amateur Radio Operator, callsign N5EG, co-founder and registered agent of the Texas Packet Radio Society, Inc. (TPRS), a member of the American Radio Relay League, Inc. (ARRL), and an employee of Alcatel Network Systems, Inc., however the opinions expressed herein are strictly my own and do not represent the opinions of TPRS, ARRL, or Alcatel.

Overview

In comments regarding RM-8737 and Docket rm8737, several organizations oppose fundamentally the proposed rule making on the grounds that spread spectrum emissions would encroach into other band users long established frequency usage. It is difficult to see how the changes proposed by the Commission degrade, in a technical sense, the impact of currently authorized amateur spread spectrum emissions on these users.

Several commenters essentially propose that Amateur spread spectrum emissions be restricted to somebody else's spectrum. However these restrictions, if implemented jointly, would eliminate a significant amount of spectrum from consideration. Such a ruling would be a significant reduction of the existing spread spectrum authorizations, seriously jeopardizing the possibility of effective experimental use of spread spectrum by amateurs.

One commenter suggests difficulty in realization of an power control algorithm well suited to amateur usage, a comment agreed to by this author.

One commenter indicates that detailed record keeping requirements imposed by 97.119(5) will discourage experimental effort. The author agrees with these comments, and wonders how such detailed records would assist the Commission. Records such as the station log, retained for one year's time would provide equal ability to trace reported cases of interference as those contained in the current rule making.

Discussion

The comments of several organizations, notably, the Southern California Repeater and Remote Base Association (SCRRBA), the Mid-America Coordination Council (MACC) , and the Part 15 Coalition express concern at the possibility of interference if the proposed rulemaking is adopted. The proposal by the Commission does not degrade the protection already afforded current occupants of spectrum as outlined in 97.311 (b).

The relevant technical changes to the regulations are 1) removal of restrictions on spread spectrum emission types and, and 2) elimination of restrictions on spreading codes. These two changes, in and of themselves, do not affect the characteristics of the spread spectrum signal in a way that changes, either adversely or beneficially, the potential of interference to existing spectrum occupants. Thus such comments appear not to accurately reflect on the proposed rulemaking. This author believes that the Commission's proposed rules in this regard are adequate and do not degrade the potential of interference.

The comments of the Part 15 Coalition suggest excluding the spectrum from 902-928 MHz from use by amateurs utilizing spread spectrum emissions. The comments of George R. Isely suggest allowing such operation only in the 902-928 MHz. band. Comments of William R. Tynan suggest small amounts of spectrum, 219-220 MHz, conditional use of 435-438 MHz. but only for satellite usage, 904-928 MHz, and larger sections of spectrum at higher frequencies. Comments of the San Bernardino Microwave Society (SBMS), and the Mid-America Coordination Council (MACC) suggest the use of local coordinators to assign frequencies to experimenters. Given the desire of each local group to protect certain different frequencies, and given the conflicting nature of the proposed frequency assignments, it is not likely that such coordination would lead to adequate contiguous spectral width for experimental purposes, nor would they be reasonably forthcoming. Thus the frequency assignments currently contained in the Commission's rules (and not proposed to be altered by the proposed rule making) are the only effective way to assure access to spectrum for these purposes; this author agrees with the Commission's plans in this regard. Ultimately, use of spread spectrum emissions for existing services could lead to significant improvements in amateur spectrum utilization, and one essence of experimentation is to pave the way for this eventuality.

Lyle V. Johnson comments on the difficulty in providing an effective power control mechanism among different experimenters who are not bound to a common protocol. Further, he explains that in multi-point usage, it may not be possible to determine a unique value for minimum acceptable power. In comments on this same subject, William A. Tynan contends that Automatic Power Control is not practical in the Amateur Radio Service (ARS), and questions whether it would be effective, even if it could be implemented. This author agrees with these comments, and requests that 97.311(g) be retained as specified under the current rules, rather than modified as in the proposed rule making. There is no existing evidence that the current regulations have lead to harmful interference. Further, spread spectrum emissions may not cause harmful interference according to part 97.311(b), and so 97.311(g) as proposed in the current rulemaking seems redundant, while probably not practical to implement in the ARS anyway.

Lyle V. Johnson comments that detailed record keeping requirements imposed by 97.119(b)(5) will discourage experimental effort, and that the record-keeping imposed by this section exceeds that required of any other amateur mode. The author agrees with these comments, and wonders how such detailed records would assist the Commission. Records such as the station log, retained for one year's time would provide equal ability to trace reported cases of interference as those contained in the current rule making. This author agrees with the commenter that Part 97.311(e) be rewritten as described by Lyle V. Johnson: "Logs and notebooks pertaining to technical investigations in spread spectrum on amateur radio frequencies be retained by the licensee for a period of one year following the date of last entry."

Conclusion

The current proposed rule making does not degrade the possibility of interference, as compared to current regulations. The spectrum needed for effective experimentation should not be reduced from that already authorized. The power control requirements of section 97.311(g) in the proposed rulemaking should be eliminated as being impractical and probably ineffective. The record keeping requirements of 97.311(e) should be simplified to be in concert with existing record keeping requirements of the Amateur Radio Service.


Respectfully submitted,

Thomas C. McDermott, N5EG
265 Daniel Dr.
Plano, Texas 75094


Reply of Glenn E Elmore, N6GN

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY OF GLENN E. ELMORE, N6GN

Background

I have been licensed in the Amateur Radio Service since 1961 when I was 11 years of age. I have held an Amateur Extra class license for most of the time since and amateur radio has been very important to me for the entire period. My amateur activities have included the following:

  • multimode HF
  • VHF through microwave weak-signal and long distance
  • amateur satellites, OSCARS 1-13
  • meteor scatter
  • earth-moon-earth (EME)
  • extensive VHF-microwave propagation monitoring and analysis
  • design, development and publication of:
    • multimode, multiband microwave equipment
    • theory of the physical layer in amateur radio networks
    • higher speed digital UHF & microwave data links and networks
    • direct sequence spread spectrum amateur equipment
    • on-channel active repeaters

II. Introduction

I am responding to previous comments to the proposed Rule Making contained in this proceeding because I believe I have experience relevant to activities represented by commenters expressing divergent viewpoints. I hope that my experiences with weak-signal VHF through microwave, signal propagation, satellites, and EME along with those in digital radio, links and networks and spread spectrum may be helpful in this rule making process.

III. Summary

I generally welcome and support the rule changes proposed by the Commission. I believe that the use of spread spectrum for experimentation and communication is of very significant value to the amateur service. While I understand and share the concern of previous commenters that existing activities could be compromised, I believe that the reality of the amateur and physical environment is such that very minimal and managable interference problems will be the norm. I believe that existing amateur rules combined with amateur cooperation can and should be used to assure that experimentation and the rich diversity of pursuits within the amateur service may be maintained and furthered.

  1. I specifically ask that the ruling not include any exclusion of SS operation in the central portions of the UHF and microwave bands.
  2. I ask that the requirement for automatic power control not be included.
  3. I ask that the 100W power limitation be waived for space applications.
  4. I ask that SS operation be permitted on all amateur bands, including HF.

IV. Discussion

1. EME Interference

There has been concern expressed by commenters that existing weak- signal amateur activities, such as EME and satellite operations, will be severely threatened by relaxation of the spread spectrum rules. As a former amateur EME operator I would like to reply to that concern.

I have enjoyed amateur EME communication and desire to see it continue. In the mid 1980s, prior to delving into higher speed digital radio hardware, I built and operated a 432 MHz EME station over 2-3 years and several EME contests. The transmitter ran about 650 watts output to a home-built 24' stressed parabolic antenna. The station made many contacts in many continents and was capable of hearing its own echoes on SSB when conditions were good.

The station was located in Santa Rosa, CA about 50-80 miles north of the San Francisco Bay area which had a moderate amount of terrestrial activity at the time. However, to my knowledge, there was never a QRM/congestion problem of any kind. In fact, the gain of a skyward pointed EME dish is intentionally low toward the side (horizon) and back (earth). If this were not so, the system noise temperature would be degraded by terra firma which is ~290 Kelvin. Comparing the rise in noise floor when the an EME antenna is pointed toward the horizon or ground with what it is when the antenna is pointed toward a "cold" spot in the sky is actually an excellent proof-of-system- performance used by EME operators. With the very weak signals and tight link budgets of EME it is extremely helpful to have a way to know that the reason you don't hear anything "isn't you". Low sidelobes and good front/back antennas are part of EME.

Even receiving other local EME stations running very high power isn't as easy as might be thought. Since both stations are typically working each other off the sides of their antennas, which have considerable front/side ratio, even with high power signals aren't all that strong. Combined with typical excess path losses due to terrain and location, signals are most often unremarkable or even small. On many occasions I have mistaken a local kilowatt EME station (~50 miles away) for a signal reflected from the moon because signals were so weak.

On the few occasions when the dish was aimed at local terrestrial stations, signal strengths were indeed impressive. But even from a distance as large as the 50+ miles, antenna directivity was such that it wasn't possible to even *copy* all stations without moving the antenna. Terrestrial path losses combined with antenna patterns just don't allow the "band obliterating" signals that one might think. From my experience I would say that a good tropospheric duct tends to generate a lot more noticeable RF than EME stations. It sure generates a lot more interest!

2. Satellite Interference

For satellite operations, signals are generally stronger and round trip path losses a good deal less than for EME. Even using non-spread signals it is not usual for amateurs to inadvertently generate high enough ERP towards a satellite to be noticed. Although additional terrestrial path losses are avoided on a freespace path to a satellite, communication through one at UHF and above generally requires antenna directivity and deliberate attention to maximizing ERP in the appropriate direction. With spreading added, the chances of unintentional interference are further reduced. As with EME, antenna directivity and typical excess path loss serve to greatly reduce the signal at other terrestrial sites. Interference to nearby terrestrial stations is limited by the same mechanisms as described above for EME. While interference is possible, I believe it is much less likely and a smaller problem than previous commenters fear.

Whether signals are SS or narrow, my experience at VHF and above, even with high power levels and large ERPs, is that small signals predominate in the amateur environment. As received at most amateur locations, I believe that the largest signals come from well situated transmitters which run relatively low power and low gain antennas and thus relatively low ERP. Repeaters are a common example. It's possible to find exceptions to this but from my experience, this is what predominates. The combination of antenna directivity and excess losses due to terrain, foliage and antenna height at most amateur installations typically produce far less signal at a distant receiver than that predicted by the freespace pathloss equation.

This large reduction in signal strength over typical paths, well above and beyond that predicted by freespace pathloss calculations, is the fundamental reason that handheld radios are so often operated in conjunction with well-situated repeaters. This is not restricted to the amateur radio environment, it is a dominant characteristic of terrestrial communications at VHF and above. It is one reason that applications like cellular telephones, which are otherwise capable of communicating hundreds or even thousands of miles in freespace, require cell sizes on the order of a few miles in diameter.

The magnitude of this signal reduction is greatly underestimated by most amateurs. The fact that two 5W, 146 MHz handheld transceivers with dipole antennas are capable of communicating on the order of 10,000 miles in freespace but often not over 10 miles in typical amateur locations is hard for many to believe.

3. Experiences With Coexisting Spread and Non-Spread Radios

During the last several years I have built and operated hardware and software which supports higher speed amateur radio networking. This has involved the design and fabrication of high speed digital radio hardware as well as extensive site and path analysis and measurement. These activities have also been a vehicle for testing the effects of SS Part 15 devices and other potential interferers on non-spread wideband communications systems. The wideband simple FSK radios being used had fairly poor tolerance of signal loss as well as of even brief interference such as that produced by FHSS devices.

In addition to nearly continual operation and monitoring of performance from a residential location over a period of several years in which Part 15 device usage in the same band was proliferating, multiple Part 15 SS transceivers (Metricom) were also co-located at the site of a key node in this digital radio network.

To my surprise, the results of these tests indicated almost no degradation in performance due to Part 15 device interference. While many Part 15 transmitters have been evident, from within a few feet to several miles of the non-spread system radios, antenna directivity combined with the spreading has virtually eliminated any loss-of-service problems.

4. The Value of Spread Spectrum to the Amateur Service

I view the amateur service as many things; a hobby, a public service, a medium to foster international good will and a means to develop interest and skills in radio, electronics and communications. It has served me wonderfully and I sincerely desire to see it continue in that same richness and diversity. I thank and support the Commission for everything that they have done and can do to further amateur radio. I believe this serves the American people well.

However, in order to stay vital, I believe the service also needs to stay relevant to the age it is in. We are now said to be in the "information age". As such, I believe that an increasingly important aspect of amateur radio is its ability to communicate quantity of information over significant distances. This trend does not displace, but rather augments existing "lower bandwidth" activities and endeavors of the service. As indicated by Shannon's well-known channel capacity equation, high information content communication requires increasingly high bandwidths. For radio communication, this requires systems which more closely approach freespace losses and tolerate the distortions introduced by propagation in the real-world. I believe that biggest gains in high information amateur communications and networks can only come about through the use of the wide bandwidths and antenna directivity available on the UHF and microwave bands while at the same time achieving pathlosses closer to freespace. However, I believe that spread spectrum techniques are also of great importance in economically reducing the multipath distortion which accompanies typical paths and which in the absence of corrective action severely limits channel capacity.

For these reasons I request that the Commission's rule making do nothing to limit the bandwidth of SS operation in the amateur UHF and microwave bands.

5. The Amateur Service as a Shared Resource

In addition to the need for relaxed rules for wideband spread spectrum operation at UHF and microwave, I believe that development and experimentation with these techniques is best supported by a minimum of additional regulations. I agree with the statements by TAPR and the amended statement by Karn that would remove the requirement for automatic power control from SS operations. In general I believe that the amateur service can and must continue to be largely self regulating and policing, within the general bounds established by the Commission. I believe that this is the only practical way that effective sharing of the amateur spectrum may be accomplished. This approach is not without the potential for contention and discord but I believe it offers the only practical method for sharing resources.

For this same reason and to promote experimentation, I also request that the Commission allow spread spectrum operation in the HF bands and waive the 100W power limitation for space communications with the expectation that existing rules and amateurs' ability to self-regulate will produce the best outcome for the service as a whole.

RESPECTFULLY SUBMITTED,

By_______________________

Glenn E. Elmore, N6GN
June 3, 1997

Mailing Address:

446 Halter Court
Santa Rosa, CA
95401


Reply Comments of Steven K. Stroh, N8GNJ

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF Steven K. Stroh, N8GNJ

14919 NE 163rd Street
Woodinville, WA 98072
steve@strohpub.com (Internet e-mail)

June 4, 1997

Introduction

Although I disclose my relevant affiliations in the next paragraph, the comments in this reply are my own, and do not necessarily represent any of the organizations I am affiliated with.

I am a member of the American Radio Relay League. I am a member of, and Secretary of Tucson Amateur Packet Radio (TAPR), and chairperson of its Networking Special Interest Group (NetSIG). I am also a participant in the Special Temporary Authority (STA) requested by TAPR for the purpose of developing and testing Spread Spectrum Systems that are more advanced than the Amateur Radio rules currently permit. Professionally I am a System and Network Administrator for a large company. I am a member of the Puget Sound Amateur Radio TCP/IP Group, who has constructed a network of Amateur repeaters and simplex links that utilize Internet technologies such as TCP/IP to create a low-speed, wireless extension of the Internet in the Seattle, Washington area.

Overview

I feel that the Commission should simply delete certain restrictions in the Amateur Radio Service rules that are currently preventing state of the art Spread Spectrum techniques from being used in the Amateur Radio Service. In particular, Spread Spectrum modes should no longer be burdened with additional rules and regulations above and beyond that of other modes, such as power limits, identification, logging, or limitations on frequencies where Spread Spectrum can be used in the Amateur Radio Service. It seems to me that the existing Amateur Radio Service Rules (vastly oversimplified) of:

  • "use the minimum power necessary to maintain communications"
  • "Identify your transmissions a minimum of every 10 minutes"
  • "Keep a record of any transmissions made with modulation methods that are not publicly documented"
  • "don't deliberately interfere with a communication in progress"

are sufficient guidance for the design and operation of Spread Spectrum in the Amateur Radio Service.

Without these changes in the Amateur Radio Service rules, it is unlikely that Spread Spectrum will be widely used in the Amateur Radio Service, and that would be a loss, both for the Amateur Radio Service and the public at large who ultimately and directly benefit from innovations in telecommunications pioneered and developed by Amateur Radio operators.

Discussion

As I read the posted comments to RM8737, I was dismayed that some Amateur Radio operators and organizations seem threatened by the prospect of the widespread deployment of Spread Spectrum in "their" normal operating frequencies, including satellite, weak signal, and voice repeater operations. Basically, it seemed as though they could not bring themselves to trust that their fellow Amateur Radio Operators, who would might eventually use Spread Spectrum systems, would not deliberately harm their operating modes, and that protecting "their" frequencies was of more concern than the advancement of Amateur Radio.

Specifically, it seems to me that all Amateur Radio operators have a great deal of respect for what has been accomplished in putting Amateur Radio onto satellites, and would not implement designs or conduct operations that are proven to be detrimental to Amateur Radio satellite communications. Amateur Radio Spread Spectrum operations may, or may well not interfere with Amateur Radio Satellite communications. Experimentation will be necessary to discover this.

An excessive rules burden now, in the infancy of Amateur Radio Spread Spectrum, will likely stifle any chance of innovation from Spread Spectrum techniques in the Amateur Radio service. Imposition of rules requiring CW identification, and automatic power control, for example, would likely prevent the use of "off the shelf" Spread Spectrum components. If off-the-shelf components can be used, it is seems reasonable that several parallel Amateur Spread Spectrum development efforts will result in at least one Spread Spectrum system unique to Amateur Radio could be available by the end of 1998.

An additional concern is the restriction of frequencies for Spread Spectrum operations in the Amateur Radio bands. My input is that the logical initial dividing line for where Spread Spectrum operations should be permitted is to permit Spread Spectrum operations on all Amateur Radio bands above 50 MHz. One of the most fertile areas of development in Spread Spectrum, one where Amateur Radio operators could make a significant contribution, is in the area of "lower frequency" Spread Spectrum operations using state of the art Spread Spectrum technology on frequencies such as 50-54 MHz.

I have no sympathy whatsoever for the concerns of non-Amateur Radio organizations such as the Part 15 coalition and Metricom, Inc. regarding Amateur Radio operations. The Commission has very clearly established the relative priorities of operations in shared bands such as 902-928 MHz. Commercial companies that manufacture products that use those bands, and make a profit from those products, understood quite clearly that as a condition of operation in those bands, their products must accept interference from licensed services in those bands such as Amateur Radio. If these commercial organizations are truly interested in Amateur Radio operations in shared bands not significantly impacting their established products and operations, they should be willing to offer to share technology and operational expertise to develop better, "friendlier" Amateur Radio systems.

Spread Spectrum offers a way to make effective use of Amateur Radio bands in a much more efficient manner. Spread spectrum has the potential to replace most other modulation methods currently in use in Amateur Radio, and can probably coexist with other modulation methods in the near future. Amateur Radio operators interested in employing digital systems and experimenting with high speed digital operations have been frustrated in their attempts to construct such systems on Amateur Radio bands on the 50 MHz, 144 MHz, 222 MHz, and 430 MHz bands because the existing users state "the band is already fully occupied, and cannot accommodate additional systems". This is especially true for systems that wish to use wide bandwidths, such as systems operating at a data rate of 56 Kilobits per second (and faster) that require 100 KHz (or more) of spectrum to operate.

My hope for Amateur Radio Spread Spectrum is that it can make use of the vast amounts of "dead airtime" on Amateur Radio frequencies above 50 MHz to accommodate digital systems and users on those frequencies. These frequencies are vastly underutilized because they are used primarily by a Frequency Modulation (FM) voice repeaters, which by their nature are only actually transmitting a few minutes of each day. Spread Spectrum techniques and systems can make effective use of this "dead airtime" with minimal impact to the existing users of those frequencies.

Amateur Radio Spread Spectrum technology could evolve rapidly if reasonable Spread Spectrum rules are adopted. An Amateur Radio Spread Spectrum system undoubtedly will be designed to accommodate advances in technology and operational advances by way of "firmware updates", in much the same way as commercial telephone modems are "upgraded from disk". This means that "bugs" found in an Amateur Spread Spectrum radio could be rapidly disseminated by posting an update file on an Internet Web page. For instance, it is widely recognized that automatic power control is desirable in Spread Spectrum systems- the trick is how to make it work well in a point to multipoint environment such as typical Amateur Radio systems. With sufficient experimentation, an effective method to do so will no doubt be developed, and then this improvement can be downloaded and implemented. If identification proves to be a problem, that too can be implemented and downloaded. If SS is proven to be harmful to certain operations, then a "don't hop on these frequencies" update can be implemented and downloaded.

Conclusion

  • An update of the Amateur Radio rules pertaining should remove the rules preventing state of the art Spread Spectrum technology from being used in Amateur Radio. There are already sufficient and appropriate rules and regulations in the Amateur Radio service. To require additional rules and regulations specific to Amateur Radio Spread Spectrum will almost certainly prevent the development and effective use of state of the art Spread Spectrum technology in the Amateur Radio service.

  • Given the chance (reasonable regulations on Amateur Spread Spectrum), Amateur Radio has much to contribute the continued development of Spread Spectrum technology and techniques, especially effective ad-hoc networking and application of relevant Internet technology and techniques to VHF/UHF frequencies where Spread Spectrum is not yet widely used.

  • Amateur Spread Spectrum could evolve and rapidly deploy advances in Spread Spectrum technology by making use of "downloading new code" into Spread Spectrum systems, likely from Internet Web pages such as TAPR's Web page (http://www.tapr.org). Problems that are identified with Amateur Radio Spread Spectrum operations could be corrected through the use of a "download new code" capability such as is currently employed in commercial telephone modems.

  • I wholeheartedly endorse the comments of Phil Karn KA9Q, Lyle Johnson WA7GXD, and TAPR. I think that their views represent fairly the promise of Spread Spectrum experimentation and development in the Amateur Radio Service.

I thank the Commission for this opportunity to present my viewpoints on this matter to them.

Steven K. Stroh, Amateur Radio callsign N8GNJ


Reply Comments of TUCSON AMATEUR PACKET RADIO CORPORATION

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )      WT Docket No.rm8737
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      RM-8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF
TUCSON AMATEUR PACKET RADIO CORPORATION


The Tucson Amateur Packet Radio Corporation ("TAPR") submits these reply comments in response to the above-referenced notice of proposed rule making (the "NPRM") released by the Commission on March 3, 1997.

As demonstrated in TAPR's initial comments, the rule changes proposed in the NPRM represent, for the most part, the logical next step in the regulation of Spread Spectrum ("SS") communications technologies in the Amateur Radio Service. By providing amateur radio operators greater design and operational flexibility, the Commission will help to promote the development and deployment of the next generation of SS technologies.

Nonetheless, in a few areas, the Commission's proposals go too far (1), and in other areas, not far enough (2). In addition, several parties have opposed various aspects of the Commission's proposed rule changes on narrow and short-sighted grounds (3). Thus, and for the reasons set forth more fully below, TAPR urges the Commission to adopt the rule changes proposed in the NPRM with the clarifications and modifications set forth in TAPR's initial comments.


DISCUSSION

I. The Parties To This Proceeding Support the Commission's Proposed Less Restrictive SS Rules.

In general, all parties support the Commission's decision to delete sections 97.311(c) and (d), in order to permit SS emissions and spreading codes that are not currently authorized. Elimination of the rule that dictates specific spreading codes in necessary to facilitate further experimentation and deployment of SS technology in the amateur radio service. In particular the removal of the provision that restricted the use of hybrid SS emissions will open up potentially new areas of interesting experimentation that have not been allowed for over fifteen years now.


II. The Parties To This Proceeding Support the Relaxation of the SS Record Keeping Requirements

There appears to be a consensus of commenters which does not agree with the Commission's decision to allow sections 97.311(e) and (f) to stand as written. Both sections place a significant record-keeping burden on any operator who wishes to make use of the SS emission mode. While these sections may have made sense back in 1985, twelve years later all they serve to do is to present a serious impediment to any amateur operator who wishes to experiment and deploy this mode. TAPR therefore asks the Commission to follow the directions of the commenters and now establish parity between SS and all of the other emission modes (including pulse) and delete the burdensome provisions and requirements of these sections


III. Some Parties To This Proceeding Support the Deletion of the 100 W Power Limit for SS

Several commenters have agreed with TAPR's position that the limit on transmit power to 100 watts of section 97.311 should also be deleted. While TAPR does feel that 100 watts of power is more than enough for most terrestrial SS operations, this limit may present problems for some of the more interesting applications in the service today such as EME (Earth-Moon-Earth) operations. It would appear that the 100 watt limit was imposed back in 1985 out of a concern for limiting the range of possible SS interference, this concern appears groundless in the operating environment that we now face today. TAPR therefore asks the Commission to strike this provision and allow SS emissions that same transmitter power levels allowed for the other emission modes authorized for the service.


IV. The Parties To This Proceeding Support the Deletion of the Automatic Power Control Proposal

There appears to be general disagreement by the commenters with the proposed automatic power control ("APC") provision of section 97.311(g). Although TAPR supported the ARRL proposal for this provision in the comments and reply comments that it filed in RM-8737, it no longer feels that this provision should become a part of the rules governing SS emissions. Further discussion and experimentation that has taken place since the petition phase of this proceeding has convinced TAPR that the implementation of this provision would impose a serious handicap on the future development of this emission mode. As was pointed out by the comments of Phil Karn, KA9Q, the idea of including the concept of APC in the League's Petition of December, 1995, originated with him as a member of the ARRL's Future Systems Committee. KA9Q has now gone on record in these proceedings as agreeing that APC is not workable under all circumstances and should be dropped as a requirement for Amateur SS communications. While TAPR agrees that technically it is simple to control the output power of a transmitter, it is quite another matter to make this control automatic and foolproof over the wide range of applications and uses that are common today in the service. For instance, the implementation of this provision would make it impossible to use SS emissions in the point-to-multipoint packet radio networks that are common in the service today because it would be difficult to transmit a single packet which would not exceed the Eb/N0 level at the nearest station. TAPR therefore asks the Commission to strike the proposed automatic power control language of this section. Several commenters, including TAPR feel that the provisions of section 97.313(a), which limits the power level to the minimum required to maintain communications is all that is necessary to cover the concerns which prompted this proposed rule change.


V. Some Parties To This Proceeding Support the Use of SS In Amateur Radio Bands Above 50 MHz

Several commenters have indicated support for TAPR's position that the Commission allow SS emissions on all amateur radio bands above 50 MHz. As we have stated earlier, TAPR feels that the Commission's rules for SS should go no further than to set a maximum transmitter output power level and to set reasonable limits on spurious emissions outside the amateur radio bands. Conventions for all other parameters of operation such as operating frequencies, modulation method, bandwidths, protocols, etc. are best left to the development of the amateur radio community itself. Such an approach would be in line with the stated policy of the Commission itself in the NPRM to develop rule changes which are "...consistent with our policy of encouraging greater spectrum flexibility by enabling licensees to introduce innovative technologies and to respond quickly to demands for new and different services and applications, without administrative delays". TAPR feels that SS technology will provide for such innovation in the service and has great applicability to amateur bands below 70 cm (SS now only being allowed on bands 70 cm and above).


VI. The Parties To This Proceeding Support the Removal of the Narrowband ID Requirement for SS

There was general support among the commenters which supported TAPR's position that the station identification requirements of section 97.119(b)(5) should be deleted. The interference and harm to the band in which an SS station is operating that would be caused by a requirement to use a CW identification far outweighs the benefits that would accrue for monitoring purposes from the use of such an ID. Further, it is vital to avoid an ID requirement that would in itself cause interference even when the associated SS emission does not. TAPR feels that it would be better for the amateur radio community to develop approaches for handling the necessary functions of monitoring and identification of SS emissions.


Conclusion

With the modifications and clarifications described above and in TAPR's initial comments, TAPR generally supports the rule changes proposed by the Commission in the NPRM.


					Respectfully submitted,
					THE TUCSON AMATEUR PACKET RADIO CORPORATION
					By:
					
					
						 
						Dewayne Hendricks
						Tucson Amateur Packet Radio Corporation
						8987-309 E Tanque Verde Rd #337
						Tucson, Arizona  85749-9399
						(940) 383-0000

June 5, 1997


1. For instance, the Commissions concerns about the need for automatic power control are unfounded. See, e.g., Comments of Phil Karn ("KA9Q"); Comments of Lyle Johnson ("WA7GXD"). Consequently, any suggestion that extreme measures such as mandatory automatic power control should be rejected.


2. As discussed more fully below, the Commission should allow the use of SS emissions in all amateur radio bands from 50 MHz.


3. See, e.g., Comments of Metricom (continuing its assault on Part 97 SS use of the ISM bands); Comments of Part 15 Coalition (same).


Reply Comments of Raphael Soifer, W2RS

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                        )
                                        )
Amendment of the Amateur Service Rules  )       WT Docket No. rm8737
to Provide For Greater Use of Spread    )
Spectrum Communication Technology       )

To: The Commission

Before the Federal Communications Commission Washington, D.C., 20554


REPLY COMMENTS OF RAPHAEL SOIFER, W2RS


1. I filed comments in this proceeding on May 5, 1997. I have since reviewed the comments filed by Radio Amateur Satellite Corporation (AMSAT), Central States VHF Society (CSVHFS), American Radio Relay League (ARRL), Tucson Amateur Packet Radio (TAPR), Metricom Inc. (Metricom), The Part 15 Coalition (Coalition), William A. Tynan (Tynan), Philip R. Karn, Jr. (Karn), Robert J. Carpenter (Carpenter), Robert A. Buass (Buaas) and Lyle V. Johnson, Jr. (Johnson). The following Reply Comments are provided with respect to the Comments reviewed.

2. As noted in my Comments, I support the views of AMSAT with respect to frequencies utilized by the Amateur-satellite Service but believe that AMSAT's proposals do not go far enough in protecting amateur earth-moon-earth (EME) communications, which because of the extremely weak signals involved is far more susceptible to potential interference from spread-spectrum (SS) emissions than is communication via amateur radio satellite.

3. CSVHFS, Carpenter and Tynan agree with me as to the need to protect narrow band weak-signal operations, such as satellites and EME, from potential SS interference, but propose a different remedy: a restriction on SS based upon bandwidth, rather than purpose. Their proposals also represent a workable approach to the problems presented, as do those made in my own Comments.

4. TAPR and Karn propose to extend amateur SS operation to the 50, 144, and 222 MHz bands. I oppose this proposal for the reasons discussed in my Comments.

5. TAPR, Karn and Johnson take issue with the Commission's proposal to require automatic power control, while TAPR and Karn also oppose the Commission's proposed power limit of 100W and any requirement for station identification using CW or other non-SS emission. I take their points, but they only serve to illustrate the difficulties which would be faced by non-SS, narrowband stations attempting weak-signal operation in the presence of SS interference. I would not oppose their suggestion as long as appropriate frequency restrictions on SS operations are adopted, E.g., those proposed in my Comments, or those of CSVHFS, Carpenter or Tynan.

6. If the Commission permits amateur SS stations to use power in excess of 100 W, the interference calculations presented by AMSAT, CSVHFS, Tynan and Carpenter would have to be amended accordingly. For example, a station transmitting the maximum power proposed by TAPR and Karn, 1.5kW, would produce SS signals approximately 11.8db stronger than those assumed by AMSAT, CSVHFS, Tynan and Carpenter in their Comments.

7. Buass states his opinion that the fears of interference to narrowband weak-signal operation expressed by commenters such as myself, AMSAT, CSVHFS, et al are merely "conjectures of doom as fact, without bothering to conduct any realistic tests." I have no idea what Buass considers to be "realistic." The types of emission and power levels proposed in the NPRM, as well as by the commenters such as TAPR and Karn, are so broadly defined as to admit a virtually infinite number of possible scenarios. In this situation, it is entirely appropriate, as well as prudent, to base one's analysis on the worst case that would be permissible under the proposed regulations.

8. In any event, Buass is wrong about the existence of tests. Radio amateurs in the United Kingdom have made detailed and fully documented measurements of the interference to amateur weak-signal operation caused by what they believe to be a military SS system operating in the 70cm band. According to one such set of measurements posted to the Internet by David G.L. Anderson, GM4JJJ, of Braeside, Scotland, an SS transmitter with power output believed to be 2.5 kW produced interference approximately 30Mhz wide, centered on 430Mhz. At a distance of 10 miles from the transmitter, the received signal strength of this interference was 13dB over the ambient noise level with a receiving antenna of 17 dBi gain. Over line-of-sight paths such as the one prevailing in these measurements, a 25W transmitter at one mile, ot a 100W transmitter at two miles, would produce interference of equivalent received signal strength to that of a 2.5kW transmitter at 10 miles. Spectrum analyzer plots of the interference in question, as received, may be viewed or downloaded from Mr. Anderson's web site at http://www.braeside.demon.co.uk/SSQRM/432QRM.html

9. Metricom and Coalition propose that amateur SS operation in the 902-928 MhZ and 2400-2450Mhz bands be limited to the same power level as is currently permitted for Part 15 users, i.e., one watt. Their proposals conveniently ignore the fact that Part 15 users are unlicensed and, therefore, are entitled to no protection whatever from licensed services. Adoption of their proposal, or for that matter, any restrictions on amateur operation designed to protect Part 15 users would be contrary to law and to established public policy, i.e. furtherance of the purposes and objectives of the Amateur and Amateur-satellite Services as set forth in the Communications Act and in section 97.1 of the Commission's Rules.

10. We now come to the issue of the best manner of determining the proper frequencies for amateur SS operation. On this point, ARRL comments as follows:

In any case, amateurs are called upon to cooperate in the use of shared frequency bands regardless of emission type. As has always been the case, advance planning and coordination will facilitate harmonious use of both SS and narrowband communications modes. Any fear of interference to voice repeaters or weak-signal communications can and should be avoided by intraservice cooperation in the selection of frequencies, rather than by restricting emissions types for SS communications The latter has served to restrict the ability to experiment with SS communications.

11. Coming from ARRL, these comments are surprising, to say the least. ARRL, the only existing U.S> organization in a position to organize such efforts on a national basis, in recent years has run from band planning and frequency coordination as rapidly as humanly possible, leaving U.S. radio amateurs today with no organizational framework whatsoever which would be capable of implementing the "advance planning", "coordination" and "intraservice cooperation" to which its Comments refer. The present "ARRL Band Plans" covering VHF and UHF frequencies were developed some years ago by a "VHF-UHF Adivsory Committee" which ARRL has cine seen fit to abolish. This was replaced by a "Spectrum Management Committee" which has since also been abolished, leaving ARRL with no roganized structure for band planning at all. ARRL's Comments are silent as to how it would propose to implement the "advance planning and coordination" which it assumes, but the recent history of this organization in spectrum management matters provides the amateur weak-signal community with no comfort whatsoever. I say this with regret, as an ARRL member, but facts are facts.

12. I understand that ARRL is cooperating which various regional frequency coordinators in the organization of a national conference through which these groups might pool their resources. However, under the Commission's Rules, the jurisdiction of such coordinators extends only to amateur repeater and remote base stations, and then only within such band segments in which these types of stations are permitted. Thus, the present structure of regional frequency coordination would provide no relief to amateur satellite, EME, and other weak-signal operations.

13. It must also be noted that EME and satellite operations are inherently international in scope. It would, therefore, not be appropriate to subject them to regional frequency coordination, since there would then be nothing in the Rules to ensure that coordinators in different U.S. regions do not designate different frequencies for such uses, rendering them incompatible with one another on a national or international scale. In this case, regional frequency coordination is not the answer.

14. Thus, the Amateur Service is without any organizational framework through which the voluntary cooperation contemplated in the ARRL's Comments might be carried out, and the only national organization of U.S. radio amateurs capable of providing one (ARRL itself) has consistently and repeatedly avoided such a role. TAPR and Karn suggest that amateur SS experimenters might publish information about their activities on the Internet. However, this would not in any way prevent interference to satellite, EME, and other weak-signal operation.

15. This leaves the Commission as the only body capable of acting to protect amateur weak-signal operation. The allocation of different amateur sub-bands to various modes of emission is as old as government regulation of amateur radio itself. Indeed, the first such regulations were imposed by the Commission's predecessor, the Federal Radio Commission, which in tun had inherited them from the former Hoover Commissions of the U.S. Department of Commerce. Over the years, U.S. amateurs have proven to be remarkably law-abiding. However, someone must first make the rules, and in this case the only available rulemaker is the Commission itself.

16. I concur with ARRL's observation that restriction of emission types for SS communication has tended to restrict the ability to experiment. This is why I do not propose to restrict SS emission types, only the frequencies on which they may be transmitted. As noted in my Comments, this would serve to protect other types of amateur experimentation, e.g., satellite and EME, while at the same time giving free rein to the development of SS technology in the Amateur Service. Based upon the results of such experimentation, the Commission may, at some future time, revisit the issue of frequencies for amateur SS communication and make whatever changes are appropriate in the light of what has been learned from such experiments.

17. My Comments of May 5, 1997, are hereby incorporated into this document by reference.

18. Copies of these Reply Comments have been served upon the commenters cited herein.

RESPECTFULLY SUBMITTED:

Raphael Soifer, W2RS 60 Waldron Ave Glen Rock, New Jersey, 07452

June 5, 1997


Reply Comments of ROBERT J. CARPENTER

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                        )       NPRM  No. WT rm8737
                                        )
Amendment of the Amateur Service Rules  )
to Provide For Greater Use of Spread    )
Spectrum Communication Technology       )

To: The Commission

Before the Federal Communications Commission Washington, D.C., 20554


REPLY COMMENTS BY ROBERT J. CARPENTER


Submitted: 4 June 1997

INTRODUCTION

I, Robert J. Carpenter, hold amateur radio license W3OTC, and have operated on the amateur VHF and UHF allocations nearly exclusively for almost 50 years. As an electronic engineer, I have been professional involved in digital and packet communication intermittently since 1951. As a radio amateur, I took part in the first 50 MHz amateur meteor burst packet communication. I am a Life Member of the American Radio Relay League (ARRL) and of the Radio Amateur Satellite Corporation (AMSAT).

These Reply Comments address Comments filed by Phillip Karn, Robert Buaas, Tucson Amateur Packet Radio (TAPR), Lyle Johnson, William Tynan, Raphael Soifer, the Central States VHF Society, the Radio Amateut Satellite Corp (AMSAT), the American Radio Relay League (ARRL), Metricom, and the Part 15 Coalition.

GENERAL

I believe that the nearly-unfettered use of Spread Spectrum (SS) on all or most amateur radio allocations, as proposed in the Karn, Buaas, and TAPR Comments, is very premature. Since actual field experience of use of SS by the amateur community is essentially nonexistent, and never formally reported, limitation of Wideband SS to bands above 420 MHz would appear sensible at the present time. As field experience is obtained, this limitation can be revisited.

As I demonstrated in the Comments, automatic power control (APC) will further exacerbate the problem of interference from SS to other amateur users, and represents useless over-regulation. The TAPR and Buaas proposals to remove the proposed 100 W power limit for SS users would make the problem even worse.

Because of the likelyhood of interference to other amateur operations, and the current lack of de facto standardization of amateur SS, it is important that SS stations transmit station identification in a manner that can be clearly understood by non-SS amateurs.

AUTOMATIC POWER CONTROL AND INTERFERENCE

The ARRL and the FCC propose that automatic power control (APC) be required for SS stations using more than one watt. Essentially all the Comments argue that APC will be unworkable in the amateur environment, and I argue that it will actually increase interference. Raising the genreal power limit for SS above 100 W would make the problem even worse. Please refer to my original Comments on this proceeding. The assertions by the ARRL that APC will reduce interference are incorrect, as shown by that straight-forward analysis.

Buaas says:

To date, no one has come forward with any evidence that Amateur SS emissions have interfered with anyone.

But what he doesn't say is that there has been infinitestimal on-the-air amateur use of SS. The examples he quotes are for FHSS on the output frequency of FM repeaters. In this case the non-SS signal is strong and easy for the FHSS stations to hear and avoid. In the case of weak- signal, EME, and satellite users, the FHSS system would be unable to hear the weak signals and would thus use their frequencies and cause serious interference.

Yes, SS has been authorized. No, essentially no one has used the authorization. The lack of reported interference to other modes is a disingenuous argument. Since the FCC allowed operation under STAs without identification that could be understood by non-participants, and with no prior or post notification of the amateur community sharing the bands, it is hardly surprising that no interference from these tests has been reported.

NARROW BAND SPREAD SPECTRUM

All of the previous discussion of DSSS has assumed high data rates and wide bandwidths, and its use for very local communication. Thomas A. Clark and Phillip Karn presented a very interesting unpublished paper at the 1996 Conference of the Central States VHF Society. They proposed that techniques which are essentially DSSS be used for extremely weak signal amateur operations such as communication by reflection off the Moon. Their proposal envisions a maximum data rate of a few bits per second, spreading over only a few kilohertz, and use of the usual maximum amateur power in the vicinity of one kilowatt output. It would be a mistake for the FCC to adopt Rules which prevent this type of advanced operation.

How can the above exciting use of DSSS be accommodated in the Rules, without the disastrous consequences that wideband DSSS would cause if allowed in the weak-signal band segments? The obvious solution is to define Narrow Band Spread Spectrum (NBSS). The FCC has a long history of allowing new modes if they occupy no more bandwidth than the existing modes used in that band-segment. I understand that William Tynan will propose a similar class of NBSS. The bandwidth allowed (or commonly used) in VHF and UHF weak signal voice and MCW subbands is no more than 10 kilohertz. I propose that the bandwidth of NBSS be limited to 10 kHz. In order to be useful, the power limit for NBSS must be the same as for the other narrow band weak signal and FM users, not the 100 watts proposed by the FCC for wideband SS, or my proposal for a one-watt limit for wideband SS..

Since NBSS uses approximately the same spectrum width as the more traditional modes such at narrow FM, MCW, etc., I feel that it should be authorized on all amateur frequencies above 50 MHz where MCW is authorized.

BANDS FOR SS USERS

Comments by Soifer, Tynan, Central States, and AMSAT, argue that weak signal and satellite users need protection from routine wideband terrestrial SS operation. I generally accept many of the frequency and use recommentations they have made. A major exception is that I feel strongly that no form of SS should be authorized in the CW-only sections of any amateur band. As you will have noted, I feel that Narrow Band SS should be authorized on all amateur band segments above 50 MHz where MCW is authorized.

IDENTIFICATION OF SPREAD-SPECTRUM TRANSMISSIONS

Since my filings on this Proceeding and RM-8737 point out a high likelyhood of interference from SS to other amateurs users, it is vital that the source of the SS transmissions be identified. Without this identification, the cooperative solution of the interference within the amateur community will be extremely difficult.

Karn says:

Indeed, given the overall industry trend toward more flexible, dynamic and efficient usage of radio spectrum, the creation of effective cooperative procedures for interference mitigation is itself an opportunity for the amateur service to contribute significantly to the state of the radio art.

Existing band users should not have mount full-scale direction-finding expeditions to find the source of other amateur transmissions. Lack of an identification readable by present users would put SS users in the same category as illegal users of the amateur bands, as far as other amateurs are concerned. SS does not need this stigma.

When de facto standards for amateur SS become widely used, the non-SS identification requirement can be removed. This two-step approach has been successful in the progress of amateur packet radio.

Johnson states:

"Many commenters to the original proposal expressed concerns about potential interference to narrowband users. Others pointed out that many SS stations could coexist with many narrowband stations over the same overall spectrum without mutual interference. To allay the fears of the former, and allow demonstration of the benefits of the latter, SS emissions must necessarily be "invisible" to a narrowband station's receiver.

But, we have in place a rule that requires the SS station to operate in a way that guarantees the emission will be heard by narrowband receivers!"

Mr. Johnson goes on to describe amazingly complex scenarios of separate transmitters for identification, etc.

Surely the Rule says no such thing. It merely requires that, if the signal is of sufficient strength [to cause interference], that it should be identified in a way that is detectable by non-SS receivers. It should be noted that the existing identification requirement does not require that a narrow-band signal be used for identification. In fact such a requirement would be nearly useless, since the choice of the exact frequency for identification would be difficult to specify. DSSS transmissions should be identified by on-off keying of the SS signal, as mentioned by Karn in his Comments. No interference exists if the spectral density of the DSSS signal is insufficient to allow reading of the on-off keyed identification.

Frequency hopping SS (FHSS) requires a different approach. What frequency should be used to transmit the identification? I suggest that the transmitter dwell on the lowest frequency of the hopping sequence during the 3 or 4 seconds required to send the on-off keyed identification.

LOG-KEEPING REQUIREMENTS FOR SS STATIONS

Johnson and others complain that the requirements of 97.311 (e) and (f) are onerous and will impede SS operation and experimentation. I accept his complaints, but only if SS transmissions continue to be identified in a manner that can be read by non-SS receivers.

INTERFERENCE TO AND FROM UNLICENSED SERVICES SHARING AMATEUR BANDS

Comments by the Part 15 Coalition and by Metricom view with alarm potential interference to their unlicensed use of the 915MHz and 2.4 GHz bands. As the these bodies, and the FCC, are well aware, their use of these bands is on the basis that they must accept any and all intereference caused to their unlicensed operation by the primary (ISM) and secondary (amateur) user of these bands. In addition, they are forbidden to cause interference to the higher-priority users (amateur) of these bands. The present time is extremely late in the day for the Part 15 Coalition and Metricom to complain that their operation has no legal protection from interference. They certainly have a careless business approach if they based their company on the hope that amateurs would not heavily use these amateur allocations. The FCC should reject the Comments of the Part 15 Coalition and Metricom as not having any standing in this Proceeding.

In addition, the FCC should agressively enforce its Rules that require that the unlicensed users not interfere with the amateur users of the 915 MHz and 2.4 GHz bands.

RECOMMENDED MODIFICATIONS TO PART 97 OF THE RULES

Based on my earlier recommendations, modified by consideration of the point made by others in the Comments, I recommend that Part 97 of the Rules be modified as shown below. As a basis, I am using the changes proposed by the FCC in the subject NPRM. My additions are shown in bold italics. Deletions are enclosed in [brackets].

-----------------------

97.119 (b) (5) Identification of SS Transmissions.

SS transmissions which simultaneously occupy essentially all of the spreading band (DSSS) shall be identified by morse keying some characteristic of the entire emission at a rate not exceeding 20 words per minute, in a manner as to be discerable by non-SS receivers. SS transmissions which sequentially hop from one frequency to another (FHSS) shall be identified by having the transmitter dwell on the lowest frequency in the hopping sequence for the duration of the identification, which shall key some characteristic of the signal so as to be discerable on non-SS receivers.

97.305 Authorized Emission Types

(a) - (c) (modified per AMSAT,Central States, Tynan, Soifer, etc, et al, except that no SS should be allowed in CW-only subbands, 50.0- 50.1, 144.0-144.1)

(d) SS emission transmissions which occupy a total bandwidth of no more than 10 kHz may use any amateur frequency above 50 MHz where MCW emission is authorized.

97.311 SS emission types.

(a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service is regulated by the FCC and between an area where the amateur service is regulated by the FCC and an amateur station in another country that permits such communications. SS emission transmissions must not be used for the purpose of obscuring the meaning of any communication.

(b) A station transmitting SS emissions must not cause harmful interference to stations employing other authorized emissions, and must accept all interference caused by stations employing other authorized emissions.

(c) Reserved.

(d) Reserved.

(e) Reserved [present text eliminated only if a non-SS identification is required.]

(f) Reserved [present text eliminated only if a non-SS identification is required.]

(g) The transmitter power must not exceed 1 W if the SS emission occupies a bandwidth of greater than 10 kHz.

The following to be removed: [100 W under any circumstances. If more than 1 W is used, automatic transmitter control shall limit output power to that which is required for the communication. This shall be determined by the use of the ratio, measured at the receiver, of the received energy per user data bit (Eb) to the sum of the received power spectral densities of noise (N0) and co-channel interference (I0). Average transmitter power over 1 W shall be automatically adjusted to maintain an Eb/ (N0 + I0) ratio of no more than 23 dB at the intended receiver .]

Respectfully submitted,

Robert J. Carpenter

4 June 1997 (Copies will be sent to parties commented upon.)


Reply Comments of WILLIAM A. TYNAN W3XO

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF WILLIAM A. TYNAN W3XO

1. I filed Comments in this proceeding on May 5, 1997. I have since reviewed the Comments filed by Radio Amateur Satellite Corporation (AMSAT), Central States VHF Society (CSVHFS), American Radio Relay League (ARRL), Tucson Amateur Packet Radio (TAPR), Raphael Soifer, (Soifer), Philip R. Karn, Jr. (Karn), Metricom, Robert J. Carpenter (Carpenter),The Part 15 Coalition (The Coalition), Lyle V. Johnson, Jr. (Johnson), Robert A. Buaas (Buaas) and The.220 MHZ Spectrum Management Association of Southern California (220 SMA). The following Reply Comments are provided with respect to the Comments reviewed.

2. To the extent that they are consistent with my comments, I support the views of AMSAT with respect to protection of frequencies utilized by the Amateur-satellite Service. I also support Soifer's comments with respect to protecting amateur earth-moon-earth (EME) communication. However, I contend that widespread use of any type of Spread Spectrum (SS) transmission in the amateur bands used for weak signal work, be it terrestrial, satellite or EME poses a serious threat to the continued viability of these activities.

3. The comments filed by CSVHFS agree with mine as to the need to protect narrowband weak-signal operations, such as long haul terrestrial, satellites and EME, from potential SS interference, by limiting its use in frequency segments currently used by those modes. I would accept CSVHFS's limitation in the bands above 3.3 GHz, but contend that other current amateur activities, such as FM repeaters and packet systems operating in the lower frequency bands, need protection from Wide Band SS interference as well. Such protection can be achieved, while permitting the development of various Wide Band SS techniques, by adoption of the frequency segments for Wide Band SS proposed in my comments.

4. TAPR and Karn propose to extend amateur SS operation to all frequencies in the 50, 144 and 222 MHZ bands as well as the bands above 420 MHZ as proposed by the Commission. Since they have not recognized a distinction between Wide Band SS and Narrow Band SS, as proposed in my comments, and those submitted by Carpenter, it can only be assumed that they are referring to Wide Band SS. Therefore, I strongly oppose this proposal for the reasons discussed in my Comments. However, as discussed in my comments, I again urge the adoption of Narrow Band SS (less than 10 kHz bandwidth) for frequencies above 50 MHz where voice operation is permitted.

5. In their comments, Carpenter, TAPR, Buaas, Karn and Johnson take issue with the Commission's proposals to require automatic power control (APC), as did I. I find it particularly interesting that Karn, who takes credit for the inclusion of APC for SS in RM- 8737, is now opposing it. In addition, TAPR and Karn also oppose the Commission's proposed power limit of 100 W. Apparently, Buaas does also when he says in his comments,"(a) operation in any amateur band above 50 MHZ, without restriction". He is unclear as to what he means by "without restriction".Does this mean at maximum authorized amateur power? He is also unclear as to whether he includes the currently restricted CW sub-bands from 50.0 to 50.1 MHz and 144.0 to 144.1 MHz. In his comments filed under RM-8737, Karn contended that SS is a power efficient mode and that it would be expected to utilizes powers of 1 Watt or less in most instances. I submit that such "flip-flops" validate my contention that APC is impractical in amateur use; and calls into question the entire proposal to foist SS on the amateur community. Nevertheless, since I believe that SS does have a potential future in amateur radio, if allowed to develop in a non-combative environment, e.g. in designated sub- bands; I would not oppose their recent suggestions to eliminate the requirement for APC and restrict SS power to less than that authorized other amateur operation..

6. Much has been written in informal correspondence regarding identification by SS stations. Some have claimed that an "adequate ID scheme" should allay any fears that the weak signal community might have with respect to SS interference. The rationale goes something like: "All the weak signal operator would have to do is identify the callsign of the SS station and inform him or her of the interference and the situation would be resolved." There are several things wrong with this imagined scenario. First, it assumes one, or only a few SS stations. What happens if there are many? It might not be possible to identify any of them. The other major problem, is the "local coverage" mentality displayed by those advocating it as a potential "solution" to the SS interference problem. They think only in terms of signals that are there consistently, day after day/short range communication. Very often, in long haul weak signal work, the available propagation is present for only a short while, not hours or days, and sometimes not even minutes. The concept of identifying an SS station and notifying the operator in time for that operator to close down so that a weak signal operator can make a fleeting contact, is absolutely ridiculous. So, from the standpoint of correcting problems of interference to weak signal operators, the ID question is irrelevant. The Commission may care about it, but that is a separate issue. TAPR, Johnson and Buaas take exception to any requirement that would require identification that could be read by non-SS stations. There is much to be said for their position, and I support it if Wide Band SS is restricted to certain frequency segments as I proposed in my comments..

7. Most of those commenting in favor of SS use terms like "no restrictions" and "maximum flexibility". RM-8737 and this Docket are absolutely silent on what SS is. No bandwidth limits are specified. Presumably amateur spread spectrum emissions would be limited to the amateur bands, but even that is not stated. The amateur community is being asked to accept this "newtechnology" without any information as to what it is or what its effect on current operations will be. Buaas take particular exception to my concerns, terming them "conjectures of doom as fact, without bothering to conduct any realistic tests". I am not in a position to conduct SS tests, realistic or otherwise. I have no SS equipment and acquiring it is not one of my highest priorities. Mr. Buaas presumably does have SS equipment, as he alludes to the STA, allowing SS operation on all bands above 50 MHz, he has had since 1994,. I assert that it is the responsibility of the SS proponents, to run tests to determine its interference potential, not the other way around. SS is the new mode trying to gain access to the amateur bands. It is the responsibility of the newmode to demonstrate it can coexist, not the responsibility of current inhabitants to prove that it can't. Mr. Buaas has had ample opportunity to test for the potential of SS interference with weak signal operators in his area. For one, E.R. (Chip) Angle N6CA, a prominent weak signal operator, has offered Mr. Buaas the opportunity of conducting tests to evaluate potential interference to weak signal modes. Mr. Angle has informed me that this offer was ignored completely. One might assume that conducting such tests was one of the Commission's intentions in issuing the STA to Mr Buaas.. The fact that he has refused to accomplish such testing, would appear to be reasonable cause for revoking his STA. The SS amateur community has had twelve years under the current rules, plus several STAs, to conduct tests with other band users and document results in literature commonly accessed by amateurs. They have not done so. The fact that SS interference to weak signal operations is likely, has been documented in simple straightforward calculations made and documented in comments submitted by Carpenter in this proceeding as well as under RM-8737. To date, SS proponents have failed to present anything that disproves these calculations. They have claimed that his assumptions were not representative of their concept of what amateur SS would be, generally a model based on cellular telephones. These same people now recommend departure from that low power model by abandoning APC and urging that SS operators be alowed to run 1.5 kW. Mr. Carpenter's assumptions were based on the proposed Rules, not some imagined fictitious situation. The failure of SS proponents to conduct and document tests and respond sensibly to fundamental radio propagation calculations, should in themselves, give the Commission pause as to whether this Docket is well founded.

8. Much has also been said in informal correspondence between SS proponents and those concerned about its possible impact, with regard to the amateurs working out "band plan arrangements among themselves. In their comments, TAPR and Karn suggest that amateur SS experimenters will publish information about their activities on the Internet. For one thing, there is no assurance that they will. Certainly, no such requirement is contained in the proposed Rules. In addition, how would this prevent interference? Not all hams are on the Internet. As I have noted, many instances of propagation in which weak signal operators engage, are of fleeting nature. In its comments, ARRL states, "As has always been the case, advance planning and coordination will facilitate harmonious use of both SS and narrowband communications modes. Any fear of interference to voice repeaters or weak-signal communications can and should be avoided by intraservice cooperation in the selection of frequencies...". Presently, however, there are no provisions to accomplish this, especially for something as undefined as SS. As I said above, there is no definition in the Docket as to how wide it will be. Even if a frequency coordinating body did exist, how does one coordinate a frequency for mode which might be 1, 2, 10, or perhaps even 30 MHz wide? The fact is, that no national frequency coordinating body presently exists in amateur radio, thus making any such "intraservice cooperation" unlikely to say the least. ARRL, is the only existing U.S. organization in a position to organize such efforts on a national basis. In recent years it has shown every intention of avoiding band planning and frequency coordination. This leaves U.S. radio amateurs with no organizational framework which might be capable of implementing the kind of planning and, coordination necessary. The present "ARRL Band Plans" covering VHF and UHF frequencies were developed some years ago by the VHF-UHF Advisory Committee (VUAC) which ARRL has since seen fit to abolish. This was replaced by the Spectrum Management Committee, which I am told by a reliable source, was not even consulted prior to submission of RM-8737 - leaving one to wonder as to its purpose. This committee has also since also been abolished, apparently leaving ARRL with no organized structure for band planning. ARRL does have a program to cooperate with various regional frequency coordinators in the organization of a national conference through which these groups might pool their resources. However, under the Commission's Rules, the jurisdiction of such coordinators covers only amateur repeater and remote base stations, and then only within such band segments as are allocated to them. Thus, the present structure of regional frequency coordination would provide no means of addressing SS operation in conjunction with amateur satellite, EME and other weak-signal operations. It must also be noted that EME and satellite operations are inherently international in nature. The same applies to other types of VHF operation, particularly on the 50 MHz band. Such operations are not, therefore, appropriate to be subjected to local or regional frequency coordination as inferred by 220 SMA in their comments. I submit that the only viable approach is for the Commission to specify the frequency segments within the amateur bands on which Wide Band SS operation can take place. I continue to feel that the segments I proposed in my comments are appropriate and will afford SS ample room in which to develop and demonstrate its worth.

9. I am particularly disturbed by the comments filed by Metricom and The Coalition. Metricom is an unlicenced user of the radio spectrum, namely 902 to 928 MHz and 2400 to 2450 MHz, and The Coalition represents various companies so engaged. Both urge the Commission to limit the power of amateur SS stations operating in these bands to the same level they, as Part 15 users, are permitted - 1 Watt. I contend that such a limitation would represent a very dangerous precedent which could have long term negative consequences for the Amateur Service and the Amateur- satellite Service.. One questions how long it would be before Metricom, or someone else, proposes to limit the power of all amateur transmission, not merely SS, in these bands, and others, to 1 Watt? The Coalition appears to go even farther, expressing concern that increased amateur activity in these bands, using equipment manufactured for the Part 15 industry, might "upset the delicate balance that has been struck between co-users of shared spectrum." In others words, Part 15 users get along fine as long as there is little or no amateur activity on the bands they occupy. The Coalition also refers to "working with the amateur radio interests ... to resolve technical and interference problems when and where they arise". I was under the impression that Part 15 of the Commission's Rules makes it clear the unlicenced users are subject to whatever interference they might receive from licensed users. Where is the requirement for amateurs (licensed users) to "resolve" interference complaints from unlicenced users? This is a very important issue which goes far beyond this Docket and, in my opinion, must be addressed on a priority basis. It would appear that, if these unlicenced spectrum users have a service that is as vital as they contend, they should compete for spectrum space like any other commercial user.

10. Copies of these Reply Comments have been provided to those individuals and organization whose comments are cited herein.

Respectfully submitted,

William A. Tynan
HCR 5 Box 574-336
Kerrville, TX 78028

E-Mail: biltynan@ktc.com
June 4, 1997


Reply Comments of THE W5YI GROUP

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                    )  WT Docket No. rm8737
                                    )
Amendment of Amateur Service        )  RM-8737
Rules to Provide for Greater Use    )
of Spread Spectrum Communication    )
Technologies                        )

To: The Commission


REPLY COMMENTS BY THE W5YI GROUP, INCORPORATEDR


Background

The W5YI Group, Inc., (W5YI), is the umbrella corporation which through its subsidiary W5YI-VEC, Inc., (a tax exempt educational organization under IRS 501-C3) and National Radio Examiners conducts Amateur and Commercial Radio operator training, examinations and electronic filing of applications. Over the past thirteen years, our organization has conducted over 300,000 amateur and commercial radio operator examination elements. W5YI is the only U.S. organization that oversees both amateur and commercial radio testing giving us wide experience and contact with the hobby and professional radio operator community.

We hereby submit Reply Comments pursuant to Section 1.415(c) of the Commission's Rules (47 C.F.R.▀1.415) in response to the Notice of Proposed Rule Making (the Notice), FCC 97-10, released March 3, 1997. The Notice seeks a provision in the part 97 Rules to authorize additional spreading codes and automatic power limiting circuitry in the Amateur Service.

Personal qualifications:

I , Frederick O. Maia, W5YI have been a licensed Amateur Radio operator for more than four decades and am a member of the Quarter Century Wireless Association (25 years licensed), the Old Old Timers Club (40 years licensed), the Society of Wireless Pioneers (ex-professional wireless telegrapher) and the Radio Club of America (the nation's oldest wireless "by invitation only" organization - formed in 1909.) W5YI was a military radio operator in the 1950's. I am the author of hundreds of radio magazine articles, publish a twice-a-month communications- oriented newsletter and am co-author of the "General Radiotelephone Operator" license manual. I believe I am qualified to speak out on the subject of radio technology.

Discussion:

I have reviewed many comments filed in this proceeding -- including ones filed by such prominent and prestigious organizations as the American Radio Relay League, Inc., the Amateur Satellite Corporation, Inc., and the Tucson Amateur Packet Radio Corporation. I have also examined comments filed by various amateur clubs, repeater groups and private companies and individuals.

It appears to me that a great many of these comments primarily address individual, company and organizational desires, rather than public needs or a look forward to telecommunications technology in the 21st century.

On the wall here in my office I have a framed photograph of myself and my W1NTK ham station as a teenager. In the photo, I am sitting in front of a brand new Johnson Viking Valiant AM 275-watt transmitter and a Hammarlund HQ-129X receiver. It took me a long time to be able to afford such a station and it was my pride and joy. Shortly after I purchased the equipment, I can remember hearing about how Air Force General Curtis Lemay, himself a ham operator, was endorsing a new alternative power and spectrum efficient voice transmission technology in the Strategic Air Command called single sideband.

I didn't understand how it worked. As far as I knew, on AM you needed a carrier to transport your modulation. "How could you possibly send sand' anywhere without a bucket' to hold it together?" I knew nothing about balanced modulators and band pass filters -- or how all of the power could be concentrated in the sideband rather than wasted in the carrier. SSB also took up half the bandwidth. More power meant better communications while taking up less spectrum.

Furthermore, I didn't care. All I knew was that I had a new state-of-the-art AM rig that I had worked hard to be able to afford. I was immediately opposed to single sideband when I heard that conventional AM and SSB were not compatible. But amateurs wanted something better ...more communications punch per pound. So it wasn't too many more months before I heard "ducks quacking" on the band and interfering with my beautiful high-fidelity transmissions. And it got worse and worse. I was frustrated and infuriated. How could the FCC permit this interference?

A couple of years went by and I finally gave in and bought a "duck," -- a rig developed by another amateur, Art Collins -- a Collins S-line. I was back in the state-of-the-art business. Then transistors and integrated circuits made that equipment obsolete also. I now have a solid-state Icom set-up that is so complicated, that only professionals can maintain it. Today, conventional AM emissions on the high frequency band are a thing of the past.

What is the point of all of this?

Well, I now hear that another new communications mode is on its way. Spread Spectrum to me seems to be just more "sand throwing." But instead of having a "bucket" (an inserted carrier) at the receiving end, the bits of "sand" are collected and assembled according to a formula by a computer "bucket." In the last couple of decades, PCs have become very sophisticated and inexpensive.

Spread Spectrum emission has the advantage of being able to share spectrum since only a tiny "bit" of the signal appears in a narrow-band analog communications channel. Theoretically you can overlay hundreds of communications signals over a wide bandwidth with no - or only a very slight - impairment to existing narrowband communications.

As spread spectrum becomes more entrenched, it is possible that the "noise floor" could increase to the point of some interference. But like the conversion from conventional AM to single sideband, the conversion from narrowband to wideband technology has huge spectrum- saving and other advantages. For example, spread spectrum signals are not prone to the type of interference that plagues narrowband communications. The day may come, as it did nearly half a century ago, when wideband technology is the universal communications method. The technology deserves as much regulatory flexibility as possible to determine its value.

Spread Spectrum technology has the capability to permit thousands -- or millions -- of different spreading codes. So many, in fact, that each amateur could have their own code. A computerized "address book" linked to a call sign and band could identify a user's personal spreading code thereby eliminating the need for frequency coordinators. In effect, an amateur could have their own frequency. It is even possible that a "band of white noise" could replace the current band plan system. This all remains to be seen.

Conclusion:

I can understand that existing users and frequency coordinators of the amateur bands are very concerned about a new technology entrenching on "their" narrow band territory. I have been there, done that. But I was wrong ...and selfish. The Commission must not adopt any rules which could impede widespread long range technological progress. Its duty is not to protect individual modes and very vocal narrow interests. The FCC is mandated to provide for the greater use of radio and its orderly development as rapidly and efficiently as possible.

Toward that end -- and after reviewing a great many of the comments filed in this Notice I suggest that the FCC:

    1.) Not consider Spread Spectrum emissions as being secondary to any other as proposed. Section 97.311(b) should be eliminated and marked as "Reserved."

    2.) We agree with the elimination of Section 97.311(c) and (d). Any type of spreading code should be permitted.

    3) Not require Automatic Power Control (APC) circuitry as proposed in Section 97.311(g.).

    4) Not require a Spread Spectrum power limit of 100 watts. Existing power level wording requiring minimum power is adequate. Section 97.311(g) should be eliminated and marked as "Reserved."

    5) Eliminate the Spread Spectrum record keeping requirements of Section 97.311(e) which requires technical descriptions, pertinent parameters, SS methods and dates of operation to be documented. If necessary, these requirements could be incorporated into Section 97.311(f) "When deemed necessary by an EIC to assure compliance..."

    6) Eliminate the CW identification requirement required in Section 97.119(b)(5) when a station transmits Spread Spectrum. SS transmissions -- including station ID -- should be as invisible as possible to existing narrowband users.

    7) Amend Section 97.305(c) to permit Spread Spectrum to be used on as many bands as possible -- and at the very least, all VHF bands above 50 MHz. The Commission should ignore pleas from the repeater community who want to preclude Spread Spectrum operation from "their bands" or "their frequency pair."

    8) The Commission should give no consideration to the comments of unlicensed Part 15 device manufacturers who primarily want to protect their low-power business interests from higher power amateur SS transmissions. The Amateur Service is a licensed, authorized service and unlicensed part 15 SS devices have no status. Part 15.5(b) clearly states that part 15 devices may not cause harmful interference to licensed stations "...and that interference must be accepted that may be caused by the operation of an authorized radio station..."

In short, the FCC must permit Spread Spectrum technology to evolve without imposing restraints which could impede its development.

							Respectfully submitted,
							THE W5YI GROUP, INC.

2000 E. Randol Mill Road, Suite 608-A
Arlington, Texas 76011
Tel. 817/461-6443

							_____________________________
							Frederick O. Maia, W5YI
							President


Reply Comments of John R Bingham, W7WKR

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.rm8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

REPLY COMMENTS OF John R Bingham, W7WKR

5719 16th Ave N.E. Seattle, WA 98105 (206) 527-3468 home (206) 335-2391 work dickrb@lsid.hp.com

June 2, 1997

Introduction

I have been a licensed amateur radio operator since 1954 and was initially attracted to this hobby by the the mystery/excitement of wireless communications. Today, 43 years later, I am a reasonably experienced RF/Analog/Microwave designer/production engineer with 27 years experience working for the Hewlett-Packard company. I enjoy designing and working on communications test equipment and the component elements that make them work.

Spread Spectrum communication in amateur radio is of particular interest to me because it represents an area of experimentation where I can apply and combine some of the SS theoretical material with hardware that I have designed and perfected. Working with and understanding the principles and limitations of spread spectrum communications (especially today where it is being designed into an incredible number of consumer products in the emerging "wireless industry") is an exciting prospect to me.

Discussion

I believe that Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) should be permitted on ALL amateur frequencies from 1.8MHz and higher. To somewhat arbitrarily limit DSSS/FHSS to frequencies above the High Frequency (HF) spectrum is, I feel, not reasonable considering the many contributions that the amateur radio community has made over the years.

A considerable amount of research by firms like Rockwell, Motorola, and military R/D programs have resulted in lots of hardware to exploit HF SS. There is a lot to be learned by those in the amateur community about the advantages and limitations of HF DSSS and FHSS by designing and operating systems in cooperation with others who have similar interests.

Today, if SS activities are to be relegated to a "2nd class-status" type existence with respect to existing and emerging (to amateur radio) technologies used in communications, then what other communications techniques/modes will not be allowed in the near future. I am reminded of the "tooth-pulling" in years past when amateurs wished to use the newer digital techniques - newer than BAUDOT transmissions. It took years to get "beyond BAUDOT signaling" into the modern age. Lets not repeat that sort of conservative "the hams can't handle anything this complicated" - WE CAN!

With the cooperation of the Seattle office of the FCC, I have worked out an agreement that permits me to operate an experimental DSSS system between an isolated mountain valley in the North-Central Cascade Mountains (Stehekin, WA) and my house in Seattle. Presently, I am limited to a one milliwatt (0dBm into 50 ohms) power level at the peak spectral lines adjacent to the center frequency. These transmissions are permitted provided they are made on a non-interference basis. To date, this has been the case. This is an inconvenient process for me because modifications to my system require two-day trips between sites!

It would be a much more satisfying experience if DSSS/FHSS were presently permitted so that real-time experimentation could happen. The power level under which I am operating severely limits the number of hours per day that a link can be established and maintained. These test results, though, do provide information useful to me and to the FCC (I promised to sent test results to the Seattle office).

What the amateur community needs today is the involvement of similarly interested individuals so that exchanges of ideas, results, and experimentation can happen. That is why I feel that SS be permitted on an equal basis with other modes of communications on frequencies 1.8MHz and higher. Line-of-sight transmissions - typically those frequencies 30MHz and higher - do not permit those who are interested in SS experimentation to participate in those situations where the nearest person is 100 miles miles away behind a high mountain range!

Conclusion

In closing, my recommendations for Spread Spectrum regulations for the amateur service are:

- DSSS/FHSS be permitted on an equal basis with all other transmission modes presently allowed to the amateur radio service.

- DSSS/FHSS be allowed on all amateur radio frequencies 1.8MHz and above. Based on my DSSS activities on 3.581MHz, SS can be used without causing problems for other modes ( CW, AMTOR, PACKET, etc).

- No license restrictions. Today, there is no need for a "license class" requirement since the technical knowledge needed to pass an "Extra" class license EXAMINATION is, I feel, a joke. You may say 'Ah! He just provided the reason to restrict usage of SS in the amateur service', but I assure you that only technically qualified individuals will be experimenting with SS.

- No station "ID" requirements other than in the DSSS/FHSS mode.

- No automatic power control requirements. This adds another layer of unnecessary circuit complexity and individuals will perform this task manually as required.

- No power limitations other than those that already exist for the amateur radio service. Restrictions would hamper those who may wish to use SS for moon-bounce experiments. Existing rules regarding power levels already exist!

Thank you for the opportunity to contribute my thoughts and recommendations to the rule-making process that affects the quality of the amateur radio service.

Dick Bingham


Reply Comments of John C. Koster, W9DDD

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )      WT Docket No.97-12
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      RM-8737
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission

Reply Comments of John C. Koster, W9DDD

June 2, 1997

Introduction

I respectfully submit these reply comments to the Commission regarding the Notice of Proposed Rulemaking that proposes to change certain rules governing spread spectrum operation in the Amateur Radio Service (ARS). I am a licensed Amateur Radio Operator, station callsign W9DDD, a director of Tucson Amateur Packet Radio Corporation (TAPR), and an employee of Control Systems International, Inc. (CSI), however the opinions expressed herein are strictly my own and do not represent the opinions of TAPR or CSI.

Overview

Over the years I have observed that amateurs have a tendency to ask, through their national organizations, for overly restrictive and conservative regulations for new modes of operation. The Commission typically gives us what we ask for. Invariably we then come back later to ask that these restrictions be relaxed or eliminated to give that new mode parity with other existing modes. I hope that with the few changes outlined here there would be little need to modify SS regulations in the future.

Discussion

The comments of several organizations express concern for possible interference if the proposed rulemaking is adopted. Protection is already afforded current occupants of spectrum in section 97.311 (b). Any additional language would not appear to provide additional protection.

Automatic Power Control has been proposed as a means to minimize interference. As others have commented, there appears to be no practical way at this point in time to implement this in a multipoint environment. I expect that multipoint operation will be the more prevalent mode of operation in the Amateur Radio Service (ARS). Of necessity an Automatic Power Control would have to adjust the power to accommodate the greatest path loss, thereby affording minimal advantage over operating with a fixed or manually adjusted power level.

Commenters have not detailed how the additional record keeping requirements proposed to be imposed by 97.119(b)(5) on SS will be of any value to the Commission or others beyond that which the current record keeping requirements for other modes provide.

Several commenters have asked that SS be excluded from various portions of the spectrum about 50MHz. They cite the case that in particular the 144-148 and 420-450 MHz bands are already congested in many parts of the country. They overlook the fact that SS is the one mode best suited to help relieve this congestion and less likely to interfere than would trying to add additional narrowband channels to the mix..

Conclusion

I ask that the Commission implement the proposed amateur SS rule in this proceeding with the following changes:

The spectrum allocated for SS should be all ARS frequencies above 50MHz.

The proposed power control requirements of section 97.311(g) should be not be implemented as they are impractical in a multipoint environment and probably ineffective.

The record keeping requirements of 97.311(e) should be no more burdensome than for other modes of operation in the Amateur Radio Service.

The proposed narrow band ID requirement be removed from section 97.119(b)(5).

Respectfully submitted,

John C. Koster, W9DDD
1821 Blake Drive
Richardson, Texas 75081


Reply Comments of Lyle Johnson, WA7GXD

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                      )
                                      )
Amendment of the Amateur Service      )
Rules to Provide For Greater          )      WT Docket No.97-12
Use of Spread Spectrum                )
Communication Technologies            )

To: The Commission


REPLY COMMENTS OF LYLE JOHNSON, WA7GXD


INTRODUCTION

My name is Lyle Johnson, and I operate amateur radio station WA7GXD. I have been a licensed radio amateur since early 1964 at age 13, and presently hold an Amateur Extra class license. I am not engaged in any commercial aspect of amateur radio. I have long been a volunteer engineer for TAPR and AMSAT, have materially contributed to several amateur satellites, and made significant contributions to the technical and organizational aspects of TAPR from its founding. It is from the perspective of a freely-contributing "do-er" that I offer the following input to this proceeding.

Of the 14 comments filed in this proceeding to which I have access, 12 "generally agree" 1 with the proposal to relax restrictions on Amateur use of SS radio techniques. Both of the comments filed which raise serious doubt 2 are from Part 15 suppliers whose equipment or services operate in the ISM bands.

I wish to reply to a number of the comments filed in this proceeding.

Record Keeping Requirements

This issue was raised by TAPR, WA7GXD, KA9Q and the Manager of the National Communications System (hereinafter referred to as "NCS"). All comments were for the relaxation of the burdensome record keeping (Part 97.311(e)) required of amateur SS stations. No commenters addressed any need to retain the current level of record keeping, nor were any arguments advanced to justify them.

Thus, I ask the Commission to carefully consider the comments made in this regard and to delete this burden from those who wish to experiment with and help further develop the uses of spread spectrum communications in the Amateur radio service.

Power Limits
100 Watt Limit

Regarding the 97.311(g) proposal to retain the existing 100 watt transmitter power output limit, I note the following:

Retain as proposed:           WA7GXD
Increase to 1500 watts:       KA9Q (for space), TAPR
Didn't specifically comment:  Part 15, CSVHF (and N7STU), ARRL, 220SMA, Metricom, NCS, K6KGS, W2RS, W3XO, AMSAT

No comments were filed that requested the Commission to reduce the maximum Amateur power limit of 100 watts for SS under this Proceeding.

I originally commented that the 100 watt power limitation was reasonable. I had not considered EME operation, nor possible planetary or deep-space missions. In light of these reasonable considerations, I ask the Commission to remove the arbitrary 100-watt power limitation for SS operation and allow SS the same status as any other Amateur mode on the frequency band in which it is used.

KA9Q suggests that the language of 97.313(f) maybe used to protect terrestrial users of these frequencies. If the Commission believes that such protection is necessary, I concur with the comments of KA9Q.

Automatic Power Control

Regarding the proposal to codify a requirement for Automatic Power Control, I note the following responses:

Retain as proposed     ARRL
Dispose of proposal    TAPR, KA9Q, 220SMA, K6KGS, WA7GXD
Won't do any good      CSVHF (and N7STU), Part 15 Coalition, Metricom
Didn't comment         NCS, W2RS,W3XO, AMSAT

I think it is reasonable to conclude that the majority of commenters either think the APC requirement is a bad idea or are neutral on it. Only the ARRL specifically commented that it was a good idea.

As pointed out by KA9Q, the idea of including APC in the Petition of December, 1995, originated with him as a member of the ARRL Digital Committee. KA9Q has now gone on record in these proceedings as agreeing that APC is not workable under all circumstances and should be dropped as a requirement for Amateur SS communications.

Automatic Power Control is not consistent with normal Amateur communications goals and practice (see comments of TAPR, KA9Q and WA7GXD), and has been shown by several commenters as not being able to achieve its desired goal in many cases. Even those who oppose expanded Amateur use of SS emissions contend that APC will not seriously mitigate the interference potential they fear.

And, many commenters point out that Part 97.313(a) already requires stations to use the minimum necessary power for the intended communication.

Since the proposed 97.311(g) APC provision will necessarily add to the complexity of an SS system, will delay the goal of increased experimentation with SS in the amateur bands, is redundant with 97.313(a) and will not achieve the goals claimed for it in the original petition, I respectfully request the Commission to delete this requirement from the proposed rules.

Exclusion from ISM Bands
Interference to Existing Unlicensed Devices
Use of Part 15 Devices with High-Power Amplifiers

I have combined these issues as they are all closely related.

Metricom argues that Amateurs don't need to operate in the 915 MHz, 2.4 GHz or 5.8 GHz bands because Part 15 devices already operate in these segments. They wish to preclude Amateur SS operation on bands for which it is already an authorized mode!

The essence of their arguments are (1) Part 15 operations have already demonstrated that SS works in these bands, so the Amateur community need not investigate and (2) a consistent reference to 100 watt transmitters and unlimited gain antennas that will disrupt unlicensed operations.

The Part 15 Coalition expresses the fear that if the NPRM is adopted, large numbers of Amateurs would rush to buy Part 15 devices, add power amplifiers, and wreak havoc in a "delicately balanced" portion of the spectrum.

I wish to reply to the scenarios raised by these commenters.

It is hard to imagine Metricom's proposal to essentially ban Amateur SS activity in the shared ISM bands is serious. One could use the same logic to argue that since narrowband FM has been shown to work commercially at 174 MHz, Amateurs should not be allowed to operate on 2-meter FM! Or, one could as reasonably argue that since there are commercial CDMA (spread spectrum) cellular telephones in the 900 MHz region of the spectrum, Part 15.247 operations should therefore not be allowed at 915 MHz

The point of Amateur investigation and experimentation is not necessarily to prove whether SS might work in the shared ISM bands. It may be to investigate propagation phenomena, research multi-path mitigation, or to leverage available IC technology in an effort to minimize the cost of SS station development. It may simply be to facilitate normal Amateur communications, including emergency and disaster-related traffic. Different frequency bands have different characteristics, and to preclude investigation of those characteristics seems contrary to the basis and purpose of the Amateur service. It also seems rather arrogant of a completely unlicensed service in an area of spectrum shared by multiple services to dictate what a currently licensed (and previously licensed before the Part 15 devices were deployed) service may or may not do.

However, close reading of the Metricom comment, and the related concerns expressed by the Part 15 Coalition comment, reveal the real issue: concern for interference to existing Part 15 devices and services. Let's look closer at the arguments raised.

Surprisingly, the Part 15 Coalition states:

"For instance, by expanding the range of spread spectrum transmission modes that may be used by amateur radio stations, operators who have little or no technical knowledge will now be able simply to purchase and use Part 15 spread spectrum equipment that is widely available in the market."

Is this not what anyone can already do? Is the implication that an amateur radio licensee is somehow less technically knowledgeable than the average citizen who can buy this same equipment? How does a change in amateur rules relate to interference caused to Part 15 devices by other Part 15 devices?

Metricom, in particular, consistently raises the specter of hordes of 100-watt transmitters with "unlimited gain" antenna systems disrupting their metropolitan wireless services. The Part 15 Coalition suggests that Amateurs will implement this by using existing Part 15 devices fitted with added power amplifiers.

Let's look at current narrowband practice, then expand our look to available technology, to weigh the reasonableness of these assertions.

Amateurs are currently allowed 1500 watts power output on most VHF and UHF bands. Commercially available amplifiers exist for these frequencies. Yet, the vast majority of Amateurs on these bands are content to run 1-watt class handheld radios and 25-50 watt mobile and base stations. Even satellite operators rarely exceed 100 watts of actual RF.

EME (earth-moon-earth, or moonbounce) has been an Amateur activity for nearly fifty (50) years, with suitable equipment commercially available for the last 20 years. The most recent ARRL EME contest was held in September, 1996. The results, published in the May, 1997 issue of QST, tabulate only 58 stations in the entire United States (including Alaska) reporting their participation. Of these, only 11 were at frequencies above 432 MHz.

Clearly, the mere fact that high-powered operation of UHF stations with highly-directive antennas is allowed under Part 97 rules does not reasonably lead to the conclusion that a significant portion of the Amateur community operates such stations. Consider there are well over 300,000 licensed Amateur operators today, and that a large fraction of them are currently active on the VHF and UHF bands.

High-gain (really, high-directivity) antenna systems require space, and most metropolitan areas (where Metricom has services) don't afford Amateur operators the luxury of large antenna systems, either because of the realities of multi-family dwellings (e.g., apartments, condos) or restrictive covenants and neighborhood associations (townhouses, gated communities).

For the relatively few Amateurs who might utilize highly-directive antennas, any potential interference is reduced to the beamwidth of the antenna. Most Amateur operations are intermittent in nature, so such potential interference will be both geographically restricted and infrequent.

Further, the net effect of the feared interference is just another case of the well-known near-far problem. It seems unreasonable to assume in a metropolitan area that a higher-powered Amateur station is likely to be much stronger at a given Metricom "cell site" than the nearby intended users to whom Metricom is selling its service. Further, it is reasonable to assume that the design of the Metricom system must have been such as to accommodate potential interference from the other ISM-band users, including higher powered Amateur stations.

Finally, even if amateur SS operation does become widespread, it will be a number of years before such operations become commonplace. This gives Metricom and others plenty of time to re-engineer their systems to allow for the increased occupation of the shared bands if they have not already done so. Most Part 15 SS equipment only achieves 12 dB or so of spreading gain, near the minimum specified by Part 15.247. These systems could easily be designed to provide another 10dB or 20 dB of spreading gain, more than enough to offset any increased Amateur transmitter power. Thus, there are readily available technical solutions to the perceived problem, which should have been already incorporated into Part 15.247 equipment..

Let us now consider the argument that Amateurs will flock to the sellers of Part 15 SS equipment and add power amplifiers as soon as the new rules come into effect.

First, commercial Part 15 equipment is not cost effective in the Amateur market. For example, a frequency-hopping, 1 watt 915 MHz SS transceiver from Freewave Technologies costs about $1295 in unit quantities. Amateurs are used to getting multi-band, multi-mode, 50-100 watt HF or VHF/UHF radios for under $1,000. Most single-band, single-mode equipment (whether for VHF, UHF or HF) costs under $600, and often less than $400. Why would an Amateur want to spend $1295 for a radio that then needs to be modified to make it suit his purposes? And if it is to be run at Part 15 power levels, the Amateur would more likely operate it as an unrestricted Part 15 device, than as a content-restricted Part 97 device.

How practical is it to generate 100 watts of RF power on 915 MHz or 2.4 GHz?

Two current major suppliers of Amateur equipment for these bands are Down East Microwave and SSB Electronics USA. Checking their Web pages in late May, 1997, shows that the highest power 915 MHz amplifier available is 35 watts. It would take four (4) of these amplifiers plus a combiner to create a 100-watt signal. This would cost well over $2,000. Thus, for the Part 15 Coalition's fears to be realized, the individual Amateur would have to be willing to spend around $3500 (plus antenna). Few Amateurs have stations whose total station equipment costs that much! It is unreasonable to assume that many Amateurs would want to spend $3500 for a modified Part 15 radio.

At 2.4 GHz, the costs are even higher. On this band it costs nearly $600 to get a 10 watt amplifier, the most powerful generally available to Amateurs. It would thus cost several thousand dollars to generate 100 watts at 2.4 GHz using currently available systems. Again, very few Amateurs would be willing to spend this sum for such a specialized piece of equipment

Clearly, the fears expressed by the Part 15 coalition are not based on reasonable assumptions.

For amateur SS to work, there will have to be development work done in the amateur community for systems which meet amateur needs. The stated reason for this rule-making is to allow such experimentation to flourish. I suspect the outcome, if the rules are adopted with changes in the APC narrow-band ID and record-keeping requirements, will be the development over a reasonable period of time of low-cost, high-capability amateur-tailored SS equipment. And it will necessarily be low power due to cost -- the range of 1-10 watts at 2.4 GHz and 1-30 watts at 915 MHz seems reasonable.

Spectrum Management/Frequency Coordination

The 220 MHz Spectrum Management Association requests specific rules to allow enforcement of local band plans be added to the proposed SS rules for Part 97. I wish to go on record as resisting this effort.

Most VHF and UHF bands in crowded metropolitan areas have coordinated repeaters. There are no more channels left to be coordinated. Yet, as K6KGS measured and documented in his comments, a scan of the band will show that the spectrum is hardly utilized, with only about 10% of its capacity ever used.

This is because the present methods of frequency coordination are actually a means of frequency "warehousing" where a local body grants a licensee exclusive use of a repeater channel in an amateur band. The owner of the coordinated repeater, however, is not then required to show sufficient activity to justify continued protection for the frequencies used.

The nature of SS systems is such that they seek to avoid narrowband interference. A frequency hopper, for example, should be designed to note that if dwelling on certain frequencies for a hop time results in poor throughput, it should skip over that channel in its hopping algorithm. In this way, it would minimize interference to narrowband users who are actually using a coordinated channel, yet be able to use unoccupied channels when they are simply "set aside" for repeaters but not actually in use.

Until a method of frequency coordination is evolved that takes into account the efficient and beneficial use (to the amateur community at large, not merely the repeater owners) of coordinated spectrum, I think it is a very bad idea to attempt to regulate an infant mode such as SS using outdated methods and concepts of "spectrum management." Let the systems be developed and deployed, then let amateurs of good will seek to resolve whatever problems might arise in mutual cooperation. Amateurs have long been noted for their pragmatic approach to solving problems of interference, and there is no evidence documented in this proceeding to suggest that they will not continue to do so.

I request the commission not make any special rulemaking concessions to the well-intended but inapplicable position put forth by the 220 MHz Spectrum Management Association.

EME
Frequency Sub-bands
Weak Signal Operation
Rising Noise Floor

I have grouped these topics together as they appear to be strongly related in the comments filed in this proceeding.

A number of commenters went on record opposing the use of spread spectrum in the so-called "weak signal" portions of the Amateur bands (W3XO, CSVHF and N7STU, AMSAT, W2RS). In some cases, calculations were put forth as evidence that allowing SS operation in these band segments would raise the noise floor by many tens of dB, rendering traditional narrowband weak-signal operation impossible.

I believe these arguments are well-intentioned, but unrealistic.

An EME station necessarily points its antennas at the moon. Further, in order to maximize the possibility of a successful contact, the antenna arrays used are highly directive. This means that the raising of the noise floor by SS would have to be coming from the moon. Since there are not likely to be a large number of SS stations actually on the lunar surface, these signals will have to be bounced off the moon along with the desired narrowband signals. This would require an extremely large number of SS stations running high power directed at the moon for the spectral power density to raise the noise floor a perceptible amount. If I had a high-power SS station trying to communicate terrestrially, I would not want my signal energy to go to the moon, so I would use an antenna system that did not direct it there. So would most other reasonable people.

On the other hand, if I wanted to set up an EME link, I would very likely want to use SS methods to help mitigate the inherent multipath. This would make me a high-powered, weak signal station just like the other EME stations. I should be allowed to use the same frequency spectrum as they use. If I cause interference, I will reconfigure my station so as to minimize that interference (and, presumably, minimize the interference to my operations caused by their high-powered, narrowband emissions).

In other words, a gentlemen's agreement will come into play if one is needed, much the same as PACKET, AMTOR, RTTY, CLOVER, G-TOR and other digital modes share limited spectrum on the 20-meter HF band, without special rules or other imposed methods.

If I am a terrestrial weak-signal operator, I will do the same thing. It is in the best interests of all Amateurs to cooperatively share the precious spectrum resource we are granted by a generous public policy towards Amateur radio operations.

Some commenters suggest that a "narrowband SS" class be established for weak-signal operation, and a "wideband SS" class be established for all other types of operation. This is like setting aside some spectrum for CW at 5 WPM and slower, and another for CW at 20 WPM and faster. It assumes that no serious weak-signal work could be done if the SS signal is wider than some arbitrary limit (in the range of 3 to 10 kHz), or that such SS emissions will somehow cause less interference to narrowband weak-signal stations than wider ones.

What if research into the physics of the motion of the moon and the nature of a particular frequency band showed an optimum bandwidth for effective EME communications at lunar perigee to be 12.9 kHz? The proposals by the "narrowband SS" proponents would make such operation impossible, and deny the very people seeking this provision the very means of their greater success!

I suggest that, rather than impose such arbitrary rules, and codify limited-use modes as having some sort of superior claim on Amateur spectrum, that we leave things as they are and allow technical imperatives and social cooperation to work. Only if such cooperation is demonstrated to be ineffective should we appeal to our regulators for assistance in solving our problems.

Narrow Band Identification

Several commenters requested that the narrow band ID requirements of Part 97.119(b)(5) be eliminated. No commenters argued for retaining this provision. I ask the Commission to rescind this part of the existing SS regulations as part of this proceeding, based on the arguments already presented during the public comment period.

CONCLUSION

I respectfully ask the Commission to implement the proposed amateur SS rules in this proceeding with the specific changes of: increased power to that of all other modes in a given amateur band, elimination of the automatic power control proposal, simplification of station record keeping, and elimination of the narrowband ID requirement.

Thank you for the opportunity to reply to the comments filed in this proceeding.

Respectfully submitted,


Lyle Johnson








(1) AMSAT, TAPR, ARRL, WA7GXD, W2RS, Central States VHF Society, W3XO, 220 Spectrum Management, KA9Q, K6KGS, Manager of National Communication System, N7STU (echoing CSVHFS)


(2) Part 15 Coalition, Metricom.


ARRL Filing December 12, 1995

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM-8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission


PETITION FOR RULE MAKING
                                             The American Radio Relay
                                             League, Incorpated

                                             Christopher D Imlay
                                             BOOTH FRERET & IMLAY, P.C.
                                             1233 20th Street. N.W.
                                             Suite 204
                                             Washington, D.C. 20036
                                             (202) 296-9100

December 12, 1995


TABLE OF CONTENTS
Summary ............................................................. i

     I.   Introduction............................................... 1

    II.   Spread-Spectrum Communications Rules Should be Flexible.... 3

   III.   Proposed Rule Changes...................................... 6

    IV.   Conclusion................................................. 9

Appendix


SUMMARY

The American Radio Relay League, Incorporated (the League), the national association of amateur radio operators in the United States, respectfully requests that the Commission issue a Notice of Proposed Rule Making at an early date, looking toward the amendment of the Commission's Rules and Regulations regarding the Amateur Radio Service, in order to facilitate, to a greater extent than is done by the present rules, the contributions of the Amateur Service to the development of spread-spectrum communications.

The petition proposes (1) to permit brief test transmissions using SS emissions; (2) to permit international SS communications between United States' amateurs and amateurs in countries that permit amateur use of those emissions; (3) deletion of unnecessary restrictions on spreading codes and repetitive definitions of "harmful interference", and (4) to provide for automatic power control to insure use of minimum necessary power to conduct SS communications.

The League urges that the Commission propose and ultimately adopt these proposed rule changes. These are, in the League's opinion, the minimum changes necessary in order to foster SS experimentation in the Amateur Service, while at the same time preserving those necessary existing protections against those who might conceivably exploit the amateur bands for non-amateur purposes. Spread-spectrum techniques are in regular use in Part 15 applications, but have not been given the attention deserved in other communications systems, such as the land mobile services, as a means of increasing the efficiency of use of crowded shared bands. The Amateur Service regularly functions as a provider of refinements of new technologies and provides means of deployment of those technologies on a cost-effective basis. In order to permit the degree of flexibility in use of this technology in particular, the Commission should provide the necessary regulatory environment to do so. These rule changes represent a conservative, and yet functional approach to reform of SS rules.


Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM - 8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission

PETITION FOR RULE MAKING

The American Radio Relay League, Incorporated (the League), the national association of amateur radio operators in the United States, by counsel and pursuant to Section 1.401 of the Commission's Rules (47 C.Z.R. &#167 1.401) hereby respectfully requests that the commission issue a Notice of Proposed Rule Making at an early date, looking toward the amendment of the commissions Rules and Regulations regarding the Amateur Radio Service as set forth in the attached Appendix. The purpose of the proposed rule changes is to Facilitate, to a greater extent than is done by the present rules, the contributions of the Amateur Service to the development of spread-spectrum communications. As good cause for the proposed changes, the League states as follows:

I. Introduction

1. Use of spread spectrum communications in the Amateur Service is relatively new. It was first authorized by the Commission by Report and Orders 58 RR 2d 328 (1985). The Commission authorized spread-spectrum communications in the Amateur Service in order to permit amateurs to develop, test and operate low-cost spread spectrum systems, thus to stimulate technical advances in radio technology, consistent with the basis and purpose of the Amateur Service (47 C.F.R. Section 97.1). The Specific Benefits to the public to be gained from amateur use of spread-spectrum (SS) communications as determined by the Commission included the following: Reduced power density and concomitant reduction of interference to narrow band communication systems; 2) Significant improvements in communication under conditions with poor signal-to-interference ratio; 3) Improved communication performance in selective fading and multipath environments; and 4) Ability to accommodate more communication channels functioning simultaneously in the same spectrum than is possible uising frequency division multiple access exclusively.

2. Since the time SS communications were first authorized in the Amateur Service in mid-1985, there have been some experimental amateur operations using SS techniques, but its use has not been widespread. The League believes that one significant reason for this reduced level of experimentation is due to limitations in the rules governing SS communications in the Amateur Service. The revised rules in the proposed appendix are intended to provide increased flexibility in the use of this mode, to encourage amateurs to experiment and use SS communications, to develop new techniques for increased spectrum efficiency using this mode, and to improve compatibility with narrow-band modes.

II. Spread-Spectrum Communications Rules Should Be Flexible

3. Commission policy is and has been to encourage experimentation and to provide a Regulatory environment for the Amateur Service which encourages modern techniques, technology and uses of amateur radio. (1)

4. SS communications are well-suited to the Amateur Service, especially in shared bands. Amateur experimentation in SS communications, in view of the apparent compatibility of SS communications and narrow-band modes commonly used in the Amateur Service, is of potential benefit in terms of spectrum efficiency. This was noted by the Commission in Docket 81-414. There were some concerns expressed by commenters in that proceeding. These initial objections fell into three categories: 1) concern about intraservice interference; 2) concern about inter-service interference; and 3) concern about monitoring issues, and the ability to protect the Amateur Service against interlopers. These issues are not of practical concern now, and they are not anticipated to become significant under the proposed revised SS rules. There have not been, in the League's experience, any established instances of actual interference to narrow-band amateur communications from SS communications. Tests conducted by amateur groups have established that certain configurations of SS operations can, due to increased in-band noise, trigger amateur repeater inputs (if those repeaters are carrier-operated), but that potential interaction is easily avoided by selection of spread-spectrum parameters. 58 RR 2d at 329, and authorities cited therein at footnotes 4-9. There are potential interactions between SS and narrow-band modes in certain circumstances, depending on processing gain and the randomness of spreading codes, however.(2) There have been no reported instances whatsoever, in the League's experience, of interference to other radio services from amateur SS communications. (3)

5. Notwithstanding the Commission's general support of Amateur SS communications, as stated in the Report and Order in Docket 81-414, the rules adopted in that proceeding were quite circumscribed. The limitations were principally aimed at facilitating station identification by other amateur stations, and limiting spreading sequences by specifying a limited number of linear feedback shift registers. SS communications are currently authorized only for domestic communications, (4) and the frequencies available for SS communications were in the bands above 225 MHz. (5) They remain as originally enacted, to the present date.

6. The Commission has generously granted and extended special Temporary Authority for SS experimentation, however. The experiences of amateurs pursuant to these past Special Temporary Authorities indicate that the present rules include certain significant limiting factors which could be liberalized without detracting at all from other, narrow-band amateur communications.

It is the League's belief, and apparently that of Commission staff as well, that experimentation in the Amateur Service, and particularly further SS experimentation, should be accommodated by increased flexibility in the rules, and not by reliance on STAs. According to a report by Mr. Buaas, K6KGS, holder of a Commission STA, which report was filed with the Chief, Private Radio Bureau in March of 1993;

Our work to date has focused on determining: a) what performance can be achieved utilizing several techniques in spectra already occupied by narrowband emitters, b) what level of interference results to existing users; c) what impact existing usage has on degrading SS performance; d) how much usage can be pressed into a given spectrum using CDMA; and e) what proposals we might make to change the Rules and thereby further encourage experimentation without the need for this STA.
*****
Several of our experiments have been particularly successful. We started with designs which would meet the limits set forth for Part 15 systems, and worked up from there. One hybrid design (DS coupled with slow FH) was particularly effective in minimizing interference...
*****
It is now clear to us that use of SS in the Amateur Service has been severely limited by the design restrictions in the Rules...

The League agrees that it is useful to relax somewhat the rules contained in Sections 97.305(b) and 97.311 governing amateur SS operation, to permit greater operating flexibility and the development of SS communications as a practical communications mode in the Amateur Service without adverse interaction with other modes.

III. Proposed Rule Changes

7. The first change proposed by the League is to permit brief test transmissions of SS emissions, as is permitted in Section 97.305(b) for other types of emissions, except that test transmissions using SS emissions would be limited to those frequency bands where SS emissions are authorized generally, as is the case with pulse modulation transmissions.

8. Second, it is proposed to amend Section 97.311(a) of the Rules to modify the requirement that SS communications be limited only to domestic communications. Amateur communications have always been permitted internationally between countries that permit it, and SS emissions should not be prohibited between United states amateurs and amateurs in countries where those emissions are permitted as well.

9. The reference in &#167 97.311(b) to unintentional triggering of repeater inputs, a reference in the rules governing SS communications since 1984, is unnecessary because it is merely repetitive of existing definitions of "harmful interference" in the ITU Radio Regulations and in commission definitions and interpretations generally. Harmful interference for non-safety-of-life radio services does not include squelch breaks and repeater activation. (6)

l0. It is proposed to delete Subsections 97.311(c) and (d), in order to permit hybrid frequency-hopping (FH) and direct-sequence (DS) emissions, and spreading codes not currently permitted by the rules, but which are desirable. The current rules permit only two techniques, neither of which is optimal for sharing. There are newer codes, including those used by Part 15 device manufacturers, which have been optimized to avoid interaction with shared users. These could be used if the rules were more flexible . Elimination of the rule limiting amateurs to specific spreading sequences is necessary to facilitate experimentation. The proposed rule changes would delete the limitations on SS configurations contained in the present Section 97.311(d). This modification is necessary to provide sufficient flexibility to experiment with other spreading sequences, tap settings and frequency hopping techniques. Nor will the changes create any difficulty with station identification, (7) or with protection of the Amateur Service from commercial or unlicensed encroachment. The narrow-band identification requirement is sufficient, together with the documentation requirement in Section 97.311(e) of the Rules, to permit the degree of monitoring of SS activities of amateurs necessary to protect the Service. As the Commission appropriately recognized in addressing monitorability of unspecified digital codes in the Amateur Service, quoted in the Report and Order in Docket 81-414:

In balancing our objectives of encouraging new technologies against ensuring our enforcement capability, it must be recognized that there is an incompatibility between authorizing experimentation with "exotic" technologies and the employment of channel monitoring as an enforcement tool. Our ability to verify that the content of messages complies with our rule requirements will be hindered by the broad relaxation of regulatory constraints that we are ordering in this proceeding. However, the Commission agrees...that special provisions we are including in the final rules, as well as existing provisions that identification be made in plain English or the international Morse code, should, when combined with the zealous effort of the amateur community to protect their allocated frequency bands, provide adequate protection against unauthorized operation in the service. 58 RX 2d at 330.

11. Finally, the proposed appendix would amend Section 97.311(g), to provide for automatic transmitter power control which would limit output power to that which is required for the communication, when more than one watt of transmitter power is used. This is a simple matter to accomplish technically, and it will insure compliance with Section 97.313(a) of the rules, which requires the use of minimum transmitter power. It will also minimize any potential for interference to other amateur stations and insure maximum spectrum efficiency.

IV. Conclusion

12. The League urges that the Commission propose and ultimately adopt these proposed rule changes, which are in the League's opinion the minimum necessary changes in order to foster SS experimentation in the Amateur Service, while at the same time preserving those necessary existing protections against those who might conceivably exploit the amateur bands for non-amateur purposes. Spread-spectrum techniques are in regular use in Part 15 applications, but have not been given the attention deserved in other communications systems, such as the land mobile services, as a means of increasing the efficiency of use of crowded shared bands. The Amateur Service regularly functions as a provider of refinements of new technologies and provides means of deployment of those technologies on a cost-effective basis. In order to permit the degree of flexibility in use of this technology in particular, the Commission should provide the necessary regulatory environment to do so. These rule changes were developed by a dedicated committee of League staff and volunteers familiar with the technology, and represent a conservative, and yet functional approach to reform of SS rules.

Therefore, the foregoing considered, the American Radio Relay League, Incorporated respectfully requests that the Commission issue a notice of proposes rule making to implement the rules contained in the attached Appendix, and adopt the same after an opportunity for notice and public comment.

                              Respectfully submitted,

                              THE AMERICAN RADIO RELAY
                              LEAGUE, INCORPORATED
225 Main Street
Newington, CT  06111

                              By: Christopher D. Imlay
                              Its General Counsel


BOOTH FRERET & IMLAY, P.C.
1233 20th Street, N.W., Suite 204
Washington, Z.C. 20036
(202) 296-9100

December 12, l995


APPENDIX

Section 97.305(b) is amended to read as follows:

    (b) A station may transmit a test emission on any frequency authorized to the control operator for brief periods for experimental purposes, except that no pulse or SS modulation emission may be transmitted on any frequency where pulse or SS is not specifically authorized.
Section 97.311(a) is amended to read as follows:
    (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service is regulated by the FCC and between an area where the amateur service is regulated by the FCC and an amateur station in another country which permits SS communications for its amateur licensees.

Section 97.311(b) is amended by deleting the last sentence thereof.

Section 97.311(c) and (d) are deleted in their entirety.

Section 97.311(g) is amended to read as follows:

    (g) The transmitter power output must not exceed 100 W under any circumstances. If more than 1 W is used, automatic transmitter control shall limit output power to that which is required for the communication. This shall be determined by use of the ratio, measured at the receiver, of the received energy per user data bit (Eb) to the sum of the received power spectral densities of noise (No) and co-channel interference (Io). Average transmitter power over 1 W shall be automatically adjusted to maintain an Eb/(No+Io) ratio of no more than 23 db at the intended receiver .

Footnotes

    1. See, the Notice of Proposed Rule Making, 3 FCC Rcd. 2076 (1988).


    2. These potential interactions are no different than those involving other mode compatibility issues in the Amateur Service except that current rules require protection by amateurs using SS emissions of users of other modes. 47 C.F.R. &#167 97.311(b). Conflicts are avoided by informal band planning and normal sharing considerations which work well in the crowded amateur bands. Avoidance of weak-signal subbands by SS operations is a reasonable preventative step.


    3. In Docket 81-414, the Commission addressed concern by the National Association of Broadcasters (NAB) about interference to television channel 2 (54-60 Mhz) reception from amateur SS operation at 50-5Z MHz as follows:

    ...NAB's principal concern was that uncontrolled amateur transmissions might fall outside the allocated band into channel 2. The Commission believes that NAB's concerns are not well founded. First, rather simple transmitter output filters can be used by amateur licensees to prevent positively out of band emissions. Second, licensees in the Amateur Service have had no significant history of operating outside the allocated bands...In other frequency bands where the Amateur Radio Service has successfully shared allocations with different services, we expect no worsening of interference since the power density from currently existing narrow band transmissions having the same total effective radiated power. 58 RR 2d at 330.

    The Commission also noted that the NAB's concerns were moot, since the authorization for SS communications extended only to bands above 225 MHz. 47 C.F.R. &#167 97.305.


    4. In the Commission's rewrite of the Amateur Rules, commenced in 1988, the Commission deleted from the rules the reference to international use of SS communications because no international agreements had been enacted to facilitate such. The Commission indicated in Docket 88-139 a willingness to consider international use of SS communications if there were international agreements enacted to permit such. No specific agreements have been enacted on that subject to date.


    5. The original proposal of the Commission in Docket 81-414 was to permit SS communications only in the 50, 144 and 220 MHz bands. Those bands were not authorized by the Report and Order because of certain comments which noted the limited size of the allocations and required limitations in bandwidth. Therefore, the Commission authorized operation only in the UHF and SHF bands.


    6. See, the ITU Radio Regulations,at Article 1, in which "Harmful Interference" is defined as interference which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs or repeatedly interrupts a radiocommunication service operating in accordance with these regulations. A virtually identical definition appears at 47 C.F.R. &#167 97.3(a)(22). Past Commission interpretations of interference to amateur repeaters have consistently applied the definition of "harmful interference" to exclude mere squelch breaks. And, the Commission held in an Order dismissing RM-7673 (DA-92-155, released February 10, 1992) there are "many other methods" available to prevent unintended triggering of repeaters besides restricting SS emissions.


    7. It is not proposed to modify the station identification provisions in Section 97.119(b)(5) which contains the CW identification requirement for SS communications. The League questions the practicality of the requirement, in view of the variability of frequency on which the narrowband CW identification requirement may be located. Nonetheless, it is not proposed to delete the requirement at this time.


Comments of WA9JOB

Wisconsin
Association of
Repeaters
MACC

Nels Harvey, WA9JOB
Chairman
2104 W. County Line Rd.
Mequon, WI 53092-5616

Secretary, Federal Communications Commission Feb. 20, 1996
1919 M Street, NW
Washington, DC 20554

Re: RM-8737

For whom it may concern:

I wish to register my opposition to the proposed Amateur Radio Spread Spectrum rule making.

The use of Spread Spectrum is totally contrary to the needs for Amateur Radio. It will prevent detection by Amateur operators who effectively police the operations in the Amateur Service. This most likely could lead to unauthorized operations by undesirable elements.

On a technical basis, operation below 902 MHz. will cause a drastic increase to the noise floor, and will cause hampered operation to a band that already is sharing ATV, Packet, Link and Auxiliary operations, specialized space communication as well as regular simplex, weak signal, moon bounce and FM voice repeater operation. The Spread Spectrum RF bursts will land, helter-skelter and interrupt virtually any type of communication in the 420 Mhz. band. For the significant Amateur population living above the line A restriction, who already operate with truncated bandwidth, such operation will be an even greater challenge.

Spread Spectrum does not need to be available to such a valuable Amateur band. If experimenters need to explore the technology, the 902 Mhz. band offers a place where Spread Spectrum already exists, but is not presently available to the Amateur Service. If manufactures wish to sell Spread Spectrum to Amateur Radio, then the 1.2 GHz. Amateur band, or even higher, may be a choice market.

Once again, I object to the operation of Spread Spectrum below 902 MHz. The (less then or equal) Meter band, from 420 to 450 MHz. is especially vulnerable to the type of interference Spread Spectrum offers.

Sincerely Yours,

Nels Harvey, WA9JOB

 


Comments of SBMS

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                    )
                                    )
Proposed Amendment of Part 97       )
of the Commission's Rules           )
Governing the Amateur Radio         )
Service to Facilitate Spread        )
Spectrum Combinations               )

To: Federal Communications Commission

The San Bernardino Microwave Society,
Statement in Opposition to:
the American Radio Relay League,
Petition for Rule Making

February 20, 1996

From: Richard Kolbly,
Corresponding Secretary
San Bernardino Microwave Society
247 Rebel Road
Ridgecrest, CA 93555

By the Membership:

Introduction

1. On December 12, 1995, the American Radio Relay League (ARRL) files, with the Federal Communicaitons Commission (FCC), a petition for rule making to amend FCC Part 97 rules to allow the use of Spread Spectrum (SS) modulation in the Amateur Radio Service.

2. The membership of the San Bernardino Microwave Society opposes this petition for the following reasons:

    a) The petition arguments appear to be based on defective scientific methods.

    b) The petition does not clearly show how the users of SS will be required to protect incumbent band users.

    c) The petition does not clearly establish band segments for SS communications to operate without causing interference to other band users in densely populated Amateur bands in urban areas.

    d) The petition does not recognize band planning and associated band use parameters which have been previously agreed to by incumbent users.

    e) The petition is not clear as to how instances of interference between band users will be resolved.

    f) The petition does not establish a uniform method of CW identification of SS signals.

    g) The petition does not adequately define "Spread Spectrum", and wished for a broad brush to be used when defining this modulation method.

Background

3. The San Bernardino Microwave Society (SBMS) is a non-profit organization "dedicated to the advancement of communications above 1 GHz". Our membership primarily consists of college-educated professionals employed in the high-tek electronics and defense industries. The Society was formed forty years ago to promote activity within the Amateur Radio Service, specifically on the microwave bands [1]. Considering our long history of activity in the Amateur microwave bands, our membership felt that our comments had relevance to the future of these bands.

4. It must be clearly understood that the SBMS wishes to promote and expand the use of the Amateur microwave bands. Our membership currently includes active Amateurs in the weak signal (including terrestrial and earth-moon-earth), repeater, point to point links and television. Our membership also includes representatives to the local spectrum planning of all the Amateur microwave bands for which such plans exist. Additionally, over the last forty-years, we have commented on numerous rule making issues affecting the Amateur microwave bands.

Statements in Support of Our Position

5. The SBMS is compelled to comment on the ARRL petition for rule making for the following reason:

    The ARRL states in its petition that "there have not been, in the League's experience, any established instances of actual interference to narrow-band amateur communications from spread-spectrum (SS) communications"

6. What does this mean and why is if contained in this proposed rule change? The statement is not supported by any scientific/technical data, nor is a source for such data referenced. Under the charter of Amateur radio contained within the FCC rules, we are required by section 97.101 (a) to:

    In all respects not specifically covered by FCC Rules each amateur station must be operated in accordance with good engineering and good amateur practice.

7. Conclusions drawn from testing of new communications modulation techniques which were not widely disclosed before, during and after such tests occurred, are not consistent with good scientific, good engineering or good amateur practice, and do not contain meaningful data. Sharing in advance test dates, test parameters and controls is the only way to insure that the results of such testing contain scientifically-meaningful data; data which benefits the Amateur community at-large and data that we can all be proud of.

8. It appears that a majority of the proposed rule changes requested by the ARRL have little or no actual relationship to implied testing, so we will oppose any rule change that does not contain the following safeguards. Additionally, the SBMS hopes that the FCC staff is well aware of the crowding which exists in many of the Amateur bands, particularly the lower microwave bands. We would like the FCC to consider the following reasonable limitations be placed on any new or expanded use of Amateur SS (just as they already apply to most other emissions):

    a) Use of SS should be limited to portions of Amateur bands as prescribed by local frequency coordination practices. If frequency coordination of SS stations is not required under local band plans, operation of such stations must still be in accordance with established local plans or practices.

    b) Users of SS, conforming to a) above, must take all reasonable precautions necessary to prevent interference to existing incumbent band users without regard to either stations transmitter power, beamwidth, elevation or ERP. This is especially critical in the weak-signal portions of the bands where current operation at or in the noise floor is commonplace but applies to other existing users as well.

    c) A standard for transmitter identification must be established so that any interested parties can easily find the source of a transmission.

    d) Definitions of general categories of SS emissions need to be established. Narrowband digital voice systems should not be forced into the same category as a SS system transporting information at megabyte data rates. Again, these decisions for band usage must be made at the local level.

Conclusions

9. It should not be interpreted from this discussion that the SBMS is against SS communications. There are less crowed Amateur microwave bands, particularly the higher frequency bands, where space exists for a variety of SS emission types. In fact, we welcome the new modes to help promote the future use of the Amateur microwave bands. The SBMS stands ready to serve all Amateurs wishing to construct and operate stations in these microwave bands.

10. Limitations similar to those required in a) above already exist in the Amateur rules, with portions of many bands set aside for CW, Voice, Repeaters, etc. To simplify the rule-making procedure and allow for integration into long-established band planning currently in-place throughout most of America, we ask that band segments and coordination requirements be decided on a local basis by the locally-recognized coordinator.

11. The future of Amateur radio communication modes may well lie in the various forms of digital communications. Everything should be done to help promote this type of Amateur activity. As in the past, however, the newer mode must establish itself as technically feasible, especially in today's highly crowded Amateur bands. A systematic and controlled integration of SS into mainstream Amateur radio combined with widespread education will insure that this new mode is taken seriously.

12. The ARRL petition, in its current form, would create chaos in the Amateur bands if implemented as written. While Amateur development of SS communications is needed, it can not simply be thrown into the bands on top of well-established incumbent band users. We must therefore respectfully oppose this petition for rule making until the protections outlined above are included.

For the Membership,

David E. Laag, President
San Bernardino Microwave Society


[1] Additional information about the San Bernardino Microwave Society is contained in an article within the pages of QST magazine, March 1995 issue, pages 46 through 50.

 


Robert A. Buaas, K6KGS, comments to RM-8737 Feb 26th, 1996

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM-8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission

The following are the comments of Robert A. Buaas, K6KGS.

I hold the Special Temporary Authorization dated December 27, 1994, that permits experimentation with any Spread Spectrum (SS) technology in all Amateur spectrum above 50 Megahertz, on behalf of the entire Amateur community. My involvement with Amateur SS dates back to its original contemplation by AMRAD, in whose STA I participated. I have contributed to the development of successful commercial Part-15 SS systems, and I am a charter member in IEEE P802.11 (the Wireless LAN Ethernet Standard development project).

I wholly support the thesis of Sections I and II of the ARRLs proposal, that the Amateur Rules should be significantly relaxed for SS. As I said in my March 1993 report to the Chief, Private Radio Bureau giving results of our investigations, a part of which is quoted in the proposal, one barrier limiting the application of SS in Amateur Radio are the limitations in the Rules.

Since that report, I have come to appreciate that there are additional barriers. One is the complexity of even the simplest SS system, compared with the equivalent-performance narrowband analog, particularly in a community of participants where cost of equipment is very sensitive. As I said previously, SS is not currently for the light-at-heart. Virtually none of the currently available amateur equipment can be utilized in the SS mode without major modifications and enhancements. The technical challenges of properly creating a quality SS signal for transmission (the easy part), then synchronizing the receiver (generally the hard part) are beyond most practitioners. There is considerable confusion about what constitutes SS; some writers describe SS only in terms of Direct Sequence modulation, other only Frequency Hopping. I prefer to think in the broadest possible terms, referring back to the original definition of the transformation of narrowband information transmitted over a wide spectrum regardless of the spreading means. So often, what gets lost are the benefits that result from the additional complexity: (a) the increased reliability of the communication channel resulting from the improved resistance to jamming and effects of multipath fading, and (b) the ability to accommodate heavier spectrum loading before performance degradation sets in.

A third and overwhelming barrier is the fear associated with the interference that the inexperienced claim that all SS systems will necessarily generate. On this point we have experienced vocal opposition to SS, particularly from the Frequency Coordination community, and to a lesser degree from the Weak Signal community. The fear is often expressed as: SS will raise the noise floor. While this is true in the abstract (just as any energy emitter makes some contribution to that which each receiver must differentiate), few real systems operate anywhere near the noise floor. Those amateurs that do would profit from applying SS technology, as Phil Karn often observes. (Virtually every commercial and military weak signal application is deeply invested in signal coding technology; SS is but one segment on this information processing continuum.) NBFM routinely operates with signal margins of 20 to 40 dB; because of this, the noise floor contribution of multiple SS systems is insignificant.

There is an important point here that must not be overlooked. For SS to be successful in Amateur Radio, high priority must be given at the system design stage to a criteria which minimizes interference to narrowband occupants. Attempting to draw interference impact conclusions by analyzing the performance of commercial and military SS designs is seriously flawed, particularly when one uses system models designed against very different criteria. For example, systems whose design criteria are (a) meet Part-15.247 requirements and (b) maximize channel data rate, do not optimize for minimum interference. As another example, one of AMRADs first experiments used commercially available NBFM transceivers to evaluate frequency hopping. The extremely slow slewing performance of the frequency synthesizer required that each transmission dwell for a long period before moving on to the next channel in the hopping sequence. At the time this experiment was conducted, many repeater systems used only carrier squelch as an access method, and the long dwell resulted in unwanted repeater transmitter keyups. The annoyance this caused the user community was reflected in the Rules change originally permitting SS. Today, commercial product synthesizer slew performance is only slightly better. Yet most repeaters have additional criteria which must be met before transmitter activation occurs. These increased system requirements were brought on by the desire for selective repeater access and by the need for the repeater to avoid unintentional interference from intermodulation products of nearby emitters. Our tests have conclusively shown that, in todays environment, that original system would represent only a slight but noticeable impact. Using advanced synthesizer design, we have demonstrated that continuous SS transmissions go completely unnoticed in all but a few special cases of users. (One example is a very high density packet data channel, where an occasional packet is lost and is recovered by later retransmission.) Except for the frequency synthesizer, the transmitter is an ordinary NBFM transmitter; it has the usual spectral power distribution and spurious emission characteristics, and is consistent in every way with good engineering practice. This evaluation system was realized as a point-to-point link and did not confront the issue of wideband receiver overload. As expected, we observed superior resistance to the kind of interference that most plagues fixed-frequency systems.

The above example is but one possible SS realization. There is considerable room for additional gain. Phil Karns work in Forward Error Correction has yet to be exploited. Use of one-half rate codes only doubles the transmitted signal bandwidth, giving it a direct-sequence- like spectral distribution and gain. Such novel ideas show that the current rules prohibiting complex hybrid systems were shortsighted. SS is but one form of coding. In order that The Commission provide the longest-reaching regulatory environment that encourages responsible innovation and advancement in the state of the art, instead of changing the Rules as proposed in paragraphs 9 and 10 of the subject NPRM, I recommend that The Commission remove Section 97.311 entirely, and include SS as part of authorized unspecified digital codes in Section 97.309(b).

Making provision for international use of SS and other novel signaling technology as suggested by the spirit of paragraph 8 is a worthwhile modification. IEEE 802.11 is truly an international endeavor, and there is worldwide interest in commercial SS in this form. I have received queries about our progress from several radio amateurs in Europe, the Middle East, and Japan, who were first exposed to SS as a result of the IEEE project. Future developments will certainly commingle between the commercial product domain and Amateur Radio.

The proposal made in paragraph 11 to require automatic power control ONLY for SS systems is one minor aspect of an elegant incentive first offered by Phil Karn. It only makes sense if implemented completely as Phil proposed it, and then only if it is applied to ALL systems competing for spectrum use. The notion of using minimum transmitter power required to accomplish the desired communication is well established in the current Rules (Section 97.313(a)), yet it is one of the most abused and violated requirements. I know of very few repeater systems who have any power control at all and none in which the output power is automatically controlled based on some criteria relating to communication quality. 97.313(a) observance is marginally better among HF amateur operators. Unless SIGNIFICANT incentive is provided to offset the considerable system complexity increase (the hardware needed to control power output is simple, the algorithms required to determine how to dynamically adjust the hardware are not), I believe that the guidance provided in the existing Rules is adequate.

I take serious exception to the general direction and the specific proposal made in paragraph 7 of this NPRM. SS is a complex art. Precious few amateurs have been willing to contribute their time and resources to participate in the development of amateur SS. Even the incentive offered by the STA has been insufficient to bring out interest in large numbers. Nowhere in the current Rules is any emission relegated to test only status. Parties wishing to test may apply for a Part-5 license. What incentive is offered to the developer to build a new SS system if all he/she can do is test it? Amateurs build new systems so that they may field them, to gain on-the-air experience in both the new systems strengths and weaknesses. This experience is invaluable to the communication art, because the criteria applied in judging the system is different from that used for systems in other radio services. Further testing of SS is not required. Our investigations have conclusively demonstrated the viability of SS along side existing users and modes, that proper use of good engineering practice and appropriate design criteria practically eliminate postulated interference. Our work now is to produce and field enough SS systems that more amateurs can participate in their use and experience for themselves the merits. The result achieved by implementing this Rules change as proposed REDUCES the chance that SS will ever find application in Amateur Radio. Such a direction is directly counter to the basic purpose for the existence of our Service.

This NPRM is silent on another important aspect of the STA, particularly the authorization for the use of 50 Megahertz and above. The VHF bands have propagation properties which differ dramatically from UHF and up. It is precisely these characteristics that deserve investigation using SS and other coding technology. 2 Meters is the most heavily congested of the VHF bands; it also provides the best vehicle for proving the promise that CDMA has to offer in increasing spectrum utilization. Commercial systems have made the case of documenting this improvement when the spectrum is clear of other use (the design criteria and implementation reflect this thrust). Amateur radio has the potential for making an invaluable contribution: that there are gains available even when the spectrum used is occupied. It is my recommendation that The Commission adopt a change in the Rules permitting SS the VHF band operation that is given me and my associates in the STA.

SS is the 1990s version of SSB, when it was introduced as an improvement to AM. The outcry I heard then rings familiar today, as the fearful contemplate this new mode. SS emission has been authorized in the Amateur Service for more than a decade. No interference to 75 cm operations has been documented at any time during this period. Further, transmissions conducted under the auspices of the STA have produced no noticeable interference. I have offered the availability of the STAs capability to any and all Amateurs wishing to do serious research consistent with the objectives stated in the STA. Some SS enthusiasm has been expressed by Weak Signal interests and this is an exciting occurrence. SSB had a powerful influence in revolutionizing the communications art. I encourage and recommend that The Commission turn aside this proposal in favor of the direction and authorizations provided in the STA, further encouraging widespread SS introduction, utilization and evaluation.

                          Respectfully submitted,




                          Robert A. Buaas


Comments of the Souther California Repeater and Remote Base Association

In the Matter Of:                              )
                                               )
Proposed changes to the Amateur Service        )      RM-8737
Rules (Part 97) to facilitate additional       )
uses of certain portions of amateur spectrum   )
by Amateur Spread Spectrum emitters            )

Re: Comments of the Southern California Repeater
and Remote Base Association in opposition to portions
of the Petition for Rulemaking by the American Radio
Relay League which proposes to "facilitate" more
Amateur Spread Spectrum uses.

February 23, 1996

SUMMARY

SCRRBA believes that this petetion should be summarily dismissed without action. We find the following defects in the petetion:

1: The petetion is based upon inference and supposotion, not scientifically collected and reported DATA.

2: SCRRBA finds this petetion to be inadequate, incomplete and wholly without technical supporting data.

3: Both the petition and the letter of "information" from the STA holder are wholly without supporting technical data.

4: The petitioner does not show how incumbent band users will be protected from new interference.

5: The petitioner does not show how band segments can be established for SS communications.

6: The petitioner is unclear on interference potentials, or methods of resolving interference.

7: The petitioner does not take notice of and incorporate the use of community based band usage plans or frequency coordinators both of which exist in every state in the union.

8: The petitioner does not provide a meaningful and uniform method of SS station identification.

9: The petitioner omits a description of SS emissions with necessary attendant definitions and discussion.

Should the Commission choose to act upon any or all of this petition, SCRRBA has incorporated within our following comments various corrections and changes to the proposed rules. These changes clarify certain areas of confusion, and add missing information and methods.

Introduction

The Southern California Repeater and Remote Base Association (SCRRBA) is a voluntary association of owners and operators of Amateur Radio Service fixed and mobile relay stations operating primarily on the UHF and Microwave Frequency amateur bands. SCRRBA has provided frequency coordination for the activities since 1970. SCRRBA is the recognized frequency coordinator for the Southern California region for the amateur 29 MHz, 50 MHz, and 420 MHz and above bands. [1] SCRRBA has actively participated in numerous Federal Communications Commission rule making proceedings pertinent to our activities.

SCRRBA currently maintains over 2,100 frequency coordination records. These data represent the activities of approximately 600 relay type amateur radio systems in Southern California. All of these systems operate on the UHF (420 MHz) and higher amateur frequency bands. These systems each have an average membership of about 60 amateurs. The largest of these systems has a membership exceeding 1,400.

SCRRBA is an active participant (usually the sponsor) in the amateur band planning process. We represent the fixed and mobile relay interests in regional band planning meetings. These meetings occur when the existing plans do not cover a desired activity, or when they need to be upgraded to match new or increased activities. These meetings are attended by representatives of ALL the amateur uses of the band. These band plans are adopted by unanimous consent of these representatives. These band plans cover activity in the Southern California region. Whenever the community adopts a new band plan for our region, we submit it to the American Radio Relay League, Inc. (ARRL) to be included in national band planning efforts.

Discussion:

The instant petition appears, on its surface, to merely be a request to simplify and relax the existing rules governing Amateur Spread Spectrum (SS) operations. Such changes to the rules are generally desirable when there are no significant side effects. Unfortunately, this petition is not well thought out. We will show in the following paragraphs that this petition is seriously flawed and totally lacking in supporting data.

The petitioner fails to define Spread Spectrum (SS) emission [2]. SS can be most generally defined as a transmission method where the occupied bandwidth exceeds the information bandwidth. Several presently authorized and commonly used transmission systems fall in this category. Most of these are analog techniques where the occupied bandwidth is only somewhat larger than the information bandwidth. These analog systems are specifically defined within the rules by emission type and require no further discussion.

One of the most common misconceptions about SS emissions is that they must occupy huge bandwidths. Spreading a Morse Code transmission with an information rate of 150 Hz over 15 kHz most certainly produces a classic Spread Spectrum signal and can easily be demodulated with the processing gain enhancement touted by the SS community. A conventional voice transmission can have a (digitally sampled) information rate as low as 8 kHz. Spreading this information over 150kHz [3] will again produce a classic SS signal. Both of these examples can be done by analog methods, but are far more easily managed to obtain useful process gain when the spreading methods are digital. These are examples of some types of SS emissions which are likely to occur regularly given the expanded SS usage the petitioner envisions.

The power density of SS emissions can be quite high. A 100 W SS transmitter occupying 150 kHz has a power density of 0.67 W/kHz. A conventional narrowband FM repeater receiver commonly has a 15 kHz bandwidth. This SS transmitter would have 10 watts of its power within the passband of the repeater receiver.

The petitioner claims several benefits occur from the use of SS transmissions. [4] The statements are formulated to imply that the listed benefits occur simultaneously. Nothing could be farther from the truth. The petitioner left out several key qualifiers in each of the listed benefits. The petition is devoid of technical fact, measurement of fully formulated premise. The following statements should clarify the petitioners' claims and the defects in each:

    SS emissions have "reduced power density" This phrase is only true when comparing identical information bandwidths and identical total transmitted power; one spread and one not spread. An SS transmission occupying 15 kHz has exactly the SAME (average) power density as any other (identically powered) emission occupying 15 kHz. A 10 W analog Amateur television transmission which is 6 MHz wide has exactly the same average power density as (for example) a 10 W SS emission generated by spreading a 1.544MB "T1" data stream over 6 MHz.

    "concomitant reduction in interference to narrowband systems." The presumptions here are that the undesired SS signal will occupy much greater bandwidth than the desired "narrowband" signal, and produce less undesired signal in the narrowband receiver. The signal produced in any receiver by an transmitter, desired or undesired, cannot be determined without technical facts. The transmitter powers, antenna gains, transmit and receive bandwidths, and path losses MUST be known before any such statement can be made. We give examples above where the SS bandwidths can easily be the same or less than those of a conventional transmission to which the SS signal is claimed to produce a reduction in interference. The SS signal WILL produce similar interference to that generated by any other emission of the same bandwidth.

    "Significant improvements in communications under interference conditions." This is simply not true. Far too many special conditions must be presumed for an SS signal to deliver better communications than a similar analog system under the same conditions. Here again, no technical specifications or examples are given. The most significant conditions are: The SS system must either be a "hopping" type in order to "skip" over an interfering carrier, or the sum of the interfering carriers must not be greater than the SS signal by the ratio of the process gain. The SS transmission also can not share spectrum with too many other similar SS systems or undesired carriers lest it "run out" of places to "skip". The SS system is also presumed by the petitioner to be a digital transmission where forward error correction can be used and propagation delay can be tolerated in order to re-send a missed "packet."

    "Improved performance in selective fading and multipath environments". This can actually be true with two important assumptions: That substantial digital forward error correction be employed, and that a lost data packet can be re-transmitted. Field experience with digital microwave systems actually demonstrate that they are more susceptible to path problems than an identical analog system. With sufficient forward error correction and even more bandwidth (to increase the process gain) this can be overcome.

    "SS can accommodate more "channels" in the same spectrum than a FDMA system " This statement is far too broad. It is fact that a digitally processed SS system utilizing "exclusive" spectrum can accommodate more traffic in the same bandwidth than can a FDMA system. This is mostly a result of the digital processing to compress (in time) the communications and the use of all the available spectrum space without having to leave "guardbands" between each channel assignment. It is also dependent upon the communications user being willing to tolerate propagation delays which will increase as the system traffic increases.

The petitioner states that "SS.. is well suited to the amateur service, especially in shared bands." [5] The petitioner also states an "apparent compatibility" between SS and "narrowband" modes. The Petitioner supplies NO supporting evidence for this far reaching broad statement. The citation of "no one reported any interference, so there must not be any", and "tests conducted by amateur groups", is absolutely unacceptable. Stating something simply does not make it so. There MUST be facts determined in an organized scientific manner. This data, together with a description of the methods by which these data were determined and analysis of the these data MUST be published or otherwise be made widely available to the amateur community and others in order to lend any credence to the petitioners' statements. As stated, they must be dismissed out of hand as suppositions and opinions, things which have no place in formal proceedings. We submit that most of the statements made in this section of the Petition are simply wishful thinking and are NOT facts.

We must also point out the circular reasoning in this same paragraph. The paragraph begins with the above quoted statements and continues: "SS .. can, due to increase in-band noise, trigger carrier squelch activated repeaters." This statement means there actually IS interference to narrowband systems by SS transmissions. This makes SS "well suited" to the Amateur Service? A discussion of the audible form this interference takes is simply a waste of time. Methods of hiding the interference may make such interference less obvious, but in NO way diminishes the actual interference. Sufficient signal received by a repeater receiver to "trigger" the repeater is often exactly the minimum amount necessary to communicate through the repeater. Adding "CTCSS" to a repeater receiver to eliminate the "triggering" does NOT reduce in any way the interference received from SS transmission. Utilization of SS parameters chosen to avoid the SS transmission "landing" on the repeater receive frequency is impractical in any crowded environment. This is because there is a repeater receiver on practically every possible frequency and the SS transmission would have so few frequencies left to use as to render the SS benefit virtually nil.

Most repeater owners make significant efforts to make their system work as well as possible. Today, there are at least as many Amateur hand held radios as there are mobile radios. The signal produced by a hand held at the repeater receiver is often quite close to the system threshold. Repeater owners strive to "quiet" that signal through a number of enhancement techniques. Adding any interference is often enough to render the repeater inaccessible to the hand held radio. A hand held radio is quite often the Amateurs equipment of choice in an emergency situation. Diminishing the performance of a repeater with SS interference will be quite likely to render some emergency communications impossible.

The petitioner quotes a report by STA holder Mr. Buaas, K6KGS [6]. Nowhere in the quoted sections or the remainder of the report are there any reported data, operating parameters, technical analysis of measurements made, or the methods used to obtain those (apparently non-existent) measurements. The report is entirely without supporting facts, and so must be dismissed as inadequate and incomplete. The report appears to actually have been intended as an interim statement of progress in testing and a request for an extension of the STA (which the commission apparently granted). Even as an interim report, this document is totally lacking in supporting data. Mr. Buaas may have actually made measurements and actually have developed some trial methods of spectrum sharing with "narrowband emitters", but without DATA to support his statements, we will never know.

The petitioner and Mr. Buaas claim [7] that the existing Rules governing Amateur SS emissions are excessively restrictive, but neither party states HOW the rules are restrictive. SCRRBA does not believe that SS experimenters should be given a "free hand" to do whatever they want without some specific explanation of what they intend and some specific DATA on what they have done to date.

Analysis of proposed rule changes:

[8] 97.305(b) add "or SS" to test transmissions. This seems unnecessary, but does not propose any actual change. SS emissions are a listed emission type and as such are already an "allowed" emission subject to the rules.

[9] 97.311(a) Proposed change is to allow international communications using SS emissions. This proposal is premature as the Petitioner has not made a technical case for the rest of the petition.

[10] 97.311(b) The proposal is to delete the last sentence of the section. The Petitioner misses the point here as well. Lack of meaningful data has caused another erroneous conclusion. The presence of sufficient signal from an SS transmission to "trigger" the repeater demonstrates that the repeaters noise floor has increased, thereby reducing its ability to hear a weak signal. We show at paragraph xx, supra, that hand held radio transmissions are the most likely to be used in an emergency, and are the most susceptible to interference.

Removing the protection provided to other authorized emissions requires that protection with a meaningful substitute. We propose that this section be amended in its entirety rather than partially:

    97.311(b): Stations transmitting SS emissions must not cause [begin strike out]harmful[end strike out] interference to stations employing other authorized emission, and must accept all interference caused by station employing other authorized emissions, unless the SS station is utilizing a frequency and bandwidth recommended by a local frequency coordinator, in which case the two station licensees are equally and fully responsible for resolving the interference. [begin strike out]For the purpose of this paragraph, unintended triggering of carrier operated repeaters is not considered to be harmful interference.[end strike out]

[11] 97.311( C)&(d). The proposal to delete these sections is out of order. The petitioner has totally failed to support its petition in any substantive way. However reasonable this request may seem, it needs to be analyzed carefully and a decision be based upon facts, preferably data supplied by the petitioner. Absent such data, deleting restrictions based just upon the statement that "present rules are not optimal for sharing" [12] cannot be supported.

[13] 97.311(G) The petitioner proposes to saddle the Amateur SS operations with an artificial method of controlling power. This concept is foreign to the Amateur rules, but, appears to be a reasonable concept, with one serious flaw in its reasoning. The presumption that controlling the power of an SS emission automatically (or any other way, for that matter) will significantly minimize interference is flawed. In most cases in the Southern California region, a transmission from almost any point in the region is easily receivable at most of the elevated locations where conventional relay stations are located. If the signal produced by an SS transmitter running 100 watts arrives at these receivers at an audible level, reducing the power by 10 or even 20 dB will only change the magnitude of the interference, not eliminate it. From most locations on the valley floor the path loss to some of these elevated locations is low enough where signal generator power levels (10-50 milliwatts) are quite audible. We visualize a normal state where two SS stations are sending data to each other across the valley floor. This example condition might have normal propagation path losses so that 1 watt is sufficient. When the typical weather inversion sets in, the path loss will vary from where 10 milliwatts might be sufficient (a rarity) to where 100 W is less than sufficient (more often the rule than the exception). It must be noted that this method of controlling power implies that the SS transmitter will run maximum power during the time necessary to establish communications and evaluate the digital performance of the path (not its signal strength).

There are two items which must be added to the proposed rules as a result of this proposal: One: Add to section 97.119(b)(5) That any SS transmitter whose power is automatically controlled must give its identification on the specified frequency at its maximum power to facilitate identification. Two: That the output power of an SS station be measured by the peak power method. The proposed section 97.311(g) would then read, in part:

    97.311(g) The transmitter output power must not exceed 100 Watts PEP under any conditions. If more than one Watt PEP is used, automatic transmitter power control shall limit the peak output power to that which is required to maintain the communication. (Section continues as proposed).

Section 97.119(b)(5) would then also be modified as follows:

97.119(b)(5) By a CW or phone emission during the SS transmission on a narrow bandwidth frequency which is either one recommended by the local amateur frequency coordinator, or, absent such a coordinator, is in conformance with the established amateur band utilization plan for the local area. If the SS transmitter utilizes automatic power control, the identification shall be transmitted at the maximum power the transmitter is normally capable of generating. [begin strike out] Alternatively, by changing one of more of the parameters of the emission so that a conventional CW or phone emission receiver can be used to determine the station call sign.[end strike out]

Conclusions:

The most serious flaw in the proposed rule changes is the attempt to place SS emissions "above" the emissions of other amateurs who are already operating within the same spectrum. This CANNOT be allowed to occur. Amateurs operating with SS emissions must have no more and no less privilege to operate than Amateurs operating with any other emissions. The Amateur community has a long history of recognizing this equal privilege. Amateur band planning and frequency coordination efforts around the nation attest to this fact.

SCRRBA is not opposed to Amateur SS emissions. We support the development of new and improved technologies. We support the development of more effective spectrum utilization methods. We do not and can not support any new uses or methods which jeopardize existing uses. Incumbent upon this position is the requirement for Amateur band planning efforts to be sufficiently forward minded to work out ways for new methods and uses to be accommodated.

The ARRL "jumped the gun" in this area, albeit incompletely. The band utilization structure, a band plan, is generated at the local level as described above. It is NOT generated at the national level, petitioned into the regulations and THEN handed to the local regions of the country.

SCRRBA submits that this petition is defective and incomplete and should be summarily dismissed. We have provided discussion and information on several areas inadequately or incorrectly covered by the petition. Should the Commission choose to act on this petition, we have provided suggestions for corrections to the proposed rule changes to make them more complete and accurate.

Respectfully submitted
For the SCRRBA Board and Technical Committee

M. Robin Critchell Board Member


[1] Please see any issue of the ARRL Repeater Directory. This Directory lists the recognized frequency coordinators throughout the nation. Please also note that this directory lists ONLY activity suitable for "itinerant" mobile use and a such is NOT a suitable list of ALL the activity occurring within an amateur band.

[2] The FCC Rules do define SS emissions. The applicable sections of part 97 do not provide an adequate basis for this petition. The petitioner should have provided the definition as part of the basis for the petition.

[3] 150 kHz is used as an example because it matches the IF bandwidth of most commercial broadcast FM receivers. These receiver IFs could very easily and inexpensively utilized to receive the SS transmission described.

[4] Instant Petition at 2

[5] Instant petition at 5 (section II, #4)

[6] Petition at 9, 10, 11. Letter in question is one page long and addressed to Mr. Haller, and dated March 31, 1993.

[7] Petition at 12, Buass letter at 4

[8] Petition at 13, Section III, Proposed Rule Changes, labeled 7, and appendix

[9] Petition at 14, Section III, labeled 8, and appendix

[10] Petition at 15, Section III, labeled 9, and appendix

[11] Petition at 16, Section III, labeled 10, and appendix

[12] The statements by the petitioner and Mr. Buaas are actually asking for the freedom to use whatever scheme they can think of without being subject to any regulatory restrictions or guidelines. In light of their total lack of technical support for their position, we cannot support this change.

[13] Petition at 17, labeled 11, and appendix

 


Comments of the SouthEastern Repeater Association, Inc.

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

2-23-96

In the Matter of               )
                               )
Amendment of Part 97 of the    )
Commission's Rules Governing   )    RM-8737
the Amateur Radio Service to   )
Facilitate Spread Spectrum     )
Combinations                   )
To: The Commission

-------------------------------------
STATEMENTS IN OPPOSITION
-------------------------------------

SouthEastern Repeater Association, Inc.

David L. Shiplett, AC4MU
President
P.O. Box 215
Tobaccoville, NC 27050
(912) 987-3000

These comments of opposition come from the SouthEastern Repeater Association, Inc., a legal non-profit corporation, incorporated in North Carolina, and representing Amateur Radio VHF and UHF coordination interests in the eight States of North Carolina, South Carolina, Virginia, Tennessee, West Virginia, Kentucky, Georgia, and Mississippi.

The SouthEastern Repeater Association, Inc., hereafter known as SERA, is the nation's largest independent Amateur Radio VHF/UHF Repeater Coordinator, and is staffed with the finest of radio amateurs and volunteer communications professionals who are responsibly concerned with effective regional and national spectrum management as they impact the Amateur Radio Service.

We make this statement of opposition on behalf of our membership, within the Amateur Radio Service (ARS), for their protection from the petitioner's most frivolous and deleterious filing to date, to protect existing and future narrowband ARS systems and networks from serious compromise.

Should the Commission's rules on spread-spectrum (SS) be flexible? It is our contention that they should not. The rules, as they are, and have existed since 1985, are already too loose and flexible. Though SS systems are fully capable of causing harmful interference with the rules as they exist today, they have served to have a positive chilling effect on the implementation of such interfering systems.

The petition, concerned with spectrum above 225 MHz, if adopted, will have a chaotic impact on the extremely popular 70 cm band (420-450 MHz). The 70 cm band, though shared, is rapidly filling with users of all existing modes. These modes include traditional weak signal terrestrial transmission (CW, SSB, etc.), amateur satellite uplinks and downlinks, amateur fast-scan television, packet radio and other relatively narrowband digital modes, FM repeaters, auxiliary stations, and voice simplex operations. The proponents of each of these modes are currently vying for dedicated slices of the 70 cm band, and none of these modes are compatible with the wideband noise typical of SS.

The key to Amateur Radio's effectiveness as a public service communications tool has been it's ability to communicate under adverse propagation conditions using various innovative techniques, and being equipped with the most modest radio transmission equipment and power systems. In practical terms this translates to, using low power and weak signals to get critical message traffic delivered.

Would there be intra-service interference? Yes! While the existing rules have already been perverted, since 1985, to allow insertion of text at 97.311(b) to state, "unintended triggering of carrier operated repeaters is not considered to be harmful interference," SS signals of sufficient strength to accomplish this effect would degrade communication channels to the detriment of these systems, and seriously degrade or obliterate weak narrowband signals typical of emergency communications.

Would there be inter-service intereference? Yes, there is the potential for this to occur, as SS emissions are currently authorized in shared spectrum allocations.

Would there be monitoring difficulties and illicit use of SS emissions? The answer, quite obviously, is yes. The mode, developed for use by the military and State Department, was not intended as a tool for spectrum conservation, but primarily to facilitate secure transmission. With the virtually unlimited number of encoding combinations that would be allowed by these proposed rule changes, it would be exceedingly difficult to decode content for common monitoring or enforcement purposes. This would make the mode very appealing to undesirable or criminal elements, as powerful equipment capable of operating in ARS spectrum would become readily available. Further, even though the petition references "brief test transmissions of SS emissions," we believe such brief transmissions have the potential to become frequent to the point of being routine. Therefore, we believe the ARS would become a target for commercial or unlicensed encroachment.

The petitioner's pro-SS arguments in this matter only address technical and experimental concerns, and do not seriously consider the ill effects of the co-spectrum use of SS and existing narrowband systems in already crowded spectrum.

The petitioner has failed to weigh the impact of its proposal on practical narrowband modes in aspects relating to vital emergency public service operations.

The petitioner has assumed that the sole purpose of the ARS is for experimentation, and has petitioned for rule changes that will result in harmful interference, while subjecting other authorized spectrum users to unwitting use as guinea pigs in experiments of dubious value.

Considering the forgoing facts, it is our request that the Commission reject the petition (RM-8737), and that the matter not be reconsidered until satisfactory spectrum can be located above 902 MHz for SS experimentation without detrimental impact to existing narrowband usage.

Respectfully Submitted,

SouthEastern Repeater Association, Inc.
David L. Shiplett, AC4MU
President
P.O. Box 215
Tobaccoville, NC 27050
(912) 987-3000


TAPR's comments to RM-8737 Feb 26th, 1996

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM-8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission


COMMENTS OF TUCSON AMATEUR PACKET RADIO CORPORATION
                                       Tucson Amateur Packet Radio Corporation
                                       8987-309 E Tanque Verde Rd #337
                                       Tucson, Arizona  85749-9399
                                       (940) 383-0000

                                             

February 26, 1996


The Tucson Amateur Packet Radio Corporation ("TAPR") submits these comments in response to the above-referenced petition for rule making (the "Petition") filed by the American Radio Relay League, Incorporated ("ARRL").

BACKGROUND AND STATEMENT OF INTEREST

TAPR is a non-profit (501(c)(3)) scientific and educational organization with more than 2,500 members worldwide. It is chartered to engage in three principal activities: scientific testing and research into the development and improvement of technological systems for use in the amateur radio service including, but not limited to, digital packet radio communications; research and testing of systems, hardware, and software for packet radio local area networks and computer network systems; and disseminating to the public the information obtained as a result of such research and testing.

TAPR was founded in 1982 as a national organization with interests in the areas of packet and digital communications. It grew out of a 1981 effort to design a packet radio Terminal Node Controller, or "TNC," that would be available to amateurs at a modest cost. From these initial designs emerged what is now the de facto standard in amateur and many commercial packet radio operations.

Today, TAPR continues as an international, membership-supported research and development organization for the amateur radio community. TAPR continues to develop new communications technology, provide kits for the amateur community, and promote the advancement of the amateur art through publications, meetings, and communications standards. TAPR also maintains a web site (http://www.tapr.org), which includes a page specifically addressing current amateur spread spectrum issues (http://www.tapr.org/ss).

DISCUSSION

TAPR generally supports the recommendations made by the ARRL in its Petition. Spread Spectrum ("SS") technology has not made great advances in the amateur radio service since it was first permitted in 1985, in part due to the fact that, by today's standards, the Part 97 regulations on amateur spread spectrum are extremely restrictive. In particular, the small number of fixed spreading codes permitted under Section 97.311(d)(1) inhibits the use and development of SS by amateur radio stations. TAPR believes that it is in the public interest, and in the interest of the amateur radio service, to change the rules for SS in order to accelerate the adoption of SS by the general amateur community.

TAPR also supports many of the specific recommendations made by the ARRL.

First, TAPR supports the ARRL's request to modify Part 97.311(b) as it pertains to the unintentional triggering of repeater inputs. This section is redundant with other parts of the Commission's rules and, therefore, is unnecessary.

Second, TAPR supports the ARRL's request to delete sections 97.311(c) and (d), in order to permit SS emissions and spreading codes that are not currently authorized. Elimination of the rule that dictates specific spreading codes is necessary to facilitate further experimentation and to match the provisions allowed under an existing amateur service SS STA, discussed below. In addition, it would facilitate the use and adoption by amateur radio operators of Part 15 SS equipment and hardware.

Third, TAPR supports the ARRL's proposed change to 97.311(g), which would provide for automatic transmitter power control to limit the output power of an SS station to that which is required for communication, when more than one watt of output power is used. TAPR, however, differs with the ARRL as to just how simple this requirement would be to implement technically. While TAPR agrees that technically it is simple to control the output power of a transmitter, it is quite another matter to make this control automatic and foolproof. If the Commission decides to proceed with this particular change to the rules, it should phase the change in over some reasonable period of time, in order to give the amateur community the opportunity to develop and deploy SS equipment that properly can meet this requirement.

While, as noted above, TAPR agrees with many of the ARRL's recommendations, it disagrees with a few of the proposals contained in the Petition.

In particular, TAPR differs with the ARRL with respect to the question of which frequencies should be authorized for SS emissions. In the Petition, the ARRL proposes that brief test transmissions of SS emissions be permitted only on those frequency bands in which SS emissions currently are authorized. TAPR believes that SS emissions should be allowed on all frequency bands covered by the SS STA currently held by Mr. Robert Buaas K6KGS (6m and 2m, in addition to the frequency bands currently authorized by Part 97). In addition, the Commission should allow SS emissions in the 219-210 MHz band, which was authorized for use by the amateur radio service after the Buaas SS STA was originally granted in 1992. Finally, the Commission should not impose any restriction on the length of time SS emissions are transmitted. Ample time already has been provided for the experimental phase of SS usage in the amateur service (five years of experimentation under the 1980 AMRAD STA and ten years under the current Part 97 rules), and it is now time to allow SS use without restriction.

TAPR also differs with the ARRL as to how station identification and documentation should be handled under a revised set of rules. The ARRL in its petition did not ask the Commission to delete sections 97.311(e) and 97.119(b)(5) of the rules, even though it questioned the practicality of the requirements set forth in these sections. TAPR, in contrast, recommends that the Commission delete these subsections of the rules. The interference and harm to the band in which an SS station is operating that would be caused by a requirement to use a CW identification outweighs the benefits that would accrue for monitoring purposes from the use of the ID.

As a result, the amateur radio community should be permitted to develop an approach for handling the necessary functions of monitoring and identification. TAPR already is working on possible resolutions to this problem and in the near future will be in a position to make a proposal to the Commission on this matter.

CONCLUSION

SS technology can provide many useful benefits to the amateur radio community if its use becomes more widespread and mainstream. In order to accomplish this, however, certain changes must be made to the Commission's rules governing the use of SS in the amateur radio service. By making these changes, the Commission will create a regulatory environment that will give members of the amateur radio service enough flexibility to develop innovative equipment and hardware employing SS technology.

For these reasons, TAPR urges the Commission promptly to issue a notice of proposed rule making to facilitate spread spectrum communications in the amateur radio service, as proposed in the Petition and as modified herein.

                              Respectfully submitted,

                              THE TUCSON AMATEUR PACKET RADIO CORPORATION

8987-309 E Tanque Verde Rd #337
Tucson, Arizona  85749-9399
(940) 383-0000

                               By: Dewayne Hendricks




February 26, l996


National Communications System, comments to RM-8737 Feb 26th, 1996

Before The
Federal Communications Commission Washington, DC 20554

In The Matter Of:

Amendment of Part 97 of the         )   RM-8737
Commission's Rules Governing        )
the Amateur Radio Service to        )
Facilitate Spread Spectrum          )
Communications                      )

February 26, 1996

To The Commission:


COMMENTS OF THE MANAGER OF THE NATIONAL COMMUNICATIONS SYSTEM

The Secretary of Defense, Executive Agent of the National Communications System (NCS) [1], through duly authorized counsel, pursuant to Section 201 of the Federal Property and Administrative Services Act of 1949, 40 U.S.C. 481, and the Memorandum of Understanding between the General Services Administration dated November 27, 1950, hereby files these comments in response to the Petition for Rulemaking filed by the American Radio Relay League, Inc. (the "League") on December 12, 1995. The League has proposed amendments to Commission Rules and Regulations to facilitate, to a greater extent than is done by the present rules, the contributions of the Amateur Service to the development of spread-spectrum communications. In its Petition, the League recites the development of the Commission's policy allowing the Amateur Service to utilize spread-spectrum technology but believes that lack of flexibility in the existing Commission Rules have not permitted such use to develop to its highest potential. According to the League:

"The experiences of amateurs pursuant to these past Special Temporary Authorities indicate that the present rules include certain significant limiting factors which could be liberalized without detracting at all from other narrow-band amateur communications" [2]

The specific rule changes proposed by the League are set forth in the Appendix to the Petition and the rationale for their adoption is contained in the Petition itself. The proposed changes would ( I ) permit brief test transmissions using spread-spectrum emissions; (2) permit international spread-spectrum communications between United States' amateurs and amateurs in countries that permit amateur use of those emissions; (3) delete unnecessary restrictions on spreading codes and repetitive definitions of"harmful interference"; and (4) provide for automatic power control to insure use of minimum necessary power to conduct spread-spectrum communications.

The Secretary of Defense, for the Department of Defense and in his capacity as Executive Agent of the NCS, has historically filed comments in Commission proceedings in support of the activities of amateur radio licensees [3]. The comments typically recite the value of amateur radio operators as a resource to be utilized by the NCS in carrying out is National Security and Emergency Preparedness (NS/EP) responsibilities. They also cite the June 2, 1983 Memorandum of Understanding between the NCS and the League, which established a broad framework of cooperation and a close working relationship with amateur operators for national emergency communications functions.

As stated on page I of the Petition, "The purpose of the proposed rule changes is to facilitate, to a greater extent than is done by the present rules, the contributions of the Amateur Service to the development of spread-spectrum communications." The Manager has examined the proposed rule changes and agrees that they will produce the intended effect.

The Manager notes that while the League questions the practicality of Section 97.119(b)(5) of the Rules (which contains the CW identification requirement for spread-spectrum communications), it does not propose a modification thereto. (Petition, footnote 7.) The Manager proposes that the requirements be deleted. To the best of the knowledge of the Manager, no currently available Commercial Off the Shelf (COTS) SPREAD-SPECTRUM equipment complies with the rule. Deletion of the requirement will likely lead to increasingly available COTS equipment for amateur use of spread-spectrum technology and concurrent increased usage.

CONCLUSION

The Manager supports the changes proposed by the League and in addition, suggests the deletion of Section 97.119(b)(5)of the Commission's rules.

                          Respectfully submitted,




                          Paul R Schwedler
                          Deputy Chief Regulatory Counsel
                          
                          
                          Carl Wayne Smith
                          Chief Regulatory Counsel
                          Telecommunications, DOD
                          Code RGC
                          Defense Information Systems Agency
                          

Footnotes

    1. Executive Order No. 12472, "Assignment of National Security and Emergency Preparedness Telecommunications functions," April 3, 1984 (49 Fed. Reg. 13471, 1984), established the National Communications System, which consists of an administrative structure involving the Executive Agent, Committee of Principals, Manager and the telecommunications assets of the federal organizations which are represented on the Committee of Principals. Section 1 (e) of EO 12472 designates the Secretary of Defense as Executive Agency for the NCS. By direction of the Executive Office of the President (EOP), the NCS member organizations (which are represented on the Committee of Principals) are; Department of Agriculture, Central Intelligence Agency, Department of Commerce, Department of Defense, Department of Energy, Federal Emergency Management Agency, General Services Administration, Department of Justice, National Aeronautics and Space Administration, the Joint Staff, Department of State, Department of Transportation, Department of the Treasury, U.S. Information Agency, the Department of Veterans Affairs, Department of Health and Human Services, Department of the Interior, National Security Agency, the National Telecommunications and Information Administration and the Nuclear Regulatory Commission. The Federal Communications Commission, the United States Postal Service and Federal Reserve Board also participate in the activities of the NCS. The vast majority of the telecommunications assets of these 23 organizations are leased from commercial communications carriers and serve the NS/EP needs of the Federal government as well as state and local governments.


    2. Petition, paragraph 6


    3. See, for example, Manager's Cornrnents in Docket 87-14 and in RM-7747.


Comments by George Isely, WD9GIG

In the Matter of                )
                                ) 
Amendment of Part 97 of the     )
Commission's Rules Governing    )   RM-8737
the Amateur Radio Service to    )
Facilitate Spread Spectrum      )
Communications                  )

To: The Commission

STATEMENT IN OPPOSITION

I am an advanced-class amateur radio operator and am currently serving as President of the Mid-America Coordination Council, Incorporated (MACC), the largest consortium of recognized volunteer state and regional Amateur Radio Frequency Coordination entities in the United States.

While the Petitioner, the American Radio Relay League (ARRL), represents itself as being 'the' national association of amateur radio operators in the United States, it should be recognized that they are not the only one and that their interests do not necessarily represent all of the amateurs when their membership is actually less than 30% of the entire licensed amateur population. In this particular filing they do not even represent a majority of the members they do claim nor did they solicit input from their general membership before making this Proposal. I am a life-member of the ARRL, and support most of their positions. However, as the MACC President I can not support RM-8737, nor can I support it as an individual amateur radio license holder.

The Proposal dismisses 'harmful interference' as an inconvenience. It is my understanding that marginal signal access to a narrow band FM repeater for would be reduced when Spread Spectrum (SS) noise has further degraded this signal to an unusable degree. The ARRL sought to further erode the integrity of repeaters by earlier appendation of 97.311(b)'s "[U]nintended triggering of carrier operated repeaters is not considered to be harmful interference"

The ARRL asserts that "There have not been, in the League's experience, any established instances of actual interference to narrow-band amateur communications from SS (spread spectrum) communications." This is not true. In their own publication, 1988 ARRL Handbook, page 21-14 they admit "The SS signals were inaudible to amateurs in QSO, but the signals did cause some interference by keying certain repeaters that did not have a receiver carrier sense activation delay."

The further incompatibility of this mode, among narrow band users, is discussed in Spread Spectrum Techniques, Robert C. Dixon, 1976 IEEE Press, page 15, whereas:

    "(I)t has been suggested that more efficient use of the available spectrum might be made by assigning both narrow-band and wide-band users the same frequencies for concurrent use. Under the right conditions, such concurrent use would be quite practical. The burden of achieving practicality would necessarily fall on the spread spectrum users, however, because of the fact that most of the frequency spectrum is already filled with narrow-band users who got there first, and the cost of modifying the present narrow-band sets would be astronomical."

The preceding quote was written twenty years ago. Since then, overall spectrum usage, including amateur use, has since increased narrow-band activity tenfold. The operations of thousands of 70 cm repeaters alone could be compromised, as well as considerable satellite, weak-signal and packet activities. RM-8737 would not impose any requirement on SS users to pay these modification costs.

The League's proposal makes reference to reports from a STA holder, Robert Buass, K6KGS. MACC Frequency Coordination Chairman, and professional communications consultant, Whit Brown, WB0CJX, attended an ARRL-sponsored spread spectrum forum in Long Beach, CA, on September 3, 1995, that also heard reports presented by Mr. Buass. His observations follow:

1. For mathematical convenience two meter 'frequency hopping' tests were set up on 25 kHz increments, even though it was known that the area band plan adhered to 15/20 kHz channel separations.

2. This 'off frequency' testing was done on the repeater outputs rather than on the inputs, hardly representative of 'testing' that would display meaningful results in the RF environment of interest.

3. There was no notification to the general weak-signal, satellite or repeater community of when these tests were to be performed. It was stated that operators could have called them or the coordinator if they experienced any interference from this 'testing', yet did not publicize the event/s or inform coordinators, some of whom were in attendance, or any regional coordinator of such operation in progress . . . how would they have even known these tests were going on, must less try to identify the source of any resulting interference?

4. When asked if it was tried on a repeater input, the answer was in the affirmative, but declined to say which one or with whom, when asked.

5. During concerns raised by one representing hundreds of weak-signal operators, the Chair was willing to offer protection to their part of the band, but balked at offering the same protection to the other coordinated users. If this mode is so transparent, why would this protection even be necessary?

While the STA holder was certainly enthusiastic and knowledgeable in the CDMA subject, the test results were seriously flawed and bore little resemblance to an unbiased evaluation and presentation.

As for the technology itself, I offer further observations from the standpoint of our MACC frequency coordinators. Spread Spectrum has been presented by some as being a "transparent panacea" for the problem of continued spectrum crowding. "Transparent" in that existing users of the band will be unaware of its encroachment. "Panacea" in that it will accommodate virtually unlimited QSO's while coexisting unobtrusively among the many users of various modes.

Real-world experience with this mode tells a different story - as again told by Wit Brown. Mr. Brown was recently involved with an engineering evaluation of the 'direct sequence' type of spread spectrum transceivers, operating within the license-free Part 15, 902-928 MHz spectrum. While evaluating a commercial unit, an IFR spectrum analyzer revealed about 15 MHz of sine waves spaced about 16 kHz apart, more than 900 of them, with the voice envelope superimposed on each one. When modulated with a Firebird digital bit-error-rate instrument, the valleys in the above sine waves increased to the level of the peaks and complete saturation resulted with an attendant increase in the 'noise-floor' of the 15 MHz of occupied spectrum.

This deliberately introduced noise envelope in the spectrum is well illustrated in pro-Spread Spectrum articles in the May '89 issue of QST and the June '89 issue of 73 Magazine. The author presents spectral displays wherein the resultant 'hump' in the noise floor is (only) 10 dB above the spectrum threshold. This 'hump' begins at 442 MHz and extends to 450 MHz! The article continues with 'lock' being maintained at over a mile with a quarter-wave antenna and only 390 milliwatts of power. The changes inherent when coupled with typical gain antennas combined with power levels amateurs are legally capable of is potentially disasterous for narrow band users. Just the power increase from 390 milliwatts to the legal SS limit of 100 watts is about 24 dB, add to that a typical antenna gain of three to 12 dB and a potentially serious compromise of existing systems and operations would seem most evident. The cumulative effect of multiple users would further increase the noise floor and interference potential.

The Spread Spectrum use being proposed in RM-8737, would not be a spectrum efficient means of communication. In fact it would alter the operational characteristics of thousands of existing coordinated FM repeaters and other relay systems. The cumulative effect of increased SS noise on the 420-450 MHz band would render carrier-accessed repeaters inoperable by having to continually tighten the squelch to overcome the keying caused by the increase in the noise floor. The introduction of CTCSS would only mask the problem, minimize nuisance keying, and give the operator one more access method to remember. Unknowing transient operators might be denied access completely. Weak-signal and satellite interests would be affected as well. Just because direct sequence SS may exceed the bandwidth of typical narrow band users' equipment, does not mean the RF amplifying stages within the rig doesn't know it's there. It just means that the recovered signal must be that much stronger, to be recovered within the increased noise threshold created by Spread Spectrum wide band emissions.

The military, State Department, and CIA do not utilize SS emissions in an effort to enhance spectral management and efficiency. Its primary purpose, development and implementation is to mask the source and content of enciphered communiques for security-oriented agencies and organizations.

I am not opposed to the use of Spread Spectrum. But I do oppose the imposition of ultra wide-band modes into frequency bands that would compromise the operations of hundreds of thousands of existing users in the name of progress alone. If this mode is to be accommodated within any VHF and higher Amateur Radio Service frequency band allocation, I ask that it be confined to the 902-928 MHz spectrum, where it can coexist with other SS users. Our frequency coordinators make every effort to accommodate the delicate proportional balance between the interests of the vast majority of narrow band FM operators and those of the lesser-used modes. Compromising the interests of 99% of the bands' users to accommodate the 1% special interests is both unrealistic and grossly inconsiderate.

The safeguards defined within 97.311(c) and (d), that RM-8737 seeks to delete, are as necessary today as when they were originally implemented. With these controls in place, there is at least an opportunity to ascertain the source of any interference. With the virtually unlimited encoding schemes now being proposed this will be nearly impossible with the resources readily available to current users in the affected bands.

I am also very concerned about the attractiveness of this mode to the criminal element in our society. If RM-8737 is adopted, this ostensible 'progress' would severely degrade the usefulness to most of the users of this band. This technology is available to this criminal element now on other bands, we don't need to introduce and encourage their use of it on our 70 cm band.

Lastly, in view of the federal government's on-going effort to restrict the use of advanced encryption technology by legitimate users, I see no reason to spread its' use to the Amateur Radio Service via Spread Spectrum.

Therefore, I respectfully request that the Commission DENY RM-8737 . . . a Proposal wherein only the equipment vendors would benefit.

Respectfully submitted,

George R. Isely, WD9GIG
President
Mid-America Coordination Council, Inc.

736 Fellows Street
St. Charles, IL 60174-3835

 


Comments by Witt Brown, WB0CJX

MID-AMERICA COORDINATION COUNCIL, INC.
FREQUENCY COORDINATION CHAIRMAN
Witt Brown, WB0CJX
14418 W. Ellsworth Place
Golden, CO 80401-5324
303-278-2580
E-mail: whitbrown@aol.com

In the Matter of                )
                                )
Amendment of Part 97 of the     )
Commission's Rules Governing    )   RM-8737
the Amateur Radio Service to    )
Facilitate Spread Spectrum      )
(S/S) Communications            )

To: The Commission

STATEMENTS IN OPPOSITION

Commenter is an extra-class amateur radio operator and is in third, two-year term as Frequency Coordination Chairman of the Mid-America Coordination Council, Incorporated (MACC), the largest consortium of recognized volunteer state and regional Coordination entities in the United States.

While the Petitioner (the League) represents itself as being the' national association of amateur radio operators in the United States, it should be recognized that they are not the only one or that their interests do not necessarily represent all of the amateurs when their membership is actually less than 30% of the entire licensed amateur population. In this particular filing they do not even represent a majority of the members they do claim, nor did they solicit input from their general membership before initiating this in-house Proposal. While Commenter is a 24-year member of the League, and generally supportive of their positions, their special-interest-serving Proposal is not shared in this instance.

The Proposal selfishly diminishes' harmful interference' as an inconvenience. Be respectfully advised that a marginal signal trying to access a repeater for emergency purposes would probably disagree when the deliberately introduced S/S noise has further degraded his signal to an unusable degree. The League previously sought to further erode the integrity of repeaters by earlier appendation of 97.311(b)'s "[U]nintended triggering of carrier operated repeaters is not considered to be harmful interference"

The League asserts that "There have not been, in the League's experience, any established instances of actual interference to narrow-band amateur communications from SS (spread spectrum) communications." This is untrue. In their own publication, 1988 ARRL Handbook, page 21-14 they admit "The SS signals were inaudible to amateurs in QSO, but the signals did cause some interference by keying certain repeaters that did not have a receiver carrier sense activation delay."

The further incompatibility of this mode, among narrow band users, is discussed in Spread Spectrum Techniques, by Robert C. Dixon, 1976 IEEE Press, page 15, whereas:

    "(I)t has been suggested that more efficient use of the available spectrum might be made by assigning both narrow-band and wide-band users the same frequencies for concurrent use. Under the right conditions, such concurrent use would be quite practical. The burden of achieving practicality would necessarily fall on the spread spectrum users, however, because of the fact that most of the frequency spectrum is already filled with narrow-band users who got there first, and the cost of modifying the present narrow-band sets would be astronomical."

The preceding exerpt was written twenty years ago. The Commission's good offices do not need to be reminded that overall spectrum usage, including amateur use, has since increased narrow-band activity tenfold within those two decades. The operations of thousands of 70 cm repeaters alone could be compromised, as well as considerable satellite, weak-signal and packet activities. The above source recently disclosed to the League's Rocky Mountain Division Director, Marshall Quiat, AG0X, that spread spectrum could indeed interfere with existing narrow-band operations.

The League's proposal makes reference to reports from an STA holder, Robert Buass, K6KGS. This Commenter attended a League-sponsored spread spectrum forum in Long Beach, CA, on September 3, 1995, that also heard reports presented by Mr. Buass. Some observations of which follow:

1. For mathematical convenience two meter frequency hopping' tests were set up on 25 kHz increments, even though it was known that the area band plan adhered to 15/20 kHz channel separations.

2. This off frequency' testing was done on the repeater outputs rather than on the inputs, hardly representative of testing' that would display meaningful results in the RF environment of interest.

3. There was no notification to the general weak-signal, satellite or repeater community of when these tests were to be performed. It was stated that operators could have called them or the coordinator if they experienced any interference from this testing', yet did not publicize the event/s or inform coordinators, some of whom were in attendance, or any regional coordinator of such operation in progress . . . how would they have even known these tests were going on, must less try to identify the source of any resulting interference?

4. When asked if it was tried on a repeater input, the answer was in the affirmative, but declined to say which one or with whom, when asked.

5. During concerns raised by one representing hundreds of weak-signal operators, the Chair was willing to offer protection to their part of the band, but balked at offering the same protection to the other coordinated users. If this mode is so transparent, why would this protection even be necessary?

While the STA holder was certainly enthusiastic and knowledgeable in the CDMA subject, the test results' were seriously flawed and bore little resemblance to an unbiased evaluation and presentation.

As far as the technology itself, I would offer some further observations from a frequency coordinator's standpoint. Spread Spectrum has been presented by some as being a transparent panacea' as an answer to continued spectrum crowding. Transparent' in that existing users of the band will be unaware of its encroachment. Panacea' in that it will accommodate virtually unlimited QSO's while coexisting unobtrusively among the many users of various modes.

My experience with this mode indicates otherwise. Most recently I was vocationally involved with an engineering evaluation of the direct sequence' type of spread spectrum transceivers, operating within the license-free Part 15, 902-928 MHz spectrum. While evaluating a commercial unit, an IFR spectrum analyzer revealed about 15 MHz of sine waves spaced about 16 kHz apart, more than 900 of them, with the voice envelope superimposed on each one. When modulated with a Firebird digital bit-error-rate instrument, the valleys in the above sine waves increased to the level of the peaks and complete saturation resulted with an attendant increase in the noise-floor' of the 15 MHz of occupied spectrum.

This deliberately introduced noise' envelope in the spectrum is well illustrated in pro-Spread Spectrum articles in the May '89 issue of QST and the June '89 issue of 73 Magazine. The author presents spectral displays wherein the resultant hump' in the noise floor is "only" 10 dB above the spectrum threshold. This hump' begins at 442 MHz and extends to 450 MHz! The article continues with lock' being maintained at over a mile with a quarter-wave antenna and only 390 milliwatts of power. The changes inherent when coupled with typical gain antennas combined with power levels amateurs are legally capable of is most distressing. Just the power increase from 390 milliwatts to the legal S/S limit of 100 watts is about 24 dB, add to that a typical antenna gain of three to 12 dB and a serious compromise of existing systems and operations would seem most evident. The cumulative effect of multiple users would further increase the noise floor and interference potential.

It cannot be persuasively argued that Spread Spectrum is a mode which promotes a spectrum efficient means of communication, when in fact it could alter the operational characteristics of thousands of existing coordinated repeaters and systems. The cumulative effect of increased S/S noise' on the 420-450 MHz bands would render carrier-accessed repeaters inoperable by having to continually tighten the squelch to overcome the keying caused by the increase in the noise floor. The introduction of CTCSS would only mask the problem, minimize nuisance keying, and give the operator one more access method to remember. Unknowing transient operators might be denied access completely. Weak-signal and satellite interests would be affected as well. Just because the direct sequence S/S may exceed the bandwidth of typical narrow band users' equipment, does not mean the RF amplifying stages within the rig doesn't know it's there. It just means that the recovered signal must be that much stronger, yet, to be recovered within the increased noise threshold deliberately introduced by the S/S wide-band emissions.

The military and State Department did not utilize S/S emissions in an effort to enhance spectral management and efficiency. Its primary purpose, development and implementation was to mask the source and content of enciphered communiques for Department and other security-oriented agencies.

Lastly, let me make it clear that I am not anti-spread spectrum per se. But I AM against the insertion and utilization of ultra wide-band modes into bands that could compromise the operations of hundreds of thousands of existing users in the name of progress alone. If this Proposal's unrestricted mode must be accommodated within the bands, confine it to the applicable portions of the 902-928 MHz spectrum, where it can coexist with other S/S users. Coordinators make every effort to maintain some degree of coherence within their bands of responsibility and accommodate the delicate proportional balance between the interests of the vast majority of narrow band FM operators and those of the lesser-used modes. Compromising the interests of 99% of the bands' users to accommodate the 1% special interests is grossly inconsiderate.

The safeguards defined within 97.311(c) and (d), the Proposal seeks to delete, are as necessary today as when they were originally implemented. With these controls in place, there was at least an opportunity to ascertain the source of any interference experienced. With the virtually unlimited encoding schemes proposed this will be nearly impossible with the resources readily available to most users in the affected bands. The enciphering possibilities will be much like the thousands of encoding combinations with commonly available garage door openers.

There is also deep concern about the attractiveness of this enciphering capability to the criminal element. If this proposal is adopted, this ostensible progress' would pervade the diminishing ham bands. This technology is available to this element now on other bands, we don't need to introduce and encourage its further use in our minimal ham bands, too.

Again, I respectfully request the Commission's good offices DENY this Proposal . . . a Proposal wherein only the vendors would benefit.

Witt Brown


Comments of John Mock KD6PAG

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, DC 20554

In the Matter of                )
                                )
Amendment of Part 97 of the     )    RM - 8737
Commission's Rules Governing    )
the Amateur Radio Service to    )
Facilitate Spread Spectrum      )
Communications                  )
-----------------------------------------------------
COMMENTS ON ARRL'S REQUEST FOR RULE MAKING ON AMATEUR
SPREAD SPECTRUM COMMUNICATION
-----------------------------------------------------
                                  John Mock <KD6PAG@Alive.Com> [1]
                                  1506 Palm Avenue
                                  Richmond, CA 94805

SUMMARY and INTRODUCTION

The ARRL has proposed needed changes in Spread Spectrum operations in the Amateur Service. There may be potential problems with unrestricted use of Spread Spectrum emissions in the presently allowable amateur bands that need to be examined either before or as a part of the proposed actions. Some of the concerns are described herein and possible solutions are suggested in some cases. Requiring that Spread Spectrum emissions be subject to rules comparable to those currently applicable to repeaters and auxiliary stations, including local co-ordination, may mitigate most of these concerns.

Changing from overly restrictive rules regarding the types of SS emission transmissions to little or no restrictions raises the question of accountability in terms of message content. There may not be a good step with regard to Section 97.331( c).

COMMENTS ON THE PROPOSAL

    1. ... The Specific Benefits to the public to be gained from amateur use of spread-spectrum (SS) communications as determined by the Commission included the following: Reduced power density and concomitant reduction of interference to narrow band communication system; 2) Significant improvements in communication under conditions with poor signal-to-interference ratio; 3) Improved communication performance in selective fading and multipath environment; and 4) Ability to accommodate more communication channels functioning simultaneously in the same spectrum than is possible using frequency division multiple access exclusively. [2]

The problems mentioned in (4) are well know, at least, in urbanized area in the Amateur radio community. This would be a welcome improvement, but one that will take years to accomplish, given the amount of narrow-band equipment currently in use. The situation described in (3) is commonplace in California and is another area where improvement would be welcomed. While users of new equipment would enjoy the benefits described in (2), if the changes are not implemented carefully, non-users may suffer. This is a particularly concern for space and weak-signal operations. Given that Spread Spectrum is not widely in use by amateurs, we are not going to see improvements described in (1), but rather, the measures being proposed are to mitigate possible interference problems.

    2. Since the time SS communications were first authorized in the Amateur Service in mid-1985, there have been some experimental amateur operations using SS techniques, but its use has not been widespread. The League believes that one significant reason for this reduced level of experimentation is due to limitations in the rules governing SS communications in the Amateur Service. The revised rules in the proposed appendix are intended to provide increased flexibility in the use if this mode, to encourage amateurs to experiment and use SS communications, to develop new techniques for increased spectrum efficiency using this mode, and to improve compatibility with narrow-band modes. [3]

There seems to be agreement in the amateur community that the rules for Spread Spectrum are overly restrictive. The important consideration here is whether the changes being proposed here are the right ones for all concerned.

    4. . . . Tests conducts by amateur groups have established that certain configurations of SS operations can, due to increased in-band noise, but that potential interaction is easily avoid by selection of spread-spectrum parameters. 58 RR 2d at 329, and authorities cited therein at footnotes 4-9. There are potential interactions between SS and narrow-band modes in certain circumstances, depending on processing gain and the randomness of spread codes, however. (2) There have been no reported instances whatsoever, in the League's experience, of interference to other radio services from amateur SS communications. (3) [4]

Unfortunately, it is difficult to determine from the text of this proposal what the nature of these tests were, and whether they address the concerns of all amateurs. Footnote (2) simply says that "potential interactions are no different than those involving other modes, and does not go into what these tests were. Footnote (3) contains a reference to 58 RR 2d at 330, but that discusses possible interfere to commercial TV, not amateur operations, and footnotes cited above are apparently in another document, as the RM-8737 proposal only contains footnotes 1-7. So the proposal discusses the effects of SS emissions on repeater operation, but it does not cover other modes. Does the Commission know what the likely effects on non-voice operations are conducted using highly directional antennas, this is not necessarily the case. According to the ARRL Handbook, LEO (Low Earth Orbit) satellites are often used with non-directional ("J-pole") antennas utilizing mast-mounted pre-amplification to make up the gain difference. [5] How will they be affected by Spread Spectrum operations, both in adjacent sub-bands, and within the same band?

If the purpose of the request for rule making is to allow the kinds of tests necessary to obtain this data, then the Commission should give serious consideration whether a rule making is the appropriate tool here. Would Special Temporary Authorities (STA) be the better way to conduct this testing? If the purpose is also to bring amateur Spread Spectrum rules up that provided by current technology, then perhaps the Commission should take a closer look how to provide suitable protection for existing users first.

    It is the League's belief, and apparently that of Commission staff as well, that experimentation in the Amateur Service, and particularly further SS experimentation, should be accommodated by increased flexibility in the rules, and not by reliance on STAs. [6]

Special Temporary Authorities are not intended to routine operations, which is what seems to be evolving in Spread Spectrum. The STA in question was obtained originally to provide a test bed for CDMA, apparently for possible satellite operations, [7] and has been extended indefinitely, to other tests as well, in part, due to the inflexibility in the existing rules. [8] It is time to look at some of those limitations and see which ones are necessarily and appropriate, and which are holding back advances in the Amateur Service and elsewhere.

    The league agrees that it is useful to relax somewhat the rules contained in Sections 97.305(b) and 97.311 governing amateur SS operation, to permit greater operating flexibility and the development of SS communications as a practical communications mode in the Amateur Service without adverse interaction with other modes. [9]

The important phase here is "without adverse interaction with other modes". We need to have rules that will facilitate this. We also need to look at how Spread Spectrum operations affect other modes. For example, the human ear is very forgiving when it comes to noise, but how does it affect ATV? Moderate-speed digital communications, in the absence of error correcting coding, are not tolerant of noise, nor does the wide range of amateur implementations of these protocols handle retransmissions well, in part because of inter-operability problems. A more serious concern about raising the noise floor", which is the purported effect of Spread Spectrum, is to weak signal and space communications. There, it may be more than just an esthetic consideration, as it is likely to be in the repeater sub-bands. Those are sub-bands that we make efforts to keep quiet, so an increase in noise that might go unnoticed in the repeater sub-bands could be problem here. We could seriously degrade our ability to communicate effectively in areas where amateurs have been doing significant work.

So, to avoid adverse interactions, we need to know what these interactions are, and where Spread Spectrum operation is appropriate. Presumably, that is the intent of this Petition for Rule Making, that is, to extend the rules somewhat, so that we can find out how Spread Spectrum should be regulated. Although it may not be necessary or appropriate to state so in Part 97, per se, it should be clear from the process that this is an interim step to ascertain where Spread Spectrum should fit into the Amateur Service and that is not intended to be a final rule making.

    ... There have not been, in the League's experience, any established instances of actual interference to narrow-band amateur communications from SS communications. Tests conducted by amateur groups have established . . . [10]

This has been a problem in the 900 MHz band in the North [S.F.] Bay area from amateur Spread Spectrum devices but with Part 15 devices. Glenn Elmore (N6GN), who is noted for his 2 Megabit/sec 10 GHz transceiver design, has been attempting to construct a high-speed IP/TCP network. His current design operates FSK in the 900 MHz band, and apparently one of his major problems has been with higher power Part 15 devices either at the same radio site, or aim at that site from other parts of the Bay Area. [11]

    7. The first change proposed by the League is to permit brief test transmissions of SS emissions, as is permitted in Section 97.305(b) for other types of emissions, except that test transmissions using SS emissions would be limited to these frequency bands where SS emissions are authorized generally, as is the case with pulse modulation transmissions. [12]

Unfortunately, this does not address the issue of band planning. There is nothing here to protect space or weak signal operations. There are already provisions in Part 97 to restrict operation of repeaters [Section 97.205(b)] and auxiliary stations [Section 97.201(b)] in these sub-bands. For example, neither is permitted to operate in the beacon sub-bands [as described in Section 97.203(d)]. Serious consideration should be given to restricting both Spread Spectrum and pulse operations to sensitive sub-bands, as is currently done with repeater operation:

    (b) A repeater may receive and retransmit only on the 10 m and shorter wavelength frequency bands except the 28.0-29.5 MHz, 50.0-51.0 MHz, 144.0-144.5 MHz, 145.5-146.0 MHz, 222.00-222.15 MHz, 431.0-433.0 MHz and 435.0-438.0 MHz segments. [13] [Section 97.205(b)]

Another possible oversight concerns the National Radio Quiet Zone. As it stands, both beacons [Section 97.203(e)] and repeaters [Section 97.205(f)] are restricted the National Radio Quiet Zone. It may be necessary to also regulate Spread Spectrum operation in this area. The National Radio Astronomy Observatory should be consulted in this matter to determine if their recommendations need to be incorporated into any rule changes.

The problems faced by Glenn Elmore and his colleagues, while not in the stations in amateur service, does illustrate a problem that we will be facing. That is, the compatibility among the various modes is likely to be more of localized issue than one that can be handled on a nationwide basis. For examples, some regions may choose to have two ATV channels in the 440 band. Others may decide that one ATV is enough for their needs, and that additional higher-speed digital channels are more important. [14] Another example is the recent with in the Amateur Service's Automatic Position Reporting System (APRS). Techniques that work well on the relatively level East Coast run into numerous anomolies in the hilly California, and that different communication strategies are needed in different area, based on terrain alone. [15] So we have differing patterns of usage due to local population differences and varying interest, and different propagation patterns due to local terrain.

What these local differences imply is that, just as in the world of repeaters, what works well in on part of the country may cause problems in another. Which is why we have local conditions. The same should apply to Spread Spectrum as well. In many areas, we are already doing local band planning with respect to both repeaters and widely accessible digital stations as well. We're seeing a trend towards combining the frequency co-ordination, for example, in the 440 band locally, Bob Wilkins (N6FRI) handles frequency co-ordination for both the regional repeater association (Northern Amateur Relay Council of California) and the North California Packet Association (NCPA). [16]

We are currently only expected to do frequency co-ordination for repeaters and auxiliary stations. We should seriously consider doing frequency coordination for Spread Spectrum stations as well, so we can make sure that they are in frequency ranges shared with compatible uses. As it stands, NCPA is already doing this on at least an informal basis in Northern California, and indeed there is already spectrum allocated for these kinds of operations at 900 MHz and above. [17]

Since Part 15 Spread Spectrum operations in the San Francisco Bay Area are already fairly widespread, this should be a good opportunity to see how Spread Spectrum emissions affect the Amateur Service. That is, examine usage patterns in the 900 MHz amateur band now, and before Part 15 Spread Spectrum was introduced, and compare that against the changes in the 400 MHz and/or 1.2 GHz amateur bands over the same time period. In some sense, one might suggest that the experiment has already done, and it's merely a matter of examining the results.

Finally, restricting Spread Spectrum emissions is not a new idea. The ARRL suggests this in footnote (2) of their Request:

    users of other modes. 47 C.F.R. #164#97.311(b). Conflicts are avoided by informal band planning and normal sharing considerations which work well in the crowded amateur bands. Avoidance of weak-signal subbands by SS operations is a reasonable preventative step. [18]

The Commission should give serious consideration making this a part of the rules, including suitable guard bands.

    8. Second, it is proposed to amend Section 97.311(a) of the Rules to modify the requirement that SS communications be limited only to domestic communications. Amateur communications have always been permitted internationally between countries that permit it, and SS emissions should not be prohibited between United states amateurs and amateurs in countries where those emissions are permitted as well. [19]

When Spread Spectrum satellites go into operation, this will need to be addressed. It is already an issue where the FCC's jurisdiction is close to another, especially along the Canadian border. However, different countries may have different regulations, and we should respect the regulatory needs of other jurisdictions. Therefore, we may want to additionally constrain communications to those emissions acceptable under the regulations of both parties. In some sense, this is covered under Section 97.309(b):

    (b) Where authorized by S S 97.307(c) and 97.307(f) of this Part, a station may transmit a RTTY or data emission using an unspecified digital code, except to a station in a country with which the United States does not have an agreement permitting the code to be used. . . [20]

So, it may be sufficient to incorporate a reference to that section in the ARRL's proposed amendment to Section 97.311(a).

    9. The reference in 97.311(b) to unintentional triggering of repeater inputs, a reference in the rules governing SS communications since 1984, is unnecessary because it is merely repetitive of existing definitions of "harmful interference" in the ITU Radio Regulations and in commission definitions and interpretations generally. Harmful interference for non-safety-of-life radio services does not include squelch breaks and repeater activation. (6) [21]

This may be the case, but most of the readers of Part 97 are not trained to interpret FCC regulations nor to understand the ITU regulations. Having this clarification in Section 97.311(b) avoids having either the FCC or Official Observers explain these definitions to well-meaning amateurs who utilize repeaters that do not employ modern squelch control techniques. (It may be worth noting here that these can be combined with carefully controlled carrier-controlled squelch to allow nearby amateurs with older equipment lacking CTSS to still access wide-coverage repeaters without permitting unintentional operations by distant users utilizing the same channel, such as is used by the W6APZ repeater in Palo Alto, California.) So, this change seems neither desirable nor useful. Removing this might also be construed as condoning unintentional triggering of properly equipped repeaters, which would discourage routine monitoring of repeater primarily intended for emergency operations.

    10. It is proposed to delete Subsections 97.311(c) and (d), in order to permit hybrid frequency-hopping (FH) and direct-sequence (DS) emissions, and spreading codes not currently permitted by the rules, but which are desirable. The current rules permit only two techniques, neither of which is optimal for sharing. There are newer codes, including those used by Part 15 device manufactures, which have been optimized to avoid interaction with shared users. These could be used if the rules were more flexible. [22]

One of the basic principles of the amateur services is that:

    [97.133] (a) No amateur station shall transmit . . . [(4)] messages in codes or ciphers intended to obscure the meaning thereof, except as otherwise provided herein [for control purposes]. [23]

and this is stated more directly for digital modes:

    [97.309(b)] . . . RTTY and data emissions using unspecified digital codes must not be transmitted for the purpose of obscuring the meaning of any communication. [24]

The problem here is that, given foreseeable FCC funding, any serious enforcement efforts will primarily be with those associated with in the Amateur Service. It is not just a matter of identifying the station(s) involved in the communication, as suggested by the ARRL:

    .... Nor will the changes create any difficulty with station identification, (7) or with protection of the Amateur Service from commercial or unlicensed encroachment. The narrow-band identification requirement is sufficient, together with the documentation requirement in Section 97.311(e) of the Rules, to permit the degree of monitoring of SS activities of amateurs necessary to protect the Service. . . . [25]

It is also important to be able to determine whether the information being transmitted is in compliance with Part 97. As it stands, what is required under Section 97.311(e) is station records which include description of the transmissions which are basically sufficient to decode it, and

    (3) A general description of the type of information being conveyed (voice, text, memory dump, facsimile, television, etc.); [26]

Without sophisticated equipment, it is, for all practical purposes, not possible for a knowledgeable amateur to determine compliance. A further complication is that one of the major uses for Spread Spectrum is likely to be as network components, both for network backbone links, for gateways to allow amateur stations to reach other stations and amateur services, and perhaps to connect on a limited basis to the Internet. When a station is doing packet forwarding, it may not be possible to determine the type of information being conveyed. So we have two problems here; Amateurs are not permitted to do what is obviously needed for modern networking, and, at the same time, we cannot easily determine compliance with the regulations we have. This is difficult dilemma and there may not be any easy answers.

Now, one of the major complaints being heard locally is that amateurs cannot do what unlicensed operators can do with Part 15 devices. That is a major issue that does need to be addressed. One way of dealing with that problem is to add an additional subsection to Part 97.311(c) such as the following proposal:

    [97.311(c) Only the following types of SS emission transmissions are authorized. . .]

    (3) Spreading techniques utilized by widely available Part 15 type-accepted devices, which can readily be received by such devices. [Text proposed here]

This will allow determination of compliance by a nearby station without opening the door to transmissions that neither that in the Amateur Service nor the Commission is in a position to monitor and regulate.

It may also be reasonable to allow Spread Spectrum emissions from published, well documented and easily reproducible devices within the construction abilities of ordinary, proficient amateurs. But going from very tight regulation to essentially no controls on the form of Spread Spectrum emissions seems unwise at this time, unless such transmissions are made subject to Section 97.311(f)(3):

    (f) When deemed necessary by an EIC to assure compliance with this Part a station licensee must:
    . . .
    (3) Maintain a record, convertible to the original information (voice, text, image, etc.) of all spread spectrum communications transmitted.

That is to say, continue the existing regulations, perhaps extending them somewhat to be consistent with the existing STA's, and then permit arbitrary Spread Spectrum emissions with mandatory compliance (rather upon demand) with Section 97.311(f)(3). Current disk prices and backup storage technology make this requirement considerably less onerous than when the rules were originally proposed. This may be one way that the Commission could encourage experimentation necessary to determine what the permanent Spread Spectrum rules should be without potentially creating a situation such as developed with the Citizen Band during the 1970's and 1980's.

    11. Finally, the proposed appendix would amend Section 97.311(g), to provide for automatic transmitter power control which would limit output power to that which is required for the communication, when more than one watt of transmitter power is used. This is a simple matter to accomplish technically, and it will insure compliance with Section 97.313(a) of the rules, which requires the use of minimum transmitter power. It will also minimize any potential for interference to other amateur stations and insure maximum spectrum efficiency. [28]

This may make sense for terrestrial communications, but almost certainly more than one watt be necessary for space communications. This may not be such a simple matter technically. On the other hand, power level control has been a problem in amateur space communication, so this may be a wise idea. This may be an area where a STA may still be the best tool and so the proposed rule may well be an appropriate one.

CONCLUSION

The ARRL is acting in a timely and responsible manner in requesting changes in the rules governing Spread Spectrum emissions in the Amateur Service. The fact that an unlicensed and technically naïve individual (at least in terms of RF technology) can operate in a manner that a competent amateur cannot without Special Temporary Authority is an unfortunate situation that does not cast either the Amateur Service or the Commission in a positive light. The rule changes requested by the ARRL have considerable merit, but the Commission should consider these changes very carefully to minimize adverse effects on other modes in the Amateur Service, and to avoid possible problems with abuse of amateur privileges.

Specific concerns described herein involve noise-sensitive modes, especially weak-signal operation, beacons, and space communications; band planning, both local and throughout the FCC's jurisdiction; and compliance in terms of message content. Most of these concerns can be met by restricting Spread Spectrum operations in the comparable manner to repeaters with regard to permissible sub-bands and local co-ordination, as implied in one of the ARRL's footnotes. [29]

Assuring compliance in terms of message content is more difficult, and the Commission should consider this problem very carefully before changes the rules regarding the types of SS emissions authorized for the amateur service. Going from overly restrictive rules to no restrictions may not necessarily be in the best interests of either the Amateur Service or the Commission.

Therefore, the Commission is respectfully urged to consider the ARRL's request for a rule making very carefully, neither accepting the proposal wholesale nor rejecting it entirely.

Respectfully submitted,

John Mock <KD6PAG@Alive.Com>
1506 Palm Avenue
Richmond, CA 94805


FOOTNOTES:

[1] A second generation computer professional with 25 years of experience, the author did pioneering work with one of the first Network UNIX systems on the ARPANET, on font design for the Xerox Graphics Printer (grandfather of the Apple LaserWriter), real-time digitally synthesized music, and has implemented numerous network protocols, including AX.25 and APRS.

[2] American Radio Relay League [ARRL}, "Petition For Rule Making" [RM-8737], ("Amendment of Part 97 of the Commission's Rules Governing the Amateur Radio Service to Facilitate Spread Spectrum Communications"), December 12, 1995. Sec. I.1

[3] ibid., Sec. I.2

[4] ibid., Sec. II.4

[5] American Radio Relay League, "The ARRL Handbook for Radio Amateurs" (1993 Edition), pp. 23-26 - 23-29.

[6] ARRL [RM-8737], Sec. II.6, para. 2.

[7] Jim Horning, "Amateur Radio Spread Spectrum Communications Page" (http://www.sp.nps.navy.mil/ss/index.html) [Naval Postgraduate School], January, 1996.

[8] Robert A. Buaas (K6KGS), Letter to Mr. Ralph A. Haller, Chief Private Radio Bureau, April 30, 1994.

[9] ARRL [RM-8737], Sec. II.6, para. 4.

[10] ibid., Sec. II.4

[11] Bob Wilkins (N6FRI), Frequency Coordinator, NARCC. Private communications, 1995.

[12] ARRL [RM-8737], Sec. III.7

[13] 47 CFR Part 15, Section 97.205(b).

[14] Bob Wilkins. Private communication, 1995.

[15] ibid.

[16] North California Packet Association, "North California Packer Association" (http://www.ccnet.com/~rwilkins/ncpa.html), January 9, 1995. Para. 4.

[17] ibid. Para. 5-6.

[18] ARRL [RM-8737], Footnote 2.

[19] ARRL [RM-8737], Sec. III.8

[20] 47 CFR Part 15, Section 97.309(b).

[21] ARRL [RM-8737], Sec. III.9

[22] ibid. Sec. III.10, para 1.

[23] 47 CFR Part 15, Section 97.113(a).

[24] ibid. Section 97.309(b).

[25] ARRL [RM-8737], Sec. III.9

[26] 47 CFR Part 15, Section 97.311(e)(3).

[27] ibid., Section 97.311(f).

[28] ARRL [RM-8737], Sec. III.11

[29] ibid., Footnote 3.

 


Comments to RM-8737 by The Indiana Repeater Council

before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of:                  ) 
                                   )
Amendment of Part 97 of the        )        RM - 8737 (assigned 1-25-1996)
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

By: The Indiana Repeater Council, the recognized frequency coordinator for all repeater and auxiliary stations in the Amateur Radio Service operating on frequencies above 29.5 MHz within the State of Indiana as defined in the FCC Rules and Regulations at 47 CFR Section 97.3 (a) (21)

                                   The Indiana Repeater Council
                                   P. O. Box 1092
                                   Logansport, IN 46947-1092
                                   William C. Wells, WA8HSU, Chairman
                                   Phone: 219-722-1338
                                   February 23, 1996

To: The Commission

CONCLUSION

The Indiana Repeater Council is opposed to the above captioned Petition for Rule Making filed by the American Radio Relay League, Inc.

DISCUSSION

It is believed by most persons who have no actually experimented with Spread Spectrum emission that a direct sequence Spread Spectrum signal will simply appear as a small increase in the noise floor over the bandwidth of the Spread Spectrum signal. Spreading the RF energy into a uniform noise floor requires an infinitely long PCode. Shorter PCodes leave the RF energy in "clumps." In practice, the RF energy is typically spread quite similarly to a video signal. When the Spread Spectrum signal is monitored on a CW/SSB receiver what one hears is a carrier every 10 KHz or so. Adding a slow frequency hopper to the direct sequence will simply have the affect of moving this side band structure around at the frequency hopper rate.

The net effect of such a signal on a band crowded with narrow band users such as the 70 cm band would be squelch breaks on open-squelch FM systems, generation of hetrodynes on tone systems, creation of dots and herringbones on ATV systems and the generation of lots of weak carriers for Weak Signal and AMSAT users.

Going the other way though the Spread Spectrum signal would have considerable immunity to interference from those narrow band signals located well away from the center of the Spread Spectrum signal it would be highly susceptible to interference from narrow band signals located near the center frequency of the Spread Spectrum signal.

A far superior Spread Spectrum technique for use on a band already crowded with narrow band signals is a simple frequency hopper with dwell points set half way between existing narrow band channels. For example, with narrow band channel of 443.00, 443.025, 443.050, 443.075, 443.100, 443.125, 443.150, 443.175, and 443.200 MHz a frequency hopper Spread Spectrum system could use as dwell points 443.0125, 443.0375, 443.0625, 443.0875, 443.1125, 443.1375, 443.1625, and 443.1875 MHz with one of these channels serving as a sync channel. Such a Spread Spectrum system is permitted by the present rules and the latest draft of the proposed new Indiana band plan defines dwell points and sync channels for such a system. The Indiana draft band plan in fact defines dwell points and sync channels for frequency hoppers on all bands from 144 MHz through 1300 MHz though a rules change would be required to allow Spread Spectrum on frequencies below 420 MHz.

The Spread Spectrum techniques embodied in RM-8737 are, without a doubt, superior in all respects to the Spread Spectrum techniques authorized by the present rules but only if they are assigned to virgin spectrum and therefore they cannot be allowed on any frequency below 450 MHz due to present high usage of these bands by narrow band users. The Indiana Repeater Council vigorously oppose any rule change expanding the types of Spread Spectrum techniques allowed below 450 MHz and will only support such changes in the 902 MHz and 1240 MHz bands if Spread Spectrum were strictly segregated into protected sub bands. On frequencies above 1300 MHz the proposed rule change would be nonproblematic due to low usage and limited range.

In the 902 MHz band two suitably sized subbands 12 MHz apart and in the 1240 MHz band two suitable sized subbands 12 MHz apart would permit the development of Spread Spectrum repeaters. Such repeaters could have hundreds of PCodes thus giving the functional equivalent of hundred of personal repeaters.

Respectfully Submitted,

William C. Wells

 


Comments to RM-8737 by Henry Ruh, KB9FO

before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of:                            )
                                             )
Amendment of Part 97 of the                  )    RM: 8737 (1-25-1996)
Commissions Rules and Regulations            )
governing the Amateur Service to             )
facilitate Spread Spectrum Communications    )

COMMENTS

The Commission is currently considering a petition from the American Radio Relay League to facilitate growth in Spread Spectrum mode communications (SS). This commentator was present as the only ham radio publication representative when the first SS Special Temporary Authority permits were issued at the Commission's offices in Washington and reported the event in my publication as a forward step for ham radio and technology. The pioneering effort began the digital communications efforts for hams and the mode has grown from a handful of experimenters to a fair number of regular operating stations. As with other modes this growth must now be accommodated as best as possible to allow further growth and development without adverse effect on other existing modes that share the same spectrum.

This commentator agrees with the comments of the Indiana Repeater Council. This commentator is not in agreement with the ARRL position as specified in their petition for rule making. It is felt that as in the past, once again the League has failed to recognize technical concerns and band sharing concerns and has failed to present a cogent approach that would maximize the protection of existing band users while at the same time providing the needed spectrum space for SS activities.

The Indiana suggested band plan to integrate SS into an already crowded band segment is vastly superior to the ARRL's approach. The ARRL's plan would cause the SS signals to encroach into other band users long established frequency assignments and cause interference to existing stations. Those stations would then need to move their existing operations to avoid the interference that, because of long established patterns of use, generate more interference potentials and a domino effect of interference among band users would erupt. This would cause even more conflicts to arise such as the Commission id presently trying to resolve in the FM repeater portions of the band.

The Indiana plan recognizes the rights of the SS operators to integrate their operations but suggests a much better approach in order to minimize interference to other modes and band users. This commentator agrees with the concepts of minimal interference integration and with the comments of the Indiana Repeater Council regarding the selection of dwell points.

This commentator supports the growth and development of SS techniques and is in favor of the techniques proposed but agrees with the Indiana position that the integration must be on a more sound technical basis.

Further, this commentator suggests that the Commission consider allowing the SS operators use of the 219-220 MHz band that has been set aside for exclusive use of packet stations. Currently operation on the mode exclusive band must register with the ARRL. Similarly SS users could share this spectrum with their digital "cousins" under the same plan. This spectrum is not available to other mode users and is still vastly under utilized. Now would be an opportune time to share the 219-220 MHz band between two digital modes where SS would not have to compete for spectrum with other users. This operation would be more suitable than 420-450 MHz operation because it would generate little if any interference to existing and planned uses. It would not add to occupancy of existing bands, and offer equal or better long distance communications than 440 MHz. The use of 219-220 MHz would also allow for higher power levels than are currently allowed for SS on other bands.

Equipment is equally available for SS operation on various bands and is not a consideration. Equipment for operation on 902-928 MHz is inexpensive and readily available from Part 15 suppliers.

CONCLUSION

The ARRL petition is technically flawed and generates interference to existing operations. The Indiana proposal is technically sound, minimizes interference to existing stations and allows for better integration of Spread Spectrum operations. The addition of operation on the 219-220 MHz band would allow even better opportunities for spread spectrum operators to develop systems and techniques, in harmony with other digital modes, with better communication distances and allowance for higher power levels and provide a maximum level of protection to the spread spectrum user and other mode users. The alternative suggested within these comments and in comments filed by the Indiana Repeater Council offer a vastly superior opportunity to foster growth and development of digital spread spectrum communications in ham radio.

Therefore the ARRL petition should be denied or modified to incorporate the technical superiority of the Indiana plan.

Respectfully Submitted

Henry B. Ruh, KB9FO
Publisher, Amateur Television Quarterly
3 N. Count St.
Crown Point, IN 46307


Charles M. Albert, Jr. KC6UFM, comments to RM-8737 Mar 3rd, 1996

Before The
Federal Communications Commission Washington, DC 20554

In The Matter Of:

Amendment of Part 97 of the         )   RM-8737
Commission's Rules Governing        )
the Amateur Radio Service to        )
Facilitate Spread Spectrum          )
Communications                      )

March 4, 1996

To The Commission:

The following are the comments of Charles M. (Marty) Albert, Jr. KC6UFM

INTRODUCTION

I have recently become interested in the idea of using Spread Spectrum (SS) systems for the purpose of high-speed Amateur Packet Radio networking and began to look for information, especially about the rules that govern this emission type. Upon reading the appropriate sections of Part 97 (97.305 and 97.311), I became somewhat discouraged due to the seemingly over-restrictive limits set on SS operation in terms of spreading systems and record keeping.

I was, however, excited to hear about the proposal for changes made by the American Radio Relay League (ARRL) and wasted no time in locating the text of their proposal. At the same time, I located comments filed by the Tucson Amateur Packet Radio Corporation (TAPR) and by Mr. Robert A. Buaas (K6KGS) both dated February 26, 1996.

After reading the proposal made by the ARRL, I was again discouraged and so I felt the need to make my opinions known to The Commission on this matter.

BASIS OF COMMENTS

I feel that, due to the fact that I am NOT currently active in the use of SS systems in the Amateur bands and am, at this time, investigating the possible use of SS to solve a specific problem, I am in the position to evaluate the impact of the proposed changes on the very issue that they are intended to solve: How can the Amateur use and development of SS systems be best enhanced?

GENERAL COMMENTS

The ARRL has addressed a very valid point in a very well worded proposal. In general, the idea behind the proposal is good in that it is an attempt to: (1) Ease access to the use of SS for all US Amateurs; (2) Clarify the rules in Part 97 (97.305 and 97.311) to make them easier to understand and meet; (3) Remove the need for The Commission to evaluate STAs for operations outside of the current rules.

Sadly, the ARRL proposal falls short on several matters, many of which have been well addressed by both TAPR and K6KGS.

SPECIFIC COMMENTS

(1) The ARRL writes:

    Section 97.305(b) is amended to read as follows:
    (b) A station may transmit a test emission on any frequency authorized
    to the control operator for brief periods for experimental purposes,
    except that no pulse or SS modulation emission may be transmitted on
    any frequency where pulse or SS is not specifically authorized.
While K6KGS takes exception to this wording, as does TAPR to a lesser extent, I agree with the ARRL. This wording will avoid possible problems with brief testing being done by those just setting up a SS station.

I do, however, agree with TAPR and K6KGS on the need to include the use of all Amateur bands above 50 MHz for the use of SS emissions. The reason for my support of this change is to allow the use of the VHF bands for SS high speed digital modes where the range of reliable communications would be increased.

This also brings up another issue: In reference to the 6m, 2m, and 125cm bands, Section 97.307(f)(5) states, in part, that a RTTY or multiplexed digital signal may not exceed 19.2 kilobaud if using an accepted code or must be limited to 20 KHz if using a non-accepted code. In reference to the 70cm band, Section 97.307(f)(6) states, in part, that a RTTY of multiplexed digital signal may not exceeded 56 kilobaud if using an accepted code or must be limited to 100 KHz if using a non-accepted code.

I feel that this matter requires clarification by The Commission as well. If using SS systems on, for example, the 2m band with a frequency hopping (FH) scheme that covers a 1 MHz spread, this would appear to violate 97.307(f)(5). Also, using SS systems, there would be little reason why a data rate well in excess of 19.2 kilobaud could not be supported with no increase in interference to other emission types sharing the band.

To this end, I would suggest that The Commission modify 97.307(f)(5) and (6) to exempt SS emissions from these limits. This exemption for SS emissions would also serve to encourage development of SS high speed data services.

(2) The ARRL writes:

    Section 97.311(a) is amended to read as follows:
    (a) SS emission transmissions by an amateur station are authorized
    only for communications between points within areas where the amateur
    service is regulated by the FCC and between an area where the amateur
    service is regulated by the FCC and an amateur station in another
    country which permits SS communications for its amateur licensees.
I agree 100% with this proposal. There is little reason to prohibit US Amateurs from using SS to communicate with those in other countries that also allow their Amateurs to use SS systems.

(3) The ARRL writes:

    Section 97.311(b) is amended by deleting the last sentence thereof.
Again, I agree with the ARRL on this proposal. Other sections of Part 97 cover this issue and there is no need to repeat it here, thereby singling out SS from other emission types.

As rather elegantly discussed by K6KGS, there is a lot of fear in the Amateur ranks of SS. This primarily due to a lack of understanding and education. (I have had one Extra Class Amateur tell me, "Yeah... I had a spread spectrum radio once... it spread its signal all over the band!") The inclusion of this Section reinforces this fear by implying that SS will cause interference to other emission types while, in reality, the idea and operation is exactly the opposite.

(4) The ARRL writes:

    Section 97.311(c) and (d) are deleted in their entirety.
This is the one area that I most strongly agree with the ARRL about. These two paragraphs must be deleted if The Commission ever expects to see any growth of SS in the Amateur Service.

There are many excellent spreading systems and algorithms available to Amateurs that can not be used due to this severe restriction. Even changing these paragraphs to allow for additional systems to be used will not solve the problem as this will continue to block any attempts at experimentation and system development.

If The Commission chooses to make only one change to 97.311, this should be the one that is made.

(5) The ARRL writes:

    Section 97.311(g) is amended to read as follows:
    (g) The transmitter power output must not exceed 100 W under any
    circumstances. If more than 1 W is used, automatic transmitter control
    shall limit output power to that which is required for the
    communication. This shall be determined by use of the ratio, measured
    at the receiver, of the received energy per user data bit (Eb) to the
    sum of the received power spectral densities of noise (No) and
    co-channel interference (Io). Average transmitter power over 1 W shall
    be automatically adjusted to maintain an Eb/(No+Io) ratio of no more
    than 23 db at the intended receiver .
Frankly, this proposed change is ridiculous. The ARRL has clearly no idea of the problems involved in creating a software or hardware system that will RELIABLY adjust the transmitter output power automatically based upon some set of criteria. The key here is "reliably"... It is a trivial matter to develop a system that will adjust the output power based on some feedback, but will it work 100% of the time? I doubt it.

As pointed out by K6KGS, the general requirement of using no more power than needed to communicate covers this issue quite well. Mr. Buaas also points out that no other stations have requirements to use such automatic controls. This segregation of SS systems will only increase the current misunderstandings of the emission type.

Also, as The Commission is aware, SS is a complex system. This complexity seems to be keeping the vast majority of US Amateurs away from the mode. The added complexity of such a useless and unattainable system would serve to keep Amateurs from entering SS operations and chase many away due to the frustrations of trying to meet an unrealistic expectation.

I would encourage The Commission to leave 97.311(g) as it now reads.

SPREAD SPECTRUM AND THE BEGINNER

As I stated earlier, I feel that I have a unique position in this discussion, that of being an "outsider looking in." I am by no means an expert in SS systems and my comments were made from that point.

It seems that SS may very well be the future of both Amateur and commercial communications. The Amateur Service has a long history and tradition, in addition to the obligation, of providing a service to the American public by developing, refining, and perfecting new and exciting communication systems. While SS is readily available at this time, there is no cause to believe that the state of the art has reached its maximum. This is where the Amateur Service can help the country...

With proper regulations that allow and encourage experimentation and system development and yet protect existing systems from harmful interference, the Amateur Service will be able to enhance new communication systems, including SS.

The Commission is charged with the difficult job of balancing the need for experimentation and preventing interference. In the past, The Commission has allowed the Amateur Service to be largely "Self Policing" and I see little reason that SS should not be the same. By providing rules that are open enough to allow the needed experimentation and yet closed enough to avoid situations that will clearly cause interference and then allowing the Amateurs themselves to handle the more or less local interference problems that will come up from time to time, The Commission will, in my opinion, once again successfully perform their balancing act.

Thank you for your attention and consideration.

                          Respectfully submitted,




                          Charles M. (Marty) Albert, Jr.   KC6UFM


Mike Cheponis, K3MC, comments to RM-8737 Mar 4th, 1996

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM-8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission

COMMENTS OF MIKE CHEPONIS

SUMMARY

The ARRL Proposal is flawed.

The Current Buaas Spread Spectrum (SS) STA should be used as the model for rules changes.

DETAILS

The Buaas STA has been successfully operational for several years. My station is one of those on the STA. I have conducted many Spread Spectrum transmissions under this STA, and have come to certain conclusions.

I agree with the ARRL in that International SS communications are desirable.

I disagree with the ARRL, in that 97.311(b), about unintentional triggering of repeater inputs, should stay as-is. The rules in this regard are working, so it is unclear why they need to be changed.

I find it exceedingly odd that the ARRL wished to include a requirement for automatic power control; doesn't 97.313(a) provide sufficient inducement? I don't understand why SS emissions need to be singled out. And, in these deregulatory times, it seems especially odd, since (as far as I am aware) no SS transmission has ever caused harmful interference to any other amateur transmission. To me, this smacks of the kind of rulemaking that caused amateurs to deal with HF amplifiers that could not be sold with a "10 meter" position because another service, Citizens Band Radio, could illegally use amateur 10 meter amplifiers.

I also take issue with the ARRL's assertion that "this is a simple matter to accomplish technically." Would the ARRL like to explain to us how the quantities Eb, No (sic) and Io (sic) are measured? And how the FCC and the amateur will know that the quantity Eb/(N0+I0) will be <= 23 dB at the intended receiver? (I shudder to think of the "SS Police" that would also be needed to enforce such a provision, if, indeed, they could determine when some station were out of compliance...)

Obviously, the ARRL proposal is suboptimal.

I believe that amateur SS systems will use minimum power necessary in order to prolong battery life, reduce RF exposure hazards, etc. There is certainly no need to require the ARRL's proposed power restriction formula.

CONCLUSION

May I suggest a simple alternative? The Buaas SS STA has been successfully providing experimenters with the possibility of doing interesting SS systems.

I suggest that the FCC adopt the Buaas SS STA as permanent rules for Amateur SS operation, including (as the STA does) operation on all amateur frequencies above 50 MHz.


                                Respectfully submitted,


                                Mike Cheponis
                                Amateur Radio Operator K3MC
March 4, l996


Mike Cheponis, K3MC, reply comments to RM-8737 Mar 6th, 1996

Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of                   )
                                   )
Amendment of Part 97 of the        )    RM-8737
Commission's Rules Governing       )
the Amateur Radio Service to       )
Facilitate Spread Spectrum         )
Communications                     )

To: The Commission

REPLY COMMENTS OF MIKE CHEPONIS

SUMMARY

Some specific recommendations in the TAPR comments are challenged. Mostly, however, TAPR got it right.

DETAILS

Sometimes it is useful to clarify certain things. Therefore, I strongly believe that 97.311(b) should stay in the rules as-is.

TAPR is incorrect in requesting automatic power control be mandated into every transmitter. I believe that if SS emissions are to require automatic power control, then every mode must require automatic power control. I sincerely hope that the Commission's wisdom prevails, and it notices that there has never been (to my knowledge) even a single complaint made by an amateur operation adversely affected by an amateur SS operation.

I do agree with the TAPR comments that operation on all bands above 50 MHz is desirable.

I also agree with TAPR that 97.311(e) and 97.119(b)(5) be deleted.

CONCLUSION

Essentially, TAPR is asking that the Buaas STA be used as the template for permanent rules changes, and this is what I proposed in my Comments.


                                Respectfully submitted,


                                Mike Cheponis
                                Amateur Radio Operator K3MC
March 6, l996


Comments to RM-8737 by Bill Tynan, W3XO

before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, D.C. 20554

In the Matter of:                            )
                                             )
Amendment of Part 97 of the                  )    RM: 8737
Commissions Rules and Regulations            )
governing the Amateur Service to             )
facilitate Spread Spectrum Communications    )

To: The Commission


REPLY COMMENTS OF WILLIAM A. TYNAN W3XO

Introduction

I have been a licensed amateur since 1945, obtaining the callsign W3KMV in early 1946. I upgraded to Class A (later called Advanced) in the fall of 1946 and to Extra in the early 70s. I obtained my present callsign in 1976. Throughout those 50 years, my principal interest has been in the bands above 50 MHz. I am currently operational on all bands from 50 to 1296 MHz. For eighteen years, from 1975 until 1992, I served as Contributing Editor to QST Magazine, responsible for the monthly column "The World Above 50 MHz". I was one of the founders of the Radio Amateur Satellite Corporation (AMSAT) and have been serving as its President since 1991.

News of the filing of this Proposal was very limited and I did not become aware of it until the day before I was to leave on a trip to Europe for AMSAT. As a result, I was not able to prepare comments before the filing date of February 29th. Therefore, I am filing Reply Comments and ask that the Commission accept them as part of the official record in this proceeding.

Summary

I have major reservations concerning the Petition for Rule Making filed by the American Radio Relay League last December. Although I am in favor of developing new technology in the Amateur and Amateur Satellite bands, including Spread Spectrum (SS) techniques, I am concerned that SS's widespread use, with no frequency restrictions, will cause major interference to satellite operation as well as to weak signal terrestrial and EME work. Therefore, I strongly suggest that any relaxation of the spread spectrum rules that the Commission may decide upon, should be accompanied by restrictions limiting it to specific frequency segments within the Amateur and Amateur Satellite bands. Otherwise, it has the potential to make reception of the relatively weak signals from amateur satellites, distant terrestrial stations and signals reflected from the Moon, all but impossible in many parts of the country, particularly in urban areas.

In support of this contention, I cite both calculations made relative to potential SS signal levels and the ARRL's own statements with regard to potential interference which Spread Spectrum might cause.

Discussion

To obtain a measure of the possible interference that could result from only a single spread spectrum station, the following parameters are assumed:

  • Spread spectrum station with an effective power of 100 W ERP = +20 dBW
  • If spread over 10 MHz -50 dBW/Hz
  • Free-space attenuation at 20 km from the spread spectrum station in the 70 cm (420 - 450 MHz) band = -110 dB
  • Spread spectrum signal at 20 km = -160 dBW/Hz

  • A receiver with a 1 dB NF (common in satellite & weak signal work) = -210 dBW/Hz
  • This results in the spread spectrum signal causing as much as a 50 dB increase in the noise floor existing without it.

    Even if the SS station has a power of only 1 W ERP (20 dB less), the noise floor would still be as much as 30 dB higher because of its presence. Similar calculations for other distances can also be done. For example, the spread spectrum signal would be 20 dB stronger at a 2 km distance. As another example, a 100 W transmitter and 10 dB gain antenna could create 10 dB more interference. Obviously, if the spread spectrum station is in close proximity to the satellite, terrestrial weak signal or EME, station, the degradation from the spread spectrum station's operation would be much greater.

    The effect of automatic power control for SS stations using transmitters over 1 W is difficult to asses, but one can envision situations in which interference from other SS stations, as well as non-SS stations, might cause the SS station(s) to increase their power in order to retain the desired signal to noise ratio. In such a case, power control would do nothing to alleviate interference for other users of the band.

    It might be said that antenna directivity would provide protection. I believe that, with increases in noise floor as great as these cited above, antenna directivity will not help much. If the increases were in the order of 5 to 10 dB antenna directivity might be of some benefit, but not for the cases noted. The reason for this is that few amateur satellite ground stations, or even terrestrial weak signal operators, have antennas with side lobes down 30 dB. I am not sure that even EME operators have antennas that good. In addition, there are many instances in which antennas being used to receive amateur satellites, or signals reflected from the Moon are pointed, near the horizon rather than being elevated. For example, LEO satellites are typically below 10 degrees elevation approximately half the time during which they are within range of a given location. Of course, antennas for terrestrial work are always pointed at the horizon. In these cases, there is no improvement from using directive antennas if an interfering spread spectrum station happens to be in the same direction as the desired satellite, terrestrial station; or even the Moon.

    The received signal strength for EME stations on 70 cm is in the order of -150 dBm, many times even less. Obviously, because of such extremely low received signal strengths, ANY increase in noise floor would be sufficient to render successful EME work impossible. Therefore, significant use of SS, which might include 432 MHz would probably spell the death knell for EME as a viable mode on that band.

    In their petition, ARRL goes to some length to state that "unintentional triggering of repeater inputs" is not considered interference, and that therefore the section of the rules dealing with it should be removed.

    It seems to me that this proves that even they believe that spread spectrum operation may well result in significant noise floor increases. Certainly if they are sufficient to trigger FM repeaters, they are sufficient to drastically degrade reception of weak satellite, terrestrial or EME signals.

    Proposal

    I believe that spread spectrum operation should be encouraged. I think that it will eventually prove to be a valuable mode for both terrestrial and satellite applications, and maybe even EME. However, I believe that it should be restricted to certain frequency segments so as to offer minimal interference to other modes, while still allowing experimentation. The Commission has done this in other amateur rules. For example, voice operation is limited to certain segments in the HF and VHF amateur bands. Unattended digital operation is restricted to certain small segments in the HF bands and unattended beacons are limited to specific segments on 10 meters through 70 cm.

    To alleviate the kinds of interference cited, I believe that spread spectrum should not be allowed below 450 MHz. I know that the current rules allow it in the 420 - 450 MHz band, It may be argued that this proves that spread spectrum poses no threat to other types of operation, since no reports of interference have been registered in the ten years since it was authorized. However, the ARRL admits in their Petition that SS operation has not been widespread. This is probably an understatement. I am not aware of the results of any SS operation. None were reported to me when I was writing The World Above 50 MHz and no papers on amateur SS experiments have been given at AMSAT's annual Space Symposiums. Specifically, I know of no reports of tests showing the potential interference to other modes of operation including weak signal modes, by SS operation even though SS operation has supposedly been taking place since 1985.

    I would like to see spread spectrum develop and become a major factor in Amateur Radio, especially on the microwave bands. But, I do not think it should be allowed to do so to the detriment of other modes of operation. It has not been demonstrated that it won't.

    In order to allow it to fulfill its potential and still protect these other types of operation, I believe that spread spectrum should be authorized only in certain band segments beginning in the 33 cm (902 - 928 MHz) band. Specifically it should be placed in segments that provide protection for weak signal terrestrial and EME operation which occur in fairly narrow segments at 432, 902, 1296, 2304, 3456, 5760 and 10,368 MHz.

    Such an approach will also protect amateur satellite operation in the 435 - 438 MHz band. It might be possible to allow SS in the 1260 - 1270 MHz (uplink only) and 2400 - 2450 MHz satellite bands, but that should be studied prior to doing so. Certainly, SS should be allowed in some satellite bands, as it will probably prove useful for satellite work in the future. Possibly restricting it in the lower 5 or 10 MHz portion of the 2400 - 2450 MHz band, but permitting it in the upper portion, would protect existing, and near-term future, amateur satellite operation and still permit the use of Spread Spectrum with satellites designed for it in the years to come.

    Conclusion

    I urge the Commission to not permit SS to continue in the 70 cm band and certainly not permit it in lower VHF bands as some may argue. If other kinds of operation, such as ATV and packet are any guide, those people interested in developing SS techniques are most likely to settle in the lowest frequency band permitted. This is only natural, as their principal interest lies in the techniques involved, rather than in the radio wave propagation and/or RF equipment aspects.

    RESPECTFULLY SUBMITTED,
    
    
    
         William A. Tynan W3XO
    
         March 11, 1996
    


    Radio Amateur Satellite Corp, reply comments to RM-8737 Mar 11th, 1996

    Before the
    Federal Communications Commission
    Washington, D.C. 20554

    In the Matter of                   )
                                       )
    Amendment of Part 97 of the        )
    Commission's Rules Governing       )    RM-8737
    the Amateur Radio Service to       )
    Facilitate Spread Spectrum         )
    Communication                      )
    
    
    To: The Commission


    REPLY COMMENTS OF THE RADIO AMATEUR SATELLITE CORPORATION

    Introduction

    The Radio Amateur Satellite Corporation (AMSAT) is a not-for-profit District of Columbia corporation established in 1969. It is the principal membership organization of the amateur-satellite community in North America. Our current membership is approximately 7,500. Together with more than 30 of our affiliated organizations throughout the world, we have constructed, launched and operated over two dozen satellites to date in the Amateur-satellite Service, of which the majority are presently in operation. These currently operational spacecraft include high-altitude, Molniya-type orbit transponder satellites capable of sustaining two-way communication over terrestrial paths well in excess of 10,000 miles (AMSAT-OSCAR 10 and AMSAT-OSCAR 13), numerous low-earth-orbit (LEO) digital store-and-forward packet radio satellites, scientific and educational payload satellites, LEO analog transponder satellites, and several spacecraft featuring combinations of these types of payloads.

    Summary

    1. AMSAT has major reservations concerning the Petition for Rule Making ("the Petition") filed by the American Radio Relay League (ARRL) December 12, 1995. We are wholeheartedly in favor of developing new technology in the Amateur and Amateur-satellite services; however we are concerned that the widespread use of spread spectrum techniques with no frequency restrictions will cause major interference to satellite operation and weak signal terrestrial work. Therefore, we urge that the Commission's relaxation of the spread spectrum Rules, as proposed in the Petition, be accomplished only within specific frequency segments within the Amateur and Amateur-satellite bands, with spreading factor limits which will be discussed later. Otherwise, widespread use of spread spectrum by amateur operators, which we hope will occur, can make reception of the relatively weak signals from amateur satellites all but impossible in many parts of the country, particularly in heavily populated regions of the U.S.

    2. In support of this contention, we submit both calculations made relative to spread spectrum signal levels and the ARRL's own statements with regard to potential interference which spread spectrum might cause.

    Discussion

    3. To obtain a measure of the possible interference that could result from only a single spread spectrum station, the following parameters are assumed:

      Case I: Line-of-sight propagation

      • Spread spectrum station with an effective power of 100 watts ERP = +20 dBW
      • If spread over 10 MHz -50 dBW/Hz
      • Free-space attenuation at 20 km from the spread spectrum station at 435 MHz = -110 dB
      • Spread spectrum signal at 20 km = -160 dBW/Hz

      • A receiver with a 1 dB NF (common in satellite & weak signal work) = -203 dBW/Hz

        Thus, a single spread spectrum station could raise the noise floor at that receiver on the order of 40 dB.

      Case II: Propagation over partially obstructed terrain

        Parameters similar to Case I except that the attenuation (at 20 km) may be as much as 20-30 dB greater, i.e., -130 to -140 dB.

        In this case, a single spread spectrum station could raise the noise floor at that receiver on the order of 10-20 dB.

    4. One can use these calculations to cite other scenarios:

    For example, if the spread spectrum station had a power of only 1 watt ERP, this is 20 dB less, yet under line-of-sight conditions, the noise floor would still be on the order of 20 dB higher because of its presence. Over flat terrain and in the absence of intervening obstructions, line-of-sight propagation over a distance of 20 km would require HAAT for both antennas of only 6 m, or for one antenna of approximately 20 m with the other at ground level. Many existing amateur repeater and packet node sites, which would be available for spread spectrum service, are on mountaintops or tall buildings hundreds of meters above average terrain and offer line-of-sight transmission over distances well in excess of 20 km.

    Similar calculations for other distances can also be done. For example, the spread spectrum signal would be 20 dB stronger at a 2 km distance. As another example, a 100 watt transmitter and 10 dB gain antenna could create 10 dB more interference. Obviously, if the spread spectrum station is in close proximity to the satellite earth station or terrestrial weak signal station, the degradation from the spread spectrum station's operation would be much greater.

    5. The requirement for automatic power control of stations using transmitters over 1 watt would not seem to alleviate interference unless ALL spread spectrum stations they contacted were prepared to transmit the data required by the power control scheme. The transmitting station couldn't guess the required power within the plus-or-minus 5 dB accuracy effectively required without some feedback from the distant receiver.

    6. In addition, if spread spectrum techniques are employed by amateur satellites or terrestrial full-duplex repeater stations, the automatic power control aspects of the Petition may prove to be unworkable. A satellite transponder is a shared resource, and digital amateur earth stations using it generally employ a Carrier Sensed Multiple Access technique to share the uplink channel. If the satellite transmitter were required to adjust its power to achieve a 23 dB signal-to-noise ratio for each successive using station in the typical time-interleaved operation, other users would not be able to hear many of the satellite's transmissions, and thus transmit at times that would cause interference. The same problem would occur in terrestrial full-duplex repeater operation.

    7. It might be said that antenna directivity would account for a significant modification of this situation. AMSAT contends that with increases in the noise floor as great as these cited, antenna directivity cannot be counted upon for a significant improvement. Only if the increases in the noise floor were in the order of 5 to 10 dB might antenna directivity be counted on to provide such protection. However, few amateur-satellite earth stations, or even terrestrial weak signal operators, have antennas with side lobes down 30 dB. In addition, there are many instances in which antennas being used to receive amateur satellites are pointed near the horizon rather than being elevated. Amateur LEO satellites, for example, are typically below 10 degrees elevation at least half the time during which they are within range of a given earth station. Of course, antennas for terrestrial work are always pointed at the horizon. In these cases, there is no improvement from using directive antennas if an interfering spread spectrum station is in the same direction as the desired satellite or terrestrial station.

    8. In addition to terrestrial operation by amateurs using weak signal techniques, a significant number employ Earth-Moon-Earth (EME) communications. A "typical" 432 MHz EME station might employ a transmitter with 1 kilowatt output and an antenna with a gain of 26 dBi and 1 dB transmission line loss. Assuming two such stations communicating with each other, the received signal strength for each would be about -180 dBW. Many EME stations have even less power and lower antenna gains than this example. Obviously, because of the extremely low received signal strengths involved in EME operation, any increase in noise floor would render successful communications impossible. Therefore, significant use of spread spectrum, which might include 432 MHz would eliminate EME as a viable mode on that band.

    9. The ARRL in Para. 9 of the Petition goes to some length to state that "unintentional triggering of repeater inputs" is not considered to constitute interference, and that therefore this section of the Rules ((7-311(b)) should be deleted. It appears to AMSAT that this is prima facie evidence that ARRL believes that spread spectrum operation will result in noise floor increases sufficient to trigger FM repeaters. If this is the case, we contend that such a noise floor increase would certainly be sufficient to drastically degrade reception of weak satellite, terrestrial or EME signals.

    AMSAT's Proposal

    10. AMSAT believes that spread spectrum operation should be encouraged. We believe that it will eventually prove valuable for both terrestrial and satellite applications. However, we contend that it should be restricted to certain frequency segments so as to offer minimal interference to other satellite, EME or terrestrial operation, while still allowing experimentation. We contend that this is consistent with Commission policy in the Amateur Service. We cite, as examples, the fact that voice operation has been limited to certain segments in the HF and VHF amateur bands for many years. In addition, unattended digital operation is restricted to certain small segments in the HF bands.

    11. In particular, AMSAT contends that spread spectrum should not normally be allowed below 450 MHz. We are aware that the current rules allow spread spectrum operation above 420 MHz, and have since 1985. It may be argued that the fact that spread spectrum has been authorized in the 420 - 450 MHz band for over ten years, with no reports of interference recorded, proves that it poses no threat to satellite operation, EME or weak signal terrestrial work. However, AMSAT cites ARRL's own words in Para. 2 of their Petition from which we quote:

    "Since the time spread spectrum communications were first authorized in the Amateur Service in mid-1985, there have been some experimental amateur operations using spread spectrum techniques, but its use has not been widespread."

    12. AMSAT believes that this is an understatement and that spread spectrum use has been extremely limited. We submit that this is the reason why no interference complaints have been registered. Furthermore, AMSAT has seen no reports of tests conducted by those amateurs who were experimenting with spread spectrum that address its potential interference to satellite operation and other weak signal modes.

    13. AMSAT would like to see spread spectrum develop. We would like to see it become a major factor in Amateur Radio, including its potential role of opening the microwave bands to greater amateur operation. However, we contend that, while it may be compatible with relatively high signal strength narrow-band modes such as FM repeaters and terrestrial packet, it is not compatible with relatively weak signal modes such as amateur-satellite operation and terrestrial weak signal work.

    14. In order to allow it to fulfill its potential and still protect these other types of operation, AMSAT strongly recommends that spread spectrum be authorized only in the following segments of the Amateur and Amateur-satellite bands:

      905 - 928 MHz
      1240 - 1260 MHz
      2410 - 2450 MHz
      3300 - 3445 MHz
      All bands above 5500 except 5750 - 5770 MHz and 10.360 - 10.380 GHz.

    15. Following this course will protect amateur-satellite operation in the 435 - 438 MHz, 1260 - 1270 MHz (uplink only) and 2400 - 2410 MHz bands and still permit its use in the bands 2410 - 2450 and all the higher bands authorized for the Amateur-satellite Service. These proposed frequencies also provide protection for existing weak signal terrestrial and EME operation near 432, 902, 1296, 2304, 3456, 5760 and 10,368 MHz.

    16. AMSAT further recommends that the Commission require spreading ratios of 100 to 1000 in order to reduce the power density of the spread spectrum signals. This would not only reduce interference to non-spread spectrum users but also interference to spread spectrum users from narrow-band signals.

    17. We recognize that, from time to time, technically advanced amateurs may wish to experiment with spread spectrum techniques specifically intended for weak-signal applications such as satellites and EME. AMSAT wishes to encourage such experimentation by those qualified to do so, but due to the potential interference problem discussed above, we recommend that if such experiments must be carried out below 450 MHz or within the Amateur-satellite service frequency allocations or the commonly used weak-signal sub-bands above 450 MHz, that they be specifically authorized, for limited periods of time, under Special Temporary Authority.

    Conclusion

    18. AMSAT urges the Commission to incorporate these recommendations in formulating new spread spectrum rules designed to foster its widespread use among amateur radio operators. We further recommend that it place no greater restrictions on spread spectrum use, such as station identification and authorized spreading codes, than absolutely necessary. We contend that such a course will foster growth of spread spectrum among amateurs and allow them to continue in their traditional pursuit of new technologies and the use of higher and higher frequencies, while not disrupting other valuable amateur operation.

                       RESPECTFULLY SUBMITTED,
                       
                       
                      Radio Amateur Satellite Corporation
                      P. O. Box 27
                      Washington, D.C.  20044
    
    
                      William A. Tynan
                      President
    
    
    March 11, 1996


    TAPR, reply comments to RM-8737 Mar 11th, 1996

    Before the
    FEDERAL COMMUNICATIONS COMMISSION
    Washington, D.C. 20554

    In the Matter of                   )
                                       )
    Amendment of Part 97 of the        )    RM-8737
    Commission's Rules Governing       )
    the Amateur Radio Service to       )
    Facilitate Spread Spectrum         )
    Communications                     )
    

    To: The Commission


    REPLY COMMENTS OF TUCSON AMATEUR PACKET RADIO CORPORATION

    The Tucson Amateur Packet Radio Corporation ("TAPR") submits the following reply comments regarding the Petition for Rulemaking (the "Petition") filed by the American Radio Relay League ("ARRL"), which proposed certain changes in the rules governing spread spectrum operation in the Amateur Radio Service ("ARS").

    I. PERMITTING MORE WIDESPREAD SPREAD SPECTRUM OPERATION IN THE ARS WOULD SERVE THE PUBLIC INTEREST.

    A number of the comments recognized the benefits that could be provided by more widespread use of spread spectrum technologies in the ARS (1). In addition to those that would accrue to ARS operators, as described in the Petition, increased use of spread spectrum in the ARS would contribute to the overall development of spread spectrum communications (2) and, as a result, would provide benefits indirectly to commercial users as well.

    Expanded use of spread spectrum in the ARS also would further the Commission's objective of promoting efficient spectrum use. At the FCC's March 5, 1996 en banc hearing on spectrum policy, Paul Barens, the "father" of one of the technologies that forms the basis of the Internet, made the following statement:

    "What do we see today if we tune a spectrum analyzer or a radio receiver across most of the scarce spectrum bands? Mostly nothing. Dead air. This strongly suggests that most of our limited spectrum space is not being fully utilized and is going to waste. Specifically, with digital technology, spectrum bands can be more efficiently packed without interfering with existing services."

    By increasing the ability of ARS operators to use spread spectrum technologies, the Commission would enhance their ability to use digital technologies to enhance spectrum efficiency, as recommended in the above passage. In turn, the Commission also would make it possible for the ARS better to accommodate the many new users seeking to use ARS bands, which are already congested due to the widespread use of non-digital equipment.

    Although spread spectrum is not a panacea, it offers the promise of increased spectrum efficiency, reduced interference, and improved communication performance without adversely affecting other spectrum users. As a result, the Commission's rules governing spread spectrum operation should be modified to enable these technologies to flourish within the amateur service community.

    II. EXPANDED SPREAD SPECTRUM OPERATIONS WILL NOT ADVERSELY AFFECT OTHER ARS OPERATIONS.

    Several repeater coordinating organizations, who are responsible for the coordination of repeater operations in their regional areas of activity, filed comments opposing to the Petition. These entities generally alleged that adoption of ARRL's proposals would cause widespread interference to, and disruption of, existing operations.

    The fears and concerns expressed in these comments defy the proven ability of properly designed and implemented spread spectrum systems to operate in harmony with other spectrum users, are based upon "worst-case" scenarios, and reflect a desire to maintain the status quo even at the cost of stifling new technologies and services. As a result, they should not be permitted to prevent the development of spread spectrum in the ARS.

    First, as discussed by Robert Buaas, claims that spread spectrum operation will raise the noise floor ignore the fact that few real systems operate near the noise floor, and those that do would profit from applying spread spectrum technology (3).

    Second, in the ten years since the Commission first allowed limited spread spectrum operation in the ARS, a great deal of work has been done to address concerns that more flexible spread spectrum operation would adversely affect other types of ARS operations. In particular, the 1991 Buaas spread spectrum STA has made it possible for experimenters to engage in widespread use of spread spectrum technologies in the amateur band allocations below 450 MHz. Notably, operation under the existing spread spectrum rules and experimentation under the spread spectrum STA have not generated substantiated claims of objectionable interference (4).

    Finally, the successful operation of Part 15 spread spectrum systems provide substantial evidence of the ability of these devices to co-exist with other users. Today, millions of spread spectrum devices operating under Section 15.247 of the Commission's rules are being used to support end-user solutions in areas such as cordless phones, location monitoring devices, and local and metropolitan-area networking. These devices have been deployed across the United States without any local coordination and without any licensing by the Commission. Yet despite this flexibility and extensive use, spread spectrum Part 15 devices have almost universally operated without causing objectionable interference to other Part 15 devices or to others operating in shared spectrum (5). This success story provides ample proof that when spread spectrum devices are properly designed, manufactured, and deployed, they can coexist successfully with many diverse applications and, in addition, can facilitate frequency reuse.

    In light of this history of successful, non-interfering operation, the Commission should not permit unsubstantiated claims of potential interference to thwart the introduction and use of new spread spectrum technologies in the ARS (6).

    III. SECTION 97.119(B)(5) OF THE RULES SHOULD BE DELETED, AS SUGGESTED BY NCS.

    TAPR supports the suggestion made by the Manager of the National Communications System ("NCS") to delete Part 97.119 (b)(5), which deals with the requirement for CW identification. TAPR agrees that no currently available commercial equipment implements such a function, and that deletion of this requirement will act to speed the rapid adoption of this equipment into use in the ARS.

    CONCLUSION

    TAPR congratulates the ARRL for its forward-looking proposal to liberalize the spread spectrum rules in the ARS. ARRL's proposal, if adopted, could provide a variety of benefits to both members of the amateur service community and to the wider public.

    Proposals to modify the status quo often generate opposition by those who are adequately served by it. Like the turmoil that occurred in the ARS during the transition from AM to SSB, the growing use of spread spectrum in the service will not be without incidents of disagreement and misunderstanding. For this reason, TAPR intends to use its resources during the rulemaking process to educate the ARS community on the theory, application, and practice of spread spectrum technology.

    Yet while fear and opposition are understandable, they should not be permitted to stifle new developments. In light of spread spectrum's strong track record and proven benefits, unsubstantiated claims of potential interference should be discounted and the Commission should act promptly to issue a Notice of Proposed Rulemaking proposing to implement the changes sought by ARRL, modified as discussed in TAPR's earlier comments.

    
                        Respectfully submitted,
    
                        THE TUCSON AMATEUR PACKET RADIO
                        CORPORATION
    
    
    
                        By:
                            Dewayne Hendricks
                            Tucson Amateur Packet Radio Corporation
                            8987-309 E Tanque Verde Rd #337
                            Tucson, Arizona  85749-9399
                            (940) 383-0000
    
    

    Footnotes

      (1) See, e.g., Comments of Robert A. Buaas ("Buaas Comments"); Comments of the Manager of the National Communications System ("NCS Comments"); Comments of John Mock; Comments of Henry B. Ruh; see also ARRL Petition.


      (2) See NCS Comments at p. 3.


      (3) Buaas Comments at p. 2.


      (4) Buaas Comments at p. 3.


      (5) See Comments of the Part 15 Coalition, PR Docket No. 93-61 (1995).


      (6) TAPR believes that a program of continuing education to the ARS community on the merits and benefits of spread spectrum technology coupled with a wider use and deployment of equipment by amateurs in various applications will go a long way towards resolving the concerns of many of the commenters who have filed in opposition. TAPR intends to use its resources to perform this function and service for the amateur radio community in much the same fashion that it helped start the packet radio revolution in the ARS during the mid-1980's.


    REPLY COMMENTS OF PHILIP R. KARN, JR, KA9Q IN FAVOR OF THE PROPOSAL

    Before the
    FEDERAL COMMUNICATIONS COMMISSION
    Washington DC 20554
    
    In the Matter of:
    
    Proposed changes to the Amateur Service		)
    Rules (Part 97) to facilitate additional	)	RM-8737
    uses of certain portions of amateur spectrum	)
    by Amateur Spread Spectrum emitters		)
    
    REPLY COMMENTS OF PHILIP R. KARN, JR, KA9Q IN FAVOR OF THE PROPOSAL I make these comments in reply to those of the Southern California Repeater and Remote Base Association, The San Bernardino Microwave Society, The Mid-America Coordination Council, The SouthEastern Repeater Association, George Isley, the Wisconsin Association of Repeaters, and John Mock to the extent that they oppose the proposal to liberalize the amateur spread spectrum (SS) rules. PERSONAL BACKGROUND
    I have held an amateur license since 1971. I have been primarily interested in and have contributed to the technical advancement of amateur communications systems, including satellite and packet radio.

    Of particular relevance to this proceeding is that since 1991 I have been a Staff Engineer at Qualcomm Incorporated in San Diego, California. At Qualcomm I participate in the design, development and testing of an advanced Code Division Multiple Access (CDMA) spread spectrum system for digital cellular telephony that is now being deployed commercially worldwide. My work with this technology has been an invaluable educational experience with useful insights into the potential benefits and drawbacks of SS in the amateur service.

    I write these comments on my own personal initiative as a radio amateur, not on behalf of Qualcomm. Qualcomm is in the commercial cellular telephone business, not the amateur radio equipment business. As far as I know, Qualcomm has no corporate position on this matter. GENERAL COMMENTS
    I strongly support the liberalization of the spread spectrum rules as proposed by the ARRL. I believe this technology has much to offer the amateur service. The potential direct benefits include substantial increases in the efficiency and quality of existing services (e.g, mobile voice communications) as well as enabling qualitatively new applications such as very high speed packet radio.

    The indirect benefits would be even greater. Spread spectrum is now an important commercial radio technology, thanks to innovations such as the Global Positioning System (GPS), Part 15 wireless LANs and CDMA cellular telephones. It is essential that radio amateurs develop a hands-on understanding of SS technology not just to improve their communications abilities, but also to continue to satisfy the basis and purpose of the amateur service relating to technical experimentation, advancement and training as stated in Sections 97.1(b), (c) and (d).

    So I am considerably distressed by the negative comments received so far in this action. They exhibit a remarkable degree of ignorance of the principles of spread spectrum and of basic communications theory, a strong fear of the unknown, and an unreasonable desire to maintain the status quo at all costs in a rapidly changing world. DEFINITION OF "SPREAD SPECTRUM"
    In my comments I will use the term "spread spectrum" in a relatively expansive sense. The usual definition includes

    • Pseudorandom frequency hopping (FH) of a conventional narrowband signal
    • Pseudorandom direct sequence (DS) spreading of a conventional narrowband signal
    • Miscellaneous spreading techniques: time hopping, etc.

    To this list I add

    • Forward error control coding (FEC)
    • Nonbinary modulation with large orthogonal signal sets, e.g., M-ary FSK where M >> 2 (many more than 2 tones)
    • Wideband analog FM

    FEC, nonbinary orthogonal modulation and wideband analog FM all resemble FH and DS in that they increase emission bandwidth beyond that occupied by an uncoded binary (or SSB-AM) signal at the same user data rate. The power spectral density is also decreased. But while FH and DS are usually "power neutral" -- the same transmitter power is generally required whether or not the signal is spread [1] -- FEC, nonbinary orthogonal modulation and wideband analog FM can all have the extremely desirable property of decreasing the total RF power required to support a given user data rate or audio S/N ratio. This necessarily comes at the expense of increased bandwidth, according to Shannon's famous formula that shows channel capacity to increase with both signal power and bandwidth.

    I use this expanded definition of SS because the Commission's existing emission bandwidth limits keep amateurs from not only using spread spectrum as it is generally defined, but also from using wider bandwidths to reduce RF power requirements. BENEFITS OF POWER-EFFICIENT SS
    This fundamental tradeoff between bandwidth and power was established by Shannon in his famous 1948 paper A Mathematical Theory of Communication, but its implications have not been well appreciated in amateur practice. An early voice in the wilderness was that of John Costas, K2EN, who published the paper Poisson, Shannon and the Radio Amateur in the Proceedings of the IRE in December 1959. Costas argued eloquently and passionately that the chaotic and congested amateur bands were ripe for wideband techniques. The notion that wider bandwidths can actually increase spectral efficiency is a seeming paradox that many find hard to accept. This was evidently true for Costas' contemporaries:

    The frequency diversity [SS] system is intuitively ridiculous because it apparently "wastes" bandwidth rather indiscriminately. As we shall see, intuition is a poor guide in these matters. The feeling that we should always try to "conserve bandwidth" is no doubt caused by an environment in which it has been standard practice to share the RF spectrum on a frequency basis. Our emotions do not alter the fact that bandwidth is but one dimension of a multidimensional situation.

    The other dimensions to which Costas alludes include time (e.g., duty cycle), RF power and geographical area. In particular, the amateur service has all but ignored the RF power dimension, giving little more than lip service to the requirement to run only the minimum power required to maintain communications. The FCC rules are also at fault to the extent that the bandwidth limits established for various band segments preclude the use of power-efficient wideband techniques.

    It's sad to consider while reading many of the comments filed in opposition to this proposal that Costas wrote this paragraph over 36 years ago. Here are some typical "NIMBY" (not in my back yard) comments:

    There are less crowded Amateur microwave bands, particularly the higher frequency bands, where space exists for a variety of SS emission types. [San Bernadino Microwave Society, at 9.]
    The petitioner's pro-SS arguments in this matter only address technical and experimental concerns, and do not seriously consider the ill effects of the co-spectrum use of SS and existing narrowband systems in an already crowded spectrum. [SouthEastern Repeater Association at 3]

    Such comments betray a complete ignorance of the potential of spread spectrum to substantially decrease congestion. Other comments, while grudgingly admitting some potential for improvement, misunderstand and deprecate the technology:

    It is a fact that a digitally processed SS system utilizing "exclusive" spectrum can accommodate more traffic in the same bandwidth than can a FDMA system. This is mostly a result of the digital processing to compress (in time) the communications and the use of all the available spectrum space without having to leave "guardbands" between each user assignment. It is also dependent upon the communications user being willing to tolerate propagation delays which will increase as the system traffic increases. [Comments of SCRRBA at 6]. [2]
    Costas shows that what a wideband system "spends" in excess bandwidth can be more than repaid by vastly increased interference resistance and by significantly reduced RF power requirements (meaning less interference to existing narrowband users.) Even with the limited analog technology of his day, Costas could show a net increase in the carrying capacity of a given frequency band. Subsequent developments in digital signal processing technology and error correcting codes have now made it possible for one commercially practical spread spectrum system (Qualcomm CDMA) to demonstrate, in carefully controlled field tests, capacity gains of 10-15x over existing narrowband analog FM cellular systems. Such dramatic gains are only possible in a wideband system. They are clearly of greatest value in our most congested bands!

    A simple thought experiment will show how reducing power is the key to spectrum efficiency, and that limiting bandwidth is actually counterproductive. Assume a 1MHz band saturated with 1000 uniformly distributed users who, because shortsighted FCC rules preclude power efficient wideband modes, must run 1KW each to maintain communications with some narrowband scheme. The total transmitted power spectral density in the band is therefore 1000x1KW/1MHz = 1 watt/Hz. This represents the spectral density of interference as seen by a new user just arriving on the band.

    Now assume that the rules are changed by an enlightened Commission to allow a power efficient wideband scheme that requires only 500W, spread over all or some random part of the 1 MHz band, to maintain communications against 1 watt/Hz of interference spectral density. If a few users switch to this mode, the overall interference level will go down by a small but nonzero amount. An individual narrowband user may see either an improvement or a degradation, depending on how close it is to a wideband station. [3]

    But let's say the new mode really catches on, and all 1000 stations switch over to it. Now the interference spectral density is only 1000x500W/1MHz = .5 watt/Hz. Since the interference has gone down by 3dB, each station can now lower its power accordingly, to 250 watts. This lowers the total interference again, to .25 watt/Hz, and the stations can all reduce their powers again by another 3dB. And so on.

    If interference from other stations were the only factor, this power "deescalation" could continue indefinitely until everyone ran virtually no power at all! Of course, at some point in a real system natural noise sources will emerge to stop the process.

    Alternatively, let's keep our original 1000 wideband transmitters at 500W and add a second batch of 1000, each also operating at 500W. This would produce an interference spectral density of 2000*500/1MHz = 1W/Hz, which we know is the most our wideband scheme can tolerate at 500W. Now we have twice as many users sharing the band as in the narrowband case. All this because we removed the rules against "wasting" bandwidth!

    The message is clear: if our objective is to promote spectral efficiency, limit power -- not bandwidth. The proposed rules achieve this by requiring automatic power control in exchange for decontrolling bandwidth. Having seen the inverse relationship between S/N ratio and band capacity, we can also understand the proposed limit on Eb/N0 ("digital S/N"). Since each decrease of 3dB in required Eb/N0 doubles the capacity of a shared band, amateurs should be encouraged to build and operate systems at the lowest possible Eb/N0 ratio. Because of the relatively generous 100W power limit, and because there is no limit on data rate, the Eb/N0 limit effectively says "take all you want, but eat all you take." Since the theoretical limit according to Shannon is -1.6 dB for infinite bandwidth, there is clearly a lot of room for improvement here. WEAK SIGNAL AND SATELLITE INTERESTS CAN BENEFIT FROM SS
    Some of the most vociferous opposition to SS comes from the weak signal operators. I believe this is because they fail to understand that they have as much to gain as anyone from the relaxation of emission bandwidth limits. Many weak signal DXers long ago reached the limits of what can be accomplished by brute force; they erect the largest antennas they possibly can, they build the lowest noise amplifiers possible, and they run the full legal power limit. ("Moonbounce" operation is perhaps the best example.) Yet these operations are severely hampered by a "narrowband" mindset. Digital modulation and coding techniques that spend bandwidth to gain power could be of enormous benefit to these operations. Indeed, they represent an argument for not limiting wideband emissions to 100W when higher powers are truly necessary and interference to other operations can be controlled. (Again, moonbounce is a leading candidate here.)

    Amateur satellite operation can also benefit substantially from wideband techniques. Power is a limited commodity even on expensive commercial satellites; on amateur satellites it is extremely scarce. The carrying capacity of these satellites could be increased considerably through the use of power-efficient wideband modulation and coding techniques. Furthermore, auxiliary applications of spread spectrum such as highly accurate tracking of spacecraft are clearly of considerable benefit.

    One of the nice aspects of spread spectrum operation by satellite is that the near-far problem is often nonexistent. A satellite in high orbit is nearly equidistant from its users, so the range of user signal strengths it sees is scarcely affected by varying propagation losses.

    I point out here that the amateur rules should not require any minimum processing gain or spreading bandwidths. Particularly in the relatively narrow weak signal band segments where the use of wideband techniques is more likely motivated by RF power savings than by minimizing power spectral density, requiring more bandwidth than necessary to achieve the desired power gains would be counterproductive. Any such standards should be promulgated by voluntary agreement among the users of each band segment. INTERFERENCE CONCERNS
    The main concern expressed by the comments in opposition involve the potential interference from SS systems to existing narrowband operations.

    To the extent that any of the comments contain actual numerical analyses, all are based on absolute-worst-case conditions. (See, for example, SCRRBA's comments at 5). They assume continuous use by the SS station of the maximum power of 100W, completely discounting the mitigating effects of duty cycle and automatic power control. They assume reckless and total disregard on the part of the SS operator for voluntary bandplans and interference complaints from nearby narrowband operations. Then they argue that because interference could occur under such extreme conditions, SS ought to be banned entirely or at most permitted under extremely restrictive rules.

    Yet with such unreasonable assumptions, any operating mode could cause harmful interference. Indeed, most would be even worse! For example, it is legal under current rules to operate local FM simplex at 1.5KW on a satellite downlink band. (Never mind that such power levels are extremely rare. Those who oppose SS ignore my protests that average power levels will be substantially less than 100W, so I am entitled to make equally unreasonable assumptions here).

    The average transmitted power spectral density of such a signal would be 1500W/20 KHz = 75 milliwatts/Hz, with many strong discrete spectral components. In contrast, a 100W SS signal spread over 1 MHz would be only 0.1 milliwatt/Hz. Whatever can be said about the interference potential of the latter signal is clearly even more applicable to the former. Yet FM is not banned from the satellite bands. Indeed, had such a ban been enacted it would have precluded the use of FM by satellites such as the Microsats.

    The potential for interference is a fact of life in amateur radio. The FCC has long charged amateurs with the primary responsibility to work things out for themselves:

    Each station licensee and each control operator must cooperate in selecting transmitting channels and in making the most effective use of the amateur service frequencies. No frequency will be assigned for the exclusive use of any station. [FCC Rules Part 97.101(b)]
    This rule would apply to SS operations with equal force. It is patently unfair to insist that "no SS interference potential whatsoever is tolerable" when no other mode is held to such an unattainable standard.

    Although some, such as the Southeastern Repeater Association, raise the issue of interference to emergency communications, I consider this a red herring. This argument no longer carries much weight given the popularity of cellular telephones. [4] The nominal purpose of the amateur service is technical experimentation and self-training; it not a "safety of life" service like aeronautical or police radio where even occasional interference really cannot be tolerated.

    But I do agree with the San Bernardino Microwave Society when they say that SS operations should adhere to local frequency coordination practices, assuming that these practices make reasonable accommodation for SS operations. For example, it would indeed be inappropriate to run a high speed SS metropolitan computer network in a band segment reserved for weak-signal DX. But this is an issue best handled by the voluntary bandplanning process, not the slow and inflexible FCC rulemaking process.

    I further believe that the voluntary bandplanning process should isolate operation "classes" without regard to modulation mode or bandwidth. For example, a band plan might specify the following subbands:

    • Terrestrial weak-signal operations
    • Satellite operations
    • Local "utility" operations, further divided into
      • Low-altitude transmitters (e.g., repeater outputs)
      • High-altitude transmitters
      • Remote receivers (e.g., repeater inputs)
      • Low-altitude simplex
    Any modulation mode would be permitted in any subband as long as the operation is consistent with the subband class and any voluntary agreements promulgated by the users of that class. For example, one could use power-efficient SS-like techniques such as forward error correction coding in the weak-signal segment to work DX, but not to run a local area network. Similarly, spread spectrum would be allowed in the satellite segment if the purpose is to communicate through a satellite in accordance with good satellite practice.

    Such band plans should completely alleviate the interference concerns of the weak signal and satellite groups while retaining the option to apply wideband techniques to their own needs as they see fit.

    FM, packet and SS operations would coexist in the "local" subbands. One segment might be shared by FM, packet and SS repeater transmitters on hilltops while another would be shared by the receivers in these repeaters.

    I note that current amateur band plans already look very much like what I have proposed here. This is not a coincidence! They have evolved in this manner to deal with the same "near-far" interference problem that is the source of so much concern with SS. That's because the near-far problem is not unique to SS, but exists to some degree with every operating mode because of the inability to build real receivers with perfect adjacent channel rejection. The "MINIMUM POWER WINS" APPROACH TO INTERFERENCE RESOLUTION
    Such band plans should nearly eliminate interference between stations using different segments. Within a given segment, however, interference may still occur. Again, such problems are best handled within the amateur service whenever possible. The FCC should only state general principles for resolving interference problems as opposed to laying down blanket prohibitions that more often than not cause spectrum to go idle altogether.

    I note that in many such interference incidents, one or more parties are running excessive power. This suggests the following principle:

    Whenever harmful interference occurs between operations otherwise in accordance with voluntary bandplans that cannot be resolved by mutual agreement of the parties involved, the primary responsibility for resolving the interference shall rest with the station running the greater RF output power, without regard to emission bandwidth.

    This elegant rule clearly encourages power efficiency, which we have seen is directly related to spectrum efficiency. Being "interference driven", it avoids arbitrary and inflexible restrictions that would apply even when no interference would otherwise be caused.

    One's mind almost boggles at the thought of two warring repeater groups in a power de-escalation battle in order to claim priority on a channel! Beyond that, this principle would certainly encourage the use of power efficient modes, directional antennas, low power relays, and of course the minimum power actually required in each instance to maintain communications. Summary of Points

  • I strongly support the ARRL proposal to liberalize SS emission types. Relaxing the bandwidth limits on amateur emissions is basic to the development of more power and spectrally efficient techniques of benefit to virtually all types of amateur operation, including local utility, DX and satellite;

  • This can be best implemented not as a specific authorization for SS per se, but as a waiver of existing emission bandwith limits on "unspecified digital codes" that may be automatically obtained by adhering to the maximum power limits and automatic power control requirements discussed herein;

  • SS should be allowed on as many amateur bands as possible, subject to the maximum power output limit and the requirement for automatic power control to limit receiver Eb/N0 ratios;

  • There should be no rule mandating a minimum processing gain;

  • Amateur SS operations should be encouraged to adhere to voluntary band plans;

  • Band planners should be encouraged to make reasonable accommodation for SS by discriminating on the "class" of operation (e.g., local utility, terrestrial DX, satellite), not by emission bandwidth;

  • Interference within each class of operation should be resolved by the "minimum power wins" principle. I encourage the Commission to adopt rules to liberalize the use of amateur spread spectrum, consistent with these points, as soon as possible. Certification
    I certify that I have made copies of these Reply Comments available to the commenters mentioned in the introduction by US mail, electronic mail and World Wide Web.
    Respectfully submitted,
    
    Philip R. Karn, Jr., KA9Q
    
    
    
    
    
    Footnotes [1] Ideal implementations of FH and DS are "power neutral" on simple nonfading channels. Spreading can achieve power gains over fading channels thanks to the ability to separate multipath components separated by one or more chips and to add them constructively, e.g., in a "rake" receiver. These gains are limited to fading channels while FEC coding gains also exist on nonfading channels.

    [2] Efficient SS systems need not "compress in time". Indeed, if that's all they did, there would be no net gain in capacity. They do compress the source material to remove redundancy, e.g., through the use of low-bit-rate speech encoders. Propagation delay is fixed; it does not increase with load (though the bit error rate will as the channel approaches capacity). And while SS does eliminate the need for inter-channel guard bands, this is generally not a major issue. The big capacity gains in an efficient spread spectrum system like Qualcomm CDMA come from the following:

  • The ability to reuse the same spectrum many times in a geographical area without "exclusion zones" around each transmitter on a given channel to protect it from co-channel interference. A typical FM analog cellular system uses a 1:7 frequency reuse pattern, i.e., each cell can only use 1/7 of the total channel set lest it interfere with its neighbors. Because of its inherently strong resistance to co-channel interference, a CDMA system can reuse the same channel in every cell.

  • The ability to exploit rapidly varying user demands (e.g., talk spurts) to reduce, through increased trunking efficiencies, the average total resources needed by a group of users sharing a CDMA channel. For a typical voice conversation, this yields a 60% reduction in average data rate. FDMA and TDMA systems could, in theory, reallocate frequency channels or time slots in an equally dynamic fashion. They generally do not do so because the considerable overhead required would squander any savings.

  • The ability to deal with fading through a combination of rapid transmitter power control and "rake" receivers that isolate and recombine multipath components in a constructive fashion. This permits reliable mobile operation with virtually no link margin (approx 1 dB). This is contrasted with the substantial link margins commonly required in narrowband systems: analog FM cellular is typically engineered for a worst-case signal-to-interference ratio of 17 dB, 7 dB above the FM threshold. On amateur FM repeaters where user densities are much lower and automatic power control is nonexistent, far higher (and extraordinarily wasteful) link margins are common.

  • The ability to operate on both fading and nonfading channels with less average transmitter power thanks to the use of strong error correction and interleaving. Field tests of Qualcomm CDMA resulted in an average reverse link (mobile-to-cell) transmitter power of only 1-10 milliwatts in a mixed urban/suburban environment, far less than the 300mW-3W common with FM in the same environment.

    [3]This is the classic "near-far" problem; strictly speaking my analysis is valid only when every station is equidistant from all other stations. But later I will discuss practical band-planning approaches that minimize the near-far problem by segregating transmitters and receivers.

    [4]On several occasions I have used amateur FM repeaters to report emergencies. About a month ago I encountered a seriously injured woman lying in the street after her car was hit by a drunk driver. I immediately called for help on a local 2m repeater. Eventually, I obtained police assistance with the help of an inexperienced albeit well-intentioned fellow ham who called 911 on his home phone. I later learned that the woman was expected to make a full recovery. But I was so frustrated by the inefficiency and undependability of the whole process that I finally bought a portable cell phone that I now carry with me at all times.


    Robert A. Buaas, K6KGS, reply comments to RM-8737 Mar 11th, 1996

    Before the
    FEDERAL COMMUNICATIONS COMMISSION
    Washington, D.C. 20554

    In the Matter of                   )
                                       )
    Amendment of Part 97 of the        )    RM-8737
    Commission's Rules Governing       )
    the Amateur Radio Service to       )
    Facilitate Spread Spectrum         )
    Communications                     )
    

    To: The Commission

    The following are the Reply Comments of Robert A. Buaas, K6KGS, 20271 Bancroft Circle, Huntington Beach, CA 92646.

    It appears to me that the Comments filed in this proceeding fall generally into two categories: those in favor of simplifying and relaxing the Rules regarding Spread Spectrum (SS) thereby further encouraging its development and use, and those against. The later come from Amateurs connected with the Frequency Coordination community, who seek to limit its use because of concerns for interference to existing operations, who cite as justification for this concern, worst-case conjectures and experiences with SS systems completely lacking in design criteria to minimize such interference. Our findings under the auspices of the SS Special Temporary Authorization show that these concerns are without significant merit, and simultaneously increased spectrum utilization is realized as a result of the coding methodology required to implement the SS aspect. I emphasize that we give high priority in the earliest design stages to interference avoidance criteria. An example of the result is given later in this filing.

    The state of the art in Amateur VHF/UHF voice communication has fallen well behind that practiced in other radio services. With few exceptions, only the simplest systems are employed. To show the contrast, I choose as an example the "trunking" system architecture in widespread use by Land Mobile. This system is significantly more complex than its predecessor, the community repeater. The payoff for this complexity increase is the improved spectrum utilization and throughput it provides. Viewed using the basic definitions of SS, it has properties of the simplest form of Frequency Hopping (FH). At the moment a user wishes to communicate, the system administrator function causes him to hop to a random free channel, where he dwells for the duration of his transmission. Corresponding receivers of the transmission hop accordingly, in synchronism. All "interference" is eliminated, until enough users want simultaneous access, when, those arriving after the system is "full" are denied service. In its basic form, this design provides no level of graceful degradation; the most this architecture can do is prioritize the user requests, denying service to those with least weight. Even with this limitation, close to maximum spectrum utilization is achieved for the transportation of user information (at least one channel must be allocated to communicate the decisions of the system administration function).

    Given the demonstrated benefits, why have no systems like these found use in Amateur Radio, particularly in places where the available spectrum is entirely committed? I conjecture that:

      (1a) The technical complexity, requiring background in both analog and digital techniques, is significantly greater than that required to field a community repeater and maintain user equipments. This significantly limits the pool of available participants;

      (1b) Surplus/low cost commercial equipment containing the necessary functionality, that are also easily modified to amateur frequencies of interest, are not available;

      (1c) Even if equipment were available, its cost would likely be higher than for equipment less complex;

      (1d) The capital investment and cooperation required to construct and operate the shared facilities may not be achievable in the Amateur context; and,

      (1e) It is not incrementally implementable: in places where the spectrum is fully allocated, some number of community repeaters would be displaced to make clear spectrum available for the new technology. Using current Frequency Coordination policy criteria, non-displacement of incumbents is given higher priority than denser spectral utilization. In geographic locations where there is empty spectrum, the extra cost and effort would not be deemed justifiable.

    The current dilemma is, then: given an already crowded (at least, on paper) spectrum, how do we increase spectral density without causing unacceptable levels of interference or outright denial of service. (These are several of the objectives called out for the STA.) I submit for consideration the following modest proposal: a workable (relatively) simple system which both meets all design criteria and also serves as a model for impact assessment. The criteria are:

      (2a) Provide relay service on the order and quality of that provided by a conventional community repeater;

      (2b) At any instant, emit spectra no wider than one conventional narrowband repeater channel;

      (2c) Avoid to the maximum extent possible, interference to current frequency occupants.

    To facilitate performance assessment, I offer the following operational parameters:

      (3a) Use voice modulation type F3E (conventional NBFM);

      (3b) Use only Frequency Hopping of the carrier frequency to accomplish the SS function;

      (3c) Operate within the 450 MHz repeater spectrum and conventions: receive within the 5 MHz allocated for repeater receivers and transmit within the 5 MHz allocated for repeater transmitters; use carrier frequencies aligned with those of current repeaters: this provides 200 discrete receiver and transmitter operating frequencies, each of width 25 KHz. (Choosing 20 KHz bandwidths provides an additional 50 hopping channels; this may eventually be operationally desirable, but for the purposes of this model it only complicates the arithmetic for interference assessment. It does not significantly alter the impact or nature of signal collisions.);

      (3d) Dwell on each channel for exactly 10-milliseconds, then hop;

      (3e) Choose a hopping control function which:

        (3e1) uses every available channel before any reuse. We will call the total time required to use all the channels the "period" of the hopping function; (taking (3c) and (3d) together, it is 2000- milliseconds) and,

        (3e2) during one period, selects channels for use such that the time since the same channels use in the previous period is statistically random; and,

      (3f) Use generally available low-cost technology.

    Implementation of this system is conventional in every way except in:

    • Frequency generation.
      Recent advances in Phase Locked Loop Synthesizer design and integrated circuit implementation make this module one of the easier parts of this system. Single synthesizer systems are possible, but economics may drive towards duals. Regardless of the method chosen, spectral purity is easily attainable simultaneously with acceptable frequency slew performance. As the cost of Direct Digital Synthesis frequency generators drops, it may well become the generator of choice;
    • Receive, transmit, and frequency/timing control.
      In hardware, this modules is a simple one-chip microprocessor. It is the software embedded herein that is the complex part of this system; and,
    • Simultaneous receive-while-transmit at the repeater site.
      This is a system tradeoff issue and not an absolute requirement, whereby complexity may be moved from user stations into the relay station.

    With the system parameters given above, interference impact evaluation is very straightforward. Parameter 3d is chosen so that SS activity does not activate the noise squelch of NBFM receivers. When the FHSS arrives on an active repeater channel, FM capture rules apply. In the case where the SS station captures the other user, the capture lasts 10 milliseconds in 2000, or for 0.5% of the transmission. This impact is so slight as to be neglected in real operations.

    This system could be fielded under the current Rules, with the significant exception of function 3e2. It is this function which pushes the infrequent potential collisions below the threshold of observability for the NBFM repeater user.

    In order to gain the benefits of Code Division Multiple Access (CDMA) allowing multiple simultaneous SS systems to operate independently in the same spectrum with each other and the NBFM repeaters, spreading codes rich in orthogonal patterns are required. The m-sequences currently required by the Rules provide dramatically inferior performance. It is such unnecessary coding limitations we seek to remove from the Rules.

    The example system not only meets the design objectives (2) (particularly 2c, the avoidance of interference to incumbents), it significantly addresses the problems of (1) affecting technology advancement while achieving more dense spectrum utilization. In addition, its performance degrades gradually as total spectrum utilization increases. The benefits it offers apply equally well to VHF situations, where the availability of jamming and multipath resistant, reliable throughput communications channels are essential in times of emergency. By altering criteria 2b and parameter 3a appropriately, a system of this type can successfully carry medium speed packet data (50- 70 KBbs) with only slightly higher impact on NBFM. This is but one of many possible designs worth implementing and evaluating.

    Other commenters are preparing and presenting the technical case in favor of using SS to the BENEFIT of Weak Signal communications. Uses abound in the research, commercial and government sectors. The tragedy of the current situation is that communications by EME and Tropo Scatter are available to very few amateurs, largely due to the high cost and space demands for exotic antennas. VHF SS has the potential to provide the means for ordinary amateurs with limited resources and facilities to participate in these exciting modes.

    Perhaps more importantly, by virtue of the necessity to combine expertise in both digital and analog practice, SS has the potential to attract and excite the young person interested in advancing his or her technical skills. Not many individuals will take up this challenge, but those that do will find handsome rewards. Amateur Radio is an attractive vehicle for gaining experience toward both professional careers and leisure-time experiences in the communications arts and sciences. It is this appeal that has kept me interested and active for more than 40 of my 52 years.

    It is my recommendation that The Commission proceed with this Rule Making, particularly in the direction of adopting into the Rules the permissions and capabilities provided in the STA. Besides being a particularly powerful technology, in Amateur Radio SS is a new way of thinking. It is this that most deserves your encouragement.

    
                            Respectfully submitted,
    
    
    
    
                            Robert A. Buaas
    


    Comments of Steven Bible, N7HPR

    Before the
    FEDERAL COMMUNICATIONS COMMISSION
    Washington, D.C. 20554

    In the Matter of               )
                                   )
    Amendment of Part 97 of the    )    RM-8737
    Commission's Rules Governing   )
    the Amateur Radio Service to   )
    Facilitate Spread Spectrum     )
    Communications                 )

    To: The Commission

    REPLY COMMENTS OF STEVEN R. BIBLE, N7HPR

    I make these comments in reply to those of George Isely, WD9GIG, President of the Mid-America Coordination Council, Inc., Whit Brown, WB0CJX, Frequency Coordination Chairman of the Mid-America Coordination Council, Inc., William Wells, WA8HSU, Chairman of The Indiana Repeater Council, and Nels Harvey, WA9JOB, of the Wisconsin Association of Repeaters each of which oppose the American Radio Relay League (ARRL) proposal and, in particular, oppose the use of spread-spectrum emissions below 450 MHz.

    PERSONAL INFORMATION

    I make these reply comments as a former student of the Naval Postgraduate School (NPS) located in Monterey, California and as an amateur radio operator. I was a graduate student at NPS from August 1993 to September 1995 upon which time I graduated with a Masters in Science Degree in Computer Science. During my entire time at NPS I was a participant in the Petite Amateur Navy Satellite (PANSAT) project sponsored by the Space Systems Academic Group (SSAG). I am writing on my own personal initiative as an amateur radio operator and not as an official representative of the United States Navy or the Naval Postgraduate School. My purpose in writing these comments is to bring to the Commission's attention information that I believe is vital and important concerning this rule making process with regard to PANSAT, and to relate my own personal experiences from the benefit of experimentation in the Amateur Radio and Amateur Satellite Service.

    GENERAL COMMENTS

    I would like to bring to the attention of the Commission an amateur satellite project currently underway at the Naval Postgraduate School (NPS) since 1989 called the Petite Amateur Navy Satellite or PANSAT. It is a proof-of-concept small satellite for packet store-and-forward communications utilizing spread-spectrum modulation techniques. The spacecraft will supply direct-sequence spread-spectrum modulation with an operating center frequency of 436.5 MHz, a bit rate of 9.84 kilobits per second and 4.5 megabytes of message storage. PANSAT will be launched into low-Earth orbit via the Space Shuttle under the HitchHiker program utilizing a Get Away Special (GAS) canister. Expected launch of PANSAT is September 1997. The spacecraft has a 2 year mission life requirement. I have attached for the Commission's review an introductory article about the PANSAT spacecraft.

    PANSAT's primary goal is in the education of officer students at the Naval Postgraduate School. It is used as a training vehicle within the Space Systems curriculum to provide a tangible project so that students can experience real world operational and design problems first hand. To date PANSAT has produced over 50 theses in areas of electrical, aerospace, and mechanical engineering and space operations. The majority of the theses are unclassified and available to the general public.

    PANSAT has many benefits to the amateur radio service. The first of which is the positive and national exposure PANSAT and amateur radio will receive when it is launched from the Space Shuttle. Secondly is the development of a spread-spectrum modem by the PANSAT engineers, the design of which is planned to be shared with the amateur community. This contribution alone represents many hours of engineering design passed on the to amateur community to build and experiment with a spread-spectrum modem for terrestrial and space communications. Next is the opportunity to operate a new amateur satellite with a new mode of communications providing an international forum for experimentation. Lastly, the many theses contribution to the body of knowledge of not only spread-spectrum communications, but many other topics of interest to the Amateur Satellite Service.

    My concern in writing these comments is the overwhelming desire of the commenters listed above to have spread-spectrum communications removed from the 420-450 MHz amateur band. I would like to impress upon the Commission the benefits that I have outlined above that PANSAT has already contributed to the amateur service and the huge potential that it has when it is launched.

    If spread-spectrum is removed from the 420-450 MHz band the PANSAT project will be irrevocably damaged. Design of PANSAT is presently in the prototyping phase and is expected to be completed at the end of this year. With launch being manifested onboard the Space Shuttle in late 1997, any changes in the design of the spacecraft at this point will cause the project to miss its intended goal. It is too late in the design process to reengineer PANSAT for a frequency out of the 420-450 MHz band. If spread-spectrum is removed from this band, the amateur community stands to loose a very valuable asset and the PANSAT project stands to loose a large amount of money and time invested.

    The Space Systems Academic Group has filed with the Commission an Information for Second Notice of Advance Publication of PANSAT dated May 2, 1995. In the document the particular operating parameters are outlined for the Commission's review.

    Information on PANSAT has been published in many public publications, in both the Amateur press and professional journals. Amateur publications include The AMSAT Journal, QEX, and the Satellite Operator. Information was also broadcasted on News Line the summer of 1995. Professional journals include Spread Spectrum Scene, AAIA Conference Proceedings of the Small Satellite Conferences, and, as mentioned previously, masters theses. Information on PANSAT has been available on the World-Wide Web since the summer of 1994 at http://www.sp.nps.navy.mil/pansat.

    The Radio Amateur Satellite Corporation (AMSAT) North America is also aware of PANSAT. The laboratory facilities were first toured by Mr. Richard Campbell, N3FKV, in 1993. From which he reported to the AMSAT Board of Directors and PANSAT was documented in the minutes of the Annual AMSAT Meeting of 1993. Recently, the AMSAT-NA President Mr. William Tynan, W3XO, toured the facilities September 1995.

    CONCERNING EXPERIMENTATION IN THE AMATEUR RADIO SERVICE

    I would also like to relate my experiences to the benefit of experimentation within the Amateur Radio Service. It has been through Amateur Radio that I have explored the concepts of radio communications, RF propagation, space communications, orbital mechanics, and recently, spread-spectrum communications. All of these concepts, mostly self taught, has enhanced my knowledge of these and many more topics and have proven invaluable in my professional duties and in volunteer emergency communications in the time of disaster.

    Amateur Radio is a perfect vehicle for an individual or group to explore these and many other concepts that embody the spirit of the advancement of the radio art and providing a pool of trained operators, technicians, and electronic experts (Part 97.1 of the Commission's Rules). It is a well known fact that the commercial sector needs trained technicians and engineers in this rapidly advancing technical world. Amateur Radio's unsung legacy toward this demand is largely undocumented and under appreciated. You will undoubtedly find amateur radio operators in all aspects of industry, no doubt contributing to their vocation those things they have learned and experienced in the Amateur Service.

    By providing an environment that promotes experimentation, the Amateur Radio Service can provide a beneficial byproduct to society and technology in general. Thus it is perhaps impossible to measure the benefits contributed to society by this experimental environment. Experimentation in the Amateur Service must be fostered and preserved. There is no other environment like it that can provide private citizens, elementary school children, high school students, and college students with the incentive, motivation, and expressive abilities the Amateur Service provides. There is no other service that allows experimentation with the variety of frequencies and modes of communications to explore topics ranging from astrodynamics to ohms law.

    The PANSAT project would not be possible without the Amateur Radio and Amateur Satellite Services. The synergy of innovation and contribution to the community at large demonstrates the benefits of learning by experimenting and eventually contributing to the body of knowledge on so many countless topics.

    It is with experimentation in mind that I support not-for-profit science and educational, research and development organizations such as the Tucson Amateur Packet Radio (TAPR) Corporation and The Radio Amateur Satellite (AMSAT) Corporation. Both of which have introduced innovations to industry and provided a climate of learning and experimenting within the amateur community. It is in this environment a student can continue to learn long past graduation.

    SUMMARY AND CONCLUSION

    My purpose in writing these comments are many, 1) to inform the Commission about the PANSAT project sponsored by the Space Systems Academic Group of the Naval Postgraduate School, 2) the possible deleterious effects to the project if spread-spectrum emmissions are removed from the 420-450 MHz band, 3) the benefits the PANSAT project has offered and will continue to offer to the Amateur community, and 4) my own personal observations and influences that experimenting in the Amateur Radio Service has had on me in my lifetime to motivate the Commission to continue to foster the climate of experimentation in the Amateur Radio Service as provided in Part 97 of the Commission's Rules.

    I urge the Commission to favorably approve the enhancement of spread-spectrum communications in the Amateur Radio Service as proposed by the American Radio Relay League (ARRL) and amended by the comments of the Tucson Amateur Packet Radio (TAPR) Corporation. I especially urge the Commission, not to remove spread-spectrum emissions from the 420-450 MHz band to the detriment of the PANSAT project.

    Respectfully submitted,

    Steven R. Bible, N7HPR


    Comments of the Naval Postgraduate School

    Before the
    Federal Communications Commission
    Washington, D.C. 20554

    In the Matter of               )
                                   )
    Amendment of Part 97 of the    )   RM-8737
    Commission's Rules Governing   )
    the Amateur Radio Service to   )
    Facilitate Spread Spectrum     )
    Communications                 )
    

    To: The Commission

    REPLY COMMENTS OF THE NAVAL POSTGRADUATE SCHOOL

    Naval Postgraduate School
    Space Systems Academic Group
    Code (SP)
    777 Dyer Rd., Rm. 200
    Monterey, CA 93943-5110

    PREFACE

    Unfortunately, I did not become aware of the proposed rule changes and the existing comments until after the deadline for comments had passed. I, therefore, respectfully request that the Commission consider the comments in this REPLY as part of the official record.

    BACKGROUND

    The Naval Postgraduate School is currently involved in amateur radio spread spectrum communications with its development of a small satellite for digital communications. The satellite is called the Petite Amateur Navy Satellite (PANSAT) and will provide spread spectrum packet radio communications for the amateur radio community while offering a diverse educational tool for the officer students at the Naval Postgraduate School (NPS). NPS has been working on the PANSAT small satellite since 1989 when it first proposed the satellite to the Radio Amateur Satellite Corporation (AMSAT). Currently, the project has working prototypes of a number of subsystems, and some flight hardware, which is to say that the design is quite mature.

    A great deal of time, effort, and money have gone into the project since its beginning. The PANSAT design has always adhered to the existing rules as pertains to amateur radio spread spectrum communications, even after hearing of the STA held by Mr. Robert Buaas, K6KGS. Specifically, PANSAT will use the prescribed 7-bit shift register for the pseudo-noise code (CFR 97.311(d)(1)). It is, therefore, relevant to note to the Commission that any changes that would restrict further the use of spread spectrum communications in the amateur radio bands could have a major impact on our project, forcing increased spending due to design changes, and delays in our launch date due to hardware readiness.

    The operating characteristics of PANSAT have been presented to the Commission most recently in the second pre-space notification. These characteristics were promulgated through the Special Section No. AR11/A/676 MOD-1, dated 30 January 1996. In short, they are as follows:

    Center Frequency:             436.25 MHz
    Frequency Range:              435.25-437.75 MHz
    Max. Spectral Power Density:  -48.8 dBW/Hz (Earth-to-Space)
                                  -53 dBW/Hz (Space-to-Earth)
    Beamwidth:                    35 degrees (Earth-to-Space)
                                  Omnidirectional (Space-to-Earth)
    Orbital Altitude:             395 km (TBD)
    Orbital Inclination:          51.6 degrees (TBD)

    SUMMARY

    NPS is aware of the Petition for Rule Making submitted by the ARRL, and comments filed by TAPR, DoD/NCS, Mr. Charles M. Albert, Jr. (KC6UFM), Mr. Robert A. Buaas (K6KGS), and Mr. Mike Cheponis (K3MC). NPS has also seen Reply Comments submitted by Messrs. Cheponis, and William A. Tynan (W3XO). NPS agrees with the spirit of the proposed changes "to encourage amateurs to experiment and use SS communications, to develop new techniques for increased spectrum efficiency using this mode, and to improve compatibility with narrow-band modes." Spread spectrum offers a number of advantages which should be exercised by amateur radio experimenters while preserving existing narrow-band communication modes.

    NPS does not agree with the changes proposed to 97.311(g) requiring the addition of "automatic transmitter power control." This is clearly counter to making the spread spectrum mode of communications more flexible, and is itself superfluous, as noted by Mr. Buaas' reference to 97.313(a). The technical hurdles implied by this rule change are not trivial; and as pertains to space-based stations in particular, would pose an unnecessary burden on the design of the space segment of the communications link.

    NPS has implemented a variable amplifier in the design of the space segment communication system, with a maximum 7 W output commanded from the ground. This was done in the spirit of using the minimum transmitter power necessary. An automatic system, however, would be a much greater challenge, and offer little advantage.

    As a matter of clarification, as Mr. Cheponis suggests, it seems prudent to leave 97.311(b) as it is.

    NPS suggests that 97.311(e) and 97.119(b)(5) should be deleted as a matter of practicality. However, it is reasonable to assume that experimenters would keep pertinent information as a matter of course.

    As far as 97.119(b)(5), it merely simplifies the design requirements of the SS system and reduces unnecessary emissions.

    NPS takes particular exception to the Reply Comments submitted by Mr. William A. Tynan where he proposes that no SS communications should be permitted below 450 MHz. Clearly, this would have a major impact on the NPS PANSAT project. Such a drastic change in frequency use is unwarranted. Mr. Tynan's arguments of interference from SS systems are based on supposition, not fact. However, as they do manifest valid concerns among a group of amateur operators, these concerns should be addressed. PANSAT will actually be one of the satellite operations that Mr. Tynan is concerned about protecting, and is itself an experiment.

    PANSAT would provide a quantitative means by which Mr. Tynan's concerns can be investigated. It should also be noted that Mr. Tynan is well aware of PANSAT, and has visited the NPS laboratories where PANSAT is being developed; as have other AMSAT members.

    It is NPS position that SS communications should be less restricted and opened to 50 MHz and above as proposed by Messrs. Buaas and Cheponis.

    CONCLUSION

    NPS has a vested interest in the future of spread spectrum communications in the amateur radio bands, especially in the 70 cm band. NPS is developing a small satellite for SS digital communications as a service to the amateur radio community and will abide by the rules as set forth by the Commission concerning amateur radio communications. NPS has invested a great deal of resources in this project with the assumption that the current rules concerning amateur radio spread spectrum communications would remain open in the 70 cm band.

    NPS does not agree with the proposed change to the CFR 97.113(g) for automatic transmitter control to limit radiated power.

    NPS does agree with the spirit of the rule changes where flexibility of amateur radio spread spectrum is increased; and with the comments proposed to make amateur radio spread spectrum available in the 50 MHz and above frequencies.

    NPS does not agree with the proposal put forth by W. A. Tynan to remove amateur radio spread spectrum from below 450 MHz.

    Thank you for your attention.

                                         Respectfully Submitted,
    
    
    
    Daniel Sakoda                        Rudolf Panholzer
    PANSAT Project Engineer, KD6DRA      Chairman,
                                         Space Systems Academic Group

    March 11, 1996

     


    National Communications System, reply comments to RM-8737 March 11th, 1996

    Summary

    The American Radio Relay, Incorporated (the League), the national association of amateur radio operators in the United States, submits its reply to comments filed in response to the above-captioned Petition for Rule Making (the Petition) filed by the League December 12, 1995

    The problem that the League's petition seeks to address is not too much spread spectrum in the Amateur Service. The problem is not enough spread spectrum experimentation. Many of the commenters are seized with protecting their existing narrow-band operations, and are concerned (unnecessarily) about increased noise levels in bands used by narrowband modes, rather than promoting spread spectrum for the benefits, including spectrum efficiency, that it can provide. While the Amateur Service is intended to be an experimental service, which requires flexible rules and some trust of the licensees carrying out experiments, some voices speak in favor of even greater restriction and mandatory control. The imposition of additional constraints would guarantee that the Amateur Service will not be able to keep up with spread spectrum developments in Parts 15 and 90 of the Commissions rules, and will be prevented from maximization of spectrum efficiency in its own bands.

    The League suggests that its petition, which after all suggests only a modest deregulatory effort, is properly aimed at increasing the flexibility of spread spectrum users in order to allow the development of compatible systems which maximize spectrum efficiency. Those who oppose this increased flexibility do not share the League's view of the Amateur Service as a fundamentally self-regulated service that makes its own efficient accommodations for the varied uses of its frequency allocations. Without mandatory frequency coordination, non-standard definitions of interference, or detailed Commission regulation of spreading codes, the League believes that additional spread-spectrum experimentation is in the best interests of the Amateur Service, and that compatible sharing, long a benchmark of amateur radio, will be as successful in the future as it has been in the past.


    Before The
    Federal Communications Commission
    Washington, DC 20554

    In The Matter Of:
    
    Amendment of Part 97 of the         )   RM-8737
    Commission's Rules Governing        )
    the Amateur Radio Service to        )
    Facilitate Spread Spectrum          )
    Communications                      )
    

    February 26, 1996

    To The Commission:


    REPLY COMMENTS OF THE MANAGER OF THE NATIONAL COMMUNICATIONS SYSTEM

    The Secretary of Defense, Executive Agent of the National Communications System (NCS), through duly authorized counsel, hereby files these Reply Comments in the above-captioned matter which regards a Petition for Rulemaking filed by the American Radio Relay League, Inc. (the "League") on December 12, 1995. The League proposed amendments to Commission Rules and Regulations to facilitate, to a greater extent than is done by the present rules, the contributions of the Amateur Service to the development of spread-spectrum communications. In its Petition, the League recited the development of the Commission's policy allowing the Amateur Service to utilize spread-spectrum technology but believed that lack of flexibility in the existing Commission Rules has not permitted such use to develop to its highest potential.

    The Secretary of Defense filed comments on February 26, 1996 supporting the League's petition and in addition suggested the deletion of Section 97.119(b)(5) of the Commission's Rules.

    Comments ranged from complete agreement with the League's proposals [1] to what are stated to be total opposition to the petition [2], and in the middle, general support [3].

    It appears the main concern of those question the proposals set forth in the petition is the use of spread spectrum below 450 MHZ. Several of the comments suggest that such use would be inappropriate because of the potential interference to narrow-band amateur communications. Some claim very serious interference problems would result. No hard data is provided. it should be noted that the use of spread spectrum to as low as 420 MHz is already authorized by the Commission's rules [4], and there have been, according to the League, no established instances of actual interference to narrow-band amateur communications from spread spectrum communications. Thus, there would be no point in precluding spread spectrum usage below the 450MHz band, which is now permitted. Moreover, any proposals to change currently authorized frequencies for spread spectrum go well beyond the scope of the instant proceeding.

    The comments of Tucson Amateur Packet Radio Corporation, as did those of the Secretary, propose the elimination of Section 97.119(b)(5) of the Commission's rules. The Secretary believed the eliminations of that section of the rules would lead to increasingly available Commercial Off the Shelf equipment for spread spectrum. Mr. Buass recognizes the current situation [5]. It is urged that the Commission make the elimination of Section 97.119(b)(5) part of a Notice of Proposed Rulemaking herein.

    The specific rule changes proposed by the League would (1) permit brief test transmissions using spread-spectrum emissions; (2) permit international spread-spectrum communications between United State's amateurs and amateurs in countries that permit amateur use of those emissions; (3) delete unnecessary restrictions on spread codes and repetitive definitions of "harmful interference"; and (4) provide for automatic power control to insure use of minimum necessary power to conduct spread-spectrum communications.

    CONCLUSION

    The Secretary of Defense, in his capacity as Executive Agent of the NCS, continues to believe the proposed changes have merit and will advance the usage of spread spectrum technology. it is urged that the Commission issue a Notice of Proposed Rulemaking proposing the League's changes and the elimination of Section 97.119(b)(5) of it rules.

                              Respectfully submitted,
    
    
    
    
                              Paul R Schwedler
                              Deputy Chief Regulatory Counsel
                              
                              
                              Carl Wayne Smith
                              Chief Regulatory Counsel
                              Telecommunications, DOD
                              Code RGC
                              Defense Information Systems Agency
                              
    

    Footnotes

      1. Secretary of Defense


      2. Wisconsin Association of Repeaters, Mid-America Coodination Council, Inc (Brown and Isely), San Bernadino Microwave Society, Southern California Repeater and Remote Base Association, SouthEastern Repeater Association, Inc., Indiana Repeater Council, and Amateur Television Quarterly.


      3. John Mock, Robert A. Buaas, and Tucson Amateur Packet Radio Corporation


      4. 47 CFR Section 97.305(c)


      5. "Virtually none of the currently available amateur equipm,ent can be utilized in the SS mode without major modifications and enhancement." Buass Comments, page 1.


    Reply Comments of Charles M. (Marty) Albert, Jr. KC6UFM

    Before the
    Federal Communications Commission
    Washington, D.C. 20554

    In the Matter of               )
                                   )
    Amendment of Part 97 of the    )   RM-8737
    Commission's Rules Governing   )
    the Amateur Radio Service to   )
    Facilitate Spread Spectrum     )
    Communications                 )
    

    To: The Commission

    March 13, 1996

    Reply Comments of Charles M. (Marty) Albert, Jr. KC6UFM

    To The Commission:

    INTRODUCTION

    Since my initial comments to The Commission (dated March 4, 1996), there have been several comments filed by a number of groups and individuals that I feel require my making additional comments.

    I beg The Commission's patience and understanding in this matter. My comments here are longer than may be optimum and than may be dictated by proper protocol, however the issue of Amateur use of Spread Spectrum (SS) systems is, I believe, of the utmost importance in bringing The Amateur Radio Service into the 21st century.

    The specific comments that I wish to address have been made by:

    BROWN, WITT (WB0CJX)
    ISELY, GEORGE R. (WD9GIG)
    TYNAN, WILLIAM A. (W3XO)
    SOUTHERN CA. REPEATER AND REMOTE BASE ASSOCIATION
    MANAGER OF THE NATIONAL COMMUNICATIONS SYSTEM
    THE INDIANA REPEATER COUNCIL
    CHEPONIS, MIKE (K3MC)
    RUH, HENRY (KB9FO)
    BUAAS, ROBERT A. (K6KGS)

    Some of my comments will address the above in groups of two or more.

    COMMENTS TO BROWN AND ISELY

    (Neither Brown's nor Isely's letter contain reference dates)

    I shall address the comments made by Brown and Isely at the same time since their initial comments are basically in "form letter" style and so are the same.

    Isely and Brown are the President and Frequency Coordination Chairperson (respectively) for the Mid-America Coordination Council (MACC). I note, however, that their letters do not state that they are acting on behalf of MACC and therefore their comments can only be taken to represent their individual views.

    There is some issue made that the American Radio Relay League (ARRL) does not represent a majority of Amateurs and that the initial proposal made by the ARRL does not represent the views of ARRL membership. This writer is not a member of the ARRL, although I have been in the past, and I make no claims that I agree with everything that the ARRL does or has to say. This does not degrade the fact that the ARRL is the single largest group of Amateurs and has traditionally represented all Amateurs, members or not, before The Commission and others on many issues. This is, frankly, a non-issue.

    Brown and Isely quote Robert Dixon from the IEEE Press in 1976. I think there is no argument on Mr. Dixon's observations. However, Brown and Isely go on to state that, "... overall spectrum usage, including amateur use, has increased tenfold..." since Dixon's statement. There is no backing for this statement. In some local areas, I am sure that VHF/UHF usage has increased several hundred times in the past twenty years. In other local areas, however, it has decreased by perhaps the same amount. Such a blanket statement shows a simple antagonistic position as opposed to one of considered replies and comments.

    Brown and Isely make comments about the possible use of SS by "the criminal element." I have no idea what this comment has to do with the issue at hand.

    Lastly, while I do not question the sincerity of the concerns expressed by Brown and Isely, I do question their motivation. With the recent and well publicized disagreements between the ARRL and various coordinating bodies over the idea of a Single Point Of Contact (SPOC) with The Commission, coupled with the antagonistic position in their comments, I can't help but wonder.

    COMMENTS TO TYNAN

    (Reference to Tynan's letter dated March 11, 1996)

    Mr. Tynan brings up some very valid concerns about the impact of SS on satellite, Earth-Moon-Earth (EME), and general weak signal operations, concerns that I share. The various satellite, EME, and weak signal band segments are well defined in the various band plans and in The Commission's Rules. My own interpretation of Part 97 and the band plans is such that all operations other than satellite, EME, and weak signal should avoid use of those segments.

    Perhaps a direct statement in Part 97 would be in order to prohibit activities other than those specified in the segments for the above usage. Actually, I doubt this is needed. The current rules seem to come this well.

    Tynan also states that SS should not be allowed below 450 MHz. This position would kill a major area of SS operation: That of high speed digital networking. The vast majority of the country is rural in nature. In the cities and towns, it is a simple matter to place digital nodes close enough together to allow the use of 33 cm and shorter wavelength bands. In the "country", for example where I live, it is nearly impossible to have nodes closer than 20 miles apart and difficult to get a link less than 40 miles. This fact coupled with the terrain (rolling hills) implies the need for a lower VHF band, with 2m being most used for current digital modes.

    The solution to all of Tynan's real concerns are for all users, SS or otherwise, to avoid the various band segments in question. After all, what would happen to the 2m satellite segment if myself and a friend were to fire up our 1 kW amplifiers dead on the center of the satellite bandpass? Much more interference than the 50 dB increase in noise offered in Tynan's example of a SS system!

    COMMENTS TO SCRRBA

    (Reference SCRRBA's letter dated February 23, 1996)

    The Southern California Repeater and Remote Base Association (SCRRBA) presents a long and detailed comment that starts with the position that the ARRL proposal should be summarily dismissed. Quite an interesting position since SCRRBA offers nothing to back this up.

    Again, I question the motivation of SCRRBA in their position but not the validity of their concerns.

    What is being discussed here is the implementation of a new mode that will be competing with existing modes for spectrum space. This is no different from the similar discussions when Single Side Band (SSB) and Frequency Modulation (FM) were first introduced.

    My wife (Gayle Albert N0UTX), a very much "non-technical" Amateur, after reading the SCRRBA comments, has asked me, "What does [SCRRBA] do?" After I explained the duties, briefly, of a frequency coordinator, she then stated, "Seems to me that they [SCRRBA] have no interest in Spread Spectrum because it could remove their reason for being." While I doubt that SS, or any other system, will remove the need for frequency coordination, there is no doubt, based on the literature, that SS can increase the ability of a given spectrum segment to support more users and reduce overall interference. This is, of course, based upon proper and careful spectrum management that will encompass and accommodate ALL operating modes. Isn't this what the Frequency Coordinators are supposed to do?

    COMMENTS TO THE MANAGER OF THE NCS

    (Reference NCS letter dated February 26, 1996)

    The core of these comments is the removal of the CW identification requirements for SS systems. I have mixed feelings on this matter...

    While it would be difficult to implement the required CW ID, I also feel that there must be some way for a non-SS user to make a positive identification of the originator of the signal in question. Couple the lack of a CW ID with the possibility of using a nearly infinite number of spreading codes, and you will have what amounts to an unidentifiable transmission.

    I would suggest to The Commission that a "Dual ID" system be implemented for SS that would allow SS stations to identify in one of two ways:

      (1) Identification signals to be transmitted with a Rules specified spreading code at the normal 10 minute timings, or:

      (2) CW identification sent "in the clear" at the center frequency.

    This area needs some work and I leave that to those more technically able than I.

    COMMENTS TO THE INDIANA REPEATER COUNCIL

    (Reference IRC letter dated February 23, 1996)

    The Indiana Repeater Council has offered some interesting, and at least partially workable alternatives to the ARRL proposal.

    The suggestion that a frequency hopping system falling between currently assigned channels is a good one and, to my mind, simply makes good common sense. This is, in fact, the very concept that I would use on a high speed digital network if the new Rules will allow.

    The comments go on, however, to state that SS should not be allowed below 450 MHz. Again, this is a limitation that will likely terminate the use of SS in Amateur Radio other than as a curiosity.

    The motivation of this group is not at question in my mind. As opposed to simply dismissing the proposal because the ARRL made it, The Indiana Repeater Council has offered some real ideas and clearly put some thought into their ideas.

    COMMENTS TO CHEPONIS

    (Reference Cheponis letters (2) dated March 4 and March 6, 1996)

    Cheponis also takes issue with the ARRL proposal to require automatic transmitter power control, as do I. Again, this is a requirement that: (1) Would be nearly impossible to implement; (2) Would be totally impossible to enforce; (3) Would be clearly discriminatory to SS; and (4) Serve no clear purpose.

    COMMENTS TO RUH

    (Ruh's letter not dated for reference)

    Ruh writes that he is in support of the position stated by The Indiana Repeater Council and further comments that the 219-220 MHz segment of the 125 cm band be opened to SS emissions.

    While the addition of the 125 cm segment is a step in the right direction, once again, no consideration is given for "real world" usage of SS in the usable 2m and 6m bands.

    COMMENTS TO BUAAS

    (Reference Buaas' letter dated March 11, 1996)

    As pointed out by Buaas, the current practice and application of Amateur VHF/UHF voice communications is at least 20 years out of date. The local 2m repeater uses a transmitter and receiver that are 27 years old!

    Buaas goes on to point out that, using conservative SS techniques, the interference to a voice channel would come to a 0.01 second (10 millisecond) burst every 2 seconds! This comes out to interfering with the voice channel for one-half of one percent of the signal. Hardly significant.

    Taking some more radical numbers, it is a simple matter to get interference levels down to the 0.001 second (1 millisecond) range. Even less significant.

    There was a lot of discussion in other comments about "average power density" and the like, but those comments have no basis in real world applications. They are looking at the problem from the standpoint that the SS signal will be on a given frequency for a long period of time when, in reality, this is simply not the case. The SS signal will gone before the narrow band station even knows it was there.

    I continue to support Buaas in his position.

    ADDITIONAL GENERAL COMMENTS

      PART 97.305(b)

      In my initial comments to The Commission, I supported the ARRL in its position concerning 97.305(b) that SS should be authorized for brief testing. I no longer support this position. SS has reached the point where it should no longer be treated as an "experimental" mode and reference to SS should be removed from 97.305(b).

      The change in my position is due to my continuing education about SS and its applications to both Amateur and commercial usage.

      INTERFERENCE

      Concerning possible interference to other modes, there has been a good deal of discussion about SS interference to voice communications, but there is a very important fact being missed in those comments...

      In spite of the best efforts of some very bright and inventive people, the best Signal Processing system available to date is the human mind. How many times have you ACTUALLY heard only part of a word or sentence and yet been able to understand perfectly what is being said? Often, we can miss all but one or two words of a sentence and be able to understand the meaning and carry on an acceptable conversation.

      If we take an average conversational speech rate of 300 words per minute (this is extremely fast.. the real number is closer to 75 words per minute, but this is to make a point) you will find this is 5 words per second. Using the 10 millisecond SS dwell time cited by Buaas, this means that you will miss only ONE-FIFTH of ONE WORD sent. If we assume that the voice transmission lasts 5 minutes and the SS makes a "hit" as often as possible, out of the 1500 words sent, you will miss only one-fifth of each of 30 different words.

      The human mind will more than be able to "fill in the blanks" of such a conversation and the people involved in the conversation will never even notice the interference.

      Simply put, the REAL WORLD impact of any interference caused by SS would likely be unnoticeable in voice communications. This could be enhanced even more by not using a repeater input frequency as part of the FH system and by using the idea suggested by The Indiana Repeater Council of FH to points between established channels.

      The impact on digital communications is, however, be a different matter. Using the 10 millisecond SS hit time and a 9600 BPS data signal, we find that the SS signal would damage a significant percentage of the digital signal. On the other hand, ANY damage to a digital signal is significant... Just one lost bit renders the entire packet worthless. So, while the various frequency coordinators are concerned about the impact on voice operations, I am more concerned about the impact of SS on digital work.

      Since it has been shown that the REAL WORLD impact on voice operations will be all but non-existent, I will not address solving that non-issue.

      To prevent interference to digital signals is simple... SS operators will need to follow the band plans and not operate in the digital segments.

      SS USE IN HIGH SPEED DIGITAL WORK

      SS offers a real option for high speed digital networking, especially in the rural parts of the US. The vast majority of the country fits this category and this is exactly the areas where the higher speeds are needed most to be able to move traffic rapidly between points.

      In such areas it is, as a rule, difficult to have nodes close together as in the cities. This problem almost requires the use of VHF operations to get the needed communications range.

      SS offers a great potential for high speed digital networks, much higher than the current 9600 and 19.2K BPS systems now in various stages of operation. Speeds well in excess of 500K BPS are not out of the question. Such a network of Amateur high speed data nodes could prove to be invaluable in the event of an emergency.

      In my research, I have become convinced that SS is the way to implement such a network. Because of the high immunity to interference, ability to co-exist with other services (see above), and the ability to use very high bit rates, SS is a natural for this type of application. The problem is that the current rules, and if the Frequency Coordinators get their way, the new rules as well, prohibit SS use below 450 MHz.

      Without access to 6m, 2m, and 125cm, the use of SS in a truly functional high speed digital network is a dead issue. This would be, in my opinion, a terrible loss to Amateur Radio and the United States as a whole, in the event of an emergency.

      FOR THE GREATER GOOD?

      Several of the writers who are part of some Frequency Coordination body cite, repeatedly, that the use of SS will cause problems in the use of voice modes. This has already been shown to be a "paper work illusion" and has no basis in the real world. These same writers continue to make reference to "... over crowded bands..." Again, this is a purely local issue and has nothing to do with the rest of the country or, indeed, the real world. Where I live, there are three 2m FM repeaters within range of a 250 mw hand-held using a rubber duck antenna. All of these repeaters have perhaps 6 users on the air during the morning and evening "drive time" periods. There are maybe 20 users on the air for the several scheduled Nets. After about 9 PM, they are dead air. This is hardly my definition of crowded.

      In other words, the various Frequency Coordinators do not speak for all of Amateur radio, or even anything close to a significant part of it. They speak ONLY for their small, local group at most, and in the case of the above noted writers, I suspect they are speaking only for the individuals that signed the letter of comment.

      I, for one, resent these groups and individuals assuming to speak for me and my situation.

      On the other hand, the ARRL does not, as pointed out, speak for all of Amateur Radio. They most certainly do not speak for me.

      Due to the ARRL's national position and Section structure, however, they are in a much better position to determine what most Amateurs need to further their activities than any local repeater group.

      It just so happens that, in this particular case, I do indeed agree with the ARRL on the basics, if not the details, of this proposal.

      STATE OF THE ART?

      As pointed out by Buaas, most Amateur voice systems are several decades out of date. The digital world is not much better off, being at least 10 years behind.

      SS offers Amateurs a unique chance to move back to the "edge of the envelope" of technology once again. If we fail to take this step as Amateurs and if The Commission fails to allow us to take the step, the chance may forever be gone.

      SS has possible applications, as pointed out by Tynan, in satellite, EME, and weak signal work. These areas can and will not be explored unless SS is allowed in such a manner so as to encourage more Amateurs to enter the mode.

      The various modes cited by Tynan are, by and large, the property of those Amateurs with the time and money needed for the expensive equipment that is required to pursue them. SS may offer a way for "the average Joe" to obtain access to these exciting modes. As I stated before, this discussion smacks of the altercations encountered when SSB and FM first came along. A similar event happened when Packet came up. Several more have happened in the past or continue on even now.

      I personally see no difference.

      THE KEYS

      The key to this problem is, in my opinion, simple. It has been shown that the real world, as opposed to a paper work illusionary world, impact of SS on existing voice services will be all but non-existent. All that needs be done is for the SS stations to follow one simple guideline:

      Follow The Local Band Plan

      The impact on digital modes could be severe. I see almost no way that a SS signal will be able to co-exist with a narrow band digital signal. Again, there is one simple rule that the SS stations need to follow:

      Follow The Local Band Plan

      As for satellite, EME, and weak signal work, the impact may be slightly higher than that on more 'normal' voice operations. This is, however, doubtful due to the human mind's ability to rebuild the missing data. This is, after all, what allows one to "hear" what the other end is sending most of the time in these modes anyway. Even so, in order to avoid problems to these operations, all that the SS stations need to do is:

      Follow The Local Band Plan

      If, for example, two stations wish to chat via simplex, how can interference to them by SS be avoided? All that needs to be done is for the two stations to follow one rule when they pick their simplex frequency:

      Follow The Local Band Plan

      I know the above is redundant, but it illustrates the fact that if people use a little common sense and courtesy, a sadly rare commodity these days, there will be no problems. Any problems that do come up will be local in nature and should be resolved by local groups, not by some coordinators several states away from the problem.

    CONCLUSION

    I would encourage the various frequency coordinators to review their comments and their motivations. While it is true that local frequency coordinators have a duty to their respective small service areas, they also have a duty to the entire nation's Amateurs to encourage and facilitate growth.

    This growth takes the form of not only exploring new technology but in maintaining a state of the art approach to all Amateur operations. Consider that SS may very well become the mode of choice for voice operations once the system has been developed and perfected by the pioneers and the hardware is widely available.

    I would encourage The Commission to evaluate all comments in full light of the facts of SS systems contained in the many professional journals and the reports made by the participants in the current STA held by Buaas.

    Lastly, I encourage all parties to look at things from the Real World perspective. As everyone no doubt knows, the "paper work illusion" can differ substantially from reality. In this case, the illusion is significant interference while reality is that the interference will not be noticed.

    I wish to thank all those who have commented for their efforts and thoughts.

    I wish to thank The Commission for their time, consideration, and understanding.

                              Respectfully Submitted:
    
    
    
                              Charles M. (Marty) Albert, Jr.   KC6UFM
                              PO Box 717
                              Fredericktown, MO  63645
    

    Copies of this letter sent via E-Mail to: Robert Buaas
    American Radio Relay League
    Tucson Amateur Packet Radio Corp.


    AMRAD Spread Spectrum Update

    The following is an article which appeared in the May-June 1996 issue of the AMRAD Newsletter.
    Submitted by: Andre Kesteloot N4ICK (July 22nd, 1996)

    Spread Spectrum Update
    by Andre Kesteloot N4ICK

    Spread-Spectrum continues to be a source of lively technical discussions at the AMRAD Taco meetings (every Saturday lunch, see the back of this Newsletter for details) but this time, I would like to reprint portions of written communications by two non-Taco attendees.

    On March 11, 1996, Bill Tynan W3XO submitted his comments to the FCC, and you will find below what I consider the most relevant technical passages.

    [...] I (writes Bill Tynan) have major reservations concerning the Petition for Rule Making filed by the American Radio Relay League last December. Although I am in favor of developing new technology in the Amateur and Amateur Satellite bands, including Spread Spectrum (SS) techniques, I am concerned that SS's widespread use, with no frequency restrictions, will cause major interference to satellite operation as well as to weak signal terrestrial and EME work. Therefore, I strongly suggest that any relaxation of the spread spectrum rules that the Commission may decide upon, should be accompanied by restrictions limiting it to specific frequency segments within the Amateur and Amateur Satellite bands. Otherwise, it has the potential to make reception of the relatively weak signals from amateur satellites, distant terrestrial stations and signals reflected from the Moon, all but impossible in many parts of the country, particularly in urban areas.

    In support of this contention, I cite both calculations made relative to potential SS signal levels and the ARRL's own statements with regard to potential interference which Spread Spectrum might cause. To obtain a measure of the possible interference that could result from only a single spread spectrum station, the following parameters are assumed:

    • Spread spectrum station with an effective power of 100 W ERP = +20 dBW
    • If spread over 10 MHz ( -50 dBW / Hz
    • Free-space attenuation at 20 km from the spread spectrum station in the 70 cm (420 - 450 MHz) band = -110 dB
    • Spread spectrum signal at 20 km = -160 dBW / Hz

      A receiver with a 1 dB NF (common in satellite & weak signal work) = -210 dBW / Hz

    This results in the spread spectrum signal causing as much as a 50 dB increase in the noise floor existing without it.

    Even if the SS station has a power of only 1 Watt ERP (20 dB less), the noise floor would still be as much as 30 dB higher because of its presence. Similar calculations for other distances can also be done. For example, the spread spectrum signal would be 20 dB stronger at a 2 km distance. As another example, a 100 Watt transmitter and 10 dB gain antenna could create 10 dB more interference. Obviously, if the spread spectrum station is in close proximity to the satellite, terrestrial weak signal or EME, station, the degradation from the spread spectrum station's operation would be much greater.

    The effect of automatic power control for SS stations using transmitters over 1 Watt is difficult to assess, but one can envision situations in which interference from other SS stations, as well as non-SS stations, might cause the SS station(s) to increase their power in order to retain the desired signal to noise ratio. In such a case, power control would do nothing to alleviate interference for other users of the band.

    It might be said that antenna directivity would provide protection. I believe that, with increases in noise floor as great as these cited above, antenna directivity will not help much. If the increases were in the order of 5 to 10 dB antenna directivity might be of some benefit, but not for the cases noted. The reason for this is that few amateur satellite ground stations, or even terrestrial weak signal operators, have antennas with side lobes down 30 dB. I am not sure that even EME operators have antennas that good. In addition, there are many instances in which antennas being used to receive amateur satellites, or signals reflected from the Moon are pointed, near the horizon rather than being elevated. For example, LEO satellites are typically below 10 degrees elevation approximately half the time during which they are within range of a given location. Of course, antennas for terrestrial work are always pointed at the horizon. In these cases, there is no improvement from using directive antennas if an interfering spread spectrum station happens to be in the same direction as the desired satellite, terrestrial station; or even the Moon.

    The received signal strength for EME stations on 70 cm is in the order of -150 dBm, many times even less. Obviously, because of such extremely low received signal strengths, ANY increase in noise floor would be sufficient to render successful EME work impossible.

    Therefore, significant use of SS, which might include 432 MHz would probably spell the death knell for EME as a viable mode on that band. [...] I believe that spread spectrum operation should be encouraged. I think that it will eventually prove to be a valuable mode for both terrestrial and satellite applications, and maybe even EME. However, I believe that it should be restricted to certain frequency segments so as to offer minimal interference to other modes, while still allowing experimentation. The Commission has done this in other amateur rules. For example, voice operation is limited to certain segments in the HF and VHF amateur bands. Unattended digital operation is restricted to certain small segments in the HF bands and unattended beacons are limited to specific segments on 10 meters through 70 cm.

    To alleviate the kinds of interference cited, I believe that spread spectrum should not be allowed below 450 MHz. I know that the current rules allow it in the 420 - 450 MHz band, It may be argued that this proves that spread spectrum poses no threat to other types of operation, since no reports of interference have been registered in the ten years since it was authorized. However, the ARRL admits in their Petition that SS operation has not been widespread. This is probably an understatement. I am not aware of the results of any SS operation. None were reported to me when I was writing The World Above 50 MHz and no papers on amateur SS experiments have been given at AMSAT's annual Space Symposiums. Specifically, I know of no reports of tests showing the potential interference to other modes of operation including weak signal modes, by SS operation even though SS operation has supposedly been taking place since 1985.

    I would like to see spread spectrum develop and become a major factor in Amateur Radio, especially on the microwave bands. But, I do not think it should be allowed to do so to the detriment of other modes of operation. It has not been demonstrated that it won't. In order to allow it to fulfill its potential and still protect these other types of operation, I believe that spread spectrum should be authorized only in certain band segments beginning in the 33 cm (902 - 928 MHz) band. Specifically it should be placed in segments that provide protection for weak signal terrestrial and EME operation which occur in fairly narrow segments at 432, 902, 1296, 2304, 3456, 5760 and 10,368 MHz.

    Such an approach will also protect amateur satellite operation in the 435 - 438 MHz band. It might be possible to allow SS in the 1260 - 1270 MHz (uplink only) and 2400 - 2450 MHz satellite bands, but that should be studied prior to doing so. Certainly, SS should be allowed in some satellite bands, as it will probably prove useful for satellite work in the future. Possibly restricting it in the lower 5 or 10 MHz portion of the 2400 - 2450 MHz band, but permitting it in the upper portion, would protect existing, and near-term future, amateur satellite operation and still permit the use of Spread Spectrum with satellites designed for it in the years to come.


    I brought the above comments by Bill Tynan to the attention of Alan Eynon N3IRL who, on 13 May 1996, offered the following observations:

    Hi Andre,

    Thanks for forwarding Bill's comments. I found them well-reasoned and thoughtful, and it is certainly a relief to read a discussion about spectrum allocation that crosses the "this is mine and you can't have it" threshold and actually goes on to concrete proposals about sharing the resource.

    I won't argue with Bill's numbers, but I don't believe their application corresponds to how those of us who design spread systems actually intend to use them. In short, I don't think his receiver is going to 'see' us.

    Here's why:

    I prefer to work backwards from Bill's numbers. Let us assume that I, too, have a receiver with a noise floor of -210 dBW / Hz over a 10 MHz reception bandwidth. Let us assume the main lobe of my spread signal fills the 10 MHz. That is a 5 Mchip/sec signal. So far, this is straight from what Bill said.

    I am going to assume that I can get 30 dB processing gain from that 5 Mchip / sec signal, so I'm either operating at 5 kbps BPSK, or 10 kbps QPSK.

    I can normally demodulate a BPSK signal and get a decent bit error rate at an output (de-spread) SNR of 15 dB. This gives me a processing margin of (30-15) = 15 dB

    In other words, my signal can be 15 dB below the noise floor of my receiver, and I'll still get enough de-spread SNR for good BER performance. That's a received signal of -225 dBW / Hz.

    Assuming the same path loss at 20 km (-110 dB), that means my transmitter power density is -115 dBW / Hz. The signal is spread over 10 MHz (70 dBHz), so my transmitter EIRP must be -45 dBW, or about 32 (W.

    If I have done the math right, that's where I would be operating, at a level that won't even break the noise floor of Bill's receiver. In fact, that 15 dB processing margin equates to a factor of roughly 30 in signal power, and since signal power is inversely related to the square of the distance, his station can be over 5 times closer (no more than 4 km away), and my spread signal still won't interfere with his receiver. Alternately, there could be 30 of us on the same 10 MHz band, all 20 km from Bill, and he won't detect our presence. Even in the Baltimore / Washington area, I can't imagine there will be enough hams doing SS to cause grief.

    Rather than allocating discrete portions of spectrum for spread operations, wouldn't it be better to open all bands above HF to SS, but as a secondary user on a not-to-interfere basis? Certainly the FCC could set power levels, spreading rates, and suitably long sequences (to provide adequate spectral content for the signal, viz.: it wouldn't make sense to use a 15 chip spreading sequence at 5 Mchip/sec, since the spread carrier tones would then be 333 KHz apart) to satisfy even the most discriminating EME and weak signal enthusiasts. And this would also give them access to all the bands, instead of (potentially) blocking portions with needlessly powerful SS transmissions.

    I encourage further discussion on how both user communities can share the entire spectrum.

    Alan N3IRL


    Wideband Noise on the 430 to 440 MHz Band
    Appendix to Reply Comments of CENTRAL STATES VHF SOCIETY

    50ohm load, AZ=120 degrees, AZ=90 degrees

    Switching between a 50 ohm load, the antenna pointed 30 degrees off the mast and the antenna pointed at the mast. 410 to 460MHz.

    I have noticed an increase in background noise on the amateur 70cm band (430-440MHz) when I point my antenna due East, which is the direction of the Craigkelly TV Mast. Other amateur stations in the area are also hearing this and in all cases they also appear to be getting it from Craigkelly. At first it was thought to be wideband noise from one of the UHF TV transmitters, however the engineers cannot see this noise on their transmitters. It has been suggested that the noise may instead be coming from another transmitter that is co-sited on the TV mast and indeed may be using some form of wideband spread spectrum modulation.

    Different receivers using different I.F.s and cavity filters ahead of the preamps have all been tried but the noise is still there - right across the band and beyond. A spectrum analyser was borrowed and the following plots were produced of the interference. The difference between pointing the yagi at the TX and away from it (nulled) or just a 50 ohm load is approx 10dB whether on Spectrum analyser or SSB RX. as can be seen on the following Spectrum Analyser plots

    Spread of signal on SA is from 420MHz to 450MHz with that antenna, however a lot of what I am seeing may be the drop off of gain of the antenna outside the 432MHz band therefore I estimate signal may be 40MHz wide.

    For the spectrum analyser tests this is what I used:- A 24 ele DL6WU 432MHz Yagi into approx 20m of 0.5" Heliax into the preamp.

    Preamp has NF=0.5dB, G=15dB (350-450MHz BW) followed by post-preamp NF=10dB, G=20dB BW= DC-2GHz into an HP Spectrum Analyser.

    The Spectrum Analyser was set to REF=-37dBm and with a 50ohm load on the input to the preamp, the noise floor was -85dBm (0dB att). RES BW 300KHz. The peak of the QRM was -70dBm on the Analyser (remember that this doesn't allow for the gain of the preamps and antenna)

    As a matter of comparison my SSB 432MHz receiver needs about 12dB attenuation (at IF) to reduce the QRM to the same level as normal background.

    The noise appears just as broadband white noise and its there continuously with no sign of any modulation.

    Another very puzzling point is - where is the freq of this mega powerful TX?
    I just don't see anything poking out of this raised noise floor more than 10dB, certainly not a 2.5KW carrier!

    The only really big signals are from the four main UHF TV TXs. (strongest at about -20dBm on SA that's about 60dB above the noise floor) and the noise floor between the TV signals is much lower than the raised noise floor from the QRM.

    The TV engineer says he sees no sign of this noise measured at the combiner on their TX. This makes me feel that this TX can't be just a strong carrier with residual noise on it, but may be a spread spectrum signal.


    The increase in background noise when beaming at the transmitting mast which is 15Km away is shown below.

    Noise on 90 degree heading


    By turning the antenna 30 degrees away from the transmitting mast the noise has fallen into the noise floor of the Spectrum Analyser

    Noise nulled on 120 degree heading


    With only a 50ohm load on the input to the preamp the noise floor of the Spectrum Analyser can be seen for reference.

    50 load on input


    A wider frequency scan shows the main UHF TV channels above the area of Wideband Noise. This is on a direct heading to the TV Mast.

    TV stations on Beam heading of 90 degrees

  • About Us | Privacy Policy | Contact Us | ©2005-2014 Tucson Amateur Packet Radio Corp unless otherwise noted.

    facebook twitter utube

    Accept Credit Cards