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Ordering Information

Sorry, ARRL 5th Computer Networking Conference 1986 is no longer available

Location:

Orlando, Florida

Coordinators:

Paul Rinaldo, W4RI
Gwyn Reedy, W1BEL

Hosted by:

American Radio Relay League (ARRL)

Abstracts:
5th Computer Networking Conference
March 9th, 1986

RF, RF, Where is My High Speed RF?
by Terry Fox, WB4JFI

Abstract: This paper presents some thoughts of where we are now an where we are heading in the RF hardware evolution of Amateur packet radio. It may be a disappointment to some in that it raises more questions than it answers. I feel it is vital to raise these questions now, since this is where we need the most work.

A High-Speed RF Modem
by Chuck Phillips, N4EZV, and Andre Kesteloot, N4ICR

Abstract: This paper will describe the approach followed by several members of the Amateur Radio Research and Development Corporation (AMRAD) to design a high-speed RF modem. Another paper, presented to this Conference in the form of an Application Note, describes the actual circuitry used to generate phase-coherent FSK.

An Application Note Describing a High-Speed Phase-Coherent FSK Generator
by Andre Kesteloot, N4ICK

Abstract: This application note is a companion paper to the one entitled "A High-Speed RF Modem' also being presented to this conference. It describes a phase-coherent FSK generator built entirely with readily-available components and requiring only a frequency counter for set-up.

FSK Methods for PACSAT Communication
by M. S. Hodgart and Jeffrey W. Ward, GO/K8KA

Abstract: The authors propose that PACSAT employ several 9600-bit/s noncoherent FSK uplinks and a 9600-bit/s coherent FFSK downlink. This combination of modulation schemes provides for simple groundstation transmitters, groundstation demodulators of several classes of complexity, and staged development of space-rated systems. A research plan is identified which will result in simple spacecraft systems being available quickly and optimised spacecraft systems being developed as time permits. Areas for further study, resulting in 1.5:1 increase in bit rate with no increase in signalling bandwidth, are discussed.

A Packet Controller for the Revolution
by Lyle Johnson, WA7GXD

Abstract: Overview of the beginning of the TAPR TNC 2 project.

TNC 2 Parameter Settings and Meanings
by Thomas A. Moulton, W2VY

Abstract: This paper will describe the command set for the TNC 2 and help the reader set the parameter values.

Link Level Protocols Revisited
by Phil Karn, KA9Q, and Brian Lloyd, WB6RQN

Abstract: The LAPB protocol on which the connected mode of AX.25 is based was originally designed for point-to-point wire links, not shared multiple-access radio channels. This paper discusses the deficiencies of LAPB in the radio environment and suggests several improvements. These include the simple (adjusting existing TNC parameters), the moderate (upward compatible implementation changes) and the radical (replacing LAPB altogether with a simpler and inherently much more efficient protocol).

We believe that these approaches deserve serious attention by the amateur packet community. The suggested AX.25 congestion control techniques should be used as soon as possible in existing networks, while the new "ACK-ACK" protocol should be considered in the design of backbone networks and eventually user-network links.

Performance Enhancements for the Amateur Packet Network
by J. Gordon Beattie, Jr., N2DSY, and Thomas A. Moulton, W2VY

Abstract: For several years the amateur packet network has been using a link level networking system based on "digipeaters". This system has allowed the user community to expand rapdily. As the packet mode has increased in popularity, many problems have developed that have caused the users some inconvenience. It is the feeling of the authors that the degraded performance levels found on the amateur packet network are largely due to the simplistic digipeater network approach.

This system has also forced users to provide control mechanisms in relative isolation. This has had the effect of reducing reliability and performance. An X.25 level 3 packet switch can provide improvements in the areas of retransmission, routing, addressing, quality of service negotiation, access mangement and data flow control.

We will examine these areas, showing how a small but intelligent packet switch can improve user operations and network performance. While discussing the enhancement of switching facilities we will also explore some of the user features and facilities available or planned for the network.

The PacketMaster Packet System for CP/M and DOS Computers
by Bernie Mans, AA4CG

Abstract: This paper outlines the Packetmaster system, a flexible packet program and simple peripheral hardware to add AX.25 to the repertoire of the personal cornputer. The advantages of the peripheral approach over the serial nethod are the enumerated later in this paper.

SAREX2 Software for the Tucson Amateur Packet Radio Terminal Node Controller, TNC 2
by Howard Goldstein, N2WX

Abstract: The custom modifications of the Tucson Amateur Packet Radio TNC 2 software for the Shuttle Amateur Radio Experiment 2 (SAREX2), and the associated operating modes (robot, meta beacon, logging functions) are discussed.

Features of the VADCG TNC+
by Douglas Lockhart, VE7APU

Abstract: This paper describes the features and design philosophy of the new VADCG TNC+ (TNC plus) terminal node controller which is the second TNC produced by the Vancouver Amateur Digital Communications Group (VADCG). The TNC+ has many unique features not found on the current TNCs being marketed. These features facilitate amateur packet radio software development and dissemination and permit the interested user to learn about the detailed operation of the TNC and various protocols. The VADCG TNC+ is an 'open' system as opposed to a 'black box' system.

The Network User Interface
by David W. Borden, K8MMO

Abstract: This paper discusses the user interface, the way the human operator interacts with the amateur digital network using their Packet Assembler/Disassembler (PAD) or older Terminal Node Controller (TNC). In this day of increasing features and networking, the packet radio user is expected to remember more and more commands to communicate on the amateur radio packet network. The user desires more and more features and vet wants to keep it simple. The past two years has seen more and more TNCs come on the market, but no standardization of user commands. Now that software is starting to appear to transform these TNCs into Packet Assembler/Dissamblers (PADs), the time is here to make this right, to standardize the user interface using X.3 and X.28 protocols.

Amateur Network Addressing and Routing
by Terry Fox, WB4JFI

Abstract: Now that we have actual packet switches on the air, it is time to take a hard look at the addressing and routing schemes proposed for use at the Network Layer. In this this paper I give my imDression of how I believe addressing and routing will evolve. I will also recommena the use of certain "direction implicit" addresses as an interim step of Network address and routing operation.

Proposal: Recommendation AX.121, International Numbering Plan for the Amateur Radio Network
by J. Gordon Beattie, Jr., N2DSY, and Thomas A. Moulton, W2VY

Abstract: The purpose of this International Numbering Plan is to facilitate the introduction of amateur data networks and provide for internetworking on a worldwide basis.

A Packet Assembler/Disassembler for Amateur Packet Radio Networking
by Howard Goldstein, N2WX

Abstract: This paper describes the operation of the prototype Packet Assembler/Disassembler (PAD) function within the Tucson Amateur Packet Radio TNC 2 the author installed at a tall tower site near Melbourne, Florida. PADs are usually considered to be devices which interface "dumb" asmchronous terminals to pacKet switched networKs. The prototype TNC 2 PAD performs this function for remote users on the AX.75 network of which it is part, while at the same time enabling a new method of establishing non-level three connections which offers improved performance over "digipeated" connections using the same path.

A Networking Node Controller for Amateur Packet Radio
by Lyle Johnson, WA7GXD

Abstract: Perceiving the need for a standardlzed hardware environment for developing, testing and implementing Amateur packet radio network and transport level protocols, the author, under the auspices of Tucson Amateur Packet Radio (TAPR), conducted a three month discussion with leading packeteers in the United States during the summer of 1985. The intent was to define the hardware desired in a controller that would be suited to this task. Having reached a general consensus, a system was designed which incorporated most of the suggestions of the group.

The resulting system, the TAPR Network Node Controller (NNC), is currently in its third hardware revision. It is expected to be placed in the field during the second quarter of 1986 for software development.

This paper describes the features of the NNC that make it a logical choice upon which to build an Amateur packet switching system.

Authentication of the Packet Radio Switch Control Link
by Hal Feinstein, WB3KDU

Abstract: This paper discusses the design of a simple authentication method which is applied to a remotely sited packet radio switch. The control path to the packet radio switch is a very high freauency (VHF) radio channel which is easily monitored and accesed. Such ease of access requires that only authorized control stations be permitted to issue switch control and maintenance commands.

The authentication design discussed in this raper provides three functions: (a) positive identification of the switch and control operator, (b) safeguard message streams flowing between switch and control operator, and (c) rapid identification and rejection of false or manipulated messages.

This paper is divided into four sections. The first section contains a brief overview of packet radio techniques. The second section aiscusses assumntions concerning the radio environment in which the packet radio switch operates. This envirnoment is characterized by unreliable radio path as well as occasional spoofing and malicious interference. In the third section we discuss the actions of each of the protocola four procedures and the make-up of its data construct. Section three also constains a discussion of the cryptographic considerations upon which this protocol is based. Lastly, in the appendix we describe an experimental one-way cipher based on a random program technique whicn we hope to incorporate into future versions of the radio packet switch.

Packet Switch Software Design Considerations
by Terry Fox, WB4JFI

Abstract: Toward the end of 1985, a new device showed up on Amateur Packet Radio, the packet switch. Soon, the packet switch will be replacing digipeaters around the country, giving more reliable (if slower) operation of the overall network. The first switches have been based on TAPR TNC-2 hardware, and therefore are somewhat limited. An accompanying paper describes what tvpes of hardware the author sees bein used in the future (both near and down the road for the switches. This paper will explain the uthor's view of how the switch software should be organized.

This paper will not provide actual switch code, but rather indicate where progress is being made, and where help is needed. Also, wherever possible, I cite Protocols and Standards I believe should be implemented.

User and Switch Packet Digital Hardware
by Terry Fox, WB4JFI

Abstract: There has been a lot of activity in the area of digital hardware for Amateur packet radio in the last year. I see this trend continuing over the next few years. This paper describes some of the present packet digital hardware, and gives some of my thoughts on what we will be using in the future, both for the "TNC" and the network devices.

An Introduction to the Hub Operating System
by Mike O'Dell, KB4RGM

Abstract: The AMRAD switch marsk a significant departure in the evolution of Amateur packet radio. This paper describes the HUB operating system.

Proposal: Recommendation AX.224, Class 1, Transport Protocol Specification for the Amateur Radio Network
by J. Gordon Beattie,Jr., N2DSY, and Thomas A. Moulton, W2VY

Abstract: The amateur packet network provides a reliable service in that it is relatively free from undetected bit errors. It does, however, have a relatively high rate of lost connections. This problem can be resolved through the implementation of a TRANSPORT PROTOCOL. This is not to suggest that all applications require a TRANSPORT PROTOCOL. In situations where end-to-end data and connection integrity are important, one must use a TRANSPORT PROTOCOL to provide error control.

Recognizing that there are many options available to the community, we the RADIO AMATEUR TELECOMMUNICATIONS SOCIETY, felt that there had to be a single defined protocol available to the broadest possible user base. To achieve this we examined several protocols and determined that the one most appropriate for amateur service was CCITT Recommendation X.224, Class 1. This protocol was chosen for its applicability, simplicity, expandability, and international acceptance.

It is hereby proposed by the members of the RADIO AMATEUR TELECOMMUNICATIONS SOCIETY that this basic subset of CCITT Recommendation X.224 be adopted by the amateur packet community as the preferred transport protocol.

Cryptography in Amateur Radio Communications
by Robert M. Richardson, W4UCH

Abstract: Some fascinating similarities between the art and science of cryptography and the amateur radio avocation, especially in the area of digital communications are discussed.

The UO-ll DCE Message Store-and-Forward System
by Harold E. Price, NK6K and Jeff Ward, G0/K8KA

Abstract: The Digital Communications Experiment (DCE) onboard the UoSAT-Oscar-ll spacecraft recently began a new phase of regular operations. Development and installation of enhanced store-and-forward message transfer software (MSG2) - capable of 200-kbytes transatlantic data transfer per day - is the second plateau in the DCE experimental program. This program is designed to gain experience with computer-based message systems in low earth orbit.

The DCE is the first orbiting store-and-forward device to carry general amateur traffic on a continuing basis. The drafts for this paper were developed and edited by the collaborators in the USA and the UK using the spacecraft as the only means of communications.

This paper provides information on the capabilities and the design of this system as well as some background information on ihe UoSAT-OSCAR 11 spacecraft.

Automated Traffic Handling Assistance
by David Cheek, WA5MWD

Abstract: Packet radio presents an opportunity to improve speed and accuracy of message handling. Speed is often limited by the typing speed of the operators. The accuracy is assured during transmission, but is only useful if the message is correctly entered into the message handling system. The normal limits to message handling include a lack of fully qualified operators, and inability to use untrained people during special situations such as disaster events. A method I have used to improve both of these is keystroke reduction.

Packet Radio Demonstrations as a Supplement to Classroom Instruction in Telecommunications
by Robert J. Diersing, N5AHD

Abstract: During the past year the author has had the opportunity to use packet radio hardware and operations to demonstrate concepts taught in telecommunications courses at an upper- level university. This article provides a brief discussion of how this was accomplished. A description of the courses and their intended audience has been included.

Outline of Satellite JAS-l
by Fujio Yamashita, JSlUKR

Abstract: The first Japanese satellite, JAS-l, is schedu1ed to be 1aunched in ]986 by Japanese H-l rocket. A special feature of JAS-1 is its digital transponder with memory, in addition to a normal analog transponder. It wil1 be possible to upload digital messages into the transponder memory, and the messages will be relayed to someone with the appropriate access code (e.g. callsign). In this way, JAS-1 will be able to carry messages (on a store and forward rather than real-time basis) between amateurs anywhere in the world.

Two birds of JAS-1 were comp1eted in the fall of 1985 and all necessary testing was carried out and certified that the characteristics of satellite were no problem. The cost for constructing this satel1ite is about 400 mil1ion yen (US$ 1. 6 million).

Appendix 1: What's All This Racket about Packet? (reprint of article in July 1985 QST)
by Harold E. Price, NK6K

Appendix 2: A Closer Look at Packet Radio (reprint of article in August 1985 QST)
by Harold E. Price, NK6K