General notes:
Copies of the papers presented at, or published for DCC are available in various ways. A paper printed in the proceedings will be available for purchase in most cases in hard copy as the DCC proceedings. It will in most cases also be available as an individual paper in PDF format as a free download via a link below the abstract (where available) It may also be available on CD-ROM. A paper printed in the proceedings may not have been presented at the conference. Also a presentation at DCC may not be in the printed proceedings. In those cases it may be available on DVD, CD-ROM or as a MP3 download. Links to what is available will be on the page specific to the particular year's DCC.
The price for the TAPR and ARRL 26th Digital Communications
Conference 2007 Proceedings is:
-
$ 20 US +applicable shipping/handling.

- Location:
- Hartford, CT
- Coordinators:
- Steve Bible, N7HPR, Conference Manager
- Steve Ford, WB8IMY
- Maty Weinberg, KB1EIB
- Steve Ford, WB8IMY
- Hosted by:
- ARRL
Abstracts:
26th ARRL and TAPR Digital Communications Conference
September 28-30, 2007
- The FSM Virtual Radio Kernel
by Frank Brickle AB2KT - DTTS Microwave Society - Abstract:
Software Defined Radio is moving fast...in some areas. In many important
ways, however, Software
Defined and Cognitive Radio are just now arriving at the .horseless
carriage. stage, where software is
being embraced mostly as a substitute for traditional circuitry, or is
being celebrated largely for what are,
after all, only incremental enhancements to a very conventional user
interface. Software Defined and
Cognitive Radio promise more than this. We outline the technological and
conceptual components that
are now making it possible to take the next steps towards those
promises, and we report on current
ongoing work at forging these pieces into a new kind of radio
environment.
- The APRS Local Voice Repeater Initiative
by Bob Bruninga WB4APR - Abstract:
For the traveler in a new area, a local-repeater-frequency packet
flashed on a
VHF/UHF mobile rig can display recommended local repeater for finding a
QSO or for local
information. This has always been a part of APRS, but seems not to be
reliably implemented in many
areas. In Jan-07 we launched the Local Info Initiative to get all areas
to support not only this
application, but other APRS objects to show local IRLP, EchoLink, and
Winlink frequencies as well for
the benefit of mobiles.
- NUE-PSK31 A digital modem for PSK31 field
operation. without using a PC!
by Milton Cram W8NUE and George L. Heron N2APB - Abstract:
PSK31 is one of the latest communications modes to capture the interest
of hams worldwide. Its inherent
ability to dig out low, near-inaudible signals is ideally suited for low
power QRP enthusiasts. The
PSK31 digital modem engine, however, requires intense DSP processing
that is only commonly
available in PC sound card. Thus the PSK operator desiring portability
for field operation is locked into
using a laptop computer as a controller, which results in a cumbersome
station. But there.s hope!
This paper presents the design and construction of a standalone,
battery-operated digital modem using a
Microchip dsPIC microcontroller. The project includes a character
display for transmit and receive text
data, and a graphic display showing band spectrum and tuning indicator.
Using GPL open source
software, the modem can be homebrewed for less than $50 parts cost. When
coupled with an SSBcapable
transceiver or with a popular PSK-xx transceiver board from Small Wonder
Labs, you too can
have an effective portable PSK31 station.
- SourceForge, Hamlib, and Rigserve: Free Beer, Free
Speech, and Rig Control
by Martin Ewing AA6E - Abstract:
Hamlib is a software library to support ham radio rig control begun in
2000, supporting
many radio types and computer platforms. Rigserve is a new network
server approach to
rig control, inspired by Hamlib and based on Python classes. Both
projects are managed
at SourceForget.net. There are many advantages to developing Open Source
Software in
this open project environment.
- The Nordic nRF2401 Single Chip Data Transceiver:
High Speed,
Short Range Data Communication At An Extremely Low Cost
by John A. Hansen, W2FS - State University of New York at Fredonia - Abstract:
The Nordic nRF2401 is a single chip data transceiver that works in the
2.4 GHz ISM band. It
provides data speeds of up to 1 Mbit/sec. The frequency can be set in
software anywhere from
2400 MHz to 2524 MHz.
- TRANSMISSION LINES, PARAMETERS, AND APPLICATION IN
COMMUNICATIONS SYSTEMS
by Hank Javan and Jerry Newman - University of Memphis - Abstract:
Transmission of information is carried out by
means of transmission media, usually is called a
Transmission Line. Transmission line is rather a
general term since it covers wide varieties of
media such as air, twisted pair, and of course,
fiber optic cable. Selection of transmission
media for communication requires
consideration of several factors such as
characteristics impedance of the line,
frequency dependent losses, radiation,
interference , and so forth. This article describes
some of the important parameters of
transmission media with tabulated results to
assist the designer of any communication
system to select a proper media for his
applications.
- DIRECT CONVERSION RECEIVER WITH COMPUTERIZED SSB
DEMODULATION
by Patrick Lindecker F6CTE - Abstract:
The improving computational performance of PCs and the near real-time
response of PC operating
systems now make it feasible to implement reasonable performance HF ARQ
messaging protocols
suitable for digital messaging. While Pactor (I, II, III) currently
dominate and generally represent the
best available performance, PC sound cards with appropriate DSP software
can now begin to approach
Pactor performance at lower cost than dedicated hardware HF modems. This
paper covers the on-going
development of an optimized sound card mode WINMOR, compatible with the
popular Winlink 2000
message system1,2,3. This effort leverages a prior feasibility project
by the author in the evaluation of
SCAMP 4, an adaptation of RDFT for digital messaging systems. The paper
reviews the development
effort of WINMOR (WINlink Message Over Radio) from motivation through
tool development,
programming, testing and deployment in the WL2K system.
- APRS and D-STAR = D-PRS
by Peter Loveall AE5PL - Abstract:
D-STAR is a digital over-the-air protocol developed by the Japan Amateur
Radio League, Inc. (JARL)
which supports Ethernet at 128 kbps (DD) or digital voice at 4800 bps
(DV). DV uses 3600 bps for
voice (2400 AMBE encoding, 1200 bps FEC) and 1200 bps for
synchronization and multiuse
(approximately 900 bps is available for general use). APRS is a protocol
designed by Robert
Bruninga WB4APR to communicate information such as positions, weather,
etc. using AX.25 as a
transport protocol. It has been adapted to use any clear-text protocol
such as Telnet. This paper
explores the methods used to bridge Icom D-STAR radios running GPS with
APRS-IS (APRS
Internet Service) and other APRS clients. We also explore using the two
D-STAR protocols to carry
APRS information over them.
- AMSAT.s Phase IV (lite)?
by Bob McGwier N4HY - AMSAT Vice President of Engineering - Abstract:
Is this ground hog day or amateur radio? In AMSAT, it is déjà vous all
over again. We have been working SLOWLY on Eagle for years, trying to
find
a way to get it into space. Follow the history and the plans of AMSAT's
next bird, the Eagle.
- On A Method for Automatic Image Balancing in IQ
Mixer Based Software Defined Receivers
by Bob McGwier N4HY - Abstract:
Over the past four years while working on a software defined radio core,
DttSP, with Frank Brickle, and
applying it to real world I/Q mixer based radios, the problem of find
the right algorithm to insure
equal amplitude and the proper phase relationship to achieve perfect
quadature between the I and Q
channels in these radios has been a source of constant work. My favorite
author of for sale amateur
radio software is Alex Shovkoplyas, VE3NEA. He has been doing wonderful
work in many areas but
specifically his work in software defined radio has been inspirational.
He did an automatic image
cancellation algorithm for his Rocky SDR as well as other interesting
software defined radio and dsp
work. His web page gives a tantalizing hint at the basis for the
algorithm but does not express a
complete derivation of the detector or show how to apply the results in
the end. We will do that here.
- TPSK31: Getting the Trellis Coded Modulation
Advantage
by Bob McGwier N4HY - Abstract:
As just about everyone who is alive and awake and not suffering from
some awful brain disease knows,
PSK31 is an extremely popular mode for doing keyboard to keyboard
communications. Introduced in
the late 1990.s it quickly swept the amateur radio world. Peter-G3PLX
will be the first person to tell you that he is not a trained
communications theorist, engineer, or
coding expert. Yet he is one of the great native intelligences in all of
amateur radio. His inspirational
muse (lend me some!) is one of the best and his perspiration coefficient
are among the highest ever
measured in amateur radio (this means he is smart and works hard, an
extremely good combination).
We will give you a tour of some of this theory, show you how Peter used
one piece of it well and then
made an attempt to aid his new mode with what in this author.s opinion
was an abortive effort to help
the mode achieve a lower error rate and an attempt to show us another
way.
- The Integration of Amateur Radio and 802.11
by Roderrick D. Mitchell KL1Y - Abstract:
Amateur Radio and 802.11 wireless networking - a good fit for emergency
message
delivery. Integrating two distinct and otherwise autonomous systems can
provide
rewarding results.
- Results of HF Digital Protocol Survey
by Paul L Rinaldo W4RI - ARRL Chief Technology Officer, - Abstract:
In February 2007, the ARRL Web site carried a Request For Information
(RFI) on HF digital protocols. Input was sought toward development of
non-proprietary, open-source protocols suitable for use by amateurs over
HF fading paths. Here are the results of that HF protocol technology
inquiry.
- RANKING DIGITAL MODES FOR A "STEALTH" QTH
by Ed Sack W3NRG - Abstract:
Using the digital mode software "MultiPSK"1 as our guide, we find that
there are something like 40
different digital transmission modes available to the amateur radio
operator. These modes range from
the "historic" (Hellschreiber) to the "classical" (RTTY) to the
"relatively recent" (example, OLIVIA.)
The availability of software to transmit and receive these modes using
the computer sound card has
rapidly expanded their use in ham communications.
- Bringing New Life in Old Computers
by Miroslav "Misko" Skoric YT7MPB - Abstract:
In this paper, we describe one of the possible implementations of older
computers
within the amateur packet radio experiments: A simulation of the local
area network
within an institution (radio club, school or university).
- Alternate Uses for the APRS Data Stream - Using
APRS mobile trackers for distributed site surveys
by Darryl Smith VK2TDS - Abstract:
Looking through the DCC proceedings in the last few years, there are a
significant number of papers
that look at how to use APRS for the benefit of the users being tracked.
With the exception of PropNet
looking at long distance propagation, very little has been written on
how to use the combined data of
the APRS network for anything other than telemetry applications such as
tracking and weather
reporting. This paper is designed to change that.
- Growing APRS' Value within the Emergency First
Responder Community
by Ev Tupis W2EV - Abstract:
What role does APRS play in emergencies? What role could it play? The
answers to these
two questions will be explored more deeply in this concept paper .
designed to engender both
fresh thoughts and strategies in hopes of more closely connecting
Amateur Radio and the
needs of the official Emergency First Responders.
- Performance Modeling of TCP and UDP over Packet
Radio Networks using the ns-2 Network Simulator
by Paul D. Wiedemeier, Ph.D., KE5LKY - The University of Louisiana at Monroe, Computer Science and Computer Information Systems Department - Abstract:
Live network tests are often used to obtain performance metrics
associated with the transmission of data
using TCP and UDP over packet radio networks. However, only individuals
who hold an amateur radio
license issued by the United States Federal Communications Commission,
as specified by Title 47, Code
of Federal Regulations, Part 97, are permitted to operate an amateur
station. For this reason, we
advocate using the ns-2 network simulator in academic environments to
allow unlicensed students to
evaluate the performance of packet radio networks. In this paper, we
discuss four topics concerning
packet radio network performance evaluation. First, the models used to
evaluate the performance of
packet radio networks are presented. We next introduce the ns-2 network
simulator and discuss the
advantages and disadvantages associated with using this tool to evaluate
the performance of TCP and
UDP data transmissions. Third, we discuss the structure of two ns-2 Tcl
scripts that can be used to
simulate the transmission of data over packet radio networks. Lastly, we
examine the output generated
by an example ns-2 Tcl script.
- Introducing the FLEX-5000A Ultra High Performance
Software Defined Radio
by Gerald Youngblood K5SDR and Bob McGwier N4HY - Abstract:
With the introduction of the FLEX-5000 family, Software Defined Radio
transceivers enter the second
generation for amateur radio applications. In May of 2003, FlexRadio
Systems shipped the first GPL
Open Source Software Defined Radio Transceiver for amateur radio use.
Many TAPR members were
early adopters as well as contributors to the open source development.
The HPSDR project and
SoftRock (Tony Parks, KB9YIG) kits sprang from the FlexRadio users and
email reflector.