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

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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).

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper

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.

Proceeding Paper