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Publications:

ARRL 9th Computer Networking Conference 1990

9th.jpeg

This proceeding is available only on CD-ROM


Location:
London, Ontario Canada

Coordinators:
Harry MacLean, VE3GRO
David Toth, VE3GYQ
Paul L. Rinaldo, W4RI

Hosted by:
Canadian Radio Relay League (CRRL)
American Radio Relay League (ARRL)

Abstracts:
9th Computer Networking Conference
September 22, 1990

9600 Baud Operation
by Phil Anderson, W0XI, and Karl Medcalf, WK5M
Abstract: Over the last month or so, we've conducted a number of on-the-air tests with the G3RUH modem in combination with the Kantronics DataEngine and the Kantronics DVR2-2 2-meter data/voice transceiver at 9600 baud. After the usual initial false starts we found the combination to work quite well. We passed a large number of 10K files in transparent mode from WK5M's station to my PBBS (mailbox in my DataEngine) without error. Additionally, we performed some informal bit error rate (BER) tests on the link, finding results comparable to those listed in Steve Goode's (K9NG) paper's.

Proceedings Paper



Digital Regenerator Modification for the TNC-2A
by William A. Beech, NJ7P, and Jack Taylor, N7OO
Abstract: Others have pointed out the network efficiency advantage of using duplex regenerators as compared to simplex digipeaters. However, the use of packet duplex regenerators entails added expense which may be the reason they have not found common usage in LAN and backbone systems. In addition to the expense of a duplexer for in-band operation, previous implementations of regenerators have required either dual TNCs or the use of a high quality land line modem as well as a TNC. This paper describes a way to make multiple use of a TNC in this application, with a realized savings in cost and simplification in equipment configuration. Furthermore, if the regenerator was set up for cross-band operation, the expense then would be comparable to a simplex digipeater since a duplexer would not be required.

This paper describes the conversion of a TNC-2A to serve as both a digital regenerator and a network node. The conversion has been in use on the 144.51-145.11 SVALAN:N700-4 repeater/node for several months.

Proceedings Paper



Considering Next-Generation Amateur Voice Systems
by Jon Bloom, KE3Z
Abstract: Next-generation voice systems are a logical outgrowth of high-speed networking. Replacement of existing systems (repeaters) which is needed to address the current spectrum-use problems must be preceded by design of appropriate multiple-access systems. Some of the key issues to consider are analog vs. digital modulation schemes and the types of multiple access arrangements.

Proceedings Paper



AVC_R_ISA: A MAC Layer for NOS/net
by F. Davoli, A. Giordano IlTD, A. Imovilli IWlPVW, C. Nobile IWlQAP, G. Pederiva IWlQAN, and S. Zappatore IWlPTR
Abstract: In this paper we describe an implementation of the protocol AVC-R-ISA (Access Virtual Channel Radionet-Independent Stations Algorithm) performed in the NOS/net program. AVC-RISA may be a solution to the problem of traffic control in a packet switched network, like for example the amateur packet network. This multiple access strategy may be viewed as an alternative for the MAC layer to the popular CSMA and is aimed at improving the channel throughput with an optimized distribution of the channel itself among the users.

Proceedings Paper



A Built in TNC for the Toshiba Mod. T1000
by Frederic de Bros, KXlS
Abstract: The idea to have a TNC + laptop computer attached to a hand held transceiver seems attractive. Several home brew versions have been tried on SHARP PC 5000 and Tandy 100 computers. None were truly portable or clutter free. We describe here how to affix a UMPAD (Universal packet assembler/disassembler) onto a modem board inside the Toshiba T1000 computer.

Proceedings Paper



A GPS Data Receiver
by Dan Doberstein, M.S.E.E.
Abstract: This paper describes the construction of a Global Positioning System (GPS) single channel data receiver using the L1 carrier. A brief explanation of the GPS system is provided. The needed details of the GPS signal structure are also covered. GPS uses Spread Spectrum techniques. It is one of the first world wide systems to implement this technology. These techniques will play an ever larger part in tomorrows communication systems.

Proceedings Paper



Physical Layer Considerations in Building a High Speed Amateur Radio Network
by Glenn Elmore, N6GN
Abstract: The high information capacity required by an amateur high speed network requires optimum use of resources. Use of both directional antennas and the UHF and microwave bands is essential to obtain efficient use of hardware and spectrum resources. The use of shorter point-to-point links and small clusters of local users can achieve dramatic increases in user information throughput. Coordination and cooperation at all levels will be necessary to make a high speed amateur network a reality.

Proceedings Paper



Hubmaster: Cluster-Based Access to High-Speed Networks
by Glenn Elmore, N6GN, Kevin Rowett, N6RCE, and Ed Satterthwaite, N6PLO
Abstract: This paper describes the link-level design of Hubmaster a packet radio network that we are currently building. Hubmaster is intended to offer medium-speed network access to collections of end users and to serve as a stepping-stone to higher-speed networks. Users are organized into local clusters. Each cluster consists of a centrally located hub and a dynamically formed group of secondaries. The hub time-multiplexes a single channel by polling the secondaries. Our initial design will provide 256 kbit/s links and operate on the 33 or 23 cm band.

Proceedings Paper



Adaptation of the KA9Q TCP/IP Package for Standalone Packet Switch Operation
by Bdale Garbee, N3EUA, Don Lemley, N4PCR, and Milt Heath
Abstract: Several new hardware systems intended for, or adaptable to, standalone packet switch use have appeared on the market in 1990. These include the Grace PackeTen, the Kantronics Data Engine, and the soon lO be available AEA PS-186. One obvious use for these systems is implementation of a TCP/IP based amateur packet network. This paper discusses some of the design issues uncovered in porting the KA9Q TCPIIP package to a standalone hardware environment, and will touch on some details of the implementations available now (or soon) for each of the mentioned hardware systems.

Proceedings Paper



Network Routing Techniques and Their Relevance to Packet Radio Networks
by James Geier, Martin DeSimio, WB8MPF, and Byron Welsh, KD8WG
Abstract: With packet radio networks, the distance between source and destination nodes typically necessitates one or more nodes to relay data to the final destination. Thus, some form of routing must take place. This paper explains several current network routing algorithms and shows their relevance to packet radio networks. In addition, current research at AFIT concerning the development of an automatic routing algorithlll for Air Force Logistics Comllland's (AFLC) HF packet radio network is explained.

Proceedings Paper



Status Report on the KA9Q Internet Protocol Package for the AppleMacintosh
by Dewayne Hendricks, WA8DZP, and Doug Thom, N60YU
Abstract: This article describes the current status of the implementation of the KA9Q Internet Protocol Package which we performed upon the Apple Macintosh family of personal computers. The unique Macintosh user interface and its proper utilization by the KA9Q software has been our major objective in the three years since we have started this project and has proved to be quite a challenge. We hope that the users of our implementation have been pleased with the results to date. As of today, there are at least 300 copies of the package out in the world which we have distributed ourselves. We are certain that there are many more copies out there which we don't know about. This is a good deal more than we expected to see three years ago. After all, the Macintosh is not the personal computer that is most linked with amateur packet radio due to its cost when compared to IBM PC's and its clones.

Proceedings Paper



Texas Packet Radio Society Projects: An Update
by Greg Jones, WD5IVD, and Tom McDermott, N5EG
Abstract: The last paper published in the ARRL Networking Conference concerning TexNet was in 1987 (1) and we felt it was about time to publish an update. This paper will discuss the current status of the Texas Packet Radio Society's TexNet development, TexNetTexLnk software forthe TNC, and the TexNet CARDINAL project. We hope this paper will serve as a method to further distribute information regarding TPRS projects and be able to generate correspondence from interested parties about our activities.

Proceedings Paper



FlexNet - The European Solution
by Gunter Jost, DK7WJ, and Joachim Sonnabend
Abstract: This paper describes the design and implementation of FlexNet. This is a packet switch software with a complete new design made in Germany. It is beginning to become the standard in Central Europe. Running on a dedicated hardware with an unique design it is easy to put cheap and reliable packet switches on our mountain sites.

Proceedings Paper



MACA - A New Channel Access Method for Packet Radio
by Phil Karn, KA9Q
Abstract: The existing Carrier Sense Multiple Access (CSMA) method widely used in amateur packet radio on shared simplex packet radio channels frequently suffers from the well-known "hidden terrninal problem" and the less well known but related problem of the "exposed terminal." This paper proposes a new scheme, Multiple Access with Collision Avoidance (MACA), that could greatly relieve these problems. MACA can also be easily extended to provide automatic transmitter power control. This could increase the carrying capacity of a channel substantially.

Proceedings Paper



Forward Error Correction for Imperfect Data in Packet Radio
by W. Kinsner, VE4WK
Abstract: Many current protocols employ retransmission to ensure error-free data transfers. This is necessary for perfect data where a loss of a single bit is catastrophic. For imperfect data, such as digitized speech transmitted in real time in which a loss of one bit in a 1000 may be acceptable, retransmission is not possible and forward error correction should be used for error control. This paper presents a review of suitable codes for such error control, as well as several code implementations including a modified Hamming code, BoseChaudhury-Hocquenghem (BCH) code, and a concatenated code capable of correcting not only random errors but also burst errors. The code has an outer Hamming code, an inner self-orthogonal l/2 convolutional code, and a code word interlace matrix.

Proceedings Paper



The Network News Transfer Protocol and its Use in Packet Radio
by Anders Klemets, SMORGV
Abstract: The exchange of news bulletins is very popular among amateur packet radio users today. But there are currently no standardized protocols in use, and there is no widespread use of news forwarding protocols at all among amateur TCP/IP stations. This paper discusses how the Network News Transfer Protocol can be used to distribute news between stations on packet radio networks. NNTP is a stadardized protocol that is widely used on the Internet. Different implementations of NNTP for the KA9Q Internet Package are presented and compared.

Proceedings Paper



Packet Radio with Rudak II on the Russian Radio-MI Mission
by Hanspeter Kuhlen, DK1YQ
Abstract: This paper will report on the mission objectives and the sofar achieved results. The transponder has been named RADIO-MI by AMSAT-U-ORBITA. A "one" because it is our first joint project and "M" because the involved AMSAT groups are located in Molodechno near Minsk (ORBITA), Moscow and Munich (RUDAK). Once the satellite is in orbit it will probably become RS 14 (Radio Sputnik).

Proceedings Paper



CELP High-Quality Speech Processing for Packet Radio Transmission and Networking
by A. Langi, and W. Kinsner, VE4WK
Abstract: This paper presents a design of a signal processing system for telephone-quality speech transmission through a packet-radio network at rates as low as 4800 bit/s in either real-time or off-line mode. A standard 64 kbit/s speech signal is compressed down to 4.8 kbit/s using the Code-Excited Linear Predictive (CELP) coding scheme adapted from the proposed U.S. Federal Standard FS- 1016. The CELP algorithm is implemented using a floatingpoint Digital Signal Processor (DSP) to achieve a realtime, interactive (full- or half-duplex) or fast off-line network-based application. An implementation using a NEC 77230 PC-based DSP Evaluation Board (EB-77230) is under development.

Proceedings Paper



The PackeTen System - The Next Generation Packet Switch
by Don Lemley, N4PCR, and Milt Healh
Abstract: This paper examines the current digital bandwidth crisis which is plaguing amateur packet networks, and details a project in the Chicago area which addresses the problem. The PackeTen~ project was conceived to provide a "next generation" hardware and software platform capable of satisfying both the current crisis and to allow for many future enhancements. The system described is a working implementation of the long awaited truly "high-speed" packet switch that is available for general use today.

Proceedings Paper



The BPQ Node in an Expanding Network
by Karl Medcalf, WK5M, and Phil Anderson, W0XI, in cooperation with John Wiseman, G8BPQ
Abstract: The release of the Kantronics Data Engine, along with the development of their 9600 baud (G3RUH compatible) modem has now added a new dimension to the meaning of a Network Node. With the open architecture of this packet controller, and the flexibility now possible, network expansion and high speed operation is now possible with future expansion in mind.

Proceedings Paper



Node Networking
by Donald R. Nelsch, K8EIW
Abstract: With the advent of NET/ROM (tm) Software 2000 Inc. and NORD<>LINK TheNet software, amateur packet radio networking became possible. However, some of the "factory standard" options in the software tend to limit performance of the system. This paper deals with some of the networking problems the author has resolved, plus some of the hardware considerations that were made in establishing and maintaining the authors' 21 transmitter interconnected node network.

Proceedings Paper



The "Cloverleaf" Performance-Oriented HF Data Communication System
by Raymond C. Petit, W7GHM
Introduction: In March of 1990, AK0X and W7GHM conducted a series of on-the-air tests of a new HF data communication system design over the 1 500-mile path between Boulder, Colorado, and Oak Harbor, Washington. On five different days, and on the 80, 40, 30, and 15-meter bands, Ed sent text from Isaiah 55 to Ray, W7GHM, at higher speeds than any other data mode was capable in the same band conditions, and Ed's "Cloverleaf" signal was so compact that twenty of them could have been packed, without mutual interference, into the same 2-kHz space now used by one packet channel. On 15 meters, Ray was printing data at 75 bit/s free of errors. On 30 and 40 meters, during a time when the packet link between AK0X and W7GHM was nothing but retries, Ray got 50 bit/s from the Clover link. (The design limit of AMTOR is 33.) On 80 meters, when it was necessary to repeat single letters several times on CW to be understood, the Clover link delivered 15 bit/s, free of errors.

Proceedings Paper



Frequency-Stable Narrowband Transceiver for 10100.5 KHZ
by Raymond C. Petit, W7GHM
Abstract: The accompanying diagrams will permit the experienced home builder to assemble a transceiver suitable for coherent-CW and Clover operation on the bottom end of the 30 Meter ham band. It has been designed for high dynamic range (SL6440C high-level mixers), exceptional i.f. selectivity (9-pole 300 Hz filters), and ultrastable operation (LO and BFO phaselocked to a frequency standard). It is kept as simple as possible and the frequency plan makes use of inexpensive microprocessor clock crystals. It is also designed with thought to the future, when its single-frequency stabilized HFO can be replaced with an 18-l9 MHz frequency synthesizer.

Proceedings Paper



PACSAT Protocol Suite - An Overview
by Harold E. Price, NK6K, and Jeff Ward, G0/K8KA
Abstract: A Low Earth Orbiting "Pacsat" has been described in the past as an orbiting bulletin board system. This is an over-simplification. A PACSAT is a multi-channel, full duplex device, with short, periodic access times dictated by orbital mechanics. These attributes mandate a different approach than the standard command-line interpreter style of BBS if the full potential of a PACSAT is to be realized.

The authors propose a new methodology for a PACSAT, and have developed several new protocols to implement more efficient access. These protocols all use AX.25, either in connected mode or with UI frames. This paper provides a description of the access model, and an overview of the new protocols.

Proceedings Paper



PACSAT Data Specification Standards
by Harold E. Price, NK6K, and Jeff Ward, GO/K8KA
Abstract: This document provides a standard way of describing PACSAT data formats in specifications, and provides certain assumptions for implementors.

Proceedings Paper



PACSAT Protocol: File Transfer Level 0
by Jeff Ward, G0/K8KA, and Harold E. Price, NK6K
Abstract: This document specifies Version 0 of the File Transfer Level 0 (FTL0) protocol designed for use on store-and-forward satellites (PACSATs). The protocol provides procedures for transferring binary files to and from a server computer using an error-corrected communication link.

Further to basic file transfer facilities, FTL0 provides file selection and directory procedures. Because a server may contain many files, only some of which are of interest to each client, the client may "select" a subset of the server's files. Subset selection is based on a flexible logical equation involving a large number of file characteristics. The scope of directory requests or file download requests can be limited to those files currently selected.

This protocol is designed to work specifically with files in which the actual "data" or "body" of the file is preceded by a standard "header", specified in the PACSAT File Header Definition document.

Proceedings Paper



PACSAT Broadcast Protocol
by Harold E. Price, NK6K, and Jeff Ward, G0/K8KA
Abstract: The case for a broadcast protocol for use on PACSATS is madc, and a suitable protocol is proposed. In the proposed protocol, files of general interest are chopped into <UI> frames and repeatedly sent by the PACSAT in round-robin fashion or on request. each <UI> frame datagram contains enough information for groundstation software to place the frame in the correct position in the appropriate file. Information indicating the type of file being received is also included in each frame. A protocol for groundstations to request retransmissions of specific frames is included.

Proceedings Paper



PACSAT File Header Definition
by Jeff Ward, G0/K8KA, and Harold E. Price, NK6K
Abstract: A flexible encoding method for PACSAT file headers is described, and "Mandatory", "Extended" and "Optional" Headers are defined. These headers are supplied by the programs which send files and/or messages to PACSAT, and by on-board programs which build files/messages intended for for downloading. PACSAT file headers are present in all files.

Proceedings Paper



A Fast Switching, Wide Bandwidth Transceiver for 70-cm Operation, The DVR 4-2
by Jerry Schmitt, WX0S, Phil Anderson W0XI, and Bruce Kerns
Abstract: After designing, building, testing, beta testing, and finally shipping DVR 2-2 transceivers in early 1990, it became apparent quickly that there was a desire by many amateurs for an even faster transceiver for the 70-cm band. lFeatures similar to those provided for by the DVR 2-2 were requested: fast TR switching, access to the modulator and discriminator without radio modification, data output independent of squelch, receiver derived carrier detection, simple design, and easy to work on. In addition, several suggested adding a filter for wide bandwidth operation, allowing for speeds higher than 9600 baud for networking (backbone) applications.

Proceedings Paper



Long Distance Packet Mail Via Satellite
by Mark Sproul, KB2ICI, and Keith Sproul, WU2Z
Abstract: The packet radio mail system is a great Electronic Mail system for amateurs. Within a local VHF area, it works fine. However, when trying to send messages farther away, they must be passed via the HF Long Haul system, which has many drawbacks and problems. Why not use satellites to bypass the HF bottleneck for a nationwide long distance mail forwarding system?

Proceedings Paper



Station Traffic System: A Traffic Handler's Utility Package with Integrated Packet Support
by Frank Warren, Jr., KB4CYC
Abstract: The Station Traffic System (STS) is a utility program for National Traffic System (NTS) traffic handlers written in C for use in MS-DOS and UNIX environments providing a set of menu-selectable functions for message operations and operating environment support.

Proceedings Paper



Comments on HF Digital Communications Part 1 -- Link Level Issues
by Tom Clark, W3IWI
Introduction: This paper and its companion Part 2. will discuss some of the issues involved in improving the throughput and reliability of amateur HF digital communications links. The intent is to present some strategies which should allow for a significant improvement with modest hardware and software investments.

Proceedings Paper



Comments on HF Digital Communications Part 2 -- Data Protocol Issues
by Tom Clark, W3IWI
Introduction: In part 1 we discussed some of the link-level issues in terms of the effects imposed by the ionosphere on HF signals and possible Digital Signal Processing (DSP) approaches to those issues.

Proceedings Paper



BULLPRO - A Simple Bulletin Distribution Protocol
by Tom Clark, W3IWI
Introduction: This paper proposes a simple protocol for the efficient local distribution of bulletins by packet radio.

Proceedings Paper



Some Comments on the Hierarchical Continent Address Designator
by Tom Clark, W3IWI
Introduction: This paper proposes a simple protocol for the efficient local distribution of bulletins by packet radio.

Proceedings Paper



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