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GATEWAY INPUT
Is there packet activity in your area which you think would be of interest to the readers of Gateway? If there is, send~it along to ARRL Hq, marked "Attention: Gateway Editor." This newsletter was started to distribute information about packet radio throughout the world. Send us a summary of activity on your packet network or tell us of any packet-radio related R+D work going on in your area.
HF PACKET BULLETIN BOARD
You can now connect to the W0RLI packet bulletinboard system (PBBS) on twenty meters. The PBBS is located near Boston, MA, and is run by Hank Oredson, W0RLI. Hank has had the PBBS on 145.01 MHz for several months, and it has become one of the major "servers" for the large Boston-area packet network.
The W0RLI PBBS software, written by Hank in Z80 assembly language, runs on a Xerox 820 with a TAPR TNC. The PBBS provides automatic time/date stamps for messages, automatically deletes inactive messages, and will even try to send you a beacon if there is mail waiting for you. Now, with the addition of a second TAPR TNC, the bulletin board is available on both RF and VHF.
On twenty meters you will find the PBBS as near 14.080 MHz as band occupation permits. Use 300 bauds, and 200-Hz shift. (The same shift and speed used by 10-MHz packet stations.) When you connect to W0RLI, the PBBS will send you operating instructions. Via W0RLI.
NTS TRAFFIC VIA PACKET
W0RLI's PBBS is also being used to originate NTS traffic. Messages are stored in standard NTS format, with the preamble information on the first line of the message. The PBBS is checked each evening and messages are then delivered to the appropriate NTS net.
Packet radio is a valuable tool for traffic handling. Of course, the national packet network that we are working toward will be a perfect traffic handling tool, but what we already have can and should be connected to NTS. The existing local networks can be used for message origination and delivery. Two packet stations on 10 MHz or OSCAR-10 could provide TCC service. These operations could begin today if NTS officials contacted packeteers, or packeteers contacted NTS officials. Let's get started!
Via The NEPRA Packeteer.PACKET RADIO AND ARES
Among packeteers, it is "common knowledge" that packet radio would be a good mode for the high-volume, error-free communications needed during emergencies. Unfortunately, this knowledge has yet to reach the leaders and operators in the Amateur Radio Emergency Service '(ARES). To remedy this, a new chapter has been added to the ARRL's Emergency Coordinator's Handbook.
In July, Mike Riley, WF4R, editor of the EC Handbook, met with Terry Fox, WB4JFI, of AMRID. The two discussed ways in which packet radio could aid the ARES. The new ten-page "Packet Radio" chapter in the EC Handbook is the result of that discussion.
The EC Handbook is sent free-of-charge to all Emergency Coordinators. The latest edition, with the packet-radio chapter, will be available early in September. At that time, packet-radio enthusiasts should be prepared to discuss emergency operations with their ECs.
HIGH-SPEED PACKETS
On August 23, Curtis Spangler, N6ECT, and Mike Flynn, W2FRT, exchanged packets at 9600 bauds using quadrature amplitude modulation (QAM) techniques. Both stations were using personal computers, 9600-bit/s modems, homemade radio/modem interfaces, and 440-MHz radios. Special software, written in Turbo Pascal, drove the synchronous data link controller (SDLC) cards in the computers. Over the five-mile path between the stations, there were no errors using 10 watts, and 60% to 70% throughput at one watt. Via KA6M
TELEPORT STA
On August 6, the ARRL and AMSAT filed a request for special temporary authority for the operation of teleport stations. The following comes from the text of the STA:
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"The operations of the stations operating under the STA will involve communications with terrestrial Amateur Radio Stations and Amateur Radio stations in space operation. They will function primarily as intermediary stations between terrestrial and space Amateur Radio stations. We hereby designate these intermediary stations 'teleports.'
"The purpose of a teleport is to relay digital messages automatically between terrestrial Amateur Radio stations and amateur stations in space operation (amateur satellites). This need to do so is twofold:
"(1) to obviate the need for every Amateur Radio station having a digital communications capability to also have an earth station capability in order to communicate with amateur satellites.
"(2) to provide a measure of traffic-flow control for the digital channel(s) on the satellite(s)...
"There are three primary objectives of this request for STA:
"(1) to determine experimentally what equipment and techniques are required to provide near-real-time relays between two or more terrestrial stations using local teleports and an amateur satellite.
"(2) to determine experimentally what is required to provide reliable store-and-forward communications wherein the teleport station buffer stores the messages between the hours that the satellite and terrestrial links are not available at the same time.
"(3) to gather the necessary information for permanent rule change to permit teleport operation."
The request for STA then goes on to list the frequencies of operation, and other administrative details. The following stations will be authorized to operate teleports when the STA is approved: John Biro, KLKSY; Tom Clark, W31WI; Den Connors, KD2S; Bob Diersing, N5AHD; John DuBois, WIHDX; David Engle, KE6ZE; Gary Garriott, WA9FMQ; Sumner Hansen, WB6YMH; Lyle Johnson, WA7GXD; Phil Karn, KA9Q; Bob McCaffrey, K0CY; Harold Price, NK6K; Bill Reed, WD0ETZ; Hank Magnuski, KA6M; Vern Riportella, WA2LQQ; Jose Sancho-Dominguez, WB5YFU; Bob Stricklin, N5BRG; ARRL club station, WLAW; and AMRAD club station, WD41WG. Building a teleport is a demanding task, and no one will have a teleport immediately. Please do not bother these operators by asking when their teleport will be on the air.
OSCAR-10 and UoSAT-OSCAR-11 are the satellites that are likely to be used by the authorized stations. OSCAR-10, with its long access times and great coverage, will be used to test the near-real-time links. UoSAT-OSCAR-11, if it is made available at all, will be used for store-and-forward teleports.
Watch Gateway for further news of the STA and the stations involved.
PACKETEERS ARE EVERYWHERE
There is a lot more packet activity out there than meets the eye! This was brought home to me on a recent weekend while my wife Linda, KALZD, daughter Deryn, and I were vacationing in New Hampshire. As we were wandering around a computer tent sale, someone spotted Linda's HT and said, "I bet you're a ham." He turned out to be Dave McLanahan, WAIFHB, and we had a long and pleasant conversation about all sorts of things. Eventually I introduced the subject of packet radio, and asked innocently if Dave was familiar with the mode. He was not only familiar with packet, he was on itt Living in a bit of an RF hole in the wilds of southwestern New Hampshire, Dave goes hilltopping with a ZX81, a 5-inch TV monitor, and a GLB TNC to connect into the Nashua, New Hampshire area. With EASTNET growing as it is, he should soon be able to packet without leaving his home. Via Dave Sumner, KLZZ.
[Dave is General Manager of the ARRL -- Ed.]
PACKET RADIO IN AUSTRALIA
There are at least two active packet clubs in Australia, one in Melbourne and one in Sydney. The newly-formed Melbourne Packet Radio Group has four members: John Smelstorius, VK3ZVR; Ian Clark, VK3YRR; Peter Jetson, VK3ZMB; and David Furst, VK3YDF. These four have started a local net using the VADCG protocol. They will be attempting to link to the larger group in Sydney.
The Sydney Amateur Digital Communications Group (SADCG) has an active net of about twenty stations with a digipeater and a packet bulletinboard system.
Perhaps someone will set up an HF or satellite gateway linking the U.S. and Australia.
Via Amateur Radio.THE PACKET ADAPTIVE MODEM
If amateurs are to construct a long-distance packet network in the near future, some of the cross-country links are going to have to be on RF. While HF links are not as reliable as VRF links, we simply cannot expect to have a complete chain of VHF sites across the country as soon as we need it. The HF links will have problems not encountered on VRF links, such as long-term fading and multipath effects. To combat these problems, Bob Watson, and Paul Rinaldo, W4RI, designed the Packet Adaptive Modem (PAM).
Briefly, PAM uses a 600-Hz shift at 75, 150, 300, 600, or 1200 bauds. Programmable switched-capacitor filters (like those used on the TAPR TNC) keep the modem passband as narrow as possible, reducing noise and QRM on the received signal. In operation, the stations using PAM can determine the highest data rate that the link can support, and then use that data rate. If the link gets worse, they can go slower. If the link gets better, they can adapt and go faster. This should allow the use of the best transmission rate for a given link. [For further discussion of PAM, see Second ARRL Amateur Radio Computer Networking Conference proceedings, published by the ARRL.]
PAM is built on an S-100 card, but only uses the S-100 power supply. Serial 1/0 and filter control lines are provided through an RS-232-C port.
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Jon Bloom, KE3Z, has built two PAMs in the ARRL lab. One of these "alpha test" modems will be sent to Ralph Wallio, WORPK, and the other will be set up at WIAW. Testing of the modems will then be conducted on several HF bands.
After these units are tested, the circuit board layout will be updated and several "beta test" modems will be made available for more widespread testing.
RMPRA PACKET BULLETIN BOARD
The Rocky Mountain Packet Radio Association (RMPRA) is now operating what they believe to be the most sophisticated packet bulletin board around.
The system is a modified version of The Bread Board System (TBBS), by Phil Becker, WBOEIV. It was donated to RMPRA and modified for packet radio operation by Phil and Dave Ebert, W7RH.
TBBS is a modular software system that can be easily modified by the system operator to fit his particular needs. The RMPRA version is accessible through the Pike's Peak digipeater or via telephone at (303)-452-4735. If you want to call up and see the software in operation, set your terminal to 300 bauds, half duplex, 8 data bits and no parity.
23-CM BAND PLANS AND PACKET RADIO
Although most packet-radio activity is now on the two-meter band, band plans for the higher VRF and UHF bands will have profound effects on the future of packet radio. The number of packet stations on the air increases daily, and the need for high-speed, wideband links is becoming obvious in many urban areas. Both of these factors will push packet radio onto the higher bands, where several hundred kilohertz of band space should be easy to come by.
Since it is important for packet-radio enthusiasts to keep track of VHF/UHF spectrum plans, we present here a proposed band plan for the 23 cm band.
The ARRL VHF UHF Advisory Committee will recommend a 23 cm bandplan to the ARRL Board of Directors at the B.O.D.'s October meeting. The latest draft of this recommendation contains the following allocations of interest to packet-radio operators:
1240.0 MHz - 1258 MHz Wideband communications
1258.0 MHz - 1260 MHz Medium bandwidth digital duplex (with 1288- 1290 ).
1275.5 MHz - 1276 MHz Single-frequency digital communications.
1276.0 MHz - 1288 MHz Wideband communications.
1288.0 MHz - 1290 MHz Medium-bandwidth digital duplex (with 1258 - 1260).
1297.0 MHz - 1300 MHz Single-frequency communications, eg. digital, control links, cross-mode and remote base."Wideband communications" includes ATV, spread spectrum, and digital. Those portions of the band allocated to wideband communications will be coordinated by region. It is further recommended that coordination of multiple users of a single channel in local areas can be achieved through isolation by means of cross polarization and directional beam antennas.
It should be remembered that the above is a draft of a recommendation that will be presented to the ARRL Board of Directors. It is not a currently adopted bandplan.
It is important that packet-radio enthusiasts keep in touch with representatives of their local and national frequency-coordination groups so that packet radio's future will be provided for. The ARRL Board of Director's meeting will be in October, so be sure to express your feelings on the 23-cm bandplan to your Director.
CLUB LISTING CORRECTIONS, ADDITIONS
Add to the listing of packet-radio clubs:
Oahu Packet Enthusiasts Club (OPEC)
P.O. Box 1355
Pearl City, HI 96782Pacific Packet Radio Society (PPRS) c/o Hank Magnuski, KA6M 311 Stanford Avenue Menlo Park, CA 94025
Change these addresses:
Florida Amateur Digital Communications Association (FADCA)
c/o Gwyn Reedy, WLBEL 812 Childers Loop Brandon, FL 33511Rocky Mountain Packet Radio Association (RMPRA)
c/o Andy Freeborn, N0CCZ
5222 Borrego Drive
Colorado Springs, CO 80918TAPR GETS OFFICE
Tucson Amateur Packet Radio (TAPR), an international Amateur packet radio research and development group based in Tucson, Arizona, is proud to announce the opening of its office.
The office address is:
TAPR
1016 East Pennsylvania Avenue Suite 302
Tucson, AZ 85714
Phone: (602) 746-1166
Office hours are 9:00 AM - 5:30 FM (MST) Monday through Friday.The office staff is provided to expedite information requests, provide spare parts support, fill orders, etc. They can NOT answer technical questions. Technical questions should be routed to the TAPR P.O. box (printed in the last issue of Gateway).
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AEA PACKET RADIO IFORMATION
John Gates, N7BTI, of Advanced Electronic Applications is willing to talk on the phone or correspond by mail to answer technical questions concerning packet radio.
Contact: AEA
P.O. Box C2160
Bldg O&P 2006-196th SW
Lynnwood, WA 98036-0918PACKET RADIO AT HAMFESTS
Several Buffalo, NY, ham radio clubs will be sponsoring the HAM-0-RAMA at the Erie County Fairgrounds on September 7 and 8. This hamfest is of interest to packeteers, since the swap meet will feature computer equipment and the presentations will address "Computers and Amateur Radio." Jeff Ward of the ARRL will give an introduction to digital communications at 9:30 Saturday morning, and Gil Bolke, of GLB Electronics, will discuss packet radio later on Saturday.
REPRODUCTION OF GATEWAY MATERIAL
Material may be excerpted from Gateway without prior permission, provided that the original contributor is credited and Gateway is identified as the source.
Gateway: The ARRL Packet Radio Newsletter
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American Radio Relay League
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Newington, CT 06111Jeffrey W. Ward, K8KA
EditorLarry E. Price, W4RA
PresidentDavid Summer, KIZZ
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