WELCOMEWelcome to Gateway, the ARRL packet-radio newsletter. Some of you reading this are deeply involved in amateur packet radio, some of you are just getting started on this exciting new mode, and some of you aren't quite sure what "packet radio" is. We hope that Gatewav will have something to offer each of you.
WHAT IS A "GATEWAY?
A gateway is a station that links two communications networks. In amateur packet radio, gateway stations are being used communicate between VHF and HF networks) and between VHF networks and satellite channels. Eventually, users of local VHF networks will use gateways to connect to an international packet-radio network. We have called this newsletter Gateway because we hope that it will, like a gateway station, facilitate communications between amateurs interested in packet radio.
Gateway will not be a technical newsletter; there are already several fine packet-radio newsletters covering technical issues. This will be a "news" newsletter. At ARRL Headquarters we have many sources of news not all of which are available to each of you. This newsletter will bring together notes from these sources. Overseas and domestic packet-radio club newsletters, the FCC, the IARU, on-line conferences and on-the-air bulletin boards will contribute. You may see items that you've seen elsewhere, but you should also see things that are new and interesting.
Some of you are receiving this packet-radio newsletter and have never even considered what packet radio can do for you, or what fun you could have on packet. We hope to provide you with an overview of the state of amateur packet radio, explaining what is being done and what can be done on this new mode.
It seems as though every packet-radio club is undertaking some project that will advance amateur packet radio. To make these projects fruitful, we must make the most of the limited resources available to amateurs. By telling a large audience about various packet-radio development efforts, Gateway should help organizers direct their efforts, and help volunteers find the groups that need them.
Perhaps when there is a worldwide amateur packet-radio network there will be no need for packet-radio newsletters. Until then, we hope that Gateway informs and interests you.
PACKET METEOR SCATTER
Last weekend's Persieds meteor shower provided a good opportunity to experiment with packet-radio meteor-scatter operation. Rich Zwirko, KlHTV, set forth some experimental guidelines, and stations throughout the U.S. attempted MS QSOs.
On August 1, well before the peak of the Persieds, W0RPK, the station of the Central Iowa Technical Society, held schedules with Bob Carpenter, W3OTC, in Maryland. The skeds were on 6 meters. Bob received about 2% of the packets sent from Iowa. Four nights later, again on 6 meters, W3OTC and W0RPK had what is believed to be the first amateur packet-radio meteor-scatter QSO.
As the Persieds approached, stations tried their luck on the 2-meter band. Stations in the East included K1HTV; Vern Riportella, WA2LQQ; Tom Clark, W3IWI; Hank Oredson, W~RLI; and Mark Wilson, AA2Z. In the West were Ralph Wallio, WORPK; Bob McCaffrey, K~CY; Ron Dunbar, W~PN; Mike McQuiston, WA~WYW; Bob Schiers, N~AN; and Terry Van Benschoten, W~VB. Several of these stations copied beacons and connect requests via MS. On the morning of August 12, during the peak of the shower, W~RPK and KlHTV completed the first packet MS QSO on 2 meters. Congratulations are in order for all stations involved in these tests, and I hope that I haven't left anyone out.
These tests were performed at 1200 bauds, using AFSK FM. While it was necessary to use this mode in order to include as many stations as possible in the experiments, a performance sacrifice was made. We should organize further tests at higher transmission rates with more efficient modulation techniques.
ARRL APPOINTED IARU PACKET CENTER
The ARRL has been appointed IARU packet radio "information clearing house." The following is exerpted from the minutes of the IARU meeting in late July: "ARRL is nominated as the international clearing house of information relating to packet radio on behalf of the IARU, with a view to encouraging common standards and regulations."
This points the way toward international understanding and acceptance of packet radio standards generated in the United States and Canada. Several European amateurs have hesitated to get involved in packet radio because they were not sure which standards would "catch on." The appointment should help to alleviate this confusion abroad as to what is really happening in North American packet radio.
PACKET RADIO ON NETWORK TV
On July 16 at 0745 PDT, a packet from N6ECT was heard throughout the nation on the CBS Morning News show. Curtis Spangler, N6ECT, was being interviewed by CBS for a piece on the HaightlAshbury and the film crew focused on his CRT. As luck would have it, Curtis was transmitting packets through the KA6M digipeater. The audio from one of the packets came through loud and clear, and the frame was heard in all 50 states and throughout half the worldt Via KA6M.
220 MHz and PACKET RADIO
The 220-MHz band is crucial to packet radio for a couple of reasons. Because it is the lowest frequency band on which we can exceed 19,600 bauds, it is going to be used for the initial high-speed intercity linking. It is not being used for any satellite uplinks or downunks, and so it is essential for full-duplex teleport stations. With these considerations in mind, we note the following:
The Tn-State Amateur Repeater Council has coordinated a 10O-kHz channel from 220.5 MHz to
220.6 MHz for wideband digital communications. This council coordinates VHF frequencies in northern New Jersey, southwestern New York (including Long Island) and Connecticut. This paves the way for EASTNET linking to begin as soon as hardware and software are ready.
On the negative side are two petitions for rule making which threaten the 220-MHz amateur band. The first is RM-4829 from the Land Mobile Communications Council. This petition calls for the FCC "to explore the potential use of vacant spectrum in the UHF TV bands, spectrum allocated for Fedral Government use, or assignments from the band 220-225 MHz to satisfy the requirements of land mobile users." This ~ay sound worse than it is, since the petition goes on to say "Because of the limited number of channels that the 220-225 MHz band will provide, however, it is not anticipated that this spectrum can meet the immediate requirements of land mobile licensees."
Another petition (RM 4831), from a manufacturer of amplitude compandored sideband equipment, explicitly requests reallocation of the band 216-225 MHz. This petition poses a serious threat to the 220-MHz amateur band.
Packet radio needs the 220-MHz band. Be sure to read these petitions and send your comments to the FCC. The comment procedure was outlined in ~, March, 1982. The comment deadline for these two petitions is August 29, 1984.
WHAT'S BREWING AT TAPR?
This piece came from Harold Price's answer to the question "Is TAPR up to something?" Harold is part of the TAPR software design team, and he made these comments while he was "Member of the Month" on Compuserve's HAMNET.
"The following views are mine alone, and do not necessarily refect those of TAPR, ANSAT, VITA, LAPG the staff, management, or janitorial departments.
"The TAPR folks are indeed up to something. We have the TAPR Pascal code running happily under a simulated environment again. The software, with only one change, runs under TURBO Pascal on the Pronto-16. This will vastly speed up development, which has slowed down as of late.
"The plan is to come up with version 4.0 of the TAPR TNC software which will allow testing of both datagram and virtual connection protocols. I think the level two wars are over. With 1300 TNCs in the field from 6 "manufactuers" all running the same level two, anyone proposing a switch now is just rocking the boat. The few proposals I've seen for different level twos offer no concrete advantages over what we've got now anyway. Besides, level two is boring (now that we have one that works). The real fun is level three.
"For the newcomer, level two refers to a point to point protocol, linking one TNC to another with no TNCs in the mi~ddle. There is currently a necessary kludge in AX.25 called digipeating which is a very demented level three feature. Digipeating allows two TNCs to be connected using a third as a relay. Without this simple addition to AX.25, packet may not have taken off as it did, since digipeating allows many more users to reach each other. If y6u haven't got a wide-coverage duplex repeater (or even if you have), digipeating is your best bet for now.
"Anyway, level two is point to point, with level two+ in current style, multibop dumb repeating. The + in level two will die a happy death when we get level three up and running. Level three links two end points thru multiple intermediate TNCs. The linking is done in an intelligent manner. ACKing is node to node rather than end to end. In level two digipeating, each intermediate point simply regenerates the packet. It does not ACK it. The final end point ACKs it, and the ACK is blindly repeated back to the starting point. If any repeat of the packet, or the ACK, is stepped on or dropped, the packet must start over from the beginning.
"In level three, an ACK can occur at each step of the way. Thus, a packet may only have to be re-sent between relay points five and six, rather than starting again at point one. So why don't we get on with it, you might ask?
"There are many problems involved in design and implementation of a level three network -- flow control, network blocking, routing, on and on. What is TAPR doing?
1) A node in a level three network will want to be connected to more than one other node. We will allow the TAPR TNG to maintain multiple level two connects. This has several implications. First, you can carry on two or more concurrent conversations. Not so good for rag chewing maybe, but great for emergency communications. Imagine a TNC in the local disaster center. Currently you can carry on a conversation with only one other TNC, with limited possibility of a priority break- in from another TNC. With all outlying TNCs connected to the central node at the same time you get closer to what you want, high reliability connections with each of the field guys at the same time.
"Next, and even better) you can automatically route one connection stream to another. Maybe an example is called for. The syntax below is probably not what we'll end up with, but the idea is:
MYCALL NK6K
[1] CONNECT WE6YMH
......[1] CONNECTED TO WB6YMH
[2] CONNECT WA6JPR
......[2] CONNECTED TO WA6JPR
ROUTE [1] TO [2]"Your TNC is now a network node. Anything that comes in from stream [1] gets ACKed at level two. The data from the packet gets routed to stream [2] where it gets sent out and saved until an ACK comes in on stream [2]. The reverse is also true, incoming from [2] goes to [1].
"Now, wouldn't it be great if you could cause the other guys board to make a connection? If I could tell WA6JPR to make a level two connection to WB5EKU? Then what we have is the level three function, endpoints linked. thru multiple intermediate points. A lot of things are missing, but this simple mechanism allows testing of level three concepts without a lot of hassle on the users part. We will also design an interface (based on asyncronous LABP) between the TNC and its attached computer to allow the computer full control over the link process. This permits the use of the TAPR TNC as a level two black box, with level three functions done in your host.
"Do I expect everyone to run verson 4? Well, why not? Version 3.1 can still be used point to point, and thru 4.0 gateways get full access to network. But just as everyone having the capability of being a digipeater added to the swift growth of packet, so will the ability of each TNC to be a level three node.
"But I ramble. Not only does a network node need to support multiple level two connections, it might also need to support connections on multiple RF channels. Let's assume a 1200-baud link on 2 meters and a 2400-baud link on 220, feeding a 9600 baud link on 440. The hardware arm of TAPR is designing a fancy multiport hardware controller. Several designs have been proposed, including a motherboard with slots for plugging in a number of channel-controller cards. Each channel-controller card is a mini TNC, handling all channel-access and level two functions. The mother board passes data between channels and handles level three and higher functions.
"We don't expect everyone to have one of these TNC-LINKs (say "tink link"). But they will make great mountain-top controllers, especially when used with the PACSAT 9600 whiz-bang modem, which has been described elsewhere.
"How long do I see TAPR building kits? There are two answers: "As long as there is a demand" or "Until we can't stand the sight of them anymore." I haven't been pressed into the chain gang of kit packaging, but isn't much fun, especially when serial number 1000 has long since gone out the door. The kits are TAPR's only source of income. An extremely small amount of each $240.00 goes into our fund for future development. I have forgotten how much. A number that does come to mind is the cost of the cabinet kit. Your cost, $69.00, our cost, $67.00. Our original goal was to make packet available to a large number of people at reasonable cost, delivering as full a function device as we could. It is possible to deliver less function for less cost. It is possible to deliver the same function assembled, tested, and warranted, for a larger cost. There are several market niches out there, and we will continue to ship as long as 1) there is a niche for us and 2) we're having a good time.
"Are we having fun yet? You bet!
"One final note. A for-profit company would be crazy to discuss future products like this before the product is ready to ship. But we're a nonprofit R&D company, trying to make packet the mode of the future. And remember, you saw it here first." Via HAMNET.
Club Listing
Here is a list of clubs active in Amateur packet radio.
Amateur Radio Research and Development Corp. (AMRAD)
P.O. Drawer 6148
McLean, VA 22106-6148Amateur Radio Satellite Corp. (AMSAT)
P.O. Box 27
Washington, DC 20044Chicago Area Packet Radio Association (CAPRA)
P.O. Box 8251
Rolling Meadows, IL 60008Central Iowa Technical Society (CITS)
c/o Ralph Wallio, W0RPK
Rural Route 4
Indianola, IA 50125Florida Amateur Digital Communications Assn. (FADCA)
c/o Ted Huff, K4NTA
1829 N. W. Pinetree Way
Stuart, FL 33494Los Angeles Area Packet Group (LAPG)
c/o Harold Price, NK6K
1211 Ford Ave.
Redondo Beach, CA 90278Minnesota Amateur Packet Radio (MAPR)
c/o Philip S. Plumbo, N0DFT
1128 Dayton Avenue
St. Paul, MN 55104New England Packet Radio Assn. (NEPRA)
P.O. Box 15
Bedford, MA 01730Rocky Mountain Packet Amateur Radio Assn. (RMPAR)
c/o Andy Freeborn, N0CCZ
52222 Borrego Drive
Colorado Springs, CO 80918San Diego Packet Group (SDPG)
c/o Mike Brock, WB6HHV
10230 Mayor Circle
San Deigo, CA 92126Tucson Amateur Packet Radio Corp. (TAPR)
P.O. Box 22888
Tucson, AZ 85734Vancouver Amateur Digital Communications Group (VADCG)
9531 Odin Road
Richmond) BC V6X lEl
CANADA
Remember to include an s.a.s.e when writing to any of these clubs. Club money spent on postage is money that can~t go into packet-radio development.
We also know of the following individual who would like to form a packet-radio club:
Doug Baker, K4CLE
8724 Cumbernauld Circle
Germantown, TN 38138Voice Nets Concerning Packet Radio
The following voice nets are devoted to discussion of packet radio.
Time Frequency Coverage Sponsor
Mon 2000 PDT 145.36 Los Angeles LAPG
Tue 2100 PDT 144.76 San Diego SDPG
Tue 2200 EDT 3.850 Eastern U.S. AMSAT
Thu 2000 EDT 147.12/72 Boston area NEPRA
Sun 1900 UTC 14.235 National TAPR
Sun 2100 UTC 7.158 National TAPR
Sun 0800 EDT 3.958 Regional FADCA
Sun 1900 EDT 147.165 Tampa area FADCA
Sun 2100 EDT 147.285 Orlando area FADCA
Sun 1500 CDT 7.158 Central U.S. CITS
Gateway: The ARRL Packet Radio Newsletter is published by theAmerican Radio Relay League
225 Main St.
Newington, CT 06111Larry E. Price, W4RA
PresidentDavid Sumner, K1ZZ
General ManagerJeff W. Ward, K8KA
Editor
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Prices are subject to change without notice. Remittance must be in U.S. funds, and checks must be drawn on a bank in the U.S.Click to read: Gateway Vol. 1, No.2
