Bulletins from the Pacific Packet Radio Society - page 126

AMSAT - Tom Clark, W3IWI, Jan King, W3GEY, John DuBois, W1HDX and Bob Carpenter, W3OTC.

Even more surprising is that this diverse group managed to agree on some things. In fact, the agreement reached on adopting a common link level protocol may prove to be extremely significant in forming the foundation for U.S. packet radio networking. The meeting which originally was supposed to iron out some AMICON details managed to have much more of an impact. Here's some background on what happened:

A year ago, in conjunction with the 181 AMSAT general meeting, Paul Rinaldo organized the first Packet Radio Networking Conference under the sponsorship of AMRAD, ARRL and AMSAT in Washington (some excellent conference proceedings are still available). Many ideas and some re al and paper networks were discussed. In the months which followed quite a few people got their packet radio controllers running and had a chance to experiment, read, discuss and think about various problems involved in implementing packet radio networks. The situation became discouraging. It seemed like a new protocol was proposed for each new set of Terminal Node Controller (TNC) hardware that came on the air. Each group started heading off in a somewhat different direction. The promise of compatible systems was growing remote. But in this dispersion of effort, people also found out how difficult it was to implement private protocols and how difficult the interconnection would be if common ground wasn't found soon. The different groups also came to realize that there were a common set of problems to be solved and that one area's solution couldn't ignore the requirements of other users. The summer doldrums saw very little activity and not much progress, and provided the background for the AMSAT meeting. This inevitable diversity during the R&D phases for each of the groups had to be reconciled with the impending launch of the Phase-3B satellite in February, 1983.

The AMICON Network
------------------

Three major areas of concern filled the agenda of the AMICON meeting: the usage of the Special Service Channel (SSC) earmarked for digital experimentation and called "AMICON" in AMSAT planning documents; the recommended modulation methods and bit rates to be used on the Phase-3B SSC; and the detailed link protocol to be used for linking ground stations via the satellite.

There was general agreement that standards accepted today must be regarded as developmental. It is to premature to ordain any single scheme at this time. The AMICON concept is not yet a detailed network design, but rather an opportunity to develop a new service for amateur radio. In the developmental phases we may well see many diverse techniques being tested. The meeting discussed the concept that the use of high-altitude

Click for Original Graphic Image of this page.