Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site petrus.UUCP Path: utzoo!watmath!clyde!burl!ulysses!gamma!epsilon!zeta!sabre!petrus!karn From: karn@petrus.UUCP (Phil R. Karn) Newsgroups: net.dcom Subject: Re: Standards for commercial packet radio Message-ID: <472@petrus.UUCP> Date: Sun, 18-Aug-85 14:42:01 EDT Article-I.D.: petrus.472 Posted: Sun Aug 18 14:42:01 1985 Date-Received: Fri, 23-Aug-85 07:17:11 EDT References: <1919@amdahl.UUCP> Distribution: net Organization: Bell Communications Research, Inc Lines: 25 So far as I'm aware, the only organization doing anything with terrestrial packet radio besides the amateur radio community is the US Department of Defense. (To me, "packet radio" doesn't include one-way data broadcasting on FM broadcast subcarriers, nor does it include hooking up a modem to your cellular phone.) The DoD has spent a considerable amount of effort in developing packet radio for mobile tactical communications, and at least some of their work has been published (see the November 1978 Proceedings of the IEEE, p. 1468.) As you might expect, IP/TCP are the standard network and transport layers in DoD packet radio networks. The characteristics of a mobile packet radio network, with its constantly changing topology and frequent node failures, (due either to a station driving into a radio "hole" or getting blown to bits by The Enemy) was one of the basic reasons the Internet Protocol is based on datagrams. The refusal of any of the commercial standards organizations to consider datagram protocols is what prompted the DoD to develop their own. DoD packet radio makes heavy use of spread spectrum, as you might imagine. Not only does this make transmissions harder to jam or intercept, but it also alleviates multipath effects common in mobile environments. See the IEEE article for more details. Phil