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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>
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Organization: Bell Communications Research, Inc
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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