Modem tones over television or radio

From: William Donzelli <william_at_ans.net>
Date: Fri Dec 18 10:02:34 1998

> Packet radio ? In the 30s ? This is a packet switching network
> thru a single chanal with halve duplex connections.

OK, poor wording on my part...

The idea of transmitting modem tones over the radio (yes, even the
broadcast bands) is nothing new. Back in the 1930s the U.S. Navy was
playing around with the idea, trying to work it into their communications
systems, but did not have a great amount of success until 1944 or so. By
then the system had evolved into quite a monster, with quite a bit of it
being automated. "Routing" as we know it was still manually done and
messages were generally not broken into "packets". One very interesting
aspect is that the radioteletype nets were integrated with the landline
nets using things called "Land Line Control Units". These allowed an
operator to use a distant radio site to contact a station not on the
landline (i.e., a ship) in a completely automated fashion - the radio
sites could be left unmanned if need be.

My point is that transmitting digital data over the land or air is really
a very old idea - most of what we know as networking theory these days was
formulated by the government and telephone companies long ago.

William Donzelli
william_at_ans.net
Received on Fri Dec 18 1998 - 10:02:34 GMT