US Gov. sends real-time audio at 2400 baud!

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Article #1083

#1083

From: By-Tor
Date: Thu, 08 Nov 1990 21:06

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Hi.  I heard that the US government uses 2400 baud modems to send real-time
audio, to get a secure line anywhere in the world.  Does anyone know what
kind of algorithm they are using for compression?  I think it would be great
if we could make a real-time audio irc for people with sampling/playback
capability.  Anyways, consider that 2400 baud=2400 bits per second, meaning
without compression, you could get 2400 hz sampling at 1 bit resoultion.
This is totally unintelligable, so how the heck could they compress it
so much?  Obviously some kind of destructive method must be used.  I thought
maybe they look for duplicate waves or something.  Any ideas?

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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!julius.cs.uiuc.edu!ux1.cso.uiuc.edu!uxa.cso.uiuc.edu!sl35746
From: sl35746@uxa.cso.uiuc.edu (By-Tor)
Newsgroups: comp.dsp
Subject: US Gov. sends real-time audio at 2400 baud!
Message-ID: <1990Nov8.210640.2893@ux1.cso.uiuc.edu>
Date: 8 Nov 90 21:06:40 GMT
Sender: news@ux1.cso.uiuc.edu (News)
Organization: University of Illinois at Urbana
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