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Path: utzoo!watmath!clyde!bonnie!akgua!mcnc!unccvax!dsi
From: dsi@unccvax.UUCP (Dataspan Inc)
Newsgroups: net.dcom,net.video
Subject: Re: Eavesdropping from TV "dish" ???
Message-ID: <275@unccvax.UUCP>
Date: Sat, 24-Aug-85 11:30:07 EDT
Article-I.D.: unccvax.275
Posted: Sat Aug 24 11:30:07 1985
Date-Received: Sun, 25-Aug-85 14:03:08 EDT
References: <171@kitc.UUCP>
Organization: UNC-Charlotte
Lines: 32
Keywords: TV satellite receivers, satellite security
Xref: watmath net.dcom:1199 net.video:1426


     Wrongo...if your friend is hearing any conversations clearly, they
are most likely subcarriers on 'backhaul' feeds used by engineers in
setting up links, sending cue signals to alert on-site talent to the
critical events in a broadcast (such as time to sell some Budwiser) etc.

     Real long distance phone calls on domestic birds are (correct me
if I'm wrong) all digital, in the T1/T1C etc time domain multiplexed
mode.  I have once in a great while heard some garbled something that
sounded like speech (on Satcom F2) and you also can sometimes hear obvious
human speech being transmitted unintelligibly, i.e. a person 'whining'
but the information content is much worse than even single sideband
on an AM receiver.

     The Soviets are evidently very good at intercepting domestic T1
transmissions and decoding them. They, however, purcahse a barn or
something (on the line of sight for terrestrial microwave) and install
a 10 foot or more dish inside. The channel demultiplexing equipment 
is extremely expensive, you wouldn't just use a 'scanner.' 

     There is a treatment of this whole issue of telephone security (both
satellite, microwave, and hard wire) in one of the recent issues of
IEEE Spectrum. I think it was March or April, but the issue was definitely
published this year.

     This is grossly oversimplified, but your friend doesn't really
have anything to worry about.

David Anthony
CDE DataSpan, Inc.

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