[636] in Commercialization & Privatization of the Internet
cable-TV networking
daemon@ATHENA.MIT.EDU (Brian Lloyd)
Thu Apr 25 18:01:19 1991
Date: Thu, 25 Apr 91 14:01:38 PDT
From: Brian Lloyd <brian@napa.telebit.COM>
To: perry@mcl.unisys.com
Cc: com-priv@psi.com, perry@mcl.unisys.com
In-Reply-To: Dennis Perry's message of Thu, 25 Apr 91 06:54:17 EDT <9104251054.AA27972@kauai.MCL.Unisys.COM>
Reply-To: brian@napa.telebit.COM
Date: Thu, 25 Apr 91 06:54:17 EDT
From: Dennis Perry <perry@mcl.unisys.com>
Some of you might be interested to know that while at DARPA I worked
with SRI and UC Berkley to put in a packet radio net using inter-frame
time on the educational or public TV channel, don't remember which.
Twelve years ago I worked on a similar project at PBS in DC. We
encoded a 9600 bps data stream into one line of the picture during the
vertical interval (the 20 or 30 scan lines that get lost while the
beam flys back to the top of the screen). For reliability we just
sent the messages over and over again to provide a high probability
that everyone would receive the messages.
The interesting kicker was that the FCC required us to strip out the
data before it was transmitted over the air. We didn't care but the
FCC did. This just points out that the regulatory issues may cause
serious technical issues to arise. Stripping out that data was
neither cheap nor easy compared to detecting it.
Brian Lloyd, WB6RQN Telebit Corporation
Network Systems Architect 1315 Chesapeake Terrace
brian@napa.telebit.com Sunnyvale, CA 94089-1100
voice (408) 745-3103 FAX (408) 734-3333
