Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.dcom.modems
Subject: Re: Error correction vs Error control
Message-ID: <16357@cbmvax.commodore.com>
Date: 6 Dec 90 21:48:09 GMT
References: <1990Dec6.115526.8595@nntp-server.caltech.edu>
Reply-To: grr@cbmvax.commodore.com (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 20

In article <1990Dec6.115526.8595@nntp-server.caltech.edu> fjs@nntp-server.caltech.edu (Fernando J. Selman) writes:
> I am confused about the terminology. Is there a modem with
> real error correction scheeme, say, 2 errors detection one
> error correction? Or do they just retransmit after one error
> detection? Thanks,

Conventional modems (protocols actually) rely on error detection
and retransmission, since this has the lowest overhead over a
a good channel.  Special purpose modems/protocols such as those
used for radio, satellite or other exotica also use forward error
correction as you describe when channel reliablilty is more
important than nominal thruput or when retransission is either
impossible or requires too long a delay.  The two may also be
combined where errors too severe be corrected by the error
correction coding cannot be tolerated.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)