Path: utzoo!attcan!uunet!mcsun!ub4b!syteke!jim
From: jim@syteke.be (Jim Sanchez)
Newsgroups: comp.dcom.lans
Subject: Re: networking on cable TV systems
Message-ID: <1649@syteke.be>
Date: 22 Oct 90 14:53:59 GMT
References: <6722@gaboon.UUCP> <149.2705d73f@stat.appstate.edu>
Organization: Hughes LAN Systems, Inc - European Support Office
Lines: 24

I would take STRONG exception to the the proposition that a CATV
system must be tuned to perfection to be used as a network medium.
Since my company (formerly Sytek) started out in the broadband (CATV)
networking business and have by far the largest installed base on this
medium, I think I can comment.  The biggest issue that you need to be
aware of is how many bits/sec do you want/need to squeeze into each
MHz of cable bandwith.  The higher that number, the smaller the
dynamic range of your system and the smaller the tolerance on the
signal level.  For example, 802.4 token buss (which IS if I remember
right what Appalacian State uses) crams 10 Mb into 12 Mhz and does not
like much variation in RF levels.  If, on the other hand, you use the
IBM Broadband PC network it puts 2 Mb into 6 MHz and has more than
twice the dynamic of the 802.4.  No mysteries here just plain old
engineering - there ain't no free lunch here either.

Cheers
-- 
Jim Sanchez          | jim@syteke.be (PREFERRED)
Hughes LAN Systems   | OR uunet!mcsun!ub4b!syteke!jim 
Brussels Belgium     | OR {sun,hplabs}!sytek!syteke!jim
-- 
Jim Sanchez          | jim@syteke.be (PREFERRED)
Hughes LAN Systems   | OR uunet!mcsun!ub4b!syteke!jim 
Brussels Belgium     | OR {sun,hplabs}!sytek!syteke!jim