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From: mep@AQUA.WHOI.EDU (Michael E. Pare)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  Any experience using commercial cable TV as a MAN?
Message-ID: <8910101303.AA01915@aqua.whoi.edu>
Date: 10 Oct 89 13:03:19 GMT
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Most cable TV companies use a sub-split format with reverse (toward the
headend) frequencies only ranging from 5-30MHz and the forward (away from
headend) strating at 54MHz to top end (300, 400, 450 etc.).  This severly
limits the useable bandwidth for data since the reverse direction is so
limited.

Most broadband equipment utilizes IEEE standard frequencies which start
above the 54MHz level for the reverse direction.  They are designed for
mid-split systems which most private CATV plants are (universities etc.).

Even if you limited the channeling to 6MHz in each direction (limited
daat bandwidth) everyone on the system would have to use 'like' equipment
in order to talk on the system.  You'd probably have to have the CATV
company coordinate the efforts.  This assumes you can find the hardware
and would it be worth it for a 6MHz bandwidth?!  Also, in many metro
areas there is usually more than one CATV company which certainly
breaks up the network within the metro area.  These companies have no
intentions of linking together.

But this is just my limited thoughts on using CATV as a MAN.