Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!rutgers!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.dcom.modems
Subject: Re: PEP vs. v.32
Message-ID: <19406@cbmvax.commodore.com>
Date: 1 Mar 91 23:06:32 GMT
References: <6895.27CDE02A@zswamp.fidonet.org>
Reply-To: grr@cbmvax.commodore.com (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 34

In article <6895.27CDE02A@zswamp.fidonet.org> root@zswamp.fidonet.org (Geoffrey Welsh) writes:
> 
>  >From: tnixon@hayes.uucp
> 
> >   I would think PEP, using more of the available frequency bandwidth
> > should be able to get consistently 18,000 bps or higher. Why not? 
> 
>  >PEP already uses virtually all of the available bandwidth;
> 
>    I think the question here is, why does V.32bis (or the newer HST 
> modulation) get 14,400 bps raw carrier throughput on all decent lines, while 
> PEP may reach 16,000 bps only under very rare 'ideal' lines.

I think you need to examine closely the relation between these "ideal" lines
and "all decent" lines.  There's not a lot of user evidence on what percentage
of call attempts will work at 14.4 and some contention even about 9600.

>    I've often wondered what could be done to improve DAMQAM modulation.  It 
> is, after all, the oldest of the current high speed dialup modem technologies, 
> predating the HST, the V-9600, and even the widespread public acceptance of 
> 2400 bps!

Yes/No.  The underlying technologies and the product implementations have
distinctly different timelines.

I hope Telebit does manage to come out with a second generation scheme that
combines the apparent benefits of multi-carrier technology with the full-
duplex nature that echo-cancellation supports.  It's hard to predict whether
they will do so while there is still a reasonably window of opportunity...

-- 
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)