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Re: Multi-mode PMDs

Ed, Roy, et. al,

I sent mail to the reflector (subject 1300 nm VCSELs, date:Wed, 16 Aug 2000) in
order to get the discussion going on short reach PMDs.  I hope folks are really
busy and just haven't had the time to discuss the issue here on the reflector.
I'd like to hear your opinions regarding the 1300 nm VCSEL and its potential
impact on the low cost short reach application space.  I'm of the mind that
fewer PMDs is better, but I was not willing to vote in favor of fewer PMDs
without being assured of a low cost option for the short reach application
space.  If 1300 nm VCSELs are going to be available in a reasonable time (less
than 1 year), and the mode conditioner is not needed for <= 100m then it seems
much more difficult to argue in favor of more PMDs.  I'd much rather see the
discussion start now, rather than burn time at the interim with the same old
arguments ending in up with no concensus.



Edward Chang wrote:

> Roy and All:
> It seems that we did not get the consensus of which specific PMDs we need in
> addition to 1550 and 1310 serial.  However, it seems we have the consensus,
> or the majority of desire, to have short reach, cost-effective PMDs, which
> will include the VCSEL based approaches.
> Since many factors we have been debating to further narrow down the
> selection lists are based on the future market trends and many technical
> assumptions, we have had quite verities of different opinions; as a result,
> we were unable to obtain a consensus.  I do not think the situation will get
> better, unless we take a lot of time in debating and testing by prolonging
> the schedule, which is unlikely the path we can afford to take.
> I think we should let all PMDs on the table to be adopted, and let us move
> on to the next target, instead of trying to pin down factors which are not
> under our control.
> Regards,
> Edward S. Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
> Tel: (610)292-2870
> Fax: (610)292-2872
> Subject: Multi-mode PMDs
> All,
> Where are we in the discussion of the multi-mode PMDs?  There has not been
> much on the reflector of late.  The last that I have on this does not
> indicate to me that there has been any consensus established.   The last
> that I have, indicates that the system vendors and other members of the
> 10GEA are still wanting the 1310nm solutions, and the rest of the TF are
> wanting the 850nm solutions.
> Has this subject been moved to an Ad Hoc?  Has this discussion been moved
> to a different forum/TF?
> Thank you,
> Roy Bynum
tel;work:(510) 486-7913
org:Lawrence Berkeley Lab;Networking & Telecommunication
title:Network Engineer
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fn:Mike Bennett