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Re: PMD discussion




[Date: 05/29/2000  From Seto]

Hello Ed,

The answer is no.  I'm suggesting another set of '3' PMDs.

Seto

> Seto:
> 
> A question for you.
> 
> If you read Walter's statement carefully, then sent out your comment.  I
> believe your are proposing 4 PMDs.  Correct?
> 
> 
> Regards,
> 
> Edward S. Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
> Tel: (610)292-2870
> Fax: (610)292-2872
> 
> 
> 
> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of Seto, Koichiro
> Sent: Monday, May 29, 2000 10:25 AM
> To: wthirion@xxxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
> Subject: Re: PMD discussion
> 
> 
> 
> [Date: 05/29/2000  From Seto]
> 
> Walter,
> 
> My understanding is that the following set is also one of the top 
favorites:
> 
> ________________optimized for	may be used for
> 1310 nm WWDM	MMF upto 300m	SMF upto 10km
> 1310 nm Serial	SMF upto 10km	MMF upto 86m
> 1550 nm Serial	SMF upto 40km
> ________________
> 
> 
> I understand there are some risks that 850nm-WWDM solution may not 
satisfy
> laser eye safety as Jonathan pointed out in the discussion on Thursday.
> Also, I learned that there are some risks that 1310nm-WWDM may not be 
able
> to achieve 10km at SMF if not impossible.  At least we have not seen any
> data that would prove the feasibility of 1310nm-WWDM over 10km SMF.  It 
is
> not to say that this can not be done, but I have not been convinced that
 the
>  same 1310nm-WWDM optics at same cost factor will serve for both 300m 
MMF
> and 10km SMF.  Also, some people pointed out that 1310nm-Serial can be 
built
>  at cost factors of x1.8 to 850nm-Serial while 1310nm-WWDM is x3.  If we
 can
>  achieve the same goal (SMF 10km), the cheaper is the better.
> 
> I hope no one is offended by my not-so-educated opinion.  I would 
appreciate
>  a healthy discussion.
> 
> Seto
> 
> >
> > First of all, thanks to everybody that presented PMD proposals at the 
last
> > meeting. I've sent my presentation to David Law, so it should be 
available
> > on the web site in the next couple of days.
> >
> > In listening to the discussion after my presentation and then going 
around
> > and talking to people, it feels to me like we're starting to converge.
 Not
> > there, yet, but making progress.
> >
> > The equipment manufacturers made it pretty clear they would like to 
see no
> > more than 3 PMDs in the standard. The PMD vendors have some concern 
that
> > using only 3 PMDs may sub-optimize certain objectives, however, they 
could
> > support the 3 PMD position if it is made clear which 3 PMDs the 
equipment
> > oems want.
> >
> > Based on an informal straw poll and anecdotal evidence, my opinion is 
the
> > first choice would be the set:
> > ________________
> > 850 nm WWDM
> > 1310 nm WWDM
> > 1550 nm Serial
> > ________________
> >
> > If that set isn't feasible, then the 2nd most popular choice is:
> > ________________
> > 850 nm WWDM
> > 1310 nm Serial
> > 1550 nm Serial
> > ________________
> >
> > Thoughts, feedback?
> >
> > Walt
> > ___________________
> > Walter Thirion
> > Chair, IEEE 802.3ae PMD Sub-Task Force
> > 301 Congress Ave.
> > Suite 2050
> > Austin, Texas 78701
> > Voice:	512-236-6951
> > Fax:	512-236-6959
> > wthirion@xxxxxxxxxxxx
> > ___________________
> >
> >
> >
>