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
> ___________________
>
>
>