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MMF PMD Selection

Title: MMF PMD Selection


In the interest of making progress on the MMF PMD selection, and in
response to Bill's request for system vendor input, I'll paint a bright
red target on myself. Here goes.

Consider the following four distinct applications:

  1. Dark fiber/SMF runs up to 40km & WAN interconnect (metro)
  2. Dark fiber/SMF runs up to 10km & WAN interconnect (campus backbone)
  3. MMF horizontal/vertical runs up to 100/300m (in-building)
  4. New fiber (any type: ribbon, MMF, SMF) runs up to 300m (intra-office)

It is easiest to explain to customers what to deploy when there is a PMD
positioned to match each application (or ideally one that does all).  I voted
serial 1550 for app-1, serial 1310 for app-2, 1300 WWDM for app-3 and
left app-4 for the OIF VSR work activity (as we don't have a general intra-
office interconnect objective, but could adopt/adapt their results in a later

So why pick 1300 WWDM for app-3? My thinking:

  1. It is the only solution which addresses up to 300m for all installed base.
  2. That is really the end of the rationale. However, considering cost arguments:

  3. 1300 VCSELs are supposedly only 6 months away (or up to 6 years

away depending on the source), which should make 1300 WWDM cost
competitive with 850 VCSEL WWDM.

Now I'll duck & cover.


David W. Martin
Nortel Networks
+1 613 765-2901  
+1 613 763-2388 (fax)