RE: From serial PMD call, 15 May
Piers - In FC, the present ristime spec is without a filter, however a
filter may be used (not required) to pass the mask test.
The concern is about risetime being too slow (the low jitter case); I
don't think anyone is worried about it being too fast. It may not have
large effect, but testing against a mask with a filter will require the
source to have a faster risetime than if measured without a filter.
Which scenario are you considering? Which case (of both) have been
considered in the link model?
Thanks,
Tom Lindsay
Stratos Lightwave
425/672-8005
-----Original Message-----
From: DAWE,PIERS (A-England,ex1) [mailto:piers_dawe@xxxxxxxxxxx]
Sent: Thursday, May 17, 2001 10:29 AM
To: '802.3ae Serial'
Subject: From serial PMD call, 15 May
Discussion of proposed deletion of risetime spec. line for 1310 serial
----------------------------------------------------------------------
We inherited this from Fibre Channel. SONET don't have it. Fibre
Channel
have discussed removing it, without strong views either way. Piers with
help from Petar and support from others will present how we can live
without
it.
Chromatic dispersion penalty
----------------------------
Our modelled number is unrealistic for two reasons:
Spectral width is likely much less than the 0.4 nm model number
Dispersion penalty is worked out for an incoherent source and
ours
is coherent. In Petar's terms, we are using a power model and we should
be
using a field model.
Luckily these two effects would move the error in opposite directions
and we
are discussing a penalty of only ~0.5 dB. This is thought to be
pessimistic.
Comments on Draft 3.0
---------------------
We had more reviewers than last time which is good. Clause 52 has
collected
about 200 comments including 34 TRs.
Next meeting
------------
There will be no meeting on 22 May. Will likely restart at the usual
time
on 29 May:
15:15 GMT = 4:15 pm BST = 17:15 CET = 11:15 am EDT = 8:15 am
PDT,
Tuesday (today)
+1(816)650-0631 Access code 39209
Piers