- Date: Tuesday, 12 July, 2005
- Time: 9:00 AM Pacific
- Duration: 1:30 max
- Number: 401-694-1515
- Access code: 421721#
Agenda
- Attendance
- Review previous minutes (thanks, Mike)
- Build agenda
- Technical discussions
- Vivek - correlation among EQ lengths
- ClariPhy - TBD
- Finisar - TWDP on TP3 setups?
- Conclusions before meeting?
- Next call
Tom Lindsay ClariPhy Communications tom.lindsay@clariphy.comphone:
(425) 608-0209 or (949) 480-9210 cell: (206) 790-3240 fax: (425)
608-0232
----- Original Message -----
Sent: Thursday, July 07, 2005 2:43
PM
Subject: [10GMMF] Minutes for TP2 call
7/5/05
Attendance (no
order)
- Lew Aronson
- David Cunningham
- Ernie Bergmann
- Piers Dawe
- Mike Dudek
- Majid Barazande-Pour
- Norm
Swenson
Agenda
- Attendance (done, see above)
- Build agenda (done)
- Technical discussions (see below)
- Next call (see below)
Mike Dudek moderated
the call in Tom Lindsay's absence.
Discussion (TWDP)
- Further
discussion took place on the comparison metrics of SNR, TWDP, and
implementation penalty (IP) with finite length EQ that Tom had
presented last week. See http://grouper.ieee.org/groups/802/3/aq/public/upload/AnalysisofSNR_TWDPandfinitelengthIPvs.measuredwaveforms.pdf.
- Norm Swenson
described work that he had performed to attempt to evaluate whether the
TWDP degradations seen for practical waveforms was related to
non-linearities or other factors. Early results showed that the TWDP
was reduced by 0.2 to 0.5dB for best linear fits to a selection of the
waveforms from Tom's presentation. He sent a graph of these early
results to the reflector (based on Ewen 4.6dB pre-cursor stressor).
He intends to present more results next week.
- Concern
was again expressed that Tom's presentation showed
that when normalized to OMSD only parts with
significant pre-emphasis had lower TWDP than the supposedly worst case
47ps Gaussian pulse, and that we need to make sure that "reasonable
practical" Tx's will pass the test. ie we may need to allocate some
of the implementation penalty to the Tx if we use this normalization
method.
- Lew Aronson suggested that practical TP3
stressed eye testers may overstress the Rx and said that he was going to be
performing TWDP like tests on his tester.
- David Cunningham stated that he had
measured Pie-D on some commercially available BERTS and found that they
had 0.2 - 0.5dB penalty not all of which was related to rise/fall
times. This indicates that making a perfect TP3 stressor will
not be easy.
- Mike Dudek suggested that we will have
to determine what to do when the waveforms have been matched as well
as possible to the pulse shapes in the standard and the TWDP like test of
the resulting waveform does not match the expected TWDP like
result. He suggested that there are 3 choices with the noted
advantages/disadvantages.
- 1 Just state that
test implementers need to minimize the difference and that the
difference will result in conservative results. (similar to what
is said about noise in the 10G 802.3ae standard for the
stressed receiver sensitivity testing). Not recommended based
on experience with the 10G stressed eye testers.
- 2 Say that any
difference in TWDP should be used as a correction factor for the
stressed sensitivity. This is still probably conservative as
it is likely to result in more distortion to equalize but with somewhat
higher input power. It is however relatively easy to incorporate
into the standard.
- 3 Say that the
waveshapes should be adjusted to create the required TWDP.
Probably the fairest test for the receivers, but may be difficult to
state in the standard how to do this.
- It was also suggested that it would be
useful to have a name for the "TWDP like test" (ie test of TP3 signal with
TWDP like code without the simulated fibers) to more easily differentiate
this test.
Next week
- Tom will be back
- Vivek planning to present on
correlation across EQ lengths (action from 6/23). (Hopefully this will take place. Vivek was
not on the call to confirm).
- Norm Swenson
planning to present more information on his analysis of the TWDP results
from the various eyes.
- Lew Aronson
planning to present information on TWDP like measurements on a TP3
stressed tester with comparison to theory.
- Requests for new sims
- ~0/30/60 psec Gaussian with pre/post, long/short
EQs, normalized with OMSD/OMA. Show SNR, TWDP, and IP. (Carried forward from 6/28 call)
- Other IP mechanisms.
- Reminder this will
be the last day for comments to rev 2.1
Next call
- Date: Tuesday, 12 July, 2005
- Time: 9:00 AM Pacific
- Duration: 1:30 max
- Number: 401-694-1515
- Access code: 421721#
Thanks,
Mike Dudek
Director Transceiver
Engineering
Picolight Inc
4663 Nautilus Court South
Boulder
CO 80301
Tel 303 530 3189
X7533.
|