Re: [10GMMF] TP3 Meeting minutes, November 23rd
Some comments:
1) I think it is very important that all are aligned on the PIE-D calculation. I would be interested in a discussion on the variables mentioned below, what differences exist now between different task force members algorithms and the likely impact of changes of each of these parameters.
2) I think it would be very useful to settle on the number of impulse response peaks with which to emulate the IPRs as well as the width of the peaks. That is, given a system with a known pulse shape, what extra filtering would be needed along with the four impulse peak values to create the expected total impulse response (when viewed with a 7.5 GHz scope.
[I for one favor 4 peaks for flexibility of implementations other than using EDCs themselves. This may make it necessary to choose dT a bit more than 1 UI, but that might not be a bad thing]
3) On a related note, we need some wording which lets one calculate the complete impulse response from the impulse peak heights, peak spacing and defined TX pulse response. This is needed as part of the characterization.
4) It would be helpful to agree (if possible) that the pre and post cursor responses are to be mirror images of one another. It would speed up our search process and simplify the tables which will results
5) As for the process, I would suggestion a combination of selection oand sythesis. That is, the process really should be based on the channel models (Cambridge and or Monte-carlo with connectors). Select a range of cases from each within a certain range of a target PIE-D. Finally, synthesize a the three cases from this group of responses, using the type of fitting metrics of Petre, but making sure the resulting impulses have the desired PIE-D as well. It would be useful to have a metric which also takes into account the overall length of the impulse repsonse (perhaps a certain finite version of PIE-D) to help drive the process realistically.
I don't think we need to exactly match a particular case. I think something which looks like the other pre-cursors from the subset of the channel model is fine. The question is what does look-like mean. It also may be desirable to try to match the more extreme cases within the subset (maintaining the same PIE-D or other metric in the process).
6) I did not see on the timeline a work item to create the wording for the TP3 signal characterization. I think one important thing there which is not done is a measurement technique for verifiying the impulse response being generated by the TP3 tester.
Lew
-----Original Message-----
From: Michael Lawton [mailto:mike_lawton@AGILENT.COM]
Sent: Wednesday, November 24, 2004 6:10 AM
To: STDS-802-3-10GMMF@listserv.ieee.org
Subject: [10GMMF] TP3 Meeting minutes, November 23rd
Dear TP3ers,
Here are my notes from yesterdays call.
1. List attendees
Abbot, John
Bhoja, Sudeep
Ghiasi, Ali
Jaeger, John
Kolesar, Paul
Lawton, Mike
Lindsay, Tom
McVey, Jim
Popescu, Petre
Rausch, Dan
Rommel, Albrecht
Savara, Raj
Telang, Vivek
Traverso, Matt
Van Schyndel, Andre
Weiner, Nick
Willcocks, Ben
Witt, Kevin
Zona, Bob
2. Review notes from last meeting
Whoops forgot, any comments please get back with me.
3. TP3 planning for Vancouver
Reviewed proposal from Mike
I've captured the following comments on my presentation... (new version attached)
In general I was proposing that we focus on TBD's. Work to an agreed deadline, and agree to use voting if necessary in order to close off issues and proceed.
ACTION: Each member review timeline and come to the next meeting ready to accept or reject
p3 Nick W: signal characterisation and measurement ... shouldn't that at TP3 itself and not as shown coming out of ISI block with filter
p5 Tom L: Slide misses the fact we have agreed the OMA value and SNR required at TP3 (Tom, My notes here were abit vague ... is this right?)
p6. Discussed outstanding work.
Key issues which were raised:-
PIE-D has variables associated with it (rise time, sigma^2, ZF vs MMSE calculation) - how do we handle that?
Different launches will produced different fiber sets and PIE-D distributions - Do we need to emulate different fiber IPRs or can we just use
different PIE-D distributions to represent results for different launches?
What would be the best approach, synthesis, selection, or measurement?, these terms need defining as used in the context or our discussion:-
- by synthesis we meant developing an algorithm which could generate 3 IPRs for any given PIE-D
- by selection we meant ranking a fiber set (Monte Carlo or 108) by our chosen Metric and then selecting appropriate channels to emulate
- by measurement we taking known fibers that are "appropriate" and then measuring either their IPR or their soft waveform at the Rx
ACTION: Each member to consider these approaches and come the next meeting ready to select our chosen technique.
p7. Timeline
ACTION: Tom and Piers agreed to work towards closing off jitter on our Nov 30 call
ACTION: Sudeep kindly agreed to look at PIE-D vs BT filters for our informative test. Aim is to remove TBDs on 7 Dec call
Time line needs to have Comment resolution deadline added ... Jan 7
Jan 4 meeting may not work as it will be first day back fo many? due to Jan 3 being a public holiday
4. TP3 Jitter testing Tom L.
Tom got agreement on two comments he will now submit:-
i) on a low frequency jitter test
ii) on an informative note to say that either Phase or Frequency modulation can be applied.
Tom and Piers still working on pk-pk UI figure for high frequency test.
5. Walk in items
Discussion on above and below the line items in Link budget. No changes just clarifications.
Any comments/corrections please get back with me.
Best Regards
Mike