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Re: [802.3_B10K] Dispersion Penalty Presentations


Thanks for sending, I hadn’t seen these. However in looking at them I don’t see that any TDECQ measurements were taken. Sone_b10k_01a_1117 does indicate some CD penalties, but it does so using a T/2 spaced 17-tap FFE as the receiver, which is quite a bit different that the reference receiver in use in a TDECQ measurement. Do you know of any TDECQ measurements taken (with the prescribed reference equalizer)?


Also, given that there are negative CD penalties  down to as low as -150 ps/nm suggests that the transmitters in use have quite a bit of chirp. Do you know if measurements were performed for any un-chirped transmitters?






From: John DAmbrosia <jdambrosia@xxxxxxxxx>
Sent: Wednesday, September 11, 2019 7:57 AM
To: STDS-802-3-B10K@xxxxxxxxxxxxxxxxx
Subject: [802.3_B10K] Dispersion Penalty Presentations



Yesterday an issue was raised regarding dispersion, and there was an inquiry regarding any presentations on the topic had been heard.  My thanks to Peter Stassar, who did the digging through the Study Group archives to find the following presentations that had explored assessing the dispersion penalty at high negative dispersion of around -200ps/nm.  As I recall now, this was a key issue for the Study Group to resolve before it finally adopted the 40km objectives and could answer the Technical Feasibility Criteria.


SG material.

November 2017:


January 2018:


March 2018




John D’Ambrosia

Chair, IEEE P802.3cn Task Force




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