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Hi Pete, I have to agree that my initial statement might have been simplistic. The measurements would be relatively easy, selecting representative parts to measure would not be. I like your suggestion on how to approach the selection process.
From: Anslow, Peter [mailto:panslow@xxxxxxxxx] Dan, I agree that measurement results for this would be desirable. I’m not sure, however, that they will be “relatively easy to capture”. Most device manufacturers need to operate with a high yield against the eye mask test, so finding a population of devices with a significant number of failures against the existing test may not be very easy. One way forward might be to operate a set of test devices at progressively higher and higher bit rates until they fail the old and new eye mask tests, then plot similar curves to the ones from my simulations. Regards, Pete Anslow | Senior Standards Advisor From: Dove, Daniel [mailto:dan.dove@xxxxxx] Hi Pete, This is good stuff. I have a question though. It seems like some experimental/empirical measurement data could be included to bolster the theoretical arguments. I would think they are relatively easy to capture by finding a set of transmitters that marginally meet the existing limit, and then comparing the results against the new limit. These transmitters should be captured from a range of devices to provide some distribution in properties.
From: owner-stds-802-3-maint@xxxxxxxx [mailto:owner-stds-802-3-maint@xxxxxxxx] On Behalf Of Anslow, Peter Jonathan, Since the eye mask test used in Clause 68 and 802.3ba allows some of the samples to be within the mask, an alternative statistical transmitter eye mask test for Clause 52 will need to use a larger mask than the current test so that it doesn’t allow a worse transmitter to pass that the current test does. I have attached a presentation on the results of some simulations aimed at investigating how much larger the mask should be. Regards, Pete Anslow | Senior Standards Advisor From: owner-stds-802-3-maint@xxxxxxxx [mailto:owner-stds-802-3-maint@xxxxxxxx] On Behalf Of Jonathan King Dear all In advance of the 802.3 revision document planned for release for comment in March, I’d like to let you know that I plan to comment on it, with a proposal to add to Clause 52 an alternative optical transmitter eye-mask test, which leverages the statistical eye mask measurement techniques developed for 802.3aq and 802.3ba. The proposal will be in the form of an annex associated with Clause 52 (assuming this is OK with the editors) since this seems to be the easiest way to add an alternative test with minimal changes to the original document. The motivation is to offer a more accurate and repeatable optical transmitter eye-mask test which can be a replacement for the 0-hit eye mask test used on legacy 10GBASE-R, which provides the same, or higher, level of confidence of test results, and which will potentially lower test time and test cost. 10G products continue to ramp up in volume, and test time is a significant bottleneck for low cost, high volume production. If you wish to be involved in early drafting of the comment and more importantly drafting the text of the alternative eye-mask test, please contact me by e-mail. best wishes jonathan Jonathan King Finisar Corp 1389 Moffet Park Drive Sunnyvale, CA 94089 ph: 1 408 400 1057 cell: 1 408 368 3071 e-mail: jonathan.king@xxxxxxxxxxx cube A262 |