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Ali, Thanks for delving in here. In addition
to your observations and proposals, I’d like to return to my question posed on
the ad-hoc call just prior to our interim meeting in Regards, Paul From: Ali Ghiasi
[mailto:aghiasi@xxxxxxxxxxxx] Jonathan In regard to statement given in your presentation, I like to add some
more color to this statement •
Note: recent work on MPN treatment, by
David Cunningham,
shown in T11 (Fibre
Channel), indicates that FEC is a necessity for 100m links 32GFC operates at 28.05 GBd, current spreadsheet model do show very
steep increase in penalty as result of mode partition noise and cross terms. The FC group wants to support 100 m on OM4 fiber, with current noise
model even with a simple FFE EQ FEC would be required to close the link budget. Also the same spreadsheet shows that if we added FEC with
overhead and operated at 28 GBd instead of 25.78 with 2.5 dBo or 5 dBe
penalty we could be worse off than using FEC. So our only option would be
to use inband FEC which has higher latency. With 100GNGOPTX investigating 2nd generation set of PMD where there
already exist set of solution, as a group we have to deliver a solution which allow seamless migration from 40G-SR4 and is lower cost than
100G-SR10. If it requires fundamental investigation then the group need to undertake it! My concern with current spreadsheet model which I have also shared with
David Cunningham is how B (bandwidth) is used for calculation of MPN, for mode partition noise and the cross term for detail analysis please
see David presentation B= 1/(T-DCD) where T is the 1/Baudrate â=π.B.D.L.σλ.λ σmpn = kOMA/√2 . [1 - e^(-β^2)] I do agree in the ISI calculation we should use DCD to increase the
effective baudrate but if you have slow laser which is the case for 25.78 operation both ISI and
MPN do not increase the laser is toggling faster but never reaches steady state! The
spreadsheet already captures the ISI penalty and double counting might have been negligible at lower
speed when the laser were fast but double counting at these speed breaks the link or
we end up with a link significantly shorter! What seems reasonable here is to use the current B for ISI penalty
calculation but for MPN and Cross use the following B1= 0.35/(Teff) where Teff is the RMS mean of sqrt(Trise^2+Tfall^2/2) as I expect
current Ts is in the spreadsheet is the Tfall time. Thanks, Ali On Feb 13, 2012, at 5:52 PM, Jonathan King wrote:
Dear all, Here is my
presentation for the MMF ad hoc call , 14th Feb 2012 This is intended to
be an introduction to, and framework for, discussion on what we do as an ad hoc
to progress towards an MMF objective. Best wishes jonathan From: Hi, By popular request,
we have moved this meeting to Tuesday 14 February at the same time as before.
(With apologies to Paul who now can’t attend.) Hi, As mentioned by Dan,
Jonathan and I are planning to hold an SMF Ad Hoc meeting immediately followed
by an MMF Ad Hoc meeting (1 hour each) starting at 8:00 am Pacific on Tuesday 14February. Peter Anslow from Ciena
has invited you to join a meeting on the Web, using WebEx. Please join the
meeting 5-10 minutes early so we may begin on time. France, Paris
: 0170375518 Hong Kong, Regards, Pete
Anslow | Senior Standards Advisor From: Daniel Dove [mailto:ddove@xxxxxxx] John,
Steve; <MMF-objective-Next-Steps.pptx> |