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Re: [10GMMF] Corrected Monte Carlo Model as LRM standard model for OM1



Hi Robert

can you say what the effect is at the 95% duplex level ?
thanks a lot

 Jonathan
  
tel: 1 408 524 5110
e-mail: jking@bigbearnetworks.com
fax: 1 408 739 0568

Jonathan King
Director, Optical Systems
BigBear Networks
345 Potrero Avenue
Sunnyvale, CA 94085


-----Original Message-----
From: owner-stds-802-3-10gmmf@ieee.org
[mailto:owner-stds-802-3-10gmmf@ieee.org] On Behalf Of Lingle, Jr,
Robert (Robert)
Sent: Saturday, July 02, 2005 2:33 PM
To: STDS-802-3-10GMMF@listserv.ieee.org
Subject: [10GMMF] Corrected Monte Carlo Model as LRM standard model for
OM1

All,

At the London meeting, several of us made a presentation on the Monte
Carlo
set corrected for mode mixing (the gamma correction). I showed duplex
coverage PIE-D results for the recommended correction of gamma = 0.9,
and
recommended that this model be used henceforth for LRM coverage
calculations. See
http://grouper.ieee.org/groups/802/3/aq/public/upload/Implicationsofdupl
exco
veragewithcorrectedMonteCarlomodelforTP3stressors.pdf

At the meeting Jon Abbott and I received useful feedback from Jon King
that
sensitivity analysis of the choice of lowest OFL-BW value admitted into
coverage calculations was needed to assess the robustness of the fiber
model. Fiber modeling for LRM typically uses 500MHz-km as the lower
cutoff
for OM1 fiber in all calculations to date.  Kasyapa Balemarthy (GaTech)
has
done this analysis, and it increases the credibility of using the Monte
Carlo model to assess OM1 coverage for LRM.

Kasyapa varied the LOWER limit of OFL-BW fibers retained in the MC model
and
found that the 99%tile duplex PIE-D point changes linearly by 0.05dB for
each 50MHz-km change between 400 and 600 MHz-km.  This relative
insensitivity arises from the fact that a wide range of both low and
high
PIE-D fibers exist in a selected range of OFL-BW, and the distribution
of
PIE-D values within a range of OFL values varies smoothly as OFL rises
from
400 to 600MHz-km.  

This is very good news and means that the MC model is robust to the
choice
of this parameter, i.e. coverage results obtained are rather insensitive
to
picking 500 MHz-km vs. 475 or 525 MHz-km.

I would like to assess whether there are any remaining technical
objections
to using the Monte Carlo model at 1355nm with a gamma=0.90 correction as
the
standard model for LRM coverage calculation.

Robert

Robert Lingle, Jr, Manager
Fiber Design and Transmission Simulation
OFS R&D, Atlanta, GA