[10GMMF] Task1: Update to MonteCarlo README.TXT file [nsec/km]
There have been some questions about the units for the mode delays in
the Gen67 Monte Carlo set (they are in nsec/km).
Piers, please upload the attached 00READ_ME_GEN67YY_2.txt file to the
802.3aq tools section, replacing 00READ_ME_GEN67YY.txt. The only change
to the *.txt file is a listing of units for mode delays, OFL BW, and
PIE-D.
The units for the Gen54 and Gen67 OM1 mode delay sets are in nsec/km
(equivalent to psec/m), and the OFL BWs provided in the ancillary files
are in MHz.km.
The example PIE-Ds which are provided have been calculated for a 300m
channel and are in units of dB. So the mode delays have been scaled by
the fraction 0.300/1.000
I will follow up with Piers to actually put this information into the
header of the data files for additional clarity.
Please continue to email me any questions/comments about the Monte Carlo
sets and I will update as needed. Thanks for your comments.
John Abbott
Advanced Modeling & Analysis
Corning Incorporated SP-PR-1-3
Corning, NY 14831
abbottjs@corning.com
00READ_ME_GEN67YY.txt
Notes for 802.3aq channel modeling ad hoc group.
------------------------------
John Abbott
Corning Incorporated SP-PR-1-3
Corning NY 14831
abbottjs@corning.com
January 10, 2005
------------------------------
++++++++++++ UPDATE 2005-02-18 ++++++++++++++++++++++
February 18, 2005 -- John Abbott
The Gen54 and Gen67 data sets consist of delays in nsec/km (equivalent to psec/m).
Similarly, the ancillary files with OFL BW which can be used to truncate
the data set at 500MHz.km (or another level) are given in MHz.km.
In modeling links the user will typically
scale the mode delay linearly with the length of the link:
for example, for a link which is 243m the delays should be multiplied by 0.243
In using delay sets the user should always check
whether they are in nsec/km or other units.
This has led to repeated confusion in the past both in TIA and IEEE modeling efforts.
Recall that the original Cambridge 81 set and the original TIA 850nm OM3 set were in
units of nsec/300m.
February 18, 2005 -- John Abbott
The ancillary files with example Gen67 PIE-Ds
have been calculated for 300m and are in units of dB.
++++++++++++ END UPDATE 2005-02-18 +++++++++++++++++++++++++++++++++
The *.zip file tau_FDDI_NOV20_GEN67YY.zip has these files:
1. tau_FDDI_NOV20_Gen67YY.dat
Monte Carlo data file with 1300nm mode delays for 5000 fibers
corresponding to installed base FDDI fiber data.
Information presented at 802.3aq San Antonio meeting
Abbott_01_1104.pdf
[2/18/05] NOTE that the units for the mode delays are nsec/km
2. OFLBW_Gen67YY.dat
A table of 1300nm OFL BW's for the 5000 fibers.
These are calculated using a theoretical weighting function
which is linear in mode group numbers 1-18 and would ignore
and mode groups above 18.
The FDDI spec requires the measured OFL BW to be >500MHz.km, which can be
approximated by using only fibers whos OFLBW_Gen67YY.dat entry is >500.
Note the actual mode power distribution for an actual OFL BW measurement
would be slightly different.
This file is included to facilitate the use of the Monte Carlo set.
[2/18/05] NOTE that the units for OFL BW are MHz.km
3-4-5-6-7 PIEprint67_NOV20_5000x4_300m_24.dat etc.
These files have the calculated PIE-D metric for the 5000 fibers for
some selected offsets.
The 1st column is the fiber, the 4th column is PIE-D.
PIEprint67_NOV20_5000x4_300m_24.dat corresponds to 23um,
PIEprint67_NOV20_5000x4_300m_21.dat corresponds to 20um, etc.
There are also columns for PIE-L and other channel metrics; these
can be ignored.
[2/18/05] NOTE that PIE-D here is calcualated for a 300m channel and the units are dB
8 -- Abbott_1_0106_Gen67_Gen54.pdf
This *.pdf was shared with the 01/06/2005 Channel Modeling Ad Hoc Task 1 group
and plots the 23um offset PIE-D metric distribution for the Gen67YY Monte Carlo
set in this *.zip file and that of the Gen54 YY Monte Carlo set for comparison.
(Gen54YY data set -- see 802.3aq Ottawa meeting abbott_1_0904.pdf)
9 -- 00READ_ME_Gen67YY.txt
This file.
Any Comments are appreciated. Please let me know if you find general agreement
or any significant discrepancy in the OFL BW or PIE-D values.