Transcript ppt00026.ppt

IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
Teleconference notes, 1 Dec 2004
Jonathan King
1 Dec 2004
IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
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Agenda
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attendees
Task 2
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Joint task 2 and task 4
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5)
status after the Nov04 meeting
discussion of residual items on task 2
launch study discussion
other business
next meeting date/time
1 Dec 2004
IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
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1) Attendees
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Jonathan King, Big Bear Networks
Yu Sun, Optium
John Jaeger, Big Bear Networks
Sudeep Bhoja, Big Bear Networks
David Cunningham, Agilent
Petre Popescu, Quake
John Ewen, JDSU
Paul Kolesar, Systimax
John Abbott, Corning
Al Brunsting, Panduit
Andre van Schyndel, Bookham
Jonathan Ingham, Cambridge
please let me know if I missed your name or organization
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2) Task 2
a) Review of task 2 status following November meeting
Input has been provided to the channel ad hoc on all task 2 study areas, including channel
time variation effects and rates, and modal noise. At the San Antonio meeting, Nov '04, it was
agreed that the slow rate of channel variation did not require a normative dynamic test, but an
informative note could be added to the draft, and that 0.5dB modal noise penalty budget was
sufficient .
b) Residual work items for task 2
Comments following:
Petre Popescu agreed to complete the 2 remaining temperature study items.
Discussion of the modal noise work determined that it covers FP & DFB lasers, since a 3 mode
laser model is assumed, as used in 1GigE).
Discussion of the content of the informative note on channel time variation: it was suggested
that the note should include a description of the relationship between variation rate and
magnitude of channel change, and it was agreed that the editor should be asked to include an
editors note (based on the recommendation included in Cunningham_1_1104) which
informatively alerts implementers that the channel impulse response may vary at 10’s of Hz
and recommend that the equalizer adaptation time be faster than this. Paul Kolesar also
agreed to write down his thoughts on an informative dynamic channel test.
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IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
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3) Task 2 & 4: joint activity on launch study - 1
a) Suggested goals and tasks for the study of launch were presented and
discussed
Notes of goals and tasks agreed :
Main goal :
To provide a specific input to the task force on launch conditions and launch testing, for the
January '05 meeting
Tasks and study areas :
Simulations of coverage vs PIE-D plots as output (for various launch conditions
Agree common model for simulations (e.g. connector offsets, rise times, per offset statistics)
Recommend (simple) launch compliance test
Measurements of real fibres
Develop a channel model for OM2
Notes on discussion following
Yu Sun described work so far in task 4 which has agreed a 4 connector link model with offsets
at a) worst case and b) average values.
Joerg Kropp offered to present some calculations and experimental results on OM3 fibres for
the next meeting
David Cunningham offered measurements and theory of different launches on TIA and other
fibre sets, for the first or second week of January. Launch types would be described by
encircled flux definitions, and include centre, offset and vortex type launches
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IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
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3) Task 2 & 4: joint activity on launch study - 2
Yu Sun offered to compare IPR statistics for cambridge and monte carlo sets with and without
polarization rotation - if the statistics are close enough, then modeling the polarisation effect
explicitly can be avoided, since it isn't adding new channel responses.
John Jaeger also offered measurements and simulations of different launches on some of the TIA
round robin fibres.
John Ewen offered to present some simulation work on launches for OM3 fibres on 15th Dec'04.
David Cunningham commented that a choice of two launches such as centre launch and an offset
launch, could improve coverage. He also noted that customers want to use one of the existing
mode conditioning patchcords, and that the concept of a universal launch would still be desirable
to customers if practical.
In the discussion on optimum launch for OM2 fibre, John Abbott agreed to draft of issues and
considerations likely to impact a model of OM2 fibres - there are OM1 like central defect issues,
but smaller OM3 like 'alpha p' issues. It was agreed that generating an OM2 model should be a
task 1 development and that Prof. Ian Whites team would be involved. It was noted that given
OM2's dual window of optimization, the launch constraints may be weaker than for OM1 or OM2,
which may simplify the OM2 model requirement.
Several on the call expressed support for an implementation non-specific launch compliance test,
such as encircled flux; it was noted that both centre launch and offset type launches could be
described this way.
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IEEE802.3aq Channel model ad hoc
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4) Other business - no issues raised
5) Next meeting
• Wednesday 8th December 2004 9.30am PCT
1 Dec 2004
IEEE802.3aq Channel model ad hoc
Task 2: Time-varying study & modal noise
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