18 Aug 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise 1 Teleconference notes, 18 August 2004 Jonathan King

18 Aug 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise 2 Agenda 1)attendees 2)agree last meeting notes 3) Presentations a)Summary connector loss and standard link proposal- David Cunningham b)Measurement of time variance in MMF - Robert Coenen, Scintera 4)other business - 5)next meeting date/time

18 Aug 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise 3 1) Attendees Jonathan King, Big Bear Networks Piers Dawe, Agilent David Cunningham, Agilent Petre Popescu, Quake Tremont Maio, Analog Ali Ghiasi, John Dallesasse, Emcore Yu Sun, Optium Jens Fiedler, Infineon Jesper Hanberg, Intel Ryan Latchman, Genum Norm Swanson, Clariphy Tom Lindsey, Clariphy Lars Thon, Aeluros Robert Coenen, Scintera Gary Schaulov, Al Brunsting, Panduit Chet Babla, Phyworks please let me know if you or your organization have been missed 2) Minutes of last meeting agreed - no issues raised

18 Aug 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise 4 3) Presentations a) Update on connector loss calculations and standard link proposal - David Cunningham David summarized his work on connector loss vs offsets for OFL, OSL launches and steady state mode power distribution. Discussion of Maximum offset discussion : It was noted that legacy links were spec'd for worst case individual connector loss of 0.75 dB with LEDs (OFL launch) at maximum 0.75dB loss per connector (ISO standard) suggesting a maximum 6-7micron offset. OM3 group settled on a 7micron offset based on 0.5dB loss due to lateral offset for steady state mode power distribution and 0.25dB other loss. Gigabit Ethernet used a 2 connector link model with 0.75dB loss per connector. There was general support on the call for 7microns as a reasonable worst case connector offset based on the evidence presented. There was also general support for a draft standard link with 4 connections: 1 single mode connection, 2 multimode connections at a maximum 7micron offset, 1 multimode connection at below 4 microns to keep the standard link within connector loss budget. Worst case offset position in the link: It was agreed that having the highest offset connections nearest to the transmitter would represent the worst case for modal noise Vibration of connector offset: After some discussion it was agreed that connector offset would not be affected by vibration because spring loaded insertion and receptacle sleeve inserts would prevent movement. It was agreed that fibre movement was expected to be the significant factor in time variance of the link. After the discussion, David Cunningham volunteered to assemble and distribute a draft summary of the agreed link configuration and supporting evidence for the values agreed upon, for discussion by the wider LRM group. Launchloss due to lateral offsetOffsetloss due to lateral offsetoffset OFL0.75dB6um0.5dB4um OSL0.75dB8um0.5dB7um steady state0.75dB11um0.5dB9um

18 Aug 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise 5 3) Presentations cont'd b) Measurement of time variance in MMF - Robert Coenen A review of Roberts updated document on measuring the effect of vibration on a MMF link. Discussion following: Worst case position in a link for fibre movement/vibration was discussed; concensus was that the worst place for modal noise was at the start of the multimode link, after any OSL patchcord and between the highest mode selective losses (this is consistent with Gigabit Ethernet approach). It was also agreed that a polarization controller should be included in a standard link model and set to maximize time variation effects. 5) Next meeting Wednesday 25th August 9am PCT, 5pm UK 4) Other business No issues raised