1. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Meeting notes, 15 July 2004 Jonathan King

2. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Attendees Jonathan King, Big Bear Networks Tricia Hill, Big Bear Networks John Jaeger, Big Bear Networks Abhijit Phanse, Scintera David Cunningham, Agilent Piers Dawe, Agilent Gary Schaulov, Rsoft Yu Lung Chau, IKRI Matt Traverso, Opnext Andre van Schyndel, Bookham Petre Popescu, Quake John Dallesasse, Emcore John Ewen, JDSU Yi Sun, OFS Nick Weiner, Phyworks Brian Taylor, Oepic Paul Kolesar, Systimax Kevin Witt, Vitesse Lars Thon, Aeluros Petar Popeljugoski contributions from Yu Sun, Optium Peter Hallemeier, Optium

3. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Objectives of meeting define goals and tasks agree time line –September input required by task 1

4. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Goals for task 2 Study the impact of time varying effects on the LRM draft spec –Provide input to the time varying component of the receiver compliance test Set a frequency below which EDC should track (TP3 test rate) define tracking 'mask' - magnitude of perturbation vs frequency of perturbation –Measure spectrum of time variation effects what is the product expected to cope with in real life ? what's already out there ? consensus that measuring this for statistically significant numbers installed links would be an extremely difficult task; –Modeling of extent of time variance of links e.g. delay vs mode sets for quasi-continuous perturbed link for listed mechanisms generate impulse responses for quasi-continuously perturbed link for selected launches, over Cambridge fibre set (tbc) and a 'standard link' Study modal noise of the MMF channel and ensure modal noise is properly accounted for in the LRM draft spec –Assess modal noise penalty for different laser types

5. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Time variation mechanisms In approx order of significance of magnitude connector offset –static offset: 3.5 average, 1.8 standard deviation for 50 micron fibre ; check if we need to scale for 62.5 micron fibre. (95% less than 7um) –temporal variability tbd fibre perturbation »import fibre shaker for measurements –mechanical and polarization laser wavelength –can be modeled with mode solver temperature –very slow, believed trackable, not main focus of study Rate tbd Faster than EQ adaption - noise –modal noise variance can be estimated using previous work Slower than adaption rate - trackable

6. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Tasks Mechanisms: determine a placeholder value for mechanical vibration rate for connectors - John Dallesasse Experiment: relationship of perturbation spectrum to modal noise spectrum - Abhijit Phanse will check capability for measurements at scintera Modelling of delay vs modes for quasi continuous perturbed link for listed mechanisms - Yu Sun/Pete Hallemeier –Generate quasi continuous impulse responses for perturbed link for selected launches (over Cambridge fibre set), 'standard link' Modal noise penalty for different laser types - David Cunningham Effect of link temperature - Petre Popescu Real environments - volunteers tbd –Measurements of spectrum of time variation effects –Input on what is the product expected to cope with in real life –What's already out there describing in building environments

7. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Previous work Modal Noise Test Methodology group –'Measurement of the optical power penalty due to modal noise in multimode fiber laser based links' Fibre shaker TIA/EIA-455-203 Sun_1_0704 –Modelled CL and OSL launch sensitivity to connector offset 10+280+10 link Aronson_1_05_04 –Proposals for measurement of channel time variance

8. 15 July 2004IEEE802.3aq Channel model ad hoc Task 2: Time-varying study & modal noise Next meeting Wednesday morning 9am PCT, 5pm UK