IEEE802.3aq%20Channel%20model%20ad%20hoc%20Task%202%20

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IEEE802.3aq Channel model ad hocTask 2 and 4
Launch study

• Summary of progress 19 Jan 2005
• Jonathan King

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Launch study goals

• Specific inputs to task force on launch
  conditions and launch testing
• in time for January meeting

• Activities
• OM1 link simulations and experiments
• OM2 model development prompted (in task1), and
  experiments
• OM3 link simulations and experiments
• Simulation and experimental results for centre
  launch and range of OSL (offset single mode)
  launches, and a universal launch candidate
  (Vortex launch)

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Findings OM1 and OM3
Results from Ewen_1_041215

• With connectors - Center launch better for OM3,
  FDDI fiber slightly better with standard 62.5µm
  OSL (17µm 23µm)
• No connectors - Center launch better for both
  OM3 and FDDI fiber
• Similar conclusions from simulation work (Joerg
  Kropp and S Botacchi)
• Supported by experimental data from many others
  (Joerg Kropp F Sugihwo J King David
  Cunningham Simon Meadowcroft Yuri Vandyshev,
  Jim Mcvey, Hongyu Deng Lew Aronson)
• Multiple launch options per fibre type improves
  coverage

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Preliminary findings OM2

• OM2 model is under development in task 1
• 50µm OSL (10µm - 16µm offset) proposed for
  primary launch , centre launch as secondary
  launch, based on reported experience with TIA
  12-96 round robin fibres
• to be confirmed with further experiments and
  simulations pending OM2 model

Preliminary findings 'Universal' launch - Vortex
launch

• Experiments comparing Vortex with CL and OSL on
  OM1 and OM3
• Varies less with connector offsets than CL,
  comparable to OSL
• Compares favourably to OSL for OM1
• Worse than CL for OM3, but may be good enough
• IPR / PIE Measurements on OM1 and OM3 Center,
  Offset and Vortex Launches (Yuri Vandyshev et al
  )
• Simulations of Vortex launch show higher PIE-D
  value than per fibre type optimized launch, but
  has advantage of single patchcord interconnect at
  transmitter Jim Morris et al
• Vortex launch would meet OM1 and OM2 primary
  launch EF definitions

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Preliminary findings 'Universal' launch - Vortex
launch

• Experiments comparing Vortex with CL and OSL on
  OM1 and OM3
• ('IPR / PIE Measurements on OM1 and OM3 Center,
  Offset and Vortex Launches', Yuri Vandyshev et
  al )
• Varies less with connection offset values than
  CL, comparable to OSL
• Compares favourably to OSL for OM1 (PIE-D is
  0.5-1dB lower than OSL)
• Typically worse than CL for OM3 (PIE-D value up
  to 1.5dB higher than CL) but may be good enough
• Simulations of Vortex launch on OM1 and OM3
• ('Vortex PIE calculations', Jim Morris et al,
  using 54YY fibre model and 850nm TIA OM3 delay
  set converted to 1300nm by P. Pepeljugoski)
• Higher PIE-D value than per fibre type optimized
  launch, but has advantage of single patchcord
  interconnect at transmitter
• On OM3, with connector offsets, the 99 coverage
  PIE-D values were 4.8, 6.7 and 6.1 respectively
  for CL, OSL and Vortex lens with M4.
• On OM1, the 99 coverage PIE-D values were 5.9,
  5.8 and 6.1dB respectively for CL, OSL and Vortex
  lens with M4.
• Vortex launch would meet OM1 and OM2 primary
  launch EF definitions

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Summary

• Launch recommendations table prepared
• Primary and secondary launch recommendations for
  each fibre type
• OM1 OSL, CL
• OM2 OSL, CL
• OM3 CL, OSL
• Encircled flux launch test definitions
  recommended for primary, secondary launches, and
  for 'universal' launches (implementation
  non-specific)
• Encircled flux launch test definition for a
  'universal' launch
• Other points of note
• Multiple launch options can increase coverage
• need to understand how/if to specify dual
  launches in standard - seeking end customer input
• Confirmation that average mode power simulations
  give worst case 99 coverage PIE-D results (i.e.
  we don't need to explicitly model IPR variation
  due to dynamic effects, because the 'new' IPRs
  are already represented in the static IPR set)

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Recommendations for changes to Launch section of
Table 68-3-10GBASE-LRM transmit characteristics
Fibre type OFL bandwidth Primary Launch TP2 encircled flux test criteria Alternative Launch TP2 encircled flux test criteria 'Universal launch' TP2 encircled flux test criteria
1 OM1 500/500 lt 30 in 5 µm radius gt 86 in 23 µm radius note 1 gt 30 in 5 µm radius gt 80 in 10 µm radius note 3 lt 30 in 6 µm radius gt 86 in 18 µm radius note 4
2 OM2 400/400 500/500 lt 30 in 6 µm radius gt 86 in 18 µm radius note 2 gt 30 in 5 µm radius gt 80 in 10 µm radius note 3 lt 30 in 6 µm radius gt 86 in 18 µm radius note 4
3 OM3 1500/500 gt 30 in 5 µm radius gt 80 in 10 µm radius note 3 lt 30 in 6 µm radius gt 86 in 18 µm radius note 2 lt 30 in 6 µm radius gt 86 in 18 µm radius note 4
note 1 For example, 20 µm offset single-mode
fiber offset-launch mode-conditioning patch cord,
as defined in 38.11.4 note 2 For example, 13 µm
offset single-mode fiber offset-launch
mode-conditioning patch cord, as defined in
38.11.4 note 3 For example, single-mode centre
launch note 4 For example, Vortex launch
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Back up
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Other valuable stuff - 1

• Do dynamic effects introduce new impulse
  responses which need to be included in link
  simulations ? - No
• Fibre models generate a set of impulse responses
  from static average modal power Simulations
  indicate that the additional impulse responses
  due to polarization / dynamic effects are already
  represented in the static impulse response set
• Average mode power simulations and individual
  mode power simulations (where input polarization
  was rotated) were compared at 99 coverage the
  PIE-D results for the average mode power
  computation were the same or worse than
  individual mode power simulations. (Yu Sun
  'PIE-D statistics comparison between averaged
  mode and individual mode computation method')
• Confirmation of the 7 micron value for a worst
  case connection offset
• Extensive measurements of tolerances contributing
  to connection offsets were reported (Al
  Brunsting Rick Pimpinella ' Lateral offsets for
  multimode fiber (MMF) connectors'