OPTICAL TECHNOLOGY TRAINING

Transcription

1 OPTICAL TECHNOLOGY TRAINING Richard Ednay WBMMF & SWDM 1

2 What Whywill do we it do need for How When did they should I me? a What new type is SWDM of develop start it & using decide this and multimode what are fibre? the what new it should technology? be benefits? like? Why do we need a new type of multimode fibre? 2

3 Why? Because the data just keeps on growing Why? Because we are seeing an increasing number of links in datacentres 3

4 Why? Because there is increasing pressure on system costs When there are lots of links, the cost of each one is important Total cost = Why? Because there is increasing pressure on system costs When there are lots of links, the cost of each one is important For short links. 4

5 Why? Because of space and power constraints But what s wrong with Let s look at 4 of today s options for transmitting 100G over 100m in a datacentre 5

6 1st Gen 100GBase-SR10 using CFPs on multimode fibre or 10G optical lanes 10G electrical lanes 10 parallel multimode fibres, OM3 or OM4, for transmit 10 parallel multimode fibres for receive Low cost 850nm CFPs are big & power hungry 1st Gen 100GBase-SR10 using CFPs on multimode fibre 6

7 1st Gen 100GBase-LR4 using CFPs on singlemode fibre 10km range! 25G optical lanes 10G electrical lanes Uses a pair of singlemode fibres 4 wavelength WDM 1295nm, 1300nm, 1305nm, 1310nm CFPs are big & power hungry 1st Gen 100GBase-LR4 using CFPs on singlemode fibre 7

8 2nd Gen 100GBase-SR4 using CFP2 or 4 on multimode CFP2 25G optical lanes 25G electrical lanes 4 parallel multimode fibres, OM4, for transmit 4 parallel multimode fibres for receive 850nm RS-FEC CFP2s still use quite a bit of power CFP2 2nd Gen 100GBase-SR4 using CFP2 or 4 on multimode CFP4s are smaller & lower power 8

9 2nd Gen 100GBase-PSM4 (non-ieee) using CFP2 or 4 on singlemode fibre 500m range 25G optical lanes 25G electrical lanes 4 parallel singlemode fibres for transmit 4 parallel singlemode fibres for receive 1310nm lasers CFP2s still use quite a bit of power 2nd Gen 100GBase-PSM4 (non-ieee) using CFP2 or 4 on singlemode fibre 9

10 TIA Task force charter To define a specification for multimode fiber with the necessary properties to support transmission of multiple wavelengths including and beyond 850nm. The performance is intended to enable transmission of at least 28Gbps per wavelength for a total transmission capacity of at least 100 Gbps per fiber to distance of at least 100m 10

11 Joint task group So WBMMF and SWDM have evolved hand-in-hand to work happily together How did they develop it & decide what it should be like? 11

12 How? Using complex modelling spreadsheets Looking at the critical parameters, such as the fibre 12

13 the transmitter the receiver 13

14 the margin The starting points were IEEE model for a 25Gb/s Ethernet channel at 850nm & Fibre Channel for 32Gb/s FC These are single channel models at 850nm to achieve 100G+ it would need FOUR of them! 14

15 So we need 4 channels but what spacing should there be? Modal dispersion Close together Further apart Wavelength So we need 4 channels but what spacing should there be? Modal dispersion The compromise was 30nm spacing which is a 90nm spread Wavelength 15

16 So 850nm is definite, but where should the 90nm spread be? Centred on 850nm? 850nm and below? 850nm and above? Wavelength Longer wavelengths have benefits. 850nm and above? Less chromatic dispersion Lower fibre attenuation Availability of high performance VCSELs So the range became 850nm up to about 950nm Wavelength 16

17 So now we have our wavelengths, it s back to the spreadsheet to consider modal dispersion performance Let s go into modal dispersion in a bit more detail 17

18 Let s go into modal dispersion in a bit more detail This pulse spreading limits the data rate and/or the distance that the fibre can support The modal dispersion at 850nm of multimode fibre has got better & better Optical Technology Training Ltd 18

19 In fact 20 times better than But we re not going to get another factor of 20 improvement So now we want to improve modal dispersion across the range 850nm to 950nm 19

20 And decide what constraints should go into the standard for WBMMF So the agreed key performance characteristics for WBMMF in the TIA are Effective modal bandwidth (EMB) 20

21 Attenuation in db/km 10/06/2016 So the agreed key performance characteristics for WBMMF in the TIA are Bend Attenuation tolerance nm nm nm the same as bend tolerant OM4 Wavelength in nm What will it do for me? What is SWDM and what are the benefits? 21

22 Next Gen 100GBase-SWDM4 using QSFP28 on WBMMF 25G optical lanes SWDM wavelengths 25G electrical lanes One pair of multimode fibres WBMMF 850nm, 880nm, 910nm, 940nm RS-FEC on host Low power (<3.5W) & compact QSFP28 transceivers QSFP28 Next Gen 100GBase-SWDM4 using QSFP28 on WBMMF Low power 22

23 What else? 200G using 50G 50G 50G 50G 940nm 910nm 880nm 850nm 850nm 880nm 910nm 940nm 50G 50G 50G 50G What else? Bi-directional single fibre options 10G 910nm 850nm 10G 23

24 What else? Bi-directional single fibre options 10G 940nm 10G 910nm 850nm 10G 880nm 10G What else? Bi-directional single fibre options 10G 25G 910nm 850nm 10G 25G 24

25 What else? Bi-directional single fibre options 25G 940nm 25G 910nm 850nm 25G 880nm 25G What else? Bi-directional single fibre options 50G 25G 940nm 50G 25G 910nm 850nm 50G 25G 880nm 50G 25G 25

26 Can I use? or Yes, but May vary with different fibre manufacturers Try it and see! Finisar have already demonstrated 100G SWDM4 over 75m OM3 error free before FEC! When should I start using this new technology? 26

27 Early adopter? So how are the standards coming along? WBMMF OM? 27

28 So what s been going on with SWDM? Is there industry support for SWDM? 28

29 Any other questions? And last, but not least. A personal THANK YOU to the FIA and to you the members who have so generously supported Richard.Ednay@ott.co.uk 29