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chandan kumar 12/5/2012 | 5:40:56 PM
re: Ciena Pushes Ahead to 400G

The real challenge for R&D is to match reach of 400G and 100G with that of 40G and 10G so that operators can plan smooth upgrades without increasing touch points. Similarly 1T per lambda later to match reach of 100G and 400G

opticaljunkie 12/5/2012 | 5:40:55 PM
re: Ciena Pushes Ahead to 400G

ALU never said if they have a soft FEC, so that's probably no? 

Pete Baldwin 12/5/2012 | 5:40:55 PM
re: Ciena Pushes Ahead to 400G

I think I left this part unclear: You need two Wavelogic 3 chips to make 400G; each one does 200G. So you'd need two lasers as well.


Sterling Perrin at Heavy Reading points out that this is Ciena's debut of a single-carrier 100G (versus dual carrier in one 50GHz spacing).  So Ciena will catch up to Alcatel-Lucent on that front.

IJD 12/5/2012 | 5:40:51 PM
re: Ciena Pushes Ahead to 400G

Other vendors (e.g. NEL) already have 100G single-carrier transceivers with soft FEC, so this isn't new -- what is new is integrating the TX MUX/DAC function, but it's not a surprise given Ciena's paper about their DAC published last year.

rhr 12/5/2012 | 5:40:45 PM
re: Ciena Pushes Ahead to 400G Ciena will need two WaveLogic 3 chipsets for 400Gbps. The WaveLogic 3, on a 32nm process, is a two-device chipset (the transmit and receive coherent DSP ASICs). And to your point, Chandan, Ciena says 400G will have a metro regional reach while 200Gbps will achieve 750-1000km. Impressive but as you say, not 100Gbps reaches yet.
rhr 12/5/2012 | 5:40:44 PM
re: Ciena Pushes Ahead to 400G Good point - I agree. That said, I would think metro regional is up to 1000km but the implication from Ciena is that the reach is somewhat less than that achieved by a 200Gbps single channel.
IJD 12/5/2012 | 5:40:44 PM
re: Ciena Pushes Ahead to 400G

Doesn't make sense -- Ciena's 200G uses QAM16 in a 50GHz channel (hence the shorter reach), surely their 400G uses 2 bonded 200G QAM16 50GHz channels so the reach will be the same?


(I doubt that it uses QAM256 in 1 channel, OSNR and reach would be awful...)


IIRC ALU's paper at ECOC used 45Gbaud QAM32 to do 400G in a single channel with 75GHz optical bandwidth, this would presumably have shorter reach than QAM16 but would need faster sampling (90Gs/s?) wider bandwidth (30GHz?) ADCs and DACs.

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