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/. Terabit Ethernet is Dead, for Now

On 2012-10-01 08:57, Masataka Ohta wrote:
> Tom Hill wrote:
>> Once you get your head (and wallet) around that, there becomes a 
>> case
>> for running each of your waves at 2.5x the rate they're employed at 
>> now.
>> The remaining question is then to decide if that's cheaper than 
>> running
>> more fibre.
> It depends on distance between senders and receivers.
> However, at certain distance it becomes impossible to use
> efficient (w.r.t. bits per symbol) encoding, because of
> noise of repeated EDFA amplification.

<500km not enough?


>> Still a hard one to justify though, I agree.
> For 50Gbps lane, it becomes even harder and, for 100Gbps lane,
> it will likely to be impossible.

Tell this to Ciena... ;)

If you can afford Wave Logic 3 interfaces for your Nortel^WCiena 
6500's, you'll find some pretty impressive things are actually possible, 
including 100G per 100GHz guide over very large distances (think 

Coherence appears to be the secret sauce in pushing the SnR boundaries, 
albeit I'm not going to pretend to even understand the physics involved, 
I was just lucky enough to speak to some people that do. :)

>> I've recently seen a presentation from EPF** (by Juniper) that was
>> *very* interesting in the >100G race, from a technical perspective. 
>> Well
>> worth hunting that one down if you can, as it details a lot about 
>> optic
>> composition in future standards, optic densities/backplanes, etc.
> This one?
> http://www.peering-forum.eu/assets/presentations2012/JunpierEPF7.pdf
> But, it does not say much about >100G.

Yes, that is the one. Slide #11 is the one I'm referring to, 
'Projection of Form Factor Evolution to 400G', which is relevant to the 
discussion on optic densities and the push above 100G.