@Stacey Thanks! I really enjoy reading GigaOm. You bring a good perspective, and I really appreciate that you were willing to follow up when presented with some additional questions.

@D. Golden This is a bit of marketing nonsense. (Your claim of 1500+km is essentially the same as Ciena’s comment that their scheme can go “thousands” of km). Your comment on the testbed is a good one, but I would be VERY surprised if Ciena does not have a functional testbed of its own.

There are two modulation schemes being widely considered for 100Gbps transmission xQPSK or OFDM. Others are have been posited, but these are the most likely due to their performance over the likely optical fiber plant. The likely optical fiber plant has a lot of fiber which has (i) high PMD; (ii) noisy amplifiers; (iii) more filters due to adoption of ROADM architectures.

The main challenges in optical transmission are: (a) Polarisation Mode Dispersion or PMD; (b) OSNR Tolerance; (c) Non-Linear effects; (d) Filtering Tolerance; (e) Residual Chromatic Dispersion. PMD is the toughest as many networks don’t have fully characterized fiber for PMD — when fiber is purchased it has a PMD of 10 years ago, but a number of companies offer components which can be placed in line with the fiber plant and correct for the chromatic dispersion of many channels (eg. C-Band and more) (cost can be amortized over ~80ch.). Since PMD has to be corrected for each channel (wavelength) then it is inherently more costly.

I’ll stop here because this is becoming too long a post.

I’ll be looking forward to more articles on 100Gbps and networking infrastructure.

BR, D

1. We chose to bring EDFA Amp to the show as support gear for the setup only. Ciena has installed base of EDFA or RAMAN based links based upon the network design and customer requirements. Our 100G implementation supports either.

2. Ciena 100G demonstration is not limited to 80Km. For portability and space restrictions at the show, we simply brought an 80km spool. Our implementation supports distances for metro and long haul applications.

1. We only brought 80 km spool but we have already lab tested a 500 km system. We will be continuing both lab and field trials so stay tuned to http://www.ciena.com for more info…

2. We used an EDFA amplifier.

And to be clear, Dimple Amin is the correct name… So Stacey no worries there…

1) What kind of amplifier was used Raman vs. EDFA? Raman add less noise but are more expensive (+other limitations), but EDFAs are widely deployed.

2) Core networks require transmission distance of hundreds of kilometers to thousands of kilometers. Is the technology being demonstrated by Ciena only limited to 80km? (80km is barely sufficient for most metro networks)

As someone who is working on 100GbE optics, I probably more informed than most of your reader base, but I can still dream that someone would ask some of the questions I want to hear.

Thanks for your non-feedback. I like that your throw a barb without actually making a case and pointing out why you say so. Seriously, please go away and never come back.