x
Page 1 / 2   >   >>
rzerockzeron 12/5/2012 | 3:07:08 PM
re: Ciena Flexes Its 40-Gig Story So Ciena came up with a press release announcing 10G, 40G and 100G on the same fiber. How is this newsworthy? Last time I checked transponders running at 10G, 40G or 100G could run on the same fiber plant, provided they adhere to the same optical specs. How is this different than running 2.5G and 10G on the same fiber plant? DWDM 101.

News would have been if Ciena had announced novel ways to transport 40G and 100G at the same 10G performance.

RZ.
Physical_Layer 12/5/2012 | 3:07:07 PM
re: Ciena Flexes Its 40-Gig Story Does anyone know if Ciena or the other folks out there are doing anything to combat PMD at this high speed of transmission? Marconi? Alcatel? Nortel?

I also wonder how the heck Ciena plans to fit 100G into a 50 GHz channel spacing "down the road".
numinary 12/5/2012 | 3:07:06 PM
re: Ciena Flexes Its 40-Gig Story "How is this newsworthy? Last time I checked transponders running at 10G, 40G or 100G could run on the same fiber plant, provided they adhere to the same optical specs. How is this different than running 2.5G and 10G on the same fiber plant? DWDM 101."

By announcing that they intend to achieve 40G & 100G DWDM channels over the same fiber plant, Ciena is indicating that they will likely use the same channel spacing. This was not significant in the past, but some 40G modulation schemes are not conducive to 50GHz spacing -- for 100G the channel spacing becomes a _significant_ challenge.

To make a sweeping generality (there are exceptions to this), the modulation schemes which are better suited to fit within the 50GHz channel and maintain high filtering tolerance have poorer performance with regards to dispersion. The impairment that most carriers are concerned with for 40Gbit/s DWDM is PMD (polarisation mode dispersion). So it's likely that Ciena is pursuing a post processing to compensate for PMD rather than go after an "interesting" modulation scheme.

I agree that if LR had put in some details on the technology that Ciena is using to acheive this it would be a great story. As it is -- just a bunch of speculative marketeering which requires the reader to guess at the detail.
AutoDog 12/5/2012 | 3:07:05 PM
re: Ciena Flexes Its 40-Gig Story Once again, I think some investigative reporting is in order here:

- How do they mix 40G and 10G on the 50GHz spacing?
- How do they address PMD @ 40G

Either Ciena has been covertly funding an internal 40G skunk-works develop team or they've partnered with a 40G expert.

Is there anyone out there that is winning and deploying real 40G DWDM systems?

-AD
kavehzpor 12/5/2012 | 3:07:03 PM
re: Ciena Flexes Its 40-Gig Story "Either Ciena has been covertly funding an internal 40G skunk-works develop team or they've partnered with a 40G expert."

Well, Ciena has worked with StrataLight in the past:

http://www.lightreading.com/do...
melao 12/5/2012 | 3:07:03 PM
re: Ciena Flexes Its 40-Gig Story PMD, OSNR, Chromatic Dispersion. I wonder if it actually works for long distances.
optiplayer 12/5/2012 | 3:07:02 PM
re: Ciena Flexes Its 40-Gig Story Does anyone know if Ciena developed this themselves or are they using a shelf and cards from Mintera?
rzerockzeron 12/5/2012 | 3:07:02 PM
re: Ciena Flexes Its 40-Gig Story Ryan,

thanks for the update, much appreciated.

However, I still cannot believe that marketing folks still spit out statements like it's 1999 all over again. They should give me a buzz when stocks hit $100 once more, I'll then take a serious look (roll eyes)

RZ.
Ryan Lawler 12/5/2012 | 3:07:02 PM
re: Ciena Flexes Its 40-Gig Story The 40G shelf uses differential phase-shift keying (DPSK) to allow 40G waves to appear like 10G, and uses adaptive dispersion compensation to combat PMD. According to Rathore, all of Ciena's products have been 40G-ready since 2005.

As for how it fits two bit rates on the same fiber - Rathore talked up a patented filtration design across Ciena's products that allows them to create different spacings for different wavelengths on the same strand of fiber.
Ryan Lawler 12/5/2012 | 3:07:02 PM
re: Ciena Flexes Its 40-Gig Story The 40G shelf uses differential phase-shift keying (DPSK) to allow 40G waves to appear like 10G, and uses adaptive dispersion compensation to combat PMD. According to Rathore, all of Ciena's products have been 40G-ready since 2005.

As for how it fits two bit rates on the same fiber - Rathore talked up a patented filtration design across Ciena's products that allows them to create different spacings for different wavelengths on the same strand of fiber.
Page 1 / 2   >   >>
HOME
Sign In
SEARCH
CLOSE
MORE
CLOSE