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100G Ethernet

Opnext Makes Its 100G Move

Opnext Inc. (Nasdaq: OPXT) is taking a do-it-yourself approach to building a 100-Gbit/s transceiver module, and while the product isn't ready yet, the vendor thinks it's got a lead over other components companies.

The Opnext technology was put to the test in an AT&T Inc. (NYSE: T) demonstration being announced today, where a 127-Gbit/s transmission was hooked up between New Orleans and Ellisville, Fla. The 127-Gbit/s figure represents a 100-Gbit/s link with heavy-duty forward error correction (FEC) attached.

Plenty of other 100-Gbit/s trials and even deployments have been announced, including one from Verizon Communications Inc. (NYSE: VZ) yesterday. (See Verizon Expects 100G Deployment in 2010, Verizon Switches On 100G in Europe, Telstra Trials 100G With Nortel, Ciena Sending 100GE Live, and Deutsche Telekom Trials 100G.)

But they've all come from systems vendors. Merchant 100-Gbit/s modules for long-haul aren't ready yet. (They can be had for short-reach distances, as demonstrated by the Finisar Corp. (Nasdaq: FNSR) CFP modules being used in yesterday's Verizon announcement.)

Other trials either haven't used coherent receivers or didn't pack the full 100 Gbit/s into one wavelength, says Ed Cornejo, Opnext's director of product marketing. In some cases, that means the receiving end is looking only at snapshots of the optical signal, because not all the electronics processing is present to verify the signal in real time, he adds.

Opnext is working on a 100-Gbit/s line-side module that will comply with the Optical Internetworking Forum (OIF) framework, which calls for the use of coherent receivers and dual parallel, quadrature phase-shift keying (DP-QPSK) modulation. (Opnext calls it polarization-multiplexed QPSK, or PM-QPSK, but it's the same thing.)

Of course, the module will also be compliant with the Institute of Electrical and Electronics Engineers Inc. (IEEE) 802.3ba standard for 100-Gbit/s Ethernet.

The AT&T test helped Opnext prove out the technologies it wants to stuff into the central ASIC of its 100-Gbit/s module. Opnext isn't giving specifics about timing, but the ASIC design should get to the factory later this year, Cornejo says.

Opnext is building that ASIC on its own, foregoing available merchant pieces such as digital signal processors. Even the high-speed analog/digital converter (ADC), which has to run at 56 billion samples per second, is available from only one company so far: Fujitsu Microelectronics Europe (FME) .

The ASIC design was started by StrataLight three years ago, before its acquisition by Opnext. (See Opnext Steps Up With StrataLight.) StrataLight did that to avoid what happened in the 40-Gbit/s generation, when Sierra Monolithics (SMI) was the only source of serializer/deserializer (SerDes) chips. During a period when Sierra stumbled, module vendors were stuck.

"SMI pretty much held the industry at ransom when they had their problems. We didn't want that to happen again," Cornejo says.

SMI has since been acquired by Semtech Corp. (Nasdaq: SMTC)

Meanwhile, CoreOptics released a challenging 40-Gbit/s SerDes in mid-2008, with promises to do a 100-Gbit/s chip eventually. (See Semtech to Buy Sierra Monolithics , Broadcom Passes on 40-Gig, CoreOptics Intros 40G Serdes, and Sierra Strikes Forth for 100G.)

Opnext's 100-Gbit/s ASIC will be built on silicon, using CMOS processes. But silicon isn't suitable for every high-speed component that's needed in a transceiver module. Opnext is building a multiplexer/demultiplexer chip out of silicon germanium, for instance. (See Opnext Builds 100G Mux/Demux.)

— Craig Matsumoto, West Coast Editor, Light Reading

dot.zen 12/5/2012 | 4:41:38 PM
re: Opnext Makes Its 100G Move

Maybe you really meant to say Dual Polarisation QPSK and Polarisation Multipexed QPSK, which are indeed the same thing.


"Opnext is working on a 100-Gbit/s line-side module that will comply with the Optical Internetworking Forum (OIF) framework, which calls for the use of coherent receivers and dual parallel, quadrature phase-shift keying (DP-QPSK) modulation. (Opnext calls it polarization-mode QPSK, or PM-QPSK, but it's the same thing.)"


 


dot.zen


Pete Baldwin 12/5/2012 | 4:41:36 PM
re: Opnext Makes Its 100G Move

That I did. Thanks for spotting it.

Pete Baldwin 12/5/2012 | 4:41:29 PM
re: Opnext Makes Its 100G Move

Thanks for the insights, Lightmonkey.  I don't think Opnext is doing what you described -- they were adamant that this test was done realtime, not in burst mode.


At the same time, Opnext hasn't taped out its ASIC, so I don't know the status of their DSP and ADC.


I do think the story was noteworthy enough. It represents progress towards long-haul 100G from the module vendors; I think all the tests we've seen so far involve homemade LH 100G from the systems vendors.


And I thought it was interesting that Opnext is insisting on designing its own ADC and DSP for this.  I wonder how many other module vendors are doing the same.

lightmonkey 12/5/2012 | 4:41:29 PM
re: Opnext Makes Its 100G Move

 


This was in the article.


Other trials either haven't used coherent receivers or didn't pack the full 100 Gbit/s into one wavelength, says Ed Cornejo, Opnext's director of product marketing. In some cases, that means the receiving end is looking only at snapshots of the optical signal, because not all the electronics processing is present to verify the signal in real time, he adds.


So the ability to do the DSP at bit rate is kind of the point of QPSK.


From where I sit, it sounds like a coherent receiver box (you can buy these from Agilent and Optometra) and a Tektronix oscilloscope with DSP done in Matlab.  It's also possible to slap a coherent Rx together from commercially available components.  There is a Matlab DSP package available for sale (not from Mathworks) that will do the carrier phase estimation.  In this arrangement the scope is simply the high-speed AD converter, waveforms are downloaded from the scope and processed in Matlab.  This is why the measurement can only be performed in "burst mode."


If this is what Opnext did, this kind of thing is being done all over the place and is hardly newsworthy. 


I think it's important to clarify what the demo really was to give people more of a picture of where the technology really is.

lightmonkey 12/5/2012 | 4:41:28 PM
re: Opnext Makes Its 100G Move <div>





"Thanks for the insights, Lightmonkey.&nbsp; I don't think Opnext is doing what you described -- they were adamant that this test was done realtime, not in burst mode.


At the same time, Opnext hasn't taped out its ASIC, so I don't know the status of their DSP and ADC.


I do think the story was noteworthy enough. It represents progress towards long-haul 100G from the module vendors; I think all the tests we've seen so far involve homemade LH 100G from the systems vendors.


And I thought it was interesting that Opnext is insisting on designing its own ADC and DSP for this.&nbsp; I wonder how many other module vendors are doing the same."


&nbsp;




So the samples can be still acquired in real-time on the scope.&nbsp; But off-line processing requires that the DSP operation is burst mode.&nbsp; I wouldn't get hung up on the nomenclature. </div>

The assumption here is that Opnext are not doing 100G with a Tek scope.&nbsp; There's nothing here that says they aren't.&nbsp; My claim is that if they are, it's not really news because this thing has been done already by numerous others.&nbsp;


My 2nd claim is that the status of their DSP ASIC is really what matters here since you can't claim to have a true bit-rate receiver without it.


It could be that they are using an FPGA...&nbsp; that would actually be newsworthy.


And on top of all that, it's still another thing to put all that in some sort of MSA form-fact transponder with all that power dissipation and get it to work.


I'm saying that this is an important clarification necessary to judge the status of the technology.&nbsp; Otherwise it's simply rehashing what a marketing guy wants you to believe (or assume in this case).


&nbsp;


PS


With the Stratalight acquistion doesn't that make Opnext kind of a quasi-system company?


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Pete Baldwin 12/5/2012 | 4:41:26 PM
re: Opnext Makes Its 100G Move

OK, I get what you're saying.&nbsp; Interesting point - i'll check it out &amp; keep it in mind as the other module vendors talk up 100G.


And yes, I still count Opnext as a "module" company -- StrataLight brought them shelves, but their main business is in making components and modules that go into other people's systems.


Do you think they should become more of a systems company? Or, more likely, that a systems company should buy something like Opnext?&nbsp; (Looking for personal opinions here; this isn't a rumor I've heard or anything.)

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