Fujitsu Network Communications Inc. is developing its own 100Gbit/s optical modules, saying they'll be shipping for the Flashwave product line in the fourth quarter of next year.

It's another example of equipment vendors building their own 100Gbit/s modules, at least for initial equipment generations, rather than relying on the optical components industry.

Fujitsu was presumed to be using a 40Gbit/s coherent receiver developed by CoreOptics. When CoreOptics was acquired by Cisco Systems Inc. midyear, one obvious question was whether CoreOptics customers would be left stranded and needing to scramble for new options for 100Gbit/s technology. (See CoreOptics Does Coherent 40G and Cisco Renews Optical Focus With CoreOptics.)

Tom McDermott, a Fujitsu strategic planner, tells Light Reading that wasn't the case. Fujitsu's 100Gbit/s modules have "always been an organic" project, he says.

That's easy to believe, considering so many related Fujitsu entities have the necessary pieces. Specifically Fujitsu Microelectronics Europe (FME) has worked on the analog/digital converter (ADC) and digital signal processor (DSP) that go into the coherent receiver.

That chip is no picnic, McDermott points out. It requires speeds beyond what's available commercially (56 billion samples per second), and Fujitsu went for an additional degree of difficulty by using soft-decision Forward Error Correction (FEC), a microwave radio technique which uses "quite a bit stronger code" than hard-decision FEC, McDermott says.

Many large equipment vendors are producing 100Gbit/s optical modules in-house, including Juniper Networks Inc., a company not typically labeled as "optical." Infonetics Research Inc. reaffirmed the trend in a recent report on optical transceivers, saying that through 2014, most 100Gbit/s modules will be shipped by network equipment manufacturers rather than components companies. (See Can Vendors Build Their Optical Components?, Vertical Integration Takes Its Lumps, and Juniper Amasses 100G Optical Team.)

Fujitsu's 100-Gbit/s transponder will conform to the CFP multisource agreement for client interfaces. Fujitsu also plans to release a muxponder that carriers 10 lanes of 10 Gbit/s.

Both would be fabricless, meaning they aren't designed for aggregating disparate streams of traffic into a 100Gbit/s payload. A module to do that would be a next step, McDermott says.

Fujitsu's 100Gbit/s transport will be done using a single optical carrier, rather than the dual-carrier method that got Nortel (now Ciena Corp.) to market first. Alcatel-Lucent was the first company to start shipping a single-carrier 100Gbit/s system, a feat that, combined with 100Gbit/s router technology, netted it Leading Lights finalist status for Best New Product (Telecom). (See AlcaLu Goes Commercial With 100G, Analyst: AlcaLu's 100G Game-Changer, and Light Reading's 2010 Leading Lights Finalists.)

— Craig Matsumoto, West Coast Editor, Light Reading