CWDM4 MSA to target 100-Gbps at 2 km for data centers

Another new industry group has arisen to address the alleged 500-m to 2-km hole in the IEEE’s 100 Gigabit Ethernet (100GbE) specifications. The four members of the Coarse Wavelength Division Multiplexed 4x25G Multi-Source Agreement (CWDM4 MSA) say they will offer interoperable 2-km 100G interfaces over duplex singlemode fiber (SMF).

The group is the third to form this year to address the application space that falls between the IEEE’s 100GBase-SR4 specification that covers 100-m reaches and the 100GBase-LR4 that focuses on links up to 10 km. Other new MSAs targeting this niche include the PSM4 MSA, which offers a four-fiber approach using singlemode, and the OpenOptics MSA, which like the CWDM4 group focuses on a 4x25-Gbps approach over singlemode fiber (see “PSM4 MSA Group targets alternative for data center 100G” and “OFC 2014 Reporter's Notebook - Day 1”). The OpenOptics group will offer interfaces using 1550-nm wavelengths and the QPSF28 form factor; the CDM4 MSA hasn’t revealed yet which wavelengths or form factors it will support. A note on the CWDM4 MSA website says technical details will be provided “soon.”

These MSAs follow the 10x10 MSA, which Google helped form in 2010 (see “Google joins tech vendors in 10x10G 100 Gbps optical transceiver multi-source agreement”). This effort has failed so far to gain significant traction in data center applications.

Founding members of the CWDM4 MSA include Avago Technologies, Finisar Corp., JDSU, and Oclaro, Inc. Both Avago and Oclaro are part of the PSM4 MSA.

"The IEEE standardized a cost-effective 100-m solution known as 'SR4'. Beyond 100 m, there is only the 'LR4' standard, which is targeted to achieve 10 km. Customers, particularly hyperscale data centers, are looking for solutions up to 2 km," remarked Dale Murray, principal analyst, LightCounting Market Research. "The industry is now coming together, through this MSA, to provide a cost-effective data center reach of 2 km. This solution will smooth the process of getting to 100 Gigabit Ethernet."

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