New CWDM8 MSA specifications cover 400 Gbps over 2 km

Members of the CWDM8 Multisource Agreement (MSA) have released a technical specification that covers 400-Gbps optical transmission at distances up to 2 km over duplex single-mode fiber. The group says a companion specification for 400-Gbps application of 10 km should be ready by the end of the year.

Members of the CWDM8 Multisource Agreement (MSA) have released a technical specification that covers 400-Gbps optical transmission at distances up to 2 km over duplex single-mode fiber. The group says a companion specification for 400-Gbps application of 10 km should be ready by the end of the year.

The CWDM8 MSA announced its formation this past September with an eye toward addressing 400-Gbps applications using NRZ modulation on the optical end while maintaining compatibility with 50-Gbps per lane electrical interfaces such as those the P302.3bs 400 Gigabit Ethernet Task Force envisions (see "CWDM8 MSA targets 400G at 2 km, 10 km via NRZ wavelengths"). The MSA specifications could be applied to QSFP-DD, OSFP, and COBO optical transceivers and modules.

The use of NRZ for the optical transmission contrasts with the upcoming 400 Gigabit Ethernet specifications, which are expected to use PAM4 in single-mode fiber applications when the Task Force completes its work, a milestone expected to be reached by the end of this year. The MSA asserts the use of NRZ modulation, already common among data center transceivers, will enable compliant modules to reach the market more quickly than those based on PAM4 or other higher-order modulation formats.

Members of the CWDM8 MSA include Accton, Applied Optoelectronics, Barefoot Networks, Credo Semiconductor, Hisense, Innovium, Intel, MACOM, Mellanox, Neophotonics, New H3C Technologies, and Rockley Photonics. All but Applied Optoeletronics and New H3C Technologies are founding members.

The specification is available for download at www.cwdm8-msa.org.

For related articles, visit the Optical Technologies Topic Center.

For more information on optical modules and suppliers, visit the Lightwave Buyer's Guide.

About the Author

Stephen Hardy

Editorial Director and Associate Publisher

Stephen Hardy has covered fiber optics for more than 15 years, and communications and technology for more than 30 years. He is responsible for establishing and executing Lightwave's editorial strategy across its digital magazine, website, newsletters, research and other information products. He has won multiple awards for his writing.

Contact Stephen to discuss:

  • Contributing editorial material to the Web site or digital magazine
  • The direction of a digital magazine issue, staff-written article, or event
  • Lightwave editorial attendance at industry events
  • Arranging a visit to Lightwave's offices
  • Coverage of announcements
  • General questions of an editorial nature
Sign up for our eNewsletters
Get the latest news and updates
Fiber
Having an arsenal of swappable building blocks that allow for continued scaling as a service provider's subscriber base grows can keep fiber operational costs in check.
www.fiberbroadband.org
Gary Bolton, CEO of the Fiber Broadband Association, addresses how AI is influencing broadband use at the recent Fiber Connect 2026 event in Orlando, Florida.
The ongoing emergence of AI means that fiber broadband is no longer just about connectivity alone, but how it is evolving to accommodate the growth of new sophisticated applications...