The October 2005 Standards Watch column (“MMF Standards Satisfy High-speed Networks,” Lightwave, page 18) summarized the evolution of multimode fiber standards to support high-bandwidth networking needs. This article focuses on a key application for multimode fiber, Ethernet, and its continuous evolution to support higher and higher data rates.
IEEE 802.3 approved a new High Speed Study Group (HSSG) at its July 2006 meeting, continuing its leadership in data communications network standards. Subsequent study group meetings will focus on the development of a set of objectives to include speed and reach objectives as well as developing a project authorization request for approval. Once this phase is complete, a task force will be formed to develop the next building block for the ubiquitous Ethernet application.
Neither the data rate nor the reach objectives has been set yet, but historically the IEEE has used each successive development to increase the supportable data rate by a factor of 10. So one obvious option will be 100 Gbits/sec, but it is anticipated that consideration of other data rates will be given in the HSSG before a final rate is chosen. With respect to reach, the 10Gb/s Standard addressed short reach (300 m), intermediate reach (10 km), and a long reach (40 km). The HSSG will likely start there but again weigh all options before reaching a decision. Regarding fiber types, one can expect proposals on both multimode and singlemode fiber will be considered, utilizing some form of parallel optics and/or CWDM. IEEE uses five criteria to evaluate all proposals coming into the group including technical feasibility, economic feasibility, and distinct identity. Broad market potential and compatibility with other IEEE standards are additional considerations.
Some may conclude that it is too soon for the next generation of Ethernet speeds, but it is clear that bandwidth demand is increasing across multiple applications. Factor in the development time for the standard (~4 years) and the need for a high-speed Ethernet solution in the 2010-to-2012 timeframe doesn’t seem like a big stretch.
Steve Swanson is responsible for standardization strategy at Corning Inc. He can be reached at email@example.com.