SAN JOSE, Calif. Ė The IEEE has kicked off a study group to define 25 Gbit/second optical interfaces for next-generation 100 Gbit Ethernet networks. The standard will enable lower cost and power products using less cabling than today's 100G nets built from ten 10Gbit/s links.
The group aims to set three standards. One will specify multi-mode fibre probably using 50 micron-diameter fibres and 850nm wavelengths to reach distances up to 100 meters. A second will define use over single-mode fibres about nine microns in diameter and at wavelengths of about 1300nm extending up to 10 kilometers.
A third part of the standard will define a 4 x 25G interface between optical modules and system ASICs. That link will eliminate 10 x 10 multiplexers now used in the modules, opening the door to smaller modules and thus denser systems.
The group expects to take until late 2012 to develop a baseline spec engineers could use to start product development, said Dan Dove, chairman of the new working group and a senior director of technology at Applied Micro Circuits Corp. A final version of the specs will probably arrive in late 2013.
"We believe that itís time to move from today's 10 x 10 Gbit/s interface to a 4 x 25G interface to achieve the advances the market needs to take 100G Ethernet to the next level,Ē said Dove. "Today the demand for 100G Ethernet is there, but the cost is not where it needs to be," he said.
"As 10G server connections achieve broad adoption and surpass Gbit server connections over the next three years, we anticipate more rapid adoption of 40G and then 100G uplinks," said Kimball Brown, a senior datacom analyst at Lightcounting, LLC.
"To achieve market success, costs must come down [and] 100G transceivers must be able to fit into the QSFP+ form factor at least for short and long wavelength media types," something the new standard will enable, Brown said.