Category Archives: FIBER OPTIC

OIF to Tie Flexible Coherent DWDM Transmission to SDN

November 19, 2015
Author Stephen Hardy
Editorial Director and Associate Publisher


Members of the Optical Internetworking Forum (OIF) will pair their work in software-defined networking (SDN) with their efforts in coherent optical transmission. The group has decided to create a Flex Coherent DWDM Transmission framework through which operators and systems houses can support software-programmable coherent transmission via a variety of modulation formats.

The OIF notes that the industry is moving away from a sole reliance on dual-polarization quadrature phase-shift keying (DP-QPSK) for coherent transmission. While that format dominated the first generation of 100-Gbps line-side optics, interest has grown in supporting greater data rates, from 150 to 400 Gbps and beyond, via different modulation formats. These include 8QAM and 16QAM for long-haul and metro applications, and 32QAM and 64QAM for data center interconnect (although there have been demonstrations of these higher QAM formats for general high-capacity networking as well; see “Putting flexible transmission rates to the test”).

A number of systems houses tout the ability to switch between multiple modulation formats, with some using such terms as “FlexCoherent” and “Flexi-Rate” to describe the functionality. However, the OIF has decided the industry would benefit from a more coordinated effort to provide this flexibility within an SDN context.

“We’ve discussed the hardware implications of SDN for a couple years now,” explained OIF board member Junjie Li of China Telecom. “We need to move away from fixed performance transceivers in order to provide service providers with a flexible solution, complete with software ‘knobs’ that can be dialed-in to achieve the desired performance.”

The OIF says the new effort will leverage its work with tunable lasers, high-bandwidth PMQ modulated transmitters, and integrated coherent receivers.

Meanwhile, the OIF also announced the results of recent leadership elections. Peter Landon, BTI Systems, is now chair of the Networking & Operations Working Group committee for a 2-year term. Newly elected to the Board of Directors are Ian Betty of Ciena for a 2-year term, Tom Issenhuth of Microsoft for a 2-year term, and Mike Tessaro of Qorvo for a 1-year term. China Telecom’s Li was re-elected to the board for a 1-year term. John McDonough of NEC America will serve as president. Dave Brown of Alcatel-Lucent will continue as vice president of marketing and Dave Stauffer of Kandou Bus will remain secretary/treasurer.