Bangor University touts 20 Gbps access tech

A UK university is claiming front-runner status in the development of next-generation optical access networks using optical OFDM (orthogonal frequency division multiplexing) technology.

In a blow for clueless commentators that describe optical networks as obsolete (in Australia, News Limited’s Andrew Bolt is one such anti-fibre cheer-leader), the researchers hope to create optical kit capable of 20 Gbps subscriber speeds as its first step.

Even better, if the Bangor University project succeeds: it would use commercial off-the-shelf components to create drop-in replacement line cards to achieve speeds of as much as 40 Gbps – per subscriber – on PON access networks.

The OCEAN project, whose commercial partners include Fujitsu, Finisar, VPISystems and the Fraunhofer Heinrich Hertz Institute, is working on using 32 wavelengths (which is no longer particularly demanding for WDM kit) and says its technology will cover distances of up to 60 km.

Optical OFDM (OOFDM) uses techniques familiar to the radio and ADSL world to overcome dispersion in optical networks. The idea is to use OFDM on each optical signal to replace the more familiar single carrier optical modulation (which becomes more prone to dispersion effects as data rates increase).

OFDM's familiarity in (as just one example) cellular networks means there is a huge base of existing device development the researchers can draw on.

Bangor’s Dr Roger Giddings has told the BCC the university is the first to have an end-to-end system in the works – although the project isn’t due to deliver completed kit for another two years (the three-year OCEAN project began during 2011).

The researchers also claim that OOFDM is less power-hungry than other gigabit-speed access technologies.

The Bangor group has already filed a slew of patents covering its techniques. ®