New technique may enable all-optical data-centre networks

A new technique that synchronises the clocks of computers in under a billionth of a second can eliminate one of the hurdles for the deployment of all-optical networks, potentially leading to more efficient data centres, according to a new study led by UCL and Microsoft. Data centres, comprising tens or hundreds of thousands connected servers, are the underlying technology empowering everything we do online, from storing films and photos to serving up webpages and online services. However, they face rapidly rising demand, with server-to-server traffic increasing by 70% each year, which is increasingly hard to meet with existing technologies. All-optical networks that use light to both transmit and route data represent a promising alternative. However, their viability has been limited due to the need for each server to continuously adjust its clock time according to incoming data, which resulted in lower overall performance. The study and programming hardware to memorise clock phase values so clock time does not have to be re-checked, the time to "recover" the clock could be practically eliminated. PhD candidate Kari Clark (Optical Networks Group, UCL Electronic & Electrical Engineering, winner of the EPSRC Connected Nation Pioneers competition ), lead author of the study, said: "Our research makes optical switching viable for the data centre for the first time by providing a solution to the clock synchronisation problem.