Fujitsu boosts optical networks with ADSL tech
March 14, 2013 | 10:55
Japanses electronics giant Fujtisu has announced the development of a technology which can increase data flow in data centres tenfold, enabling 100Gb/s transmission using components originally designed for 10Gb/s.
Anywhere vast computers gather, high-speed networking can be found. In data centres, it's how each server can quickly offload data and jobs to each other; in supercomputing, it's how each individual node can communicate with other nodes at a speed that makes the system seem like a single, giant computer. Increasing these speeds is also one of the biggest challenges in computing, with companies like Intel spending billions on developing next-generation interconnection technologies to boost performance.
Fujtisu's system, however, is somewhat different. Based around a discrete multi-tone (DMT) modulation/demodulation format - the same format used for consumer-grade ADSL connectivity, whereby data is divided among multiple sub-carrier waves each running at a different level of modulation - running on a high-speed digital signal processor (DSP) the system allows components designed to transmit and receive data at 10Gb/s to operate instead at 100Gb/s - a ten-fold increase in bandwidth for very little cost.
High-end Ethernet transceivers, as used in enterprise-grade products, typically have four optical channels running at 10Gb/s each for a 40Gb/s overall throughput. Using the new system, Fujitsu claims, one of these transceivers could support 400Gb/s with just minor hardware changes - providing the extra capacity needed as the world increasingly turns to cloud systems for its data processing needs.
The system has already been proven in the lab: using off-the-shelf direct-modulation laser components specified for 10Gb/s transmission, a team at the Fujitsu R&D Centre was able to successfully transmit data to a remote system at 100Gb/s - the first time such a thing has been achieved, and the first time the DMT modem format has been applied to high-performance optical Ethernet transceivers rather than consumer-grade ADSL hardware.
The team claims that almost any 10Gb/s rated components can be used to transmit and receive at 100Gb/s, with lesser-quality components that fail to maintain linearity being detected at the point of modification and the resulting device tweaked to ensure sustained data throughput at top speeds. For enterprise customers, it opens the door to the promise of a cheap, drop-in replacement for 10Gb/s technology in the near future - and, indeed, Fujitsu has reported that it is working on the creation of an integrated DMT modem for optical Ethernet transceivers, although has not yet provided a timescale for its release.
For home users, the system promises a potential boost for the growing number of fibre broadband services: current fibre to the cabinet (FTTC) systems could enjoy a tenfold boost to the cabinet to eliminate congestion, while those lucky enough to enjoy a fibre to the home (FTTH) connection could see their own speed jump by a similar factor.
Fujitsu's research team is to present its findings at the Optical Fibre Communication Conference and National Fibre Optic Engineers Conference in the US next week.