Cheap and practical 100Gig networking has come a step closer, with Siemens researchers demonstrating 107Gbit/s per channel over a public long-haul optical network.

A data channel running at 107Gbit/s could transfer almost three DVDs per second or support 100,000 ADSL connections, and is more than two and a half times faster than the 40Gig channels in use today.

The breakthrough was achieved on a 100-mile fibre network in the US, and has been hailed as an enabler for the upcoming 100Gig Ethernet spec. It involved the optical signals being fully electrically-processed at both ends of the link - electrical processing is essential to cut costs by reducing the amount of expensive optical processing needed.

Project co-ordinator Dr Rainer Derksen, of Siemens Corporate Technology, said that although 107Gbit/s rates had been achieved before, that was in the lab - and it still used optical multiplexing in the transmitter.

"Now we've designed a complete system with 100 percent electrical processing of the data in both the receiver and the transmitter," he said. He added that this increases the performance of the system enormously.

As well as the Siemens team, the project involved German ASIC developer Micram, and researchers from Germany's Fraunhofer Institute for Telecommunications and Eindhoven Technical University in The Netherlands.

Derksen said that products based on this new opto-electronic technology will be on the market within a few years.