Japan's National Institute of Information and Communications Technology and Oki Electric have claimed a first with the carriage of data using a next-generation optical transmission technology on a metropolitan-area fibre-optic network.
In the demonstration, two channels of 10gbps bandwidth were transmitted over a distance of about 100km, from central Tokyo to the city of Tsukuba, and then back again using a system called Optical Code-Division Multiplexing (OCDM).
This is a method for sending more than one signal down an optical fibre. Technologies such as Dense Wavelength-Division Multiplexing already exist to squeeze more bandwidth out of an optical fibre, but the Japanese researchers said OCDM can accomplish the task more economically and flexibly.
The 200km total distance of the demonstration is a record for OCDM, said Takeshi Kamijoh, general manager of Oki Electric's advanced devices laboratory.
Successful use of OCDM over such a distance means the technology is suitable for metropolitan-area networks, the city-wide fibre-optic networks that are becoming common in many cities, he said.
The test was carried out on Japan Gigabit Network II, which is a testbed network linking 63 access points at research establishments and universities across Japan.
Martyn Williams writes for IDG News Service