Japan plays catch-up in high-speed PLC

Telecom Asia, June, 2004

Nine high-speed Internet trials have recently started in Japan using power lines for transmission at between 2 MHz and 30 MHz. The trials will finish at the end of March 2005 and are likely to lead to the Ministry of Public Management, Home Affairs, Posts and Telecommunications (MPHPT) permitting commercial services as early as 2006.

The move comes after the MPHPT modified its regulatory ordinances in January to permit high-speed power-line communications (PLC) experiments following a study released last August that concluded that "it is likely that power-line communications equipment will become a source of harmful interference with radio communications including air traffic control and short-wave broadcasting."

The main purpose of the trials, which include both in-building and outdoor access systems, is simply to demonstrate that the radio interference problems have been solved.

Sataoshi Kobayashi, managing director of the Association of Radio Industries and Businesses, expects the in-building trials to be successful and services permitted, but says there are doubts whether the outdoor access system trials would be successful.

High-speed and low-speed PLC, or broadband over power lines, in Japan as well as Korea is lagging behind Europe and the US partly due to the regulatory issues.

Japan's largest power utility, Tokyo Electric Power Co (TEPCO), had long conducted R&D on PLC but gave up in the late 1990s after failing to overcome the electromagnetic radiation leakage and radio interference problems. Kyushu Electric Power Co has been the most aggressive utility promoting PLC and its research in Japan.

Recent developments such as the ability to put "notches" on frequencies and the use of technologies such as orthogonal frequency division multiplexing and wavelet technologies have arguably overcome these problems. However, PLC is still fanatically resisted, especially by ham radio operators who are using similar frequencies.

The trials are being conducted by TEPCO, Kyushu Electric Power Co, Mitsubishi Electric, Matsushita Electric Industrial Co, LineCom and Preminet.

Both Matsushita and Mitsubishi Electric have been focusing strongly on PLC products. Matsushita announced in January that it had developed the world's first home-networking PLC technology capable of delivering broadband. It hopes to introduce PLC adaptors for office and home use by the end of 2004.

Does high-speed PLC threaten the future of ADSL and FTTH carriers? That was the dream of researchers at power utilities. However, it seems that high-speed PLC still has too many major barriers to overcome before it can be considered a threat.

"We believe the big opportunity in Japan for high-speed PLC will be in distribution of Internet inside buildings," said Avner Matnor, president of ITRAN Communications, an Israeli company that has set up high-speed PLC joint ventures with two Japanese companies. ITRAN also supplies low-speed PLC technology and chips to Japan.

Low-speed PLC at up to 450 kHz has been permitted in Japan for about ten years but hasn't proved popular. Its main use to date is telemetering.

--Staff writer