JARL home page: Internet: http://www.jarl.or.jp/
JH5ESM, a member of JARL Technical Board on EMC: Internet: http://www.qsl.net/jh5esm/
JARL PLC Information Page (Japanese): Internet: http://www.jarl.or.jp/Japanese/2_Joho/2-7_plc/powerline.htm

Official press release on PLC issue in Japan, from Ministry of Public Management, Home Affairs, Posts and Telecommunications (English)
Internet: http://www.soumu.go.jp/joho_tsusin/eng/Releases/Telecommunications/news020809_3.html
Summary: English summary of statement from the Japanese Ministry of Public Management, Home Affairs, Posts and Telecommunications. Japanese original tetxt is available from the Internet URL above.
Author: MPHPT

Japan's Government Concluded That It is not suitable to allow HF band for PLC (English)
Internet: http://www.jarl.or.jp/English/4_Library/A-4-1_News/jn0208.htm)
Summary: On April 30, 2002, the Ministry's study group on PLC held its first public hearing with JARL, Association of Radio Industries and Business, and others. At the meeting, the results of collaborated field tests, which were held in January, 2002, were reported. The tests included monitoring leakage of electric waves from power lines -- specifically in cases of providing Internet access via power lines to homes. In this way, JARL actively cooperated with the group. As a result, MPHPT's study group officially announced in its fifth meeting on July 31 that it is too early to allow PLC between 2 MHz and 30 MHz due to hazardous effects on HF users. This news was reported by major newspapers including Yomiuri, Asahi and Mainichi, as well as the major financial daily, Nihon Keizai Shimbun.
Author: JARL

Campaign Against Power Line Communications Operating in the HF Bands (English)
Internet: http://www.qsl.net/jh5esm/PLC/JARLcampaignPLCe.pdf
Summary: This paper gives a tutorial of PLC and presents summaries of the interference level from measurements made of several access PLC field tests in Japan. Japan has chosen not to allow access PLC at this time.
Author: JARL, Cosy MUTO, JH5ESM

Campaign Against Power Line Communications Operating in the HF Bands (Japanese)
Internet: http://www.qsl.net/jh5esm/PLC/JARLcampaignPLCj.pdf
Summary: This paper gives a tutorial of PLC and presents summaries of the interference level from measurements made of several access PLC field tests in Japan. Japan has chosen not to allow access PLC at this time.
Author: JARL, Cosy MUTO, JH5ESM

7th International Symposium on Power Line Communications and Its Applications (ISPLC2003) (English)
Internet: http://www.darc.de/referate/evm/plc/isplc2003.html
Summary: This is a short summary of the symposium written by Cosy MUTO, JH5ESM.
Author: JARL, Cosy MUTO, JH5ESM

On Radio Interference Assessments of Access PLC System
Internet: http://www.qsl.net/jh5esm/PLC/isplc2003/isplc2003a2-3.pdf
Summary: Access PLC system is considered one of the "last mile" solutions. However, HF PLCs using overhead distribution would be an interference source to radio communications services and scientific observations in this band. This paper describes assessment test results in Japan. One of them is carried out as a part of government's investigation. Bad LCL characteristics of mains results large amount of radio interference, and thus the deregulation in Japan is shelved.
Authors: Cosy MUTO, Norikazu MORI and Toshiyuki KONDOH
Note: Presented at the ISPLC2003 Symposium.

On Radio Interference Assessments of Access PLC System -- Presentation Material
Internet: http://www.qsl.net/jh5esm/PLC/isplc2003/isplc2003a2-3presentation.pdf
Summary: This file is the presentation material from the above paper.
Authors: Cosy MUTO, Norikazu MORI and Toshiyuki KONDOH

The following 2 papers were also presented at the ISPLC2003 Symposium:

Interference measurements in HF and UHF bands caused by extension of power line communication bandwidth for astronomical purpose
Internet: http://www.qsl.net/jh5esm/PLC/isplc2003/isplc2003a7-1.pdf
Summary: Power line communication (PLC) system which extends the available frequency bandwidth up to 30 MHz has been proposed in Japan. The electromagnetic interference problems on PLC had been investigated by the PLC study group organized by the Ministry of Public Management Home Affaires, Post and Telecommunications (MPHPT). The study group held collaborated field experiments of the PLC facility and we measured interferences caused by the PLC facility in the HF and UHF bands in order to evaluate the inflences of the expansion of PLC bandwidth on radio astronomical observations. In the field experiment, two sets of PLC modems (SS and OFDM) were tested as an access system. During the PLC modems were on, the HF spectra observed showed strong increase of the noise-floor level, and it was found that the PLC noise exceeded the level of galactic noise by more than 30 dB. In UHF band, spurious emission around 327 MHz was identified. In both HF and UHF band, the interferences exceeded the limit of harmful interference level for radiop astronomical observation which is given in Recommendation ITU-R TA769-1. Safety distances where the Recommendation was satisfied are estimated to be 219 km and 12 km at 9.2 MHz and 327 MHz, respectively. PLC seems to be a harmful interference source for the radio astronomical observation in both HF and UHF bands.
Authors: F.Tsuchiya, H.Misawa, T.Nakajo, I.Tomizawa, J.Nakajima, M.Ohishi, M.Tokumaru, T.Ono and A.Morioka

Sharing studies between the radio astronomy telescopes and the power line communication systems in the HF region
Internet: http://www.qsl.net/jh5esm/PLC/isplc2003/isplc2003a7-4.pdf
Summary: Radio Astronomy has frequency allocations in 13.36-13.41 MHz and 25.55-25.67 MHz on a primary basis worldwide. These bands are extensively used by radio astronomers to observe electromagnetic waves emitted by the Sun, the Jupiter and other large, gaseous planets in the solar system. The powers from a single PLC system in the above radio astronomy bands are --33 dBW and --29.2 dBW respectively and therefore the PLC sytems seem to be a harmful interference source for the radio astronomical observation in the HF band. It is necessary to keep an adequate separation distance to avoid harmful inteference to the radio astronomy telescope, and we calculated the separation distance based on the free-propagation method. We obtained a value of 424 km. If the PLC system is widely deployed, it is sure that the interference level increase greatly and the separation distance will become much larger. Thus it was recognized that it is quite difficult to share frequencies with the PLC systems and radio astronomy telescopes, at least, in Japan, and that a new technology to dramatically reduce leaked emissions from the power lines are crucial for the PLC systems to coexist with other radiocommunications services.
Authors: by M.Ohishi, J.Nakajima and M.Tokumaru

Other JARL PLC Web Pages (Japanese)