Forthcoming IARU Activities at the ITU
Working Parties 1A and 1B of the International Telecommunication Union’s (ITU) Study Group 1 will meet in Geneva from June 21-28. A major item of discussion will be protection of radio services from interference from Broadband over Powerline (BPL), called Power Line Communications (PLC or PLT) in Europe. The International Amateur Radio Union (IARU) has already contributed to the ITU-R report SM2158, Impact of Power Line Telecommunication Systems on Radiocommunication Systems Operating in the LF, MF, HF and VHF Bands Below 80 MHz. This report shows the acceptable criteria for degradation of the HF radio noise floor caused by BPL is defined as being 0.5 dB. Work in WP1A will concentrate on the protection of radio services from the effects of BPL in range from 80-200MHz.
The IARU delegate to Study Group 1 and its working parties is Peter Chadwick, G3RZP. One of items Chadwick has prepared for these meetings is a report on the effects of intermodulation in power supplies causing the amateur band frequency notches in the BPL spectrum to be degraded. This report has been prepared from the work by Richard Marshall, G3SBA, published in the RSGB’s member journal RadCom, and also points out the difficulty such effects could have on the BPL system itself.
Chadwick will also present protection criteria for those amateur stations operating in the 2 meter band. Chadwick, who along with Ian White, GM3SEK, helped prepare the criteria, said it is considered that the Amateur and Amateur Satellite Services require protection such that BPL interference does not exceed -45 dB µV/m in the main lobe of the antenna, with a separation between antenna and the BPL installation being at least 10 meters.
Chadwick said that there are a number of non-amateur services that could suffer interference from BPL or its harmonics, such as applications including social alarms for the elderly, pagers and medical implant telemetry, as well as broadcast services, and when aggregation of radiation is concerned, aircraft navigation and communications: “When the differences in range between BPL and mains leads and the social alarms and medical implant ‘base’ stations and the like are taken into account, the acceptable levels of radiation to protect the Amateur Service are of the same order as those needed to protect these other services.”