Net over power lines irks amateur radio lovers

NET OVER POWER LINES IRKS AMATEUR RADIO LOVERS
[SOURCE: USAToday, AUTHOR: Peter Svensson, Associated Press]
In a fight of old and new, it appears that the old -- ham radio, in this case -- will be left standing. Broadband over power line, or BPL, is in danger of becoming an also-ran in the race to bring broadband Internet to the American home, even as it's overcoming some technical hurdles. BPL is an attractive idea because of the power grid's ubiquity. It has been touted as a “third wire” into the home, a possible competitor to broadband via cable and telephone wires — and a way to bring high-speed service to rural areas underserved by cable and phone companies. However, most of the utilities that have tried it have backed away, largely because of skepticism about the economic viability of the technology in the face of competition. BPL hasn't lived up to its early promise as a rural broadband alternative, either, because of a technical quirk that is also the source of the ham radio frustrations. For broadband, a radio-frequency signal is applied to the power line, much like a high-frequency signal is applied to phone lines to create a digital subscriber line, or DSL. But unlike phone and cable wires, power lines that run above ground can act as large radio antennas, emitting the high-frequency signal as radio waves. According to the American Radio Relay League (ARRL), the national ham radio association, radio waves from an improperly designed system can drown out amateur radio within a quarter of a mile. The antenna nature of the line also means the signal loses its energy quickly, while the line picks up radio noise from the surroundings. A long line running in a rural area needs amplifiers at short intervals, adding to the costs; even so, the signal gets lost after a few miles.
http://www.usatoday.com/printedition/money/20060320/powerline20.art.htm