Note: comments posted are strictly the opinion of the poster and not necessarily those of Fiber Planners Inc. or any other posters.
Tuesday, January 27, 2004
"Could Broadband Over Power Lines be Dangerous?" -- No!
Last week, Slashdot ran a feature on possible drawbacks of BPL (broadband over power line) technology, alleging that high energy levels of RF (radio frequency) energy on power lines could burn people, among other problems.
Even folks from the ARRL (American Radio Relay League) -- a major group opposed to BPL deployments for fear of widespread interference to ham radio operators -- felt compelled to write in explaining that RF emissions from BPL do not even remotely pose a threat:
"The FCC has limits to human exposure to RF energy, but broadband over power line that operates at the FCC limits of 30 uV/m at 30 meters distance cannot, under any circumstances, exceed those RF safety standards. On 30-300 MHz, the part of the spectrum with the most stringent exposure limits, the exposure level is at about 27.5 volts/meter -- a level about 120 dB higher than the levels permitted by Part 15 to unlicensed emitters such as BPL. Expressed in power, the BPL systems are permitted to operate at a level that is 1/1,000,000,000,000 of the FCC's exposure standards. The risk to broadband over power lines is that the levels are strong enough to cause harmful interference. As a secondary issue, at least one system has been demonstrated to be susceptible to interference from amateur radio and presumably other HF operation. The RF levels of BPL systems are, however, nowhere near the levels that could exceed the RF-exposure limits." (posted by Ed Hare)
Ed Hare with the ARRL has proven to be an important and credible voice in the BPL discussion in part because he's been scrupulous in sticking to the technical facts as he can measure them. The BPL page he maintains on the ARRL web site contains not just anti-BPL material but links to BPL vendors, users and advocates. Ed has also urge others in the amateur community to find ways to work cooperatively with utilities and BPL vendors in gathering information on BPL emissions. posted by Al Bonnyman
Tuesday, January 27, 2004#