Here's a response from Ron Hranac of Cisco. He responds:
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With regard to radiated interference, the same thing that keeps other
over-the-air ingress out of the plant: A tight network! ;-)
For those on the List unfamiliar with BPL (broadband over power line), this
is technology that uses frequencies in the 2 - 80 MHz range to transmit
high-speed data over power lines. A number of trials are underway in the U.S. As one
might expect, there is concern about possible interference to licensed
over-the-air users of the shortwave spectrum: FEMA, Red Cross, shortwave
broadcasters, amateur radio operators, etc. Power lines were designed to transmit 60 Hz
AC, not RF. Preliminary tests indicate that interference is an issue, and both
FEMA and ARRL have commissioned independent tests to determine the extent of
interference to over-the-air users. To my knowledge, no tests are being
conducted to see whether or not BPL represents an interference threat to cable.
I'm not sure how consumer devices--TVs, VCRs, FM tuners, STBs and cable
modems--will handle RF conducted over the power lines (as mentioned previously,
radiated interference can be dealt with by good ingress management). I would
think that if the BPL energy makes it inside the home at an appreciable level, the
device's power supply may attenuate potential interference in the 2-80 MHz
range a fair amount. In worst-case situations, it may take brute force AC
filters or perhaps common mode chokes to keep interference from being conducted
through the AC cord of a cable CPE device into the reverse path.
Re: Data Transfer Over Power Lines--Soap Box again
Member #: 14229
Registered: 1996-2001
Posted:
221
Name:
David M. Rosner
Name:
David M. Rosner
Company:
DR Telecom Consulting & Solar Energy Solutions
Occupation:
Telecom consultant & Solar EnergySolutions
Location:
Based out of CT
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