There is a good article in the February 2002 issue of Scientific American
discussing the emergence of power line networking technology. It seems
that the news isn't all bad. The article mentions that engineers at
Intellon, Inc
moved the operating range of their modems up above 4.5 MHz (4.5 to 21
MHz), and then deleted 8 of the 84 OFDM channels which were most
likely to cause interference to amateur radio operators.
The article also devotes several paragraphs to describe just how poorly
a home's electrical wiring performs as a multi-MHz transmission system.
This has been my argument all along. These devices really should be
considered as being "wireless" with the homes electrical wiring serving
as a crude antenna system rather than a controlled impedance transmission
system. At the very least they are quasi-wireless.
Hopefully, the Intellon engineers have done a good job notching the
ham bands with their DSPs. Of course, on the reciprocal side, I wonder
if their A/D converters will have enough bits to handle the ingress from
a 1.5 KW HF amplifier. If we are lucky, the combination or error
correction, and our intermittment duty cycle transmssions will manifest as
nothing more than lower throughput on the power line devices.
Lets hope, Oy!
73 de Mike, W4EF................................
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