FYI
I have forwarded this message from our local ham email group. BPl is still
hanging around!
Bob Tinney, K8LR, [log in to unmask]
----- Original Message -----
From: Ronald Schubot, N8CML
To: [log in to unmask]
Sent: Wednesday, August 18, 2004 12:12 PM
Subject: [kalamazoohamradio] Re: diy BPL - frequencies and FCC-03-100A1
(notice of inquiry)
Here is a link to an FCC Notice of Inquiry on BPL.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-03-100A1.pdf
In answer to the frequency question, here is section II, paragraph 7 (from
page 3):
7. As indicated above, until recently, carrier current devices have operated
generally on frequencies
below 2 MHz with limited communications capabilities over the electric power
wiring. The power line is
a noisy communications medium, characterized by several unpredictable and
strong forms of interference
generated by devices such as dimmer switches, motorized electrical
appliances and computers. The
power line potential communication channels between different outlets are
further characterized by fast
fading, non-flat frequency responses and changing impedances. Because of
these inherent non-linear
characteristics, reliable high-speed communications over power lines have
been difficult to achieve.
However, the availability of faster chip sets and the development of
sophisticated modulation schemes
have produced new designs that can overcome these earlier technical
obstacles, e.g., extreme vulnerability
to power line noise, which causes drop-off in transmission speeds and
disruptions due to random home
power usage of other appliances. New BPL devices operate on multiple
carriers that are spread over a
wide spectrum (e.g., from 4.5 MHz to 21 MHz), with adaptive algorithms to
counter the noise in the line.
Data transmission speeds rated at 14 Mbps and higher have been claimed for
in-house communications.(9)
BPL devices intended to carry high-speed broadband services to neighborhoods
over a utility's power
lines have claimed speeds comparable to DSL and cable in actual BPL
experimental installations.(10) This
new generation of high-speed BPL devices that use wide spectrum was not
contemplated under the
existing Part 15 rules when they were formulated.
Footnotes:
(9) For example, the HomePlug Alliance, a consortium of over 90 companies,
has published its HomePlug 1.0
standard for PLB systems operating inside the home, with rated data speeds
up to 14 Mbps and with multiple carrier
frequencies spread between 4.5 and 21 MHz. Various independent tests
performed by interested groups (see e.g.,
<http://www.pcworld.com/features/article/1,aid,86935,pg,7,00.asp>)
demonstrated sustained data throughput for
HomePlug devices in the range of 5 to 6 Mbps.
(10) The Commission has recently granted experimental licenses to certain
companies under 47 C.F.R. § 5, to evaluate
outdoor PLB equipment installed on overhead power lines that operate over
the range 1.7 to 80 MHz. A list of the
experimental grants may be found at
https://gullfoss2.fcc.gov/prod/oet/index_els_ie.html.
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