I think this may (IOW, use the info below cautiously)
have been done before, but, may I surmise that these
researchers, locked away in academia and seeking
'research dollars' managed to mildly hornswaggle
some front office bidness types into funding a study
to discover AWAU (a wheel already uncovered), to
wit, the:
"Surface-wave Transmission Line"
Description (Google cache):
http://216.239.63.104/search?q=cache:TkTRpUZwBmAJ:sunsite.tus.ac.jp/pub/acad
emic/agriculture/agronomy/ham/ANTENNAS/20030218.ant+%22surface-wave+transmis
sion+line%22+launcher&hl=en&start=2
Applicable excerpt:
The book decsribes this as a surface-wave transmission line,
normally using a thick dielectric (total diameter is often 3 or more
times the diameter of the single conductor). "A mode of
propagation that is practically non-radiating is excited on the line
by means of a conical horn at each end [called launchers] ... mouth
of the horn is roughly 1/4 to 1/2 wavelength in diameter. Losses are
about half those of a two-wire line, but the surface-wave line has a
practical lower limit of about 50 megacycles.
The losses in the two launchers combined vary from less than
.5 dB to a little more than 1.0 dB, according to their design."
A reference is given to an article "Designing surface-wave
transmission lines" by Georg Goubau in Electronics vol. 27, April
1954. I wonder whether Goubau is the "G" in "G-line"?
Also described in my Sixth edition/3rd printing 1979
ITT "Reference Data For Radio Engineers" on page 24-30.
Commercial adaptation (as far as I can determine):
http://www.corridor.biz/news.htm
Jim P / WB5WPA /
----- Original Message -----
From: <Jimk8mr@aol.com>
To: <rfi@contesting.com>
Sent: Tuesday, January 11, 2005 11:07 AM
Subject: [RFI] Gigibyte BPL?
>
> And now comes this joker who proposes that by making power lines into
well
> matched antennas, they can send gigibytes down those wires in front of
your
> house!
> Earth to WA3FET... can you walk down the hall and talk some sense into
this
> guy, or if not maybe spill some super glue into his hard drives? :>)
> Jim K8MR
> ------------------------------------------------------
> January 5, 2005
> University Park, Pa. -- Penn State engineers have developed a new model
for
> high-speed broadband transmissions over U.S. overhead electric power lines
and
> estimate that, at full data rate handling capacity, the lines can provide
> bit rates that far exceed DSL or cable over similar spans.
> Dr. Mohsen Kavehrad, the W. L. Weiss professor of electrical engineering
and
> director of the Center for Information and Communications Technology
> Research, led the investigation. He says, "Although broadband power line
(BPL)
> service trials are now underway on a limited basis in some locations in
the U.S.,
> these trials run at DSL- comparable rates of 2 or 3 megabits per second.
> "We've run a computer simulation with our new power line model and found
> that, under ideal conditions, the maximum achievable bit rate was close to
a
> gigabit per second per kilometer on an overhead medium voltage unshielded
U.S.
> electric power line that has been properly conditioned through impedance
> matching. The gigabit can be shared by a half dozen homes in a
neighborhood to
> provide rates in the hundreds of megabits per second range, much higher
than DSL
> and even cable."
> Kavehrad adds, "If you condition those power lines properly, they're an
> omni-present national treasure waiting to be tapped for broadband Internet
> service delivery, especially in rural areas where cable or DSL are
unavailable."
> The researchers say they are the first to evaluate data rate handling
> capacity for overhead medium voltage unshielded U. S. electric power lines
and will
> outline their findings at the IEEE Consumer Communications & Networking
> Conference in Las Vegas, Nev., Jan. 5. Their paper is titled,
"Transmission
> Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage
Power-lines
> for Broadband Communications." The authors are Pouyan Amirshahi, a
doctoral
> candidate in electrical engineering, and Kavehrad.
> In their paper, the authors note that the junctions and branches in the
U.S.
> overhead electrical grid cause broadband signals to reflect and produce
> multipath-like effects on these lines.This causes degradation in
power-line
> broadband transmission performance and decreases transmission capacity.
> Kavehrad explains, "The signal can bounce back and forth in the lines if
> there is no proper impedance matching. The bouncing takes energy away from
the
> signal and the loss is reflected in the ultimate capacity.
> "In service, performance will depend on how close the power company
chooses
> to place the repeaters," he adds.
> The researchers are continuing their studies. Kavehrad predicts that the
> engineering issues to make BPL a technical alternative to DSL and cable
will be
> solved. Whether it will be an economical alternative remains to be seen
since
> there are interference issues that have to be overcome.
> The study was supported by a grant from AT&T Corporation.
>
> **bah**
> EDITORS: Dr. Kavehrad is at _kavehrad@engr.psu.edu_
> (mailto:kavehrad@engr.psu.edu) or (814) 865-7179.
>
> Contacts:
> Barbara Hale (814) 865-9481 _bah@psu.edu_ (mailto:bah@psu.edu)
> Vicki Fong (814) 865-9481 _vfong@psu.edu_ (mailto:vfong@psu.edu)
>
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