US
Senator Ted Stevens (R-Alaska) was ridiculed extensively on Internet
message boards this summer for a speech he gave that attempted to
explain how the Internet works. He tried to explain channel capacity
with the analogy that the Internet is "a series of tubes." One comment
on the Steven's speech, in particular, seems to summarize a lay
person's understanding of technology, "indeed, our senators conceive of
the internet as a mysterious metaphysical entity." As if inspired by
Steven's analogy, Nethercom, a San Diego startup has developed a method
to send high speed signals through gas utility pipes. According to the
American Gas Association, 62% of US households have a gas connection.
Data communications is big business, and every utility is trying to
get a piece of the pie. Telephone companies were first, with dial-up
connection, followed by cable television's offering of broadband
Internet. The telephone companies responded with DSL, and they are now
deploying optical fiber to provide the same services as cable
television. Even the electrical utilities are experimenting with
transmitting data signals on power lines, a technique called Broadband Over Power Line (BPL) that has significant opposition.
The gas utility companies, envious, but powerless, thought they were
the only one of the four utilities out of the ball game, until now.
The idea of putting data signals though pipes is not new. A pipe of the proper dimension can be an electromagnetic waveguide, an idea demonstrated by Oliver Lodge in 1894. Waveguides were subsequently developed at Bell Telephone Laboratories, leading to the WT4 Millimeter Waveguide System,
a buried waveguide used in long distance telephony. Of course, common
gas pipes are quite crude compared to perfectly dimensioned waveguides,
and gas pipes will not transmit data signals very far using standard
techniques. The technical innovation of Nethercomm is the use of ultrawideband signals. Ultrawideband is a relatively new radio technology, but it is now used in products such as WiFi wireless internet. Since the signals are contained in an underground pipe, the high power levels needed to ensure a low bit-error-rate will not cause interference. The power levels are still low enough to prevent ignition of a gas stream infiltrated by air.
Several years ago, Dan Stancil, a Professor at Carnegie Mellon University
and a past collaborator [2, 3], investigated a similar method [4]. This
involved using existing HVAC ducts in buildings for wideband
transmission.
References:
1. Gas-line broadband a pipe dream? (USA Today article on Yahoo News).
2. S.D. Silliman, D.M. Gualtieri, and D.D. Stancil, Improvement of FMR
Linewidth in Bi-Substituted Lutetium Iron Garnet Thin Films for the
MSW-Optical-Mode Interaction, J. Appl. Phys. 73(10), 6460-6462 (1993).
3. M. Ramesh, D.M. Gualtieri, S.D. Silliman, J. Peruyero, and D.D.
Stancil, Effect of Sodium Doping of Rare-Earth Iron Garnet Films on
Magnetic and Magneto-Optic Properties, J. Appl. Phys. 70(10), 6289-6291
(1991).
4. D. D. Stancil, O. K. Tonguz, A. Xhafa, A. Cepni, P. Nikitin, and D.
Brodtkorb High-speed Internet access via HVAC ducts: a new approach,
IEEE Global Telecommunications Conference, November, 2001.