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Turning Your Home Wiring Into a Giant Antenna
An anonymous reader writes with this IBT snippet: "Imagine if you could run a wireless sensor device for years without ever having to replace the battery. Turns out, the idea of a battery-less wireless device might not be too far off. Researchers at the University of Washington and the Georgia Institute of Technology developed a small node sized device that uses the residential wiring from a building or home and transmits information to and from almost anywhere else from within. The device is called Sensor Nodes Utilizing Powerline Infrastructure, or SNUPI. It uses basic copper wiring as a giant antenna to receive wireless signals at a set frequency. When the device is within 10 to 15 feet of electrical wiring, it uses the antenna to send data to a single base station." (For "node-sized," think "size of a breakfast cereal prize.")
For those of you who have never eaten or purchased pre-sweetened "kids" cereals, popular breakfast cereals marketed to children in the U.S. and elsewhere in the West often have a little toy stuffed in them. A famous (infamous?) example that may be an urban legend is a plastic whistle that once came in Cap'n'Crunch cereal boxes that (allegedly) blew a tone of 2600 Hz, the exact frequency needed to place free phone long-distance phone calls on AT&T's POTS network.
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This new "node-sized" device consumes 1mW when transmitting and the home wiring is used as a receiving antenna. If HomePlug radiated this much, ham guys would be really happy.
It's 3.8 cm by 3.8 cm by 1.4 cm (second page, first column, second paragraph).
Actually that record is still being held by Arnold Rimmer in Red Dwarf, when he suggested to form the Comitee for Liberation and Integration of Terrorizing Organisms and their Reintegration Into Society.
snooki. I'm not proud of the fact that I know that, however.
In the UW paper, there was no detailed description of the powerline inside the test home. What was the wiring? I'm guessing it was NM cable (a.k.a. "Romex"), or wire in nonmetallic conduit. If a home is wired with wire in metal conduit or armored cable (f.k.a."BX"), the grounded metal enclosure probably has an adverse effect on performance of the SNUPI system.
I don't have one, but I do remember them. The Wikipedia article on the cereal has citable references. And a little googling turns up photos of the whistle.
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