University of Rochester engineers are trying to adapt technology developed for the "Star Wars" missile program into an alert system that utility companies could rely on during natural disasters.
During catastrophes such as the ice storm that slammed the Rochester area in March of 1991, or the earthquakes that regularly rock Southern California, utilities depend on customer complaints to find downed power lines. This slows repairs since company personnel must piece together scattered bits of information to track down faulty lines.
University faculty and students are working with engineers from Rochester Gas and Electric Corp. to develop an automated process so engineers would know immediately which lines are down.
The idea is to outfit each power line with a transmitter that every so often transmits a distinct signal back to the utility signifying that the line is working. A missing signal would indicate that a line is down.
But how to tell apart all the signals from hundreds of power lines? That's where "Star Wars" comes in. Several years ago the Navy turned to Edward Titlebaum, professor of electrical engineering, to solve a similar problem: develop codes so that the signals from sonar-guides torpedoes remained distinct and did not become crossed.
"It's like talking at a loud cocktail party," says Titlebaum. "The room is packed with people, yet you're somehow able to hear the voice of the one person you're listening for -- perhaps your husband calling to you from across the room. We're trying to pick out particular signals from a tumult of signals."
So Titlebaum began studying ways to classify signals and settled on a family of codes known as frequency hop codes, where a signal hops across several frequencies per second. Last year he published a paper that showed how the codes could accommodate a virtually infinite number of users on networks of computers, cellular phones, radar, and other applications where multiple users are drawing on the same resource.
The inspiration for Titlebaum's work? Bats -- animals with enviable signal-processing abilities.
"About 20 years ago I became fascinated with bats," says Edward Titlebaum, professor of electrical engineering. "Bats are flying sonar systems. When they fly, how does one bat know its signal apart from the others, so it doesn't get confused?"
Now Titlebaum's codes have been incorporated into a computer chip designed by students working with faculty members Alexander Albicki and Edwin Kinnen. In recent tests with RG&E, the team has successfully inserted and then extracted distinct signals from the sea of electricity that surges along a utility's power grid. The team has sent and received signals between engineers' homes in Pittsford and between offices in the University's Computer Studies Building just by plugging in their computers to wall outlets.
"The signals travel throughout the entire building, says Albicki, "but unless you know just what you're looking for, they're practically invisible."
Though promising, RG&E has not implemented the system because it is currently too costly. University engineers are working to bring the cost down.
This work was funded by the Navy, RG&E, and the former Star Wars program. tr