A breakthrough technology being developed by a Huntsville, Ala. company called Time Domain could revolutionize school networks and communications in the not-too-distant future.

Called “digital-pulse technology,” it’s a way to transmit information wirelessly by using pulses of energy instead of radio waves. Each pulse represents a 1 or a 0, the digital language of computers. Ten to 40 million pulses can be sent per second, according to Time Domain–fast enough to carry voice, video, and data.

“Time Domain appears to have developed a ‘fundamental and enabling’ technology that will do things that no other technology on earth can do,” said Paul Turner, a Price Waterhouse technology analyst, who also serves on the Time Domain’s board of directors. The new technology will significantly enhance three existing technologies simultaneously, he said: radar, global positioning technology, and wireless communications.

Since the first demonstration of wireless communication in the 1880s, a Time Domain web site explains, all practical uses of radio have relied on the transmission of continuous sine waves: “The modulation of those sine waves allows the transmission and reception of information in either amplitude (AM radio) or frequency (FM radio). From 1890 to the present, industry has searched for ways to send more information more reliably.”

“Now,” says Time Domain, “the entire wireless landscape has changed.” The digital-pulse wireless medium does not rely on sine waves, does not require an assigned frequency, does not need a power amplifier, and is so random and low powered that it is indistinguishable from noise, says Time Domain founder Larry Fullerton, inventor of the technology.

“The medium does require precise pulse placement in time,” the company says, “and it also requires a coherent correlating receiver–a ‘Fullerton correlator’.”

Time Domain, founded in a garage in 1987, now is working with IBM, Worldcom, and the U.S. Marines, among others. Two dozen working prototypes of product applications exist, the company says, and miniaturization of the technology to the chip level is under way. The company predicts an ultimate demand of more than a billion chips per year in ventures such as “last-mile solutions,” covert communications, wireless LANs, through-wall radar, E-911 positioning, asset tracking, and security systems. Industry observers say the technology has the potential to revolutionize the entire wireless industry.

Pulse technology offers several significant advantages over today’s wireless devices. For one thing, there are limits to how much information radio waves can carry and how much space there is on the radio dial. But pulses have no frequency, so they’re not confined to a single channel. Pulse technology could free up the crowded radio spectrum that today’s wireless devices use to transmit information.

Another advantage is that pulses require much less battery and transmitter power, because the signals are so far apart they don’t collide with each other. Pulse-technology devices could operate on one-thousandth the power of devices that use radio waves, Time Domain says, so a wireless communicator could conceivably be made the size of a quarter.

For schools, pulse technology offers exciting possibilities for wireless networking. According to Time Domain senior vice president Peggy Sammon, the technology could enable schools to quickly and easily set up a wireless LAN or even create a “mobile campus,” in which students carry laptops from classroom to classroom while always maintaining a network connection.

“To get that kind of mobility now requires a great deal of infrastructure,” Sammon said, such as wireless bridges in the ceiling of every fourth or fifth classroom. “This (digital-pulse wireless) application would require very little infrastructure.”

A further advantage of the new technology is that pulses are timed according to a complex code shared only by the sender and receiver. For one device to listen to another, each must share a code that tells the listening device which positions to listen to in what order. Because of the enormous number of possible combinations of positions, Time Domain says, there’s no way to intercept this kind of signal–so completely secure transactions might soon be possible as well.

Hand-held radar

Because the pulses are read by timing the incoming signals to the nearest trillionth of a second, any pulse device can tell how long it takes for a signal to get to it or bounce back from it. Using pulse technology, the positions of objects can be pinpointed to within less than an inch, compared to a position-identification capability ofwithin about five feet for current global positioning satellite technology.

Besides offering cheap, secure wireless communication, a cellular phone built with Time Domain’s technology could double as a handheld radar device. Unlike today’s radar, though, pulse signals can travel through walls.

Time Domain already has made hand-held prototypes for police to use to “see” inside a room before bursting in, and a few small companies are using the technology to make pulse radar devices for measuring the liquid in steel storage tanks. Meanwhile, the Marines have been looking at Time Domain prototypes because they’d like a walkie-talkie that’s undetectable and can tell the location of every member of a unit.

The technology’s radar application has significant potential for schools as well, Sammon said. For example, schools could use a pulse-radar device for inventory control. By equipping items such as projectors and computers with radio frequency (RF) tags, Sammon said, you could keep track of inventory on expensive equipment.

The technology could even be used to monitor the security of students, Sammon’s said–though she said Time Domain doesn’t necessarily advocate such a use. For example, elementary students at recess or on a field trip could be outfitted with wearable RF tags to keep track of their whereabouts.

Mass-market products, including those for the education market, are still “a couple years off,” Sammon said. Right now, the company is developing specific applications of the technology for its business partners, but applications for the education market would be “a very easy offshoot” from these, she said.

Time Domain still faces many hurdles before its digital-pulse technology really can take off. One of the biggest is clearance from the Federal Communications Commission (FCC), which has not yet granted the company permission to test its products. Because pulse technology doesn’t resemble anything the FCC has experienced before, the agency has been wary to grant its approval. But Time Domain chief executive officer Ralph Petroff met with FCC commissioners at their request April 6–a possible sign this hurdle, at least, will be cleared.

Time Domain