how UWB pulses are propagated and how the pulses can be recog- nized by potential receivers. A UWB transmission uses ultrashort pulses that distribute power over a wide portion of the radio frequency spectrum. Because power density is dis- persed widely, UWB transmissions ideally won't interfere with the signals on narrow-band frequencies, such as AM or FM radio or mobile phone signals. ASSET TRACKING In fact, UWB transmissions pose SO little threat of interference with licensed frequencies that the FCC now allows companies to operate UWB technology within the 3-GHz to 10-GHz range without obtaining radio spectrum licenses. The bandwidth of UWB signals is SO wide that signal energy is available for use at both high and low frequencies. "The low-frequency content of UWB devices can penetrate solid structures," says Buehrer, an assistant professor of electrical and computer engineering and the project's principal investigator. That would make UWB highly useful for transmitting signals through build- ings and other manmade and natural obstacles. "Additionally, the high- frequency content can detect the details of objects," notes Buehrer. This capability, combined with the technology's low power, makes UWB radar an excellent surveillance tool. UWB also has the potential to become a significant military communica- tions medium. "Because of the low level of energy in UWB signals, a military unit using the technology could communicate without a nearby enemy even perceiving that transmissions are taking place," says Buehrer. UWB also has many commercial applications. For example, most home wireless devices, such as television remote controls, are limited in the amount of data they can send and receive. UWB signals can achieve significantly higher data rates. As a result, there's a potential for UWB wireless home com- puter networks, wireless camera-to-computer downloads, and wireless con- nections to thin-screen wall-mounted televisions. In the project's first phase, Buehrer and his colleagues will develop models to show