UWB technology sends ultra low power pulses across a wide band of spectrum, with the idea being to supply higher bandwidth, less possibility of interference than narrowband radio, and lower probability of detection. Although Federal agencies are still trying to carve out new channels in the licensed wireless spectrum, their focus is expanding to a fuller acceptance of new unlicensed wireless technologies. The licensed spectrum is limited, and efforts to use more of it for public safety have encountered obstacles. Last November, the FCC's Spectrum Policy Task Force expressed concern in its report that the "increased demand for spectrum-based services and devices is straining longstanding and outmoded spectrum policies." The newer unlicensed technologies, however, also face distinctive challenges. Some experts have labeled them as still immature, insecure, and difficult to manage. Other technical barriers include interoperability, integration, interference, and the less than highly advanced state of mobile battery technology. On the business side, vendors must decide whether to seek licensed spectrum and how to build the large markets needed for staying power. A potential innovation would tie together wireless networks in an end user device through software radios. "Cognitive radio" technology could assist in finding which networks are best to use. Consumer use of software radio could be at least 5 years off, due to software radio's demands for hefty battery power. Although software radio and cognitive radio won't solve all the problems associated with spectrum scarcity and the newer unlicensed wireless networks, many Federal officials are becoming convinced that these technologies offer promise for the future.