UWB

Ultra-wideband (UWB) is a radio technology that uses very wide bandwidths to enable high data rate communications over short distances and to provide precise time-based ranging and positioning. UWB can transmit information either as short, nanosecond-scale pulses (impulse radio UWB) or by spreading data across multiple wide subbands (multiband OFDM UWB).

UWB signals occupy a broad portion of the radio spectrum, often spanning several gigahertz. In practice, systems implement a wide instantaneous bandwidth and operate under regulatory limits on emitted power to minimize interference with other services. In the United States and Europe, regulators define allowable bands and power spectral density limits for UWB devices, which shape device design and deployment.

Applications include high-rate wireless links over short distances, indoor positioning and ranging with centimeter-level accuracy, asset tracking, automotive radar-like sensing, and gesture/presence sensing in consumer electronics.

Advantages include very fine time resolution that enables precise ranging, low average power, and resilience to multipath in some scenarios. Limitations include limited coverage range compared with lower-frequency technologies, the need for specialized hardware, and regulatory constraints.

Standards and adoption: The technology has been standardized within IEEE 802.15.4a, which supports IR-UWB for indoor positioning and ranging; subsequent amendments such as 802.15.4z have added security enhancements. UWB is used in various commercial products for location services, asset monitoring, and short-range communications.