UWB

UWB

(Ultra-WideBand) A wireless technology that uses less power and provides higher speed than 802.11 Wi-Fi networks or first-generation Bluetooth products. UWB is expected to provide wireless video transmission for home theater systems, cable TV, auto safety and navigation, medical imaging and security surveillance. Bluetooth's second-generation technology uses UWB based on the WiMedia Alliance standard (see WiMedia Alliance).

Pulse Radio
Unlike other radio transmission systems, UWB does not use a continuous carrier frequency. It transmits extremely short pulses, and the durations between pulses do not use power. There are two ways to transmit this so-called "pulse radio." One method transmits the pulses in continuously varying time slots based on a pseudo-random number sequence like CDMA. The other divides the spectrum into smaller frequency bands that can be added and dropped as necessary.

UWB Sees Through Walls
Because UWB can transmit through materials that would bounce other radio signals, it is also used to pinpoint objects behind barriers or buried underground. First invented by Gerald Ross at Sperry Rand Corporation in the late 1960s, UWB has been used by the military for various radar systems. In 1998, the FCC allowed UWB for police work and fire fighting. In 2002, it sanctioned the technology at considerably lower power for commercial use. See WiMedia Alliance, 802.15 and GPR.

                 Highest   Frequency   Cell
   Wireless      Speed     Range       Radius
   Technology    (Mbps)    (GHz)       (ft.)

   UWB           480       3.1-10.6     33

   Bluetooth 1.2   1       2.4       3, 33,  330
   Bluetooth 2.0   3       2.4       3, 33,  330
      distance based on power in mW: 1, 2.5, 100

   802.11b        11       2.4         150
   802.11a        54       5.0          95