USB does not have the power to broadcast/receive quality signals through dense materials (thick walls or many walls)
People often forget the a signals strength must be strong at both ends (Tx/Rx) to determine signal quality. or, there do not know what is actually involved in wireless tech!!!
UWB, Bluetooth, ZigBee, and Wireless USB are intended for use as wireless personal area network (PAN) systems. They are intended for short range communication between devices typically controlled by a single person. A keyboard might communicate with a computer, or a mobile phone with a handsfree kit, using any of these technologies. The distance between devices is normally less than 5-6metres (at best).
Bandwidth will also NOT be fully utilized.
PCI +1