Method and apparatus for sensing channel availability in wireless networks

Describes a method and apparatus for detecting the availability of channels in a wireless network, the method comprising: transmitting and switching to a first candidate channel for operational data received; detecting the availability of a previous operating channel; determining a previous operation channel is available; in the case of previous operating channel is available to switch back to the previous operating channel; and when unavailable said previous operating channel (Cop), one of the following steps: continue for operating a data transmission and receiving candidate channel, immediately switches to the second candidate channel for operational data transmission and reception, the transmission and switching to a second candidate channel for operational data received after a predetermined period. Also describes a system for detecting the availability of channels in cognitive network, comprising means for RF channel switching, detecting means for detecting the availability of a channel, and a media access control unit for controlling the detecting unit and the RF unit.