IEEE 802.22: the first worldwide wireless standard based on cognitive radios

In November/2004, we witnessed the formation of the first worldwide effort to define a novel wireless air interface standard based on cognitive radios (CRs): the IEEE 802.22 working group (WG). The IEEE 802.22 WG is chartered with the development of a CR-based wireless regional area network (WRAN) physical (PHY) and medium access control (MAC) layers for use by license-exempt devices in the spectrum that is currently allocated to the television (TV) service. Since 802.22 is required to reuse the fallow TV spectrum without causing any harmful interference to incumbents (i.e., the TV receivers), cognitive radio techniques are of primary importance in order to sense and measure the spectrum and detect the…