Date Added: Jan 2012
Opportunistic access of the unused frequency bands across the licensed radio spectrum is currently being considered as a means to reduce the spectrum shortage. Cognitive radio is the key technology to implement opportunistic access of spectrum. Due to the unlicensed access, the authors need to implement certain safeguards so that the unlicensed users do not interfere with the ongoing operations of the licensed users. Spectrum sensing is one of the various issues in cognitive radios in which the unlicensed (secondary) user has to sense the licensed band. In this paper, they separated the spectrum sensing task from the secondary user for the opportunistic spectrum access in the smart building environment.