Introduction to Cognitive Radio Network and survey on MAC protocols for Cognitive Radio Networks

Spectrum is a scarce resource and traditional spectrum assignment policies does not make efficient use of spectrum which leads to wastage of allocated spectrum. With increase in the number of wireless devices spectrum demand is growing rapidly. Cognitive Radio Networks (CRN) can provide solution to these problems by using the spectrum in dynamic manner. Cognitive Radio (CR) users can access the spectrum allocated to Primary Users (PUs) without affecting the primary network communication. MAC protocols are needed when multiple CR users want to access the spectrum allocated to primary users. A brief overview of the requirement of CRN is provided. Basic working and architecture of CRN is introduced. Moreover, classification of various types of MAC protocols used in CRN is given with protocols used in past. Comparison of the MAC protocols is also provided in the end