Date Added: Jul 2011
Today's wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm, referred to as Dynamic Spectrum Access (DSA) and cognitive radio networks. The dynamic spectrum access technology can allow unlicensed secondary systems to share the spectrum with the licensed primary systems. In this paper, different methods of DSA are discussed which include Game-theoretic approach, Group Intelligence technique, Markovian Queuing Model and fuzzy logic based method.