Date Added: Feb 2013
Due to huge demand for radio spectrum in wireless communication networks, fixed spectrum access policy is a major problem in solving spectrum crisis. Dynamic spectrum access is a method which gives the solution by allocating the available limited radio spectrum band between different licensed and unlicensed users. Dynamically accessing the unused spectrum is known as Dynamic Spectrum Access (DSA) which becomes a promising approach to increase the efficiency of spectrum usage. This allows unlicensed wireless users (secondary users) to dynamically access the licensed bands from legacy spectrum holders (primary users) on an opportunistic basis.