Enhancement Proposals of Routing Protocols Performance in Cognitive Radio Networks

Abstract

Classical wireless networks are suffering from spectrum scarcity due to limited number of channels in unlicensed spectrum and rapid growth in wireless communication devices. With explosive growth of communication services and wireless mobile, the spectrum availability has become a bottleneck. However, it has been shown that several spectral bands of the licensed bands are underutilized. Consequently over most of the bands, the spectrum utilization measurements displayed very low. Efficient utilization of spectrum has been a major concern toward the increases of the demand for opportunistic usage of spectrum and growth of wireless technologies because spectrum is a natural resource [1]. On the other hand, while a major amount of the spectrum remains unutilized, the spectrum usage is concentrated on certain portions. Therefore, cognitive radio (CR) is proposed by the Federal Communications Commission (FCC) [2] to solve the problem of spectrum scarcity. CR can effectively identify free channels which will be utilized by cognitive users (CUs) while protecting primary users (PUs) activity and allows the CUs opportunistically use the temporarily vacant bands named “white spaces” or “spectrum holes”, thus providing and maintaining an efficient solution to the ever increasing user demand [3-5].When PU request to access their bands, the