International Journal of Computer Science Issues

More than a traditional journal...

Cognitive Radio (CR) technology is envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. CR networks, equipped with the intrinsic capabilities of the cognitive radio, will provide an ultimate spectrum aware communication paradigm in wireless communications. Such networks, however, impose unique challenges due to the high fluctuation in the available spectrum as well as diverse Quality-of-Service (QoS) requirements. Specifically, in Cognitive Radio Ad Hoc Networks (CRAHNs), the distributed multi-hop architecture, the dynamic network topology, and the time and location varying spectrum availability are some of the key distinguishing factors. In this paper, current research challenges of the CRAHNs are presented. First, spectrum management functionalities such as spectrum sensing, spectrum sharing, and spectrum decision, and spectrum mobility are introduced from the viewpoint of a network requiring distributed coordination. Moreover, the influence of these functions on the performance of the upper layer protocols are investigated and open research issues in these areas are also outlined. Finally, the proposed tools, and best simulator to solve research challenges in spectrum management are explained. This gives an insight in choosing the suitable tool, and the suitable simulator that fit for solving different challenges.