Spectrum Handoff Management in Cognitive Radio Networks: Solutions, Modeling, and Future Directions

Cognitive radio (CR) is a promising technology that can enhance the radio spectrum utilization by enabling unlicensed users to exploit the spectrum in an opportunistic manner. However, the main challenge is to share the licensed spectrum without interfering transmissions of other licensed users. A CR node needs to vacate the spectrum upon detection of licensed users on a particular frequency band (e.g., spectrum handoff or spectrum mobility) leading to significant network performance drops and switching overheads. This chapter aims to propose a proactive spectrum handoff management scheme to overcome the problem of handoff latency management in CR ad hoc networks. The proposed scheme is modeled and its performance is evaluated using an OPNET simulation tool. Simulation results are presented to evaluate the performance of the proposed system. The chapter concludes with a brief discussion and future research directions.