A Survey on Spectrum Handoff in Cognitive Radio Networks

Cognitive Radio Networks offer a promising solution for spectrum scarcity problem. To ensure the optimal utilization of spectrum, when the authorized user (also known as the primary user, PU) or spectrum quality deterioration occurs, the cognitive users (also known as secondary users, SU) need to change the spectrum, which is called as the spectrum mobility. Among the spectrum mobility issues, spectrum handoff strategy plays an important role in spectrum mobility performance. This paper describes different spectrum handoff schemes and modeling techniques of PR user to perform spectrum handoff.