An intelligent spectrum handoff scheme based on overflow queuing theory in Cognitive Radio Networks

As one of the key technologies to achieve spectrum mobility, spectrum handoff has received high attention in Cognitive Radio Networks (CRNs). When all of the channels in the system are occupied by the primary users (PUs) and the switching queue (SQ) is full of secondary users (SUs), an arriving PU cannot be accepted by the system or the SQ. In this paper, an intelligent spectrum handoff strategy based on overflow queuing theory is proposed to solve this problem. Numerical results show that the proposed scheme can improve the smooth spectrum handoff of the arriving primary users and the second users, as compared with the previous queuing theory strategy and channel utilization strategy.