A Novel Approach to Real Time Spectrum Handoff

Cognitive radio (CR) can significantly improve spectrum efficiency by allowing the secondary users to temporarily access the primary user’s under-utilized licensed spectrum. Spectrum mobility issues arise when the primary user appears at the channels being occupied by the secondary users. The secondary users return to the occupied channel because the primary users have the preemptive priority to access channels. Spectrum handoff technique can help the interrupted secondary user to vacate the occupied licensed channel and find a suitable target channel to resume its unfinished data transmission. Preemptive resume priority (PRP) M/G/1 queuing network model characterizes the spectrum usage behaviors of the connection-based multiple channel spectrum handoffs. The proposed model derives the closed-form expression for the extended data delivery time of different proactive designed target channel sequences under various traffic arrival rates and service time distributions. The analytical method analyzes the latency performance of spectrum handoffs based on the target channel sequences specified in the IEEE 802.22 wireless regional area networks standards. We also suggest a traffic-adaptive target channel selection principle for spectrum handoffs under different traffic conditions. KeywordsCognitive radio, Spectrum handoff, PRP, M/G/1 queuing model, WRAN, Primary user, Secondary