TPSH: A Novel Spectrum Handoff Approach Based on Time Estimation in Dynamic Spectrum Networks

Cognitive Radio technology improves spectrum utilization by enabling secondary users to access primary user´s unutilized spectrum in an opportunistic manner. However, it causes disruptions to both primary and secondary communication and leads to high switching overhead. In this paper, we propose a novel proactive spectrum handoff approach based on time estimation(TPSH) to reduce the communication disruptions to primary users and increase the channel utilization efficiency. Secondary users utilize past channel histories to maintain an estimation vector of the channel remaining idle period and make predictions on future spectrum availability, and then schedule the channel usage in advance. We propose a smart channel selection and switching algorithm to implement above approach. In addition, a threshold is introduced when handoff happens to maintain a tradeoff between the disruption effects on primary users and channel efficiency. Simulation results show that our approach can significantly reduce the communication disruption to primary user by up to 32%, and improve the overall channel efficiency by about 7%-18%.