Link Maintenance Probability for Pool based Spectrum Handoff in Cognitive Radio Networks

Cognitive Radio (CR) is an emerging technology which proposes to solve the spectrum inefficiency problem in licensed spectrum band via dynamic spectrum access (DSA). Spectrum handoff plays a major role in DSA to ensure the seamless and robust service of the cognitive user (CU) in order to maintain the quality of service of the CR network. This paper presents an analytical model of pool based spectrum handoff process under heterogeneous environment (HetSE) of two different licensed spectrum pools (LSPs). We model link maintenance probability and link failure probability in both opportunistic and negotiated situations considering a waiting threshold period (D
th
) for a CU. The propose model offers higher link maintenance probability under opportunistic situation as compared to negotiated situation. This work also presents the impact of D
th
on the performance measuring metrics and results show that the model with longer D
th
offers higher link maintenance and lower link failure probabilities for a CU under HetSE of LSPs.