Multi-Channel Preemptive Priority Model for Spectrum Mobility in Cognitive Radio Networks

Abstract

Cognitive Radio techniques have been proposed for improving utilization of the spectrum by exploiting the unoccupied bands of the licensed spectrum. This paper proposes a preemptive multi-channel access model for prioritized cognitive radio networks using an iterative method of queuing theory to solve the spectrum scarcity problem. The proposed model formulates accurate closed form of an expected waiting time in the queue, an expected number of users in the queue, an expected waiting time in the system, and an expected number of users in the system. The results compared to the basic model (without preemptive priority) show that, the waiting time in queue and the waiting time in the system compared to the basic model will be improved by 92.99% and 33.15% respectively for class one secondary user. The results also show that, the waiting time in queue and the waiting time in the system will be improved by 43.25% and 15.42% respectively for class two secondary users. The proposed model investigates the desirable schedules of primary and secondary users.

Sensing schedule optimization to minimize interference with primary users in cognitive radio network

“…Accurate identification of the modulation scheme used to modulate PU signal is explored in [19]. Authors of [20] projected a preventive multi-channel access model for prioritized CR networks using queuing theory to resolve the spectrum scarcity issue. The sensing duration is altered dynamically, with reference to changing RF environment, to maximize overall throughput of a CR, is presented in [21].…”