Analysis of Preemptive Resume Priority and Non Preemptive Priority Access of Secondary Users with Opportunistic Perspective in Cognitive Radio Networks

摘要

This paper analyses preemptive and non preemptive opportunistic spectrum access of secondary user in cognitive radio network (CRN) using M/D/1 analytical queuing model. Secondary users opportunistically access the spectrum of primary user if the channel is free. For preemptive priority high priority packet preempt a low priority packet and for non preemptive a high priority packet does not preempt a low priority packet instead it waits at head of line (HOL) until channel becomes free. Preempting a Secondary packet and not preempting a secondary packet has effect on packet waiting time and revenue collected from SUs for spectrum sharing. Through spectrum sharing spectrum owner tries to generate more revenue whereas SUs tries to maximize their satisfaction. Numerical illustration is presented using utility function to determine upper and lower boundary of primary arrivals for both preemptive and non preemptive. By using boundaries Optimal secondary packet arrival rates are derived .Analytical results demonstrate that the preemptive priority allow many Secondary packets to be transmitted in short time and in case of non preemptive priority the transmitting secondary packet uses short time but transmitting probability of secondary packet waiting in queue to get a channel becomes very low.