Analysis on the transmission delay of priority-based secondary users in cognitive radio networks

In this paper, we employ the preemptive resume priority (PRP) M/M/1 queuing model to analyze the transmission delay of priority-based secondary users (SUs) in the opportunistic spectrum access (OSA)-based cognitive radio networks (CRNs). The SUs in the OSA-based CRNs are with different priority levels. The SU with the high priority level can access a channel in preference to the low priority level SU when the channel is available. Moreover, to reduce the transmission delay of the interrupted SUs, the interrupted SUs are assigned the higher priority than the newly arrived SUs with the same priority level. The expression of the transmission delay for the interrupted SUs is derived based on the PRP M/M/1 queuing model. Simulation results show that the queuing model with priority-based SUs can effectively guarantee the quality of service of the high priority level SUs and reduce the overall transmission delay of the interrupted SUs.