Performance evaluation of finite-source cognitive radio networks with collision using simulation

The present paper deals with a finite-source retrial queueing system to model cognitive radio networks. Two non independent frequency bands servicing two classes of users are considered: Primary Users (PUs) and Secondary Users (SUs). PUs have preemptive priority over SUs at the licensed spectrum while Sus are served at the normal spectrum containing an orbit for the retrial users. The novelty of this work is that we introduce the server with conflict in the retrial part of the cognitive radio network. Therefore, the arriving secondary customers involve into collision with the secondary customers under service in the SUs, and both joins the orbit. We established a simulation program to model the queueing system and to obtain estimation for the basic performance measures. Since individual users mostly interested in their sojourn time in the system we analyze the impact of the service time distribution (s.t.d) on the expectation and variance of sojourn time of the PUs and SUs, respectively. For illustration various sample examples are derived and Figures are generated for better understanding.