Performance analysis of cognitive wireless retrial queueing networks with admission control for secondary users

ABSTRACT This paper designs and analyzes a novel single-channel cognitive radio retrial queueing network wherein a waiting line buffer is deployed for secondary users (SUs). A finite source system generates the primary users (PUs). Apart from these, PUs having preemptive priority over SUs, the effect of retrial/repeated attempts of PUs is taken into consideration. In such a system, the stability condition and the joint steady-state probability distribution of PUs and SUs are studied by using the matrix-analytic method. Several performance metrics of interest, such as blocking probability, throughput, mean waiting time, etc., have been determined. The first-passage time to reach a congestion level in the SUs waiting line buffer and its related characteristics are investigated by employing the first-step principle. In addition, correlation coefficients for various events of SUs and PUs during this period have been assessed. Finally, extensive numerical results are presented graphically for the system insights.