| Popis: |
Primary users' activity in cognitive radio networks (CRNs) affects the performance of a cognitive radio (CR) node in the terms of delay and backlog. The delay overhead of CR nodes has great impact on the performance and delay-based quality of service (QoS) of network protocols in CRNs. In this study, we propose two queuing systems of MlM/1 and MIMIC with PU-based breakdowns for a single-channel and multichannel CR node, respectively. The mean delay and backlog of the CR node are analyzed in the queuing systems with finite and infinite queue capacities as a function of the mean arrival, the service rates of the CR node, the mean entrance and departure rates of primary user, channel number and queue capacity. Finally, the proposed models are verified through several simulation experiments and some performance analysis are presented. |
