Delay analysis for multiple channel access in cognitive radio networks

With the rapid development of radio technology, the problem of spectrum scarcity becomes an important area of research in the wireless communications field. Cognitive Radio (CR) technology is introduced as a solution to allow secondary (unlicensed) users to utilize the available frequency bands that are unutilized by primary (licensed) users. This feature, offered to CR users, has shown great potential for enhancing the performance of wireless networks and meeting the demands of future generation wireless applications. However, using this technology will impose several challenges influence the performance of the primary network. In this paper, the queuing system delay is studied, and a dynamic channel allocation technique for CR networks is presented. Based on multi-channel and time slotted scenario, the proposed scheme determines the optimal channel for spectrum switching. Moreover, in this paper, we discuss the interference problem caused by a simultaneous transmission of CR users and primary users. The large message segmentation subject to collision constraints is also investigated in this work. The simulation results have shown that the average delay can be reduced using the M/D/1 queuing model, which can improve the CR network performance. The proposed model is then used to evaluate the effects of the number of channels and channel utilization on the network performance.