Abstract
We consider a carrier sense multiple access (CSMA) in an unslotted cognitive radio network with random residence time. In this system, if an arriving secondary user (SU) does not find any idle channels, then the SU either enters the back-off group or gives up its service and leaves the system. SUs in the back-off group have random mobility, so may re-access the channel after random time or go to the other network after random residence time. We model the system by 3-demensional Continuous Time Markov Chain (CTMC) and obtain the steady state probability of the system by matrix analytic method. In numerical results, we compare the performance of two systems with and without residence time of SUs. It is shown that the random mobility of SUs has an impact on the performance of SUs in cognitive radio networks.
Highlights
Advances in wireless communication systems and development of new services have significantly increased the demand for more frequency bands
We model the system by 3-demensional Continuous Time Markov Chain (CTMC) and obtain the steady state probability of the system by matrix analytic method
We analyze the system by CTMC with a level dependent QBD structure and obtain the steady state probability of the system using matrix analytic method
Summary
Advances in wireless communication systems and development of new services have significantly increased the demand for more frequency bands. Zhu et al [10] proposed and analyzed the performance of the random m-sensing scheme in unslotted cognitive radio network based on the VAC scheme. Fang et al [12] proposed and analyzed the performance of the grouped sensing scheme in unslotted cognitive radio network. These literatures all assume that the number of SU in the network is fixed. The number of SU is not fixed because of the random mobility of SUs. SUs in the network may stay current network for continue its service or leave the current network for better service at any time.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have