Measurement of the Performance of Cognitive Radio Spectrum Handoff

The novelty of this work lies in the fact that we consider the effect of retrial phenomenon of SUs in performance modeling of radio frequency licensing by using queuing models which takes the unreliability of radio transmission into account. It is focusing on the Priority Queuing Systems. Simulate network traffic is used with MATLAB simulator environment in order to obtain the reduction of the network congestion using queuing theory. A mixed queuing network model has been adopted in order to illustrate a Preemptive Resume Priority (PRP) M/M/C queuing in the licensed spectrum band and the M/M/C retrial queuing in the unlicensed spectrum bands. The simulation was performed using M/M/c models of queue theory. The results observed the dependences of the number of customers in the queue on time and show the Priority queue behaves in unlicensed band. The simulation results illustrated the reduction of the network congestion and the increasing of network performance in the proposed model. Moreover, the performance of the scheme under different scenarios and various parameters such as total delay and channel utilization has been investigated.