Effect of the Spectrum Sensing Period on the TCP Performance Over Cognitive Radio Ad-hoc Networks

Modeling of spectrum occupancy by both primary and secondary users in the Cognitive Radio Ad-hoc Network (CRAHN) can be helpful to improve spectrum usage efficiency. Modelling the prioritized spectrum access policy is a significant need to analyze a CRAHN. Sensing the spectrum is a basic aspect in a CRAHN, and in the design of sensing strategies, there are some trade-off between the PU occupancy rate, throughput, and delay and energy consumption. This paper provides a Continuous-Time Markov chain (CTMC) to describe the spectrum usage by both primary and secondary users in a CRAHN that enables the evaluation of throughput and delay. The steady-state analysis is performed to analytically derive the probability of this new packet loss in CRAHN. In addition, the average end-to-end delay together with the throughput, as two main parameters of quality of service, are improved as per the modification based on the proposed CTMC model. The results derived by these parameters are compared with some well-known transport protocols. The comparison confirms the accuracy of the proposed model. The experimental results have justified the fitness of the joint analysis model in the practical environment using the NS2.