Equilibrium Analysis for Spectrum Access in Cognitive Radio Networks with Traffic Prioritization

Spectrum access decision-making is one of critical problem of the secondary user (SU) in cognitive radio networks (CRN). Each SU has two options: either to join the CRN and get the service or to balk. This decision depends on the cost the SU may pay to get the service. In this paper, decision-making problem is investigated in presence of prioritized cognitive user traffic. We will study the decision process of low priority cognitive users in the presence of primary and high priority cognitive user. This decision-making problem is investigated using queuing analysis and game theory. An almost unobservable queuing model is proposed to represent the admission of the SU, while the game theory is used to develop optimization algorithms to address decision-making problem. Closed-form expression for average number of SUs at each queue as well as expected waiting time are derived. According to both primary user (PU) and higher priority SU's state, a mixed equilibrium balking strategies is obtained.