Analysis and Modeling of the TDMA Protocol in Cognitive Radio Using Queueing Theory

In this work, we studied spectrum access modeling in cognitive radio networks using the TDMA (Time Division Multiple Access) protocol. Given the scarcity of spectrum, we considered cognitive radio as a solution enabling secondary users to dynamically exploit free bands without interfering with primary users. We modelled this behaviour using an M/M(a,b)/1 queuing system with delayed vacations and switching states, represented by a continuous-time Markov chain. This modelling enabled us to analyse the organisation of the service as a function of the number of customers present and the availability of the channel. We established the equilibrium equations for the system in order to evaluate various performance indicators, in particular the average number of customers waiting or in service. We then developed numerical applications in Python to analyse the impact of the model’s parameters on the system’s overall performance.