(Multiple) Channel acquisition and contention handling mechanisms for dynamic spectrum access in a distributed system of cognitive radio networks

In dynamic spectrum access, cognitive radio networks compete with one another to acquire under-utilized and idle channels for data transmission. Each network strives to acquire as many channels as possible to satisfy its maximum channel requirement. The main goal of a network is to maximize its utility and at the same time minimize the amount of contention it experiences with other secondary networks. In this paper we focus on the study of channel acquisition and contention handling mechanisms that a system of networks can adopt to maximize utility and minimize contention. A system of networks becomes stable if all networks have acquired enough number of channels to satisfy their channel requirements without any contention between them. It is obvious that a network´s utility depends on the stability of the system and how fast the stability is attained. The mechanisms proposed in this paper ensure fast convergence of the system by minimizing the contention experienced until a state of equilibrium is finally attained. Simulation experiments were conducted taking into consideration the unpredictable behavior of the primary users who are the licensed owners of the spectrum bands.