A MAC protocol with an improved connectivity for cognitive radio networks




This paper presents a medium access control protocol that is designed for wireless cognitive radio ad hoc networks (W-CRAHN). The cognitive radio network consists of a number of channels and a group of secondary users or subscribers. Each subscriber has access to a certain number of the available channels. The channels vary in their availability to the secondary users according to the activity of the primary users, so some channels are more common (can be accessed by a large number of subscribers) than other channels (accessed by less number of subscribers). Subscribers inside the cognitive network are connected in pairs, and each pair has a set of channels in common, so the pair can choose from a dedicated list known as the common channel list (CCL) to establish a communication link. A feature of this proposed protocol is the "random pairing algorithm" which enables each subscriber to connect to each subscriber inside the network. In this work, we show how the proposed method helps in adding more flexibility and providing more freedom to the subscribers of the network as compared of the other previously suggested methods. This results in a better quality of service offered by the network.​