Selective Broadcasting in Multi-Hop Cognitive Radio Networks

Cognitive networks enable efficient sharing of the radio spectrum. Control signals used to setup a communication are broadcast to the neighbors in their respective channels of operation. But since the number of channels in a cognitive network is potentially large, broadcasting control information over all channels will cause a large delay in setting up the communication. Thus, exchanging control information is a critical issue in cognitive radio networks. This paper deals with selective broadcasting in multi-hop cognitive radio networks in which, control information is transmitted over pre-selected set of channels. We introduce the concept of neighbor graphs and minimal neighbor graphs to derive the essential set of channels for transmission. It is shown through simulations that selective broadcasting reduces the delay in disseminating control information and yet assures successful transmission of information to all its neighbors. It is also demonstrated that selective broadcasting reduces redundancy in control information and hence reduces network traffic.