Primary receiver-aware opportunistic broadcasting in cognitive radio ad hoc networks

Broadcasting is an important operation in wireless networks, as well as in cognitive radio (CR) networks. The operation of most network protocols in ad hoc networks depends on broadcasting control information among nodes. In traditional ad hoc networks, due to uniform channel availability, broadcasting is easily implemented as all nodes can be tuned to a single common channel. However, broadcast in cognitive radio ad hoc networks is a much more challenging task. The complexity emerges from the fact that harmful interference with the transmissions of primary users (PUs) must be avoided. In this paper, we propose a fully-distributed broadcast protocol for cognitive radio ad hoc networks that alleviates the interference collision risk to the PU communications, explicitly protect primary receivers that are not detected during spectrum sensing and provides a high successful broadcast ratio. Furthermore, we consider practical scenarios in our design where no global network topology is known or no common control channel is assumed to exist. A key novelty of this work is the formulation of the broadcast issue from the viewpoint of protecting PU-receivers, which is a distinctive feature in CR networks.