QoS multicast routing and transmission scheduling in multi-hop cognitive radio networks

In this paper, we discuss the issues of QoS multicast routing in multi-hop Cognitive Radio (CR) networks. The problem of our concern is: given a CR network and a QoS multicast request, how to set up a multicast connection so that the total bandwidth consumption of the multicast is minimized while the QoS requirements are met. We propose a distributed protocol which uses shortest path tree as the multicast routing tree. To minimize the bandwidth consumption, we introduce an auxiliary graph to represent timeslot assignment in the network. The slot assignment problem is then transformed into the minimum set cover problem and a heuristic method is adopted to solve it. Extensive simulations are conducted to show the performance of our proposed method.