Joint interference optimization and user satisfaction improvement for multicast routing and channel assignment in wireless mesh networks

Multicast communication is a key technology for wireless mesh networks. In order to reduce co-channel interference in multicast transmission, we jointly study multicast tree construction and channel assignment in this paper. First, interference in multicast is analyzed and measured with considerations of hidden node problem and user coverage. Then, an algorithm called CIOMT is proposed to construct multicast routing tree, In which we find the path with minimum interference to root and add it to the constructing multicast tree, give an upper limit to the source-to-destination distance for QoS consideration, and tree structure is optimized to relieve interference among multicast links. Moreover, we propose a channel assignment algorithm for the constructed multicast tree with the name CIOCA. In CIOCA algorithm, in order to provide good service to the users as much as possible, we take the user coverage of each destination as the top priority in channel assignment, and the nodes are assigned the sending channels by descending order of priority. In each step, we find the channel with minimum interference to the whole tree, and assign it to the related nodes. For making full use of spectrum resources, the non-overlapping and overlapping channels are both taken into consideration. At last, simulation is done, and the results show the effectivity of the proposed multicast routing scheme. As far as user satisfaction is concerned, the proposed scheme has much better performance than the other two classic algorithms.