Online multicast tree construction with bandwidth and delay constraints in multi-channel multi-radio wireless mesh networks

This paper deals with online QoS multicast tree construction problem, which is essential to support multimedia services, in multi-channel multi-radio wireless mesh networks. The proposed algorithm satisfies both delay and bandwidth requirements of each arrived session. It breaks down the original problem into two phases of satisfying delay and bandwidth constraints. The first phase devotes to preserving delay constraint of the arrived session, in which a number of delay-bounded paths are determined between each receiver and the source node. In the proposed scheme, to diminish the utilized bandwidth, the overlapping of the regarding paths of the receivers is maximized as much as possible. We propose a mathematical model to satisfy bandwidth requirement in the second phase, which constructs the tree over the selected paths. The data transmission rate on the tree is set to the requested rate by the session, to satisfy its bandwidth requirement. The proposed model has a global view over the network and constructs the most appropriate trees. It also exploits wireless broadcast advantage property to enhance the performance. Through extensive simulations, the effectiveness of the proposed algorithm is verified. In particular, it improves the acceptance rate by 60% compared to previous schemes.