Constructing shared-tree for group multicast with QoS constraints

Group multicast refers to the kind of multicast in which every member of a group may transmit data to the group. Several QoS-aware routing algorithms for group multicast proposed previously take into account bandwidth requirement (which is the most important QoS metric to consider for many applications) and build source-based tree for each individual group member. Per-source tree approach has some advantages over shared-tree approach but suffers the drawbacks of higher control overhead and being less scalable especially with group size. In this paper we present an algorithm which builds shared tree for group multicast and can accommodate multiple QoS requirements including bandwidth and inter-member delay. Besides the advantages of having less control overhead and better scalability, our algorithm can support dynamic membership without recomputing the whole tree. The results from simulation experiments for multicast with bandwidth reservation show that our algorithm has similar performance in terms of tree cost and bandwidth utilization compared with two other per-source tree algorithms.