Bandwidth-ratio-based light-tree selection in dynamic multicast traffic grooming for optical WDM mesh networks

This paper studies the dynamic multicast traffic grooming problem in optical WDM mesh networks. A key step in dynamic multicast traffic grooming is to select a subset of exiting light-trees to support a new multicast request. A number of selection rules have been used in algorithms proposed in the literature. This paper proposes to use the bandwidth usage per multicast destination called bandwidth ratio as the light-tree selection criterion and to employ a light-tree selection rule that chooses the shortest-path tree branch with the smallest bandwidth ratio. Based on the light-tree selection rule, this paper develops an effective dynamic multicast traffic grooming algorithm. A number of performance measures including request blocking ratio, bandwidth utilization factor, unnecessary bandwidth utilization factor, mean number of light-trees per accepted connection request, and computation time are used to compare the proposed algorithm with other algorithms in the literature that employ various light-tree selection rules. Simulation results show that the proposed algorithm is able to make efficient utilization of the bandwidth resource and yield significantly lower request blocking ratio.