Abstract
At first, we study the multicast routing problem considering both cost minimization and fulfillment of QoS requirements in terms of the end-to-end delay. Secondly, for the scenario of a single link failure, we investigate the backup paths planning problem also considering both cost minimization and delay fulfillment. Thirdly, we discuss the bandwidth issues related to the routing problems. The bandwidth allocation about estimating the bandwidth requirement of the traffic is discussed. Furthermore, when multiple multicast sessions occur simultaneously, the problems of constructing a set of multicast trees are also discussed. Tabu Search (TS) approach is applied to solve both the QoS-based multicast routing and QoS-based backup path planning problems. According to the path restoration scheme, a TS algorithm is proposed to determine the optimal or near optimal delay-constrained backup paths. Based on the link, subtree, and tree restoration schemes, four delay label heuristic algorithms are proposed to minimize the total cost of all the backup paths with the satisfaction in end-to-end delay constraint for all the cases of a single link failure. Additionally, the bandwidth allocation process model is proposed to allocate the adequate amount of bandwidth to the traffic. When multiple multicast sessions occur simultaneously, the mathematical model is formulated for the delay-constrained multicast tree packing problem. The possible solution procedures and key issues are suggested in the development of the efficient algorithm.