非同步傳輸模式網路環境中供多媒體通訊之機率式動態多點播送路由安排方法

Abstract

In this thesis, we propose a dynamic multicast routing algorithm based on {\em probability} formultimedia communications in an Asynchronous Transfer Mode (ATM) networkenvironment. In the immediate future, the provision of multicast in ATM networks will be necessary to achieve multimediacommunications. Due to the connection-oriented characteristic of ATM networksand the real-time requirement of multimedia communications, we must guarantee that a connection path can not be modified during the transmission period and the transmission delayshould be within the preset threshold.For multimedia communications, we not only arrange a transmission pathwith the minimal cost from a source node to each destination node,but also consider the dynamic multicast situation with node joining/leaving.To meet the above requirements, we develop a newmethod based on the probability of each node being truncated from the multicast connection tree, such that we could arrange a better path for a new joining node in a way to reduce the impact of leaving requests by other nodes in the multicast connection tree. The main contribution of this thesis is providing a newand efficient dynamic multicast routing algorithm for multimedia communications whichkeeps the whole multicast connection tree near optimal in terms of {\em costinefficiency} and guaranteesthe transmission delay less than the preset bounded end-to-end delay. Simulation results show that under various sizes of network and request, thecost of the multicast connection tree constructed by our approach is less than that by the greedy algorithm and the weighted greedy algorithm, respectively.