Algorithms For Multicast And Group Multicast Routing In Computer Communication Networks

With fast development of computer networks, the functions of networks arestrengthened increasingly and developed from simple transmission to many real-timeapplications. Multicast and group multicast are the key of supporting these multimediaapplications. Multicast routing is a network-layer function that constructs paths alongwhich data pachets from a source are distributed to reach many, but not all, destinationsin a communication network, A fundamental issue in multicast communication is how todetermine an efficient message route (multicast routing). Tree construction is acommonly used approach in solving the multicast and group multicast routing problem.This paper centers on the algorithms to construct low cost multicast routing trees withQoS requirements. Now, researches on multicast routing algorithm mainly focus on multicastingalgorithm without constraints, delay-constrained and bandwidth reserved multicastrouting. In this thesis, firstly, the theory on multicast is introduced. Secondly, a researchis made on algorithm satisfying multiple constraints and an adaptive and reliablealgorithm satisfying QoS for multicast is proposed. It overcomes the shortcoming of theexistent algorithms. As a result, it effectively reduces the transmission of informationand the delay of propagation. Its time complexity is Ο(m D logn) . Thirdly, the groupmulticast routing problem with bandwidth constrained is studied, three heuristicalgorithms for group multicast routing are presented. The former two group multicastalgorithms are the improvement of GTM algorithm. Simulation results show that ouralgorithms performed better in terms of cost compared with GTM algorithm and havethe same time complexity Ο(p3n2) . At the same time, a fast heuristic algorithm ofmimimum cost tree with delay constraint are presented, its time complexity is Ο(pn2) .