摘要
YAM、QoSMIC、DSDMR等一类支持QoS的动态组播路由算法允许组播成员动态地加入和离开,同时为接收方提供多个可选择的组播接入路径,以满足不同应用的QoS需求。但这些算法普遍存在控制信令开销大和结点加入时延长,可扩展性不好等问题。本文在分析这些算法的基础上,提出改进的支持QoS的动态组播路由算法,即拓扑自适应动态组播路由(Topology Adaptive Dynamic Multicast Routing,TADMR)算法。该算法避免了以往算法中大部分盲目的路径搜索,并使结点加入时延不再受限于固定的等待时钟,而与网络拓扑相自适应。性能分析和仿真结果表明,该算法具有较低的控制信令开销和结点加入时延,适用于各种网络规模和群组规模,具有良好的可扩展性。
QoS-aware dynamic multicast routing algorithms such as YAM, QoSMIC and DSDMR allow receivers to access and leave the groups freely without breaking the existent multicast trees. They can find the most suitable path to access existent multicast trees while meeting the user抯 QoS requirements. However, they suffer from poor scalability resulting from high control overhead and access latency. Accordingly, a modified QoS-aware dynamic multicast routing algorithm named TADMR is proposed. Most of aimless searching in previous algorithms can be avoided. The access latency is no longer limited by the long waiting for responses from other nodes, but adaptive to the distance from the new member to existent multicast tree. Analysis and simulations show that this algorithm can be used to construct low cost tree similar to optimal greedy strategy with adaptation to the topology of network. Control overhead and access latency can also be reduced greatly.
出处
《电路与系统学报》
CSCD
2002年第3期1-7,共7页
Journal of Circuits and Systems
