中文摘要：

提出一种以树状拓扑为主干，Mesh状拓扑为辅助的组播策略．首先定义严格单源树状拓扑，并根据普适环境下结点的自治性行为提出放松单源树状拓扑．其次分析树状拓扑动态性带来的带宽瓶颈问题．通过Mesh状辅助拓扑和结点带宽使用情况动态调整结点状态，实现了自适应的带宽使用策略，保证了较高的使用率和可用性．分析模拟结果表明，与现有的方法相比，该策略能够取得较好的组播性能．

英文摘要：

This paper presents an application-level multicast using a tree-bone overlay and an auxiliary mesh. We firstly define the strictly simple resource tree-based overlay, and then propose the relaxed simple resource tree-based overlay according to the observation of self-contained performance of peers in pervasive environment. Next we analyze the churn of tree-based overlay and the resulting issue of bandwidth bottleneck. With an auxiliary mesh and state transitions based on the dynamic size of bandwidth, we design an adaptive bandwidth slrategy which enables the multicast better bandwidth utilization and usability. Experimental results show that the application-level multicast achieves a good performance.