支持流媒体的应用层组播研究

Research of Application Level Multicast for Streaming Media

在当前没有IP组播支持以及大多数端主机访问带宽有限的Internet网络条件下,普通的端主机提供实时流媒体应用服务缺乏有效的通信手段,应用层组播是解决这一问题的有效通信技术。针对网络电视、视频点播类型的大规模实时流媒体应用,本文提出一个两层应用层组播框架结构ALMF,并对其中组播服务结点覆盖网络的构建和维护进行了研究,提出了一个覆盖网络路由组播模型MOSSMRM和基于智能蚁群的路由算法IACSMR,随后将该路由算法和几种启发式算法进行了比较。仿真实验结果表明,IACSMR算法是一个有效的应用层组播路由算法。

Because most of end hosts in today＇s Internet have limited access bandwidth and the Internet does not support IP multicast, a general end host can hardly provide service of real time streaming media applications. Application layer multicast is a novel communication method to solve this problem. The paper puts forward a two-tier application layer multicast framework for large-scale real time streaming media applications such as IPTV and VOD. Then how to construct and maintain overlay network between multicast service nodes is discussed. After that an application level multicast routing mode for overlay network and a routing algorithm based on intelligence ant colony are devised. A simulation experiment compared the routing algorithm with some other heuristic algorithms and the result shows that the routing algorithm is efficient.