摘要
为增强基于应用层组播的流媒体广播性能,该文提出构建具有分层排列图结构的应用层组播系统。在该结构中,参与主机组合成多个排列图,每一个排列图中嵌入多个独立组播树;排列图间形成树状结构,对应组播树相互衔接并保证独立性。流媒体数据采用多描述编码(MDC),每一描述数据通过一个独立的组播树传输,使得单个主机故障至多影响一个数据流,以提高系统流媒体服务的稳定性。实验表明,在节点故障率为5%时,分层排列图结构的容错能力与传统随机多组播树结构相比提高20%以上。利用拓扑测量技术,分层排列图结构将参与主机根据相互距离进行聚类,以提高系统的传输效率。
A fault-tolerant system, the hierarchical arrangement graph (HAG), was developed for application layer multicast to support streaming media service. In HAG, the hosts are grouped into many arrangement graphs, with these arrangement graphs assembled into a tree structure. Independent multicast trees can be embedded into HAG to deliver different descriptions of the MDC media streaming. With HAG, a single host failure disrupts only one multicast tree, without affecting the data delivery in the other multicast trees which improves media delivery fault-tolerance. Simulation results show that HAG achieves up to 20% improvement of the average received bitrate compared with the traditional multicast strategy with a 5% host failure probability. In addition, HAG can cluster adjacent hosts into the same arrangement graph to improve the data delivery efficiency.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第4期493-497,共5页
Journal of Tsinghua University(Science and Technology)
