一种高效的冗余编码Mesh流媒体覆盖网  

An Effective Redundant Coded Mesh Overlay Streaming Network

作　　者：王锐[1] 钱德沛[1,2] 朱青林[1] 刘涛[2] 栾钟治[1] 

机构地区：[1]北京航空航天大学计算机学院,北京100083 [2]西安交通大学电子与信息工程学院,西安710049

出　　处：《西安交通大学学报》2009年第10期56-60,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(60673180;90612004);国家高技术研究发展计划资助项目(2006AA01A106;2006AA01A118);科技部国际合作项目(2006DFA11080)

摘　　要：为了减小以Mesh方式传输流媒体的覆盖网络节点动态加入和退出对数据流传输稳定性的影响,建立了一种基于冗余编码的流媒体多播机制.数据源以冗余方式将数据流编码为多个等长的分支,以数据流分支作为路由和传输单位,而网络中的每个节点通过与其他节点建立邻居关系来获取所需的数据分支.在新节点加入的过程中,提出了一种高效的邻居节点选择算法,它充分利用了冗余编码特点,以此降低自身的时间复杂度.在节点失效处理的过程中,推出了一种数据分支替换机制,通过已有父节点的轮转替换可快速恢复数据传输,从而避免了传输中断问题.模拟试验表明:所提机制可以在网络抖动度小于10的范围内保证90%以上节点的传输质量,使得高冗余度的编码更好地适应高度变动的网络;在网络抖动度大于8时,冗余度在0%～33.3%范围内的编码不会显著降低网络的传输效率.The network dynamics is one of the most important factors that impact the stability of the mesh streaming networks. A streaming multicast mechanism using redundant coding is proposed to alleviate the influence to the transmission performance from dynamic nodes. The media source encodes the stream into several sub-streams with equal length redundantly, and distributes them to different successors. Each node in the network establishes the cooperative relationships with others to get the required sub-streams. A parent selection algorithm with relatively lower complexity is proposed to take full advantage of redundant coding. In case of node＇s failure, a repairing algorithm of swap-in-turn between different sources of sub-streams is proposed. The algorithm makes the best use of the current parents to ensure high continuity of steaming transmission. Simulation results show that the multicast mechanism can ensure high quality for more than 90% users when the churn rate is below 10; and the codes with higher redundant degree can adapt to more dynamic scenario; and that the codes with redundancy less than 33.3% does not significantly decrease the effective transmission rate when the churn rate is beyond 8.

关 键 词：覆盖网 流媒体 冗余编码 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]