基于网络编码的多射频Mesh网组播时延建模与分析  

Modeling and Analysis of Multicast Delay in Network Coding-Based Multi-Radio Wireless Mesh Networks

作　　者：王维[1] 杨明[1] 罗军舟[1] 吴文甲[1] 

机构地区：[1]东南大学计算机科学与工程学院,南京211189

出　　处：《计算机研究与发展》2012年第6期1174-1184,共11页Journal of Computer Research and Development

基　　金：国家"九七三"重点基础研究发展计划基金项目(2010CB328104);国家自然科学基金项目(60903162;60903161;61070161;61003257);国家科技支撑计划基金项目(2010BAI88B03);高等学校博士学科点专项科研基金项目(20110092130002);江苏省自然科学基金重点项目(BK2008030);江苏省网络与信息安全重点实验室基金项目(BM2003201);计算机网络与信息集成教育部重点实验室基金项目(93K-9)

摘　　要：网络编码在提高多射频无线Mesh网组播吞吐量的同时也增加了组播传输时延.针对该问题,在建模分析基于网络编码的多射频无线Mesh网组播传输时延特征的基础上,设计了平均组播传输时延(AMTD)的计算方法并给出时延整体优化方案.首先提出1个由双排队系统串联构成的多射频组播模型.其次,运用该模型对组播传输时延特征进行分析,通过计算每个排队系统平均等待时间之和给出AMTD计算公式,得到时延与各网络参数之间的量化关系.最后通过理论分析和仿真实验指明如何调整多个网络参数以优化平均组播传输时延.结果表明,网络状态确定时,同样的射频比例在不同网络编码体积下未必总是最优,应用提出的AMTD公式恰当调整射频用于收?发的比值,可以最优化平均组播传输时延.Network coding greatly improves the throughput in multi-radio wireless mesh networks （MR-WMNs）, however, it also increases the multicast transmission delay due to packets buffering during the coding/decoding procedure. In order to optimize multicast transmission delay, it is crucial to quantitatively analyze key parameters affecting the performance of WMNs. An average multicast transmission delay （AMTD） optimization scheme is proposed based on modeling and analysis of MR- WMN multicast transmission delay using network coding. Firstly, we propose a multi-radio rnulticast model consisting of M/M/Nr and GI/GI/1 queueing systems in tandem. Secondly, we analyze the features of multicast transmission delay based on the proposed model, and obtain the quantitative relationship between AMTD and network parameters by computing the sum of average waiting time of two queueing systems. Finally, theoretical analysis and simulation results show that the parameters among network load intensity, channel quality, multicast group size, network coding size and RF allocation ratio, can be used to optimize the average multicast transmission delay. The conclusion is given that the best ratio with lowest delay may not still hold within different network coding sizes for a given network and the average multicast transmission delay optimization can be achieved by adjusting RF receive/send ratio suggested by the AMTD formula.

关 键 词：射频分配 组播 时延优化 网络编码 多射频无线Mesh网 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]