基于网络效用最大化理论增强无线Mesh网VoIP传输性能的机制研究

无线Mesh网具有自组织、自配置、自愈合的优势，能够快速部署，易于维护，具有广阔的应用前景，但其多跳传输、无线信道开放、节点资源受限等特征导致现有的网络协议对实时业务效率较低，难以保证VoIP传输的时延、丢包率和容量要求。目前国内外研究针对该亟待解决的问题提出了一些性能增强方法，但缺乏对不同方法的系统化认识和联合使用的效果评价。本项目首先通过网络效用最大化理论建立网络优化模型来表征VoIP业务在无线Mesh网中的用户体验质量要求和传输机理；然后，对所得到的网络效用最大化模型进行问题分解，导出在无线Mesh网中的分布式求解算法和网络控制机制；在此基础上，提出适用于无线Mesh网VoIP传输的协议架构和协议实现方法。本项目拓展了网络效用最大化理论的全面性和深度，系统化地指导了增强无线Mesh网VoIP传输性能的机制和协议设计，同时开展了这些理论和技术成果在无线Mesh网中的实验验证。

The Wireless Mesh Network has the advantages of self-organizing, self-configuring, and self-healing, which enable its quick deployment, easy maintainence, and promising broad applications. However, its characteristics of multi-hop transmission, open radio channels, limited resource of network nodes cause very low efficiency for real-time services with current network protocols, and it is difficult to ensure VoIP transmission requirements on delay, packet loss rate and capacity. To deal with this urgent problem, the present domestic and overseas study has some proposals on VoIP performance enhancements, but lacks systematic understanding and evaluation of joint effects of proposed methods. By using the theory of Network Utility Maximization (NUM), this project first establishes network optimization model to characterize the Quality of Experience (QoE) of VoIP services and the transmission essence in Wireless Mesh Network. Then, the project performs problem decomposition of the established NUM model, and derives the distributed solution algorithms and network control mechanisms in Wireless Mesh Network. Next, the project proposes appropriate protocol architecture and protocol implementations for VoIP transmission in Wireless Mesh Network. This project expands the comprehensiveness and depth of the NUM theory,systematically guides the design of mechanisms and protocols to enhance the VoIP transmission performance in Wireless Mesh Network, and conducts verification of these theoretical and technical achievements with application experiments.