本项目针对无线网络中异构终端接入速率具有多样性这一实际情况，拟通过多速率网络编码技术实现多媒体信息组播传输的速率分配。从而满足不同终端的速率需求，增加传输吞吐量，提升用户体验。. 本项目面向应用需求，研究内容涵盖多速率网络编码研究的四个层面：一是对分析模型的研究，通过求解模型的优化解获得多媒体数据传输的速率分配方案；二是针对MRC（多分辨率）方案，设计多速率网络编码方案的启发式构造算法；三是对多速率网络编码的性能进行优化，拟通过设计确定性多速率网络编码算法来实现优化；四是基于多速率网络编码技术的实际应用，本项目拟在WiFi网络下实现一套基于该技术的多终端实时视频会议系统。. 本项目的研究成果可以广泛应用于多媒体信息分发，网络视频会议，多媒体数据分布式存储等方面，并丰富网络编码在无线异构网络中应用的理论和方法。

For the access rates of different wireless terminals are often different in practical applications, this project tries to implement the rate allocation scheme for multimedia information multicast by using multi-rate network coding. Thereby, the rate demand of the different terminals could be satisfied, and the transmission throughput could be increased, as well as the user experience..This is an application-oriented project, and the research content covers four aspects of multi-rate network coding: firstly, we study the analysis model, and obtain the rate allocation scheme by calculating the optimal solution of the model; secondly, we design heuristic algorithms to obtain the multi-rate network coding approach for MRC scheme; thirdly, we study the performance optimization of multi-rate network coding, we try to achieve this goal by designing deterministic multi-rate network coding algorithm; fourthly, we study the practical application of multi-rate network coding, and we will implement a multi-terminal real-time video conference system based on this technology in WiFi networks..The research results of this project can be widely used in the distribution of multimedia information, network video conference, distributed storage of multimedia data and so on. Moreover, the results can enrich the theory and method of network coding in wireless heterogeneous networks.