中文摘要：

该文研究了基于网络编码的分层媒体多播中的层速率优化分配问题。通过优化分配层速率,最大化所有接收节点的接收速率总和。由于该问题是一个非线性整数规划的问题,该文提出了一个时间复杂度为O（｜V｜｜T｜2｜E｜2）的启发式的层速率分配算法MRAA。算法MRAA根据各接收节点的接收带宽将网络图按分层层数优化分解成子图,每个子图中各接收节点的最大流的最小值即是相应的层速率。模拟实验表明,算法MRAA相比已有算法对网络吞吐量提高15%-18%,对各接收节点的平均带宽利用率改善6%-10%。

英文摘要：

This paper focuses on layer rate allocation in network coding based layered media multicast.The sum of receiving rates of all receivers is maximized by optimizing layer rate allocation.Since it is a nonlinear integer programming,a heuristic algorithm,MRAA（M-layer Rate Allocation Algorithm）,is proposed with the time complexity O（｜ V ｜｜ T ｜2 ｜ E ｜2 ） to solve it.Algorithm MRAA decomposes the network graph into several subgraphs,and the minimum of the maximum flows of all receivers in each subgraph is the corresponding layer rate.Numerical results indicate that the algorithm MRAA can increase the network throughput by 15%-18% and improve the average bandwidth utilization rate of the receivers by 6%-10%,compared with the algorithm in the existing work.