【摘要】 层间等级网络编码是一种联合利用信源分层编码与组播间线性网络编码优势的多速率线性网络编码技术。与分层组播网络编码相比,层间等级网络编码能够进一步提高异构信宿网络的资源利用效率。然而,网络中各链路上进行的编码类型,是影响层间等级网络编码多速率传输性能的决定性因素。本文面向单信源异构信宿网络,研究层间等级网络编码的优化;基于微分进化算法,提出了一种最优编码类型配置的快速搜索方案。该方案充分体现了信源输出链路上进行的层间等级网络编码对整个网络传输性能的影响;具体设计了符合层间等级网络编码本质特性的微分进化操作。实验结果表明,与现有的启发式算法相比,本文提出的基于微分进化算法的层间等级网络编码优化方案,能够为单信源异构信宿网络获得更高的网络总吞吐量。更多还原

【Abstract】 Inter-layer hierarchical network code is a special type of multi-rate linear network code, which combines the advantages of layered source code and inter-session linear network code. Compared to the layered multicast network code, inter-layer hierarchical network code can take higher utilities of the network resources. The optimization of the code types’ allocation for the interlayer hierarchical network code in the single-source heterogeneous-receivers network is investigate in this paper. Based on the differential evolution algorithm, a fast searching strategy is proposed. This strategy emphasizes the optimization of the code types on the outgoing links of the source node. All evolutional processes are designed according to the special characteristics of inter-layer hierarchical network code. Simulation results show that higher network throughputs can be achieved by the inter-layer hierarchical network code with the optimization strategy proposed in this paper, compared to the existing heuristic method.更多还原