Abstract: It is a hot topic to study the implement of network coding in Ad Hoc. But how to find out an efficient way of choosing the coding nodes has become a bottleneck of the development of network coding. This paper presents a model of network coding NCMA which combines the way of choosing the coding nodes with the routing information. It also proposes a scheme of choosing the coding nodes based on the routing information. This scheme can find out the coding nodes in a simple but efficient way during the process of data transmission. The algorithm can reduce the delay made by the process of choosing the coding nodes. NCMA makes it easier for nodes to listen to each other and can reduce the errors because of the complex transmission routes in the way of combining the traditional way of data transmission and the coding way which may control the coding benefits in the network of one-hop. The analysis shows that NCMA has characteristics of efficiency, commonality and simplicity.

Key words: Ad Hoc, network coding, Network Coding Model in Ad Hoc（NCMA）, coding node, coding algorithm

摘要： 在Ad Hoc无线网络上实现网络编码是当前网络编码研究的热点之一，如何高效地选取编码节点已经成为网络编码研究的瓶颈。提出了一个适应用Ad Hoc网络的网络编码模型NCMA，NCMA将编码节点的选取与路由紧密结合，并给出了一种基于路由的编码节点选取方案，该方案可以在数据传输过程中简单、高效地选取编码节点，编码节点选取算法可以有效地控制因编码节点选取带来的延迟；NCMA实现了传统数据传输方式和编码数据传输方式的结合，可以将编码损益控制在一个单跳网络范围内，方便于无线节点之间的侦听操作，有利于减少复杂传输路径带来的各种失误。分析表明，该模型具有效率高、通用性好、实现简单等特点。

关键词: Ad Hoc, 网络编码, Ad Hoc下的网络编码模型（NCMA）, 编码节点, 编码算法