网络编码中的侦听管理策略

摘要

For wireless unicast applications based on opportunistic network coding, each node caches some packets in a buffer called overhearing buffer for decoding.Traditional FTFO-based(First In First Out) overhearing management policy for "X" coding structure is discussed. With finite overhearing buffers, theoretical result shows that throughput decreases rapidly as the buffer size decreases. Therefore, we propose a Best Effort-based overhearing management policy, which improves the probability of cached packets to be used for decoding, and thus increases the system throughput. Furthermore, to buffer less useless packets, we propose an overhearing management policy based on historical information, which could effectively decrease the impact of interfering flows on system throughput.%在基于机会式网络编码的的无线单播应用中,每个节点需要缓存一些数据包,用来对编码数据包进行解码,该缓存称作侦听缓存.本文针对“X”型拓扑分析了传统的基于先入先出的侦听管理策略,理论结果表明侦听缓存有限时吞吐量随侦听缓存的减小而迅速降低.为此,提出了一种基于尽力服务的侦听管理策略,提高了侦听缓存中数据包被用作解码的概率,进而提高了系统吞吐量.为减少无用数据包被缓存的概率,提出了一种基于历史信息的侦听管理策略,可有效减少干扰流对系统吞吐量的影响.