无线多跳网络中网络编码感知的机会转发机制

摘要

A network coding-aware opportunistic forwarding（NCAOF） mechanism was proposed to overcome the defects of COPE with passive coding.Taking advantage of broadcast characteristic of wireless channel,NCAOF combines the features of opportunistic forwarding and network coding.Compared with traditional methods using predetermined route forwarding mechanism,NCAOF can create more coding opportunities.In delivering packets process,the intermediate node employs the defined coding gain function to evaluate how much the opportunistic coding gain can be obtained if some packets are coded together.Then some packets are selected to encode together based on the computed coding gain,dynamically and intelligently.NCAOF assigns a higher dynamic priority according to coding gain function to forwarding the encoded packets than the native packets.The simulation results show that NCAOF can achieve a remarkable improvement in terms of the network throughput and packet delivery fraction for delivering packets in wireless multi-hop networks.%提出一种适用于无线多跳网络的网络编码感知的机会转发机制（NCAOF,Network Coding-Aware Opportunistic Forwarding）.NCAOF利用无线信道的广播特性,结合机会转发和网络编码,动态确定有编码机会的节点进行编码后机会转发,从而比传统的采用预定节点的转发机制获得更多编码机会.分组转发过程中,中间节点考虑局部拓扑信息及自身负载情况,通过定义的编码收益函数评估节点的机会转发效能,动态选择能获取编码性能更好的分组进行机会编码,并基于编码收益赋以编码分组动态的转发优先级,有效利用编码机会同时避免冗余转发.实验结果表明,相比传统的基于网络编码的转发机制,NCAOF能获得更好的编码机会,并有效提高了网络的吞吐量和分组送达率.