一种低丢包率无线网络中基于网络编码的广播重传方法

Broadcasting Retransmission Approach in Lower Packets Loss Rate Wireless Networks Based on Network Coding

重传是无线网络广播传输中实现错误处理的重要技术.普通重传方法通常逐一发送丢失包来进行错误处理,这种处理在丢包分散的低丢包率无线网络上重传次数相当大.本文将网络编码减少无线传输信息量的特性应用在低丢包率无线网络广播重传中,提出一种基于网络编码的广播重传方法(BRANC).该方法按照丢失分布概率特点生成新的重传序列;采用基于多节点的网络编码方法进行丢失包组合实现重传.为达到更佳重传目的,进一步分析了编码组合包重传再丢失时的处理.数学分析表明,该方法能保证接收节点的编码可解性,同时重传次数可达到局部最优性;模拟测试结果表明:与普通重传方法相比,BRANC有效地减少了信息包的平均传输次数,提高了传输效率.

Retransmission is an important technique to ensure the error correction of wireless broadcasting transmission. Tradiional retransmission approach always sending lost packets in sequence to ensure the error correction of networks. This approach needs a great deal of transmissions in the lower packets loss rate wireless networks because of the decentralization distribution of lost packets. This paper presents a novel retransmission approach （BRANC）in lower packets loss rate wireless networks based on network coding. Firstly, retransmission packets list can be generated based on the distribution probability of lost packets. Then, lost packets is coding combined by using multi-node network coding theory ; In order to achieve optimal results, dynamically adjust combination strategy is selected and a dynamically approach is presented to reduces the number of retransmissions. Mathematic analysis reveals that our approach can ensure the solvability in the received nodes, and have optimization performance in local retransmission. Simulation results indicate that comparing with existing approach; the approach in this paper can effectively reduces the average number of transmissions and advances the transmission efficiency.