摘要： 传统无线网络编码协议在单播传输模式中较少考虑速率自适应对网络性能的改善作用,而利用RTS/CTS握手信号进行信道估计的速率自适应机制则存在开销大、网络吞吐性能差等缺陷。为此,提出一种基于网络编码的速率自适应协作介质访问控制协议RACNC。该协议使用网络编码模型和基于ACK帧的速率自适应机制,当源节点传输的原始数据帧未被成功接收时,选取中继节点对原始数据帧进行编码处理,然后转发编码数据帧,在保证数据帧可靠传输的同时减少其在网络上的传输次数。同时利用改进的ACK帧进行速率反馈,避免在估计信道质量时发送多余的RTS/CTS控制帧。仿真结果表明,与基于网络编码的NCAC-WTC协议相比,RACNC协议可有效减小平均端到端时延,提高网络吞吐量。

关键词: 无线网络, 网络编码, 协作通信, 介质访问控制协议, 速率自适应, 网络吞吐量

Abstract: Traditional wireless network coding protocols seldom consider the improvement of rate adaption on network performance in unicast transmission mode,and using RTS/CTS handshaking signal to estimate channel will generate additional overhead and decrease the throughput capacity.Aiming at these problems,this paper proposes a Rate-adaptive Cooperative Medium Access Control(MAC) Protocol Based on Network Coding(RACNC).It uses network coding model and rate-adaptive mechanism based on ACK frame.When the original data frame transmitted by the source node is not received successfully,the selected relay node will encode the original data frame and forward the encoded data frame,so as to ensure reliable transmission of data frames and reduce the number of data frames transmitted over the network.Meanwhile,it uses the modified ACK frame for rate feedback instead of sending extra RTS/CTS control frames for channel quality estimation.Simulation results show that,compared with NCAC-WTC protocol based on network coding,RACNC protocol can effectively reduce the average end-to-end time delay and improve the network throughput.

Key words: wireless network, network coding, cooperative communication, Medium Access Control(MAC) protocol, rate-adaptive, network throughput

中图分类号: 

• TP393