摘要
大量研究分析表明,退避机制和竞争窗口的优化设计能够改善IEEE 802.11 DCF MAC协议的性能。结合无人机编队和卫星编队自组织分布协同应用场景,给出了基于IEEE 802.11DCF MAC协议的优化改进机制:DCF/CCW。该机制改变IEEE 802.11 DCF MAC协议中根据MAC帧的多次碰撞以确定竞争窗口值的方法,通过监控信道获得系统中竞争节点数目,使用最优常数竞争窗口,从而减少碰撞机率,获得网络性能的提高。该机制具有一定的拓扑适应性,当网络结构发生变化时,监控信道获得的系统竞争节点数随之变化,从而可动态调整最优常数竞争窗口。对该机制下的系统吞吐量和接入时延的分析结果显示:网络规模一定时,系统吞吐量受竞争窗口大小的影响较大,而系统平均接入时延的影响较小。该机制对提高和完善编队协同网络的通信性能具有一定的意义。
A lot of research result indicate optimization design of backoff mechanism and contention window can improve performance of IEEE802.11 DCF MAC. Based on the formation of small UAVs, the information flying satellites and IEEE802.11, an optimized MAC mechanism was proposed： DCF/CCW. A station estimated the number of competing terminals through monitoring the channel, and used constant contention window. This mechanism is of topology, the system contention code obtained from monitoring channel changes with network configuration. Thereby it can adjust optimal constant contention window dynamically. The analysis results indicate when network scale is definited, system throughput have more effect on contention window, and less effect on system access delay. The optimized mechanism can develop and improve the communication performances of the cooperative network.
出处
《空军工程大学学报（自然科学版）》
CSCD
北大核心
2009年第1期56-59,共4页
Journal of Air Force Engineering University(Natural Science Edition)
