车载自组织网络的竞争窗口自适应退避算法  

Adaptive backoff algorithm of competitive window in vehicle ad hoc networks

作　　者：张显飞 赵一帆 高明虎 姚应东 周思达 Zhang Xianfei;Zhao Yifan;Gao Minghu;Yao Yingdong;Zhou Sida(School of Electrical and Information Technology,Yunnan Minzu University,Kunming 650000,China;Institute of Unmanned Autonomous System,Yunnan Minzu University,Kunming 650000,China)

机构地区：[1]云南民族大学电气信息工程学院,昆明650000 [2]云南民族大学无人自主系统研究院,昆明650000

出　　处：《电子测量技术》2023年第17期43-50,共8页Electronic Measurement Technology

基　　金：国家自然科学基金(62063035)项目资助。

摘　　要：随机多址接入协议对于保障车载自组织网络的服务质量(QoS)至关重要。由于该网络中车辆节点的高速移动特性使得网络拓扑变化频繁,固定的媒体接入控制协议机制会限制高动态自组织网络的整体服务质量。本文针对该问题,在CSMA/CA系列协议退避算法基础上,提出了一种基于车辆节点密度、信道占用因子和冲突门限的竞争窗口自适应退避算法(NCW-COCT)。首先,为使冲突概率最小化,以车辆节点密度和竞争窗口值为基础建立一维马尔可夫模型进而构造目标函数;其次,提出信道占用因子并结合最优冲突门限值,实现以车载自组织网络通信服务质量最优化为目标的竞争窗口自适应退避。仿真结果表明,NCW-COCT算法与同类的DCW算法和IM-BEB算法进行比较,吞吐量性能分别提升了11.64%和6.77%,丢包率分别降低了19.46%和13.29%。The random multiple access protocol is of great significance to the quality of service(QoS)of the vehicular ad hoc networks.Due to the high-speed mobility of the vehicle nodes in the network,the network topology changes frequently.The fixed media access control protocol will limit the overall QoS of the high-dynamic ad hoc network.In order to solve this problem,based on the CSMA/CA series protocol backoff algorithm,a competitive window adaptive backoff algorithm(NCW-COCT)is proposed,which is based on vehicle node density,channel occupancy factor and collision threshold.Firstly,in order to minimize the collision probability,a one-dimensional Markov model is established based on the vehicle node density and the competition window value,and then the objective function is constructed.Then,the channel occupation factor and the optimal conflict threshold are proposed to realize adaptive backoff of the competition window aiming at optimizing the communication quality of vehicular ad hoc networks.Simulation results show that NCW-COCT is compared with similar DCW algorithm and IM-BEB algorithm,the throughput performance is improved by an average of 11.64%and 6.77%;the packet loss rate performance is reduced by an average of 19.46%and 13.29%respectively.

关 键 词：车载自组织网络 CSMA/CA协议 退避算法 竞争窗口 马尔可夫模型 

分 类 号：TN92[电子电信—通信与信息系统]