车载自组网网络拓扑稳定性研究

摘要:节点高速移动是车载自组网络（Vehicular Ad hoc Network VANET）区别于传统移动自组网络（Mobile Ad hoc Network MANET）的重要特征之一.寻找网络拓扑相对稳定的区域,有利于开发更加稳定的路由协议,降低节点移动对网络性能的影响.研究表明,同向行驶的车辆更容易保持网络拓扑的稳定性,路径有效时间随车辆运动方向的夹角、车辆运动速度和时间的增加而降低,仿真结果验证了结论的正确性.仿真结果还表明,车辆间的初始距离越大,网络拓扑越不稳定,这一现象的发现对开发分区型路由协议具有重要意义.
关键词:车载自组网络;拓扑;稳定性
中图分类号:TP393       文献标识码:A
Study on the Topology Stability in Vehicular Ad hoc Network
Abstract: Unlike conventional Mobile Ad hoc Network (MANET), node experiences a high mobile velocity in the Vehicular Ad hoc Network (VANET). Looking for relatively stable area in the network topology is helpful for developing more stable routing protocols and reducing the effect of nodes movement on the performance of the network. Researches find that the vehicle traveling in the same direction is easier to maintain the stability of the topology of a VANET, and the valid time of the path will decrease with the increase of the intersection angle in the direction of the vehicle movement, the vehicle movement velocity and the time. The simulation results verify the correctness of the conclusion. Besides, the simulation results also show that the bigger the initial distance among the vehicles is, the less stable the network topology is. The discovery of this phenomenon has great significance for developing zoned routing protocols.
Key words: Vehicular ad hoc Network, Topology, Stability

1.引言

车载自组网作为移动自组网的典型应用受到很多研究者的关注^[1,2,3,4],它在交通控制、交通安全、辅助驾驶和商务服务等方面具有广阔的应用前景.在车载自组网中,节点高速移动,运动轨迹被限制在道路上,网络拓扑快速变化,车辆行驶中更加关注前方道路的交通状况^[5].因此,在车载自组网络中,寻找可靠稳定的传输路径将前方道路的交通状况信息快速传递给后面的车辆是车载自组网研究的重点.节点高速移动是导致网络性能下降、限制网络规模扩展的关键因素之一^[6,7],因此最大限度地减少节点移动造成的路径中断次数,对网络性能提高具有非常重要的