车载自组织网络中AODV协议研究进展

Research progress of AODV protocol in vehicular ad hoc networks

车载自组织网络(VANET)中频繁变化的拓扑结构以及严格的实时性和可靠性要求给路由协议的设计提出了新的要求。为得出更适用于VANET的路由协议,分类阐述了主动路由协议和按需路由协议两类路由协议,并且从多方面比较目的节点序列距离矢量路由(DSDV)协议和源驱动路由(AODV)协议的性能。结果表明,AODV协议更适用于VANET环境。针对AODV协议存在的路由不稳定、传输延迟高和广播风暴问题(BSP),分类综述了常见的改进措施:对于路由不稳定问题,从借助车辆网络信息的路由选择和借助RSU的路由发现两个方面来改进;对于延迟问题,从单独改进路由搜寻过程和与其他协议相结合改进路由搜寻过程两个方面改进;对于BSP,通过控制RREQ转发和将车辆分簇来改进。最后,从路由稳定性、传输延迟和BSP三方面展望未来的研究方向。

The frequently changing topological structure and strict real-time and reliability requirements in the vehicle ad hoc network(VANET)put forward new requirements for the design of routing protocols.To get a more suitable routing protocol for VANET,two types of routing protocols,namely,active routing protocol and on-demand routing protocol,are classified,and the performances of DSDV protocol and AODV protocol are compared from many aspects,showing that AODV protocol is more suitable for VANET environment.To solve the problems of routing instability,high transmission delay and BSP in AODV protocol,the common improvement measures are summarized.For the problem of route instability,improvements can be made from the aspects of routing choice with the aid of vehicle network information and of routing discovery with the aid of RSU.For the problem of delay,improvements can be made from the aspects of improving the routing search process alone and of improving the routing search process by combining with other protocols.For BSP,improvements can be made from controlling RREQ forwarding and clustering vehicles.Further research directions of routing stability,transmission delay and BSP are finally prospected.