城市道路混合路由算法研究

针对城市道路中车辆密度突变而导致车联网系统的信息冗余和数据丢失等问题，提出了一种基于贪婪转发（GPSR）和距离矢量转发（AODV）的自适应限制性混合路由算法（ARHP），以适应网络环境的高速变化。ARHP将通信网络分为贪婪转发、贪婪-距离矢量转发、距离矢量转发3种模式。通过对有效节点密度和网络状态进行实时评估，可实现转发模式间的切换；通过考察链路质量和端到端的时延性能择优选取邻域节点。采用交通模拟器和离散事件模拟器比较ARHP、AODV和GPSR在改变节点密度或车辆速度时的性能表现，结果表明ARHP在数据包的投递率和端到端的时延性能等方面均优于AODV和GPSR。

Research on Urban Hybrid Routing Algorithm

In view of such flaws as information redundancy and data loss of vehicle networking system due to a sudden change of vehicle density in urban roads, an adaptive restrictive hybrid routing algorithm (ARHP) based on greedy forwarding (GPSR) and distance vector forwarding (AODV) is proposed to adapt to the rapid change of network environment. As a routing algorithm that combines the greedy forwarding and distance vector forwarding together, ARHP divides the communication network into three modes: greedy forwarding, greedy-distance vector forwarding, and distance vector forwarding. Switching between forwarding modes can be realized based on real-time evaluation of effective node density and network status; meanwhile, a preferable choice can be made of the neighbor nodes by examining the link quality and end-to-end delay performance. Traffic simulator and discrete event simulator are used to compare the performance of ARHP with AODV and GPSR with node density or vehicle speed changed. The results show that ARHP is superior to AODV and GPSR in terms of packet delivery rate and end-to-end delay performance.