中文摘要：

针对现有车联网（VANET）中数据转发效率低的问题,提出了软件定义网络（SDN）的数据转发机制。首先,设计了软件定义车联网的分层次网络模型,该模型由局部控制器和车辆组成,实现控制与数据转发分离,具有可扩展性、独行性等特点;其次,设计了车辆路由转发机制,该机制采用动态规划和二分搜索的方法,以实现高效的数据转发;最后,通过仿真验证,对比无线自组网按需平面距离向量路由（AODV）、目的节点序列距离矢量路由（DSDV）、动态源路由（DSR）和最优链路状态路由（OLSR）算法,所提的数据转发机制在传递成功比上提高大约100%,而端到端延迟时间降低大约20%。实验结果表明,软件定义车联网的数据转发机制能够提高路由转发效率、减小延迟。

英文摘要：

Since the efficiency of data forwarding in Vehicular Ad Hoc Network （VANET） is low, a data forwarding mechanism in VANET based on Software-Defined Network （SDN） was proposed. Firstly, a hierarchical architecture of SDN based VANET was designed. This architecture was consist of local controller and vehicular, it could implement the separation of control and data forwarding, and also could achieve high sealability, reliability and efficiency. Secondly, a new data forwarding mechanism was proposed, which used dynamic programming and binary search. Finally, compared with Ad Hoc On-demand Distance Vector routing （AODV）, Destination Sequenced Distance Vector routing （DSDV）, Dynamic Source Routing （DSR） and Optimized Link State Routing （OLSR） algorithm, the proposed algorithm could improve packet delivery fraction and end-to-end delay. Therein, the average increase of packet delivery fraction was about 100%, while the average reduction of end-to-end delay was about 20%. The simulation results show that the data forwarding mechanism in software- defined VANET can effectively improve the packet delivery and reduce the end-to-end delay.