软件定义的网络(SDN)是一种数据控制分离、软件可编程的新型网络体系架构。将SDN架构应用于车辆自组织网络(VANET)将提高VANET的灵活性、可控性，优化网络数据传输性能。本课题将结合VANET的节点移动性、拓扑动态性、网络自组织性等特性，设计软件定义的VANET的数据平面和控制控制平面的组成和交互模式。在此基础上，研究基于任务调度和数据业务需求的动态QoS路由框架，并着重解决该框架下的网络链路状态实时估计、优化路径计算等问题。分析网络状态信息动态变化场景下的链路性能估计方法以及状态信息不精确性的量化和评估方法，以减少链路性能估计不准确对QoS路由性能的影响；建立多业务流多约束条件下的优化路径选择模型，以实现满足多业务流QoS需求的路由机制。研究网络流表更新一致性方案，以减轻网络流表更新的控制负载以及提高更新的效率。本课题对于提升VANET网络QoS性能有重要理论意义和应用价值。

Software defined networking (SDN) is a new programmable network architecture which separates data forwarding and control. Applying the SDN in vehicular ad hoc networks (VANET) will improve its flexibility and controllability and optimize its data transmission performance. This project will study on VANET architecture based on SDN. Considered the properties of node mobility, topology dynamics and self-organizing, the framework and interaction model of data plane and control plane are designed. On this basis, the dynamic QoS routing framework under central control is proposed. In order to reduce the estimation inaccurate effect on the performance of QoS routing, the link state estimation method under dynamic network is analyzed. The optimization path selection model under multiple flows and multiple constraints is constructed in order to meet the QoS routing demand of multiple flow. Network flow table update scheme is studied in order to achieve the update consistency, simultaneously reduce the control traffic and improve the update efficiency. This project provides new ideas and new methods to improve the quality of service in VANET network.