基于锚节点的车载网地理路由算法

Geographic routing algorithm based on anchor nodes in vehicular network

车载网络存在节点移动速度快、拓扑结构变化迅速等特点,直接利用全球定位系统(GPS)进行定位存在误差大和路由连通率低等问题。因此现有的基于地理位置的路由算法包递率不高,无法提供可靠路由。提出一种基于锚节点的车载网地理路由算法(GRAN),利用城市路灯作为锚节点,车辆通过锚节点定位自身位置,结合道路网关及中心数据,建立分层次的路由结构。通过这种方式,GRAN去除了路由发现过程及全网广播,达到降低路由开销、提高路由效率和包递率的目的。利用NS-2软件,选取接近现实的城市场景仿真。实验结果证明,与典型的基于地理位置的路由协议如贪婪转发与周边转发相结合的无状态路由(GPSR)和图形源路由(GSR)协议相比,GRAN能以较低的负荷提供较低的平均时延、较高的包递率和吞吐量。

Vehicular network has the following characteristics such as nodes moving fast, topology changing rapidly. The direct use of Global Positioning System （GPS） devices causes large positioning error and low routing connectivity rate. Therefore, the packet delivery rate of the existing location-based routing algorithm is not high enough to provide reliable routing. A geographic routing algorithm based on anchor node in vehicle networks named Geographic Routing based on Anchor Nodes （GRAN） was proposed. Using street lamps as anchor nodes, a vehicle could locate itself through the anchor nodes. Combined with the road gateway and the central data, GRAN established a hierarchical routing structure, thus removing the steps of route discovery and the whole network broadcast. Thus, the routing overhead was reduced and the routing efficiency and the packet delivery rate were improved. By using the NS-2 software and selecting a realistic urban scene, a simulation was conducted on Greedy Perimeter Stateless Routing （GPSR）, Graphic Source Routing （GSR） and GRAN. The experimental results show that GRAN can provide a lower average delay, higher packet delivery ratio and throughput at a lower load, compared with several typical location-based routing protocols.