城市车载网络中基于停放车辆辅助的数据分发

Parked-Vehicle Assisted Data Dissemination Paradigm for Urban Vehicular Ad Hoc Networks

VANETs(vehicular ad hoc networks)具有节点高速移动、网络间歇性连通和拓扑高度动态变化等特点.要分发的数据很难被维持在目标区域的道路上,不能持续为行驶经过的车辆提供服务.鉴于城市区域道路两旁长时间拥有大量停放车辆这一事实,提出了VANETs中基于停放车辆辅助的数据分发策略PADD(parked-vehicle assisted data dissemination).PADD按照簇的结构对目标区域内的路边停放车辆进行管理,将要分发的数据从数据源路由到目标区域合适的停车簇,并采用订阅/发布机制在停车簇一跳范围内实现数据分发.理论分析证明了停放车辆辅助的有效性;基于真实城市地图和交通数据的模拟实验结果表明:与现有的几种数据分发算法相比,PADD能以较低的网络负载和较小的传输延迟获得较高的数据传输成功率.

Vehicular ad hoc networks （VANETs） are characterized by high mobility of vehicle nodes, intermittent connectivity, and rapid dynamic topology. Data to be disseminated can hardly be kept within a target area, and therefore cannot provide continuous services for the vehicles passing by. Motivated by the fact that there are large amounts of roadside parked vehicles in urban areas, this paper proposes a parked-vehicle assisted data dissemination （PADD） paradigm for vehicular ad hoc networks （VANETs）. In PADD, the parked vehicles in the target area are managed on the basis of parking cluster, the data to be disseminated are forwarded from the data source to the selected parking clusters, and the pub/sub scheme is adopted to achieve data dissemination within one hop of the parking cluster. Theoretical results illustrate the effectiveness of the proposed approach, and meanwhile simulation results based on a real city map and realistic traffic situations show that PADD achieves a higher delivery ratio with lower network load and reasonable transmission delay.