Data distribution method for vehicle ad hoc network based on topology discovery

Abstract

The invention provides a topology-discovery-based data distribution method of a vehicle self-organizing network. The method comprises the steps as follows: a broadcast cycle of a source vehicle is calculated, and an event message monitored by the source vehicle is broadcasted according to the broadcast cycle; the event message serves as a probe of topology discovery, and the source vehicle is colored according to a coloring principle; and waiting time for a receiving vehicle is calculated, after the receiving vehicle receives the event message, whether the event message is forwarded at the waiting time is determined, if yes, the receiving vehicle is colored dark grey, and the event message is broadcasted, otherwise, the receiving vehicle is colored grey, and the process is finished. The topology-discovery-based data distribution method of the vehicle self-organizing network defines the broadcast cycle of the source vehicle and the waiting time of the receiving vehicle, so that the time delay of message transmission is reduced effectively, the reliability of event message transmission is improved, the number of transcripts of event message in the network is controlled, and the network communication load is reduced.

Description

technical field [0001] 本发明涉及无线通信领域和智能交通领域,特别涉及一种基于拓扑发现的车辆自组织网络的数据分发方法。 Background technique [0002] 车辆自组织网络(VANETs)是一种特殊的无线自组织网络,也是智能交通系统的一个重要组成部分。它是将无线通信技术应用于车辆间通信的自组织网络,它除了解决车辆间的通信外,对于交通安全及车辆的智能化、便利化也极为重要。车辆自组织网络除了有无线自组织网络的基本特性外,也具有其独自的特性:首先,车辆节点高速移动会造成网络的间歇连通性和快速动态网络拓扑的特点,这样将难以保证移动节点间持续稳定的连接;其次,车辆节点可装配GPS,方便获得自身及邻近节点的地理位置信息,其运动轨迹具有一定的可预测性;再次,车辆节点的传感器等设备使用可充电电池,无能源受限问题;因此,传统无线自组织网络的一些已有的研究方法在车辆自组织网络环境下并不适用。 [0003] 采用车辆自组织网络,可以实现以下三种应用服务:与安全相关的应用服务,与交通监测和管理相关的应用服务,以及与资讯娱乐相关的应用服务;而要实现这些应用服务则需要将数据信息通过多跳的方式在大范围车辆间传递;由于车辆自组织网络的间歇连通性,单播的多跳传递常常是不可靠的和高延时的,所以数据的传输是在一定发射功率下通过多跳广播的方式实现的,有效的数据分发策略是实现这些应用服务的基础。 [0004] 现有技术中提出了不同的VANETs中数据分发的方法: [0005] a)现有技术中提出了Epidemicscheme算法;在该算法中,数据分发是按照一轮一轮的方式进行的。在每一轮中,每个发送节点随机地挑选f个邻居节点进行数据包转发,每个数据包都以这种形式发送t轮。算法采用随机路由机制,并通过如下两点来保证数据分发的可靠性:一是数据分发路径的多样性,数据包一次分发给多个邻居节点,即使有一些节点失效,其他没有失效的节点仍然可以转发数据;二是数据包的重复多次发送,这样即使有些节点在第一轮中没有接收到数据,它们仍然可以在以后的数据分发轮数中接收到数据。 [0006] 但是,该算法虽然规定了移动节点相遇时随机地成对交换消息,避免了无差别泛洪发送数据造成的网络拥塞,但是它不适合于节点缓存和网络带宽受限制的网络,特别是当车辆密度较...

AI Technical Summary

Problems solved by technology

[0012] In this scheme, after the vehicle receives the forwarding message, it obtains the information of the neighbor nodes through continuous active inquiry, and then determines the forwarding vehicle according to the mutual comparison of the neighbor nodes, which causes a certain degree of communication delay. Somewhat imperfect for higher vehicular ad hoc networks

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