基于OSPF协议的路径诱导系统

路径诱导系统是智能运输系统最具代表性的一个功能子系统。本文设计了一种基于Internet目前广泛使用的OS-PF(Open Shortest Path First)路由选择协议的诱导系统。该系统由交通网络和相应的诱导数据网络组成;数据网络系统包括带有无线接入单元的交叉口诱导设备和连接诱导设备的数据链路。交叉口诱导设备之间通过泛洪过程交换实时的路段状态信息,使用最短路算法计算诱导方案。车载诱导单元使用IEEE 802.11无线局域网协议通过无线接入单元找到距离最近的交叉口诱导设备,通过发送路径请求报文和接收路径应答报文获得最短路径。分析表明,基于OSPF协议的路径诱导系统具有收敛快、可靠性强、可扩充性好以及成本低等特点。该方法为我国交通流诱导系统的研究提供了新的思路。

Route Guidance System Based on OSPF Protocol

Route Guidance System(RGS) is a representative part of Intelligent Transportation System.The object of this paper is to present the framework of RGS based on OSPF(Open Shortest Path First) protocol,the most widely used Internet routing protocol.RGS based on OSPF is composed of two parts:traffic network and guidance-data network.Guidance-data network includes Intersection Guidance Equipment(IGE) with Wireless Access Unit(WAU) and the data links between IGEs.The In-vehicle Guidance Unit(IGU) looks for the nearest IGE through IEEE 802.11 Wireless Local Area Network Protocol by WAU.The real-time Link-State information is exchanged between IGEs through flooding process.IGE calculates the shortest paths to every other intersections using Dijkstra algorithm.Vehicles can acquire the shortest path information through sending Routing Request message and receiving Routing Response message.The results indicate that RGS based on OSPF has the characteristics of rapid convergence,high reliability,good expandability and relatively low cost.This paper might provide a new insight into the construction of route guidance system.