基于WLAN的轨道通信系统的数据中转方法

摘要

Metro wireless communication systems is an important part of the integrated rail traffic control system. The existing metro wireless communication systems is based on WLAN technology, due to the train nodes must be frequently switch between ground wireless access points. Wireless link is needed to establish new connections frequently, so network routing has also to be frequent changed, which will affect the real-time transmission of data. Which will make the video incoherent and the appearance of mosaic. This paper describes a technology using raw socket to encapsulate the date which sending to the STA (Station, mobile station) in the AP (Access Point, mobile access point)side, this package contains the destination STA MAC address and destination server IP address. By using this technology we realize the data transfer in the condition of train STA frequent switching between ground wireless access points. Thus reducing the switching time.%车地宽带无线通信系统是构成轨道交通综合监控系统中不可或缺的组成部分,现有的车地无线通信系统是基于WLAN技术的,由于车载节点频繁地在地面无线接入点间进行切换,无线链路需要频繁建立连接,网络路由也会频繁发生变化,网络路由的频繁变化会影响数据的实时传输.使得监控视频存在不连贯和马赛克现象.本文介绍一种在AP(Access Point,移动访问接入点)端利用原始套接字封装发往STA(Station,移动站)的数据包,该数据包内包含目的STA的MAC地址、目的车载服务器的IP地址的技术.通过该项技术实现了在轨旁AP和车载STA频繁切换的情景下的数据中转.从而减少了切换时间.