介绍IEEE802．11无线局域网（WLAN）的基本原理及特点，分析城市轨道交通行业乘客信息显示系统发展的趋势，阐述乘客信息显示系统的移动宽带传输子系统的设计理念（包括覆盖设计、无线接入点切换、网络带宽、覆盖冗余实施措施、应用的标准和措施、设备防护、系统网管、数据安全入侵检测、覆盖范围限定、干扰及防干扰等方面）、系统结构、链路结构；结合这些分析成果，阐述WLAN技术在城市轨道交通乘客信息显示系统中应用的适用性。

The paper describes the basic principles and characteristics of IEEE 802． 11WLAN，analyzes the development trend of passenger information display systems in urban rail transit industry，and elaborates mobile broadband transmission subsystem design ( including the cover design，AP switching，network bandwidth，redundant implementation of the measures covered by the application of standards and measures，protective equipment，system network management，data security，intrusion detection， limit coverage，interference and anti-interference，etc． ) in passenger information display system，together with system architecture and link structure． Based on the analysis of the results，the feasibility of applying WLAN technology in urban rail transport passenger information display system is highlighted．

U231. 8