Analysis And Implementation Of WLAN In The Subway Passenger Information System

With the development of science and technology and the trend of urbanization, subway is playing a more and more important role in modern cities. How to provide high-quality service to passengers has become an urgent issue facing the construction of rail transportation, so emerges the concept of passenger information system.The passenger information system is a computer system relying on multimedia network technology to provide information services by display terminals in stations and vehicles. It can provide passenger notice, service time, arrival and departure time, government announcement, live sports broadcast, advertisements and other real-time information; also it can provide guidance on evacuation in the event of fires, traffic jam, terrorist attacks and other emergencies.This paper proposes a wireless network in the actual subway tunnel environment which is constituted with central system, station system, wireless access point and vehicle wireless unit. The WLAN frequency planning in this system is analyzed to guarantee 6M MPEG-2 video stream download and 2M monitor information upload to center subsystem. A test is conducted in the real environment and results are presented to show the performance of the system.