Research And Implementation Of A Wireless Communication System In Subway Cars

With the subway plays a more important role in the metro traffic, the communications and the signal acquisitions have enrolled more and more focus from the researchers and suppliers. To improve the safety and comfort of the subway operation, it is necessary for equipment providers to construct a real time equipment monitoring system, by acquiring the operating parameters and transmitting the information to the maintenance center through some communication technology. But the irregular assembling and the mobility of the subway hinder the system constructionFor this, this paper builds an infrastructure network with a communication gateway between the cars and in the cars based on mobile Ad Hoc. Meanwhile, a reliable channel is established between the subway vehicle and the maintenance center based on the public wireless communication network. Like this, the communication infrastructure for the real time equipment monitoring system is set up, which can easily solve the problems above. In this research, after the analysis on the operating data of the equipment, i.e. subway door, ZigBee protocol is selected as the mobile Ad Hoc transmission protocol. Then, the packet size is determined by the tests of the constructed ZigBee network through quantitative research method. The research also includes the frame format design, packet encapsulation and packet decapsulation, the design of the communication gateway based on CDMA, the data analysis and storage in the maintenance center, and the data demonstration.Through the constructed equipment monitoring system, providers can reduce the failure rate of the equipment. And the maintenance can be realized based on the equipment status and failure risks.