Short-range wireless communication methods for overhead height limit devices subtitle as needed (paper subtitle)

The height limit gantry of urban viaducts has being playing an important role in the information management and traffic dispatch. However, it also limits special vehicles. This paper discusses and analyses three kinds of short-range wireless communication methods in detail (including ZigBee, Bluetooth and Radio Frequency Identification (RFID)), establishes a transmission distance estimation model, analyses some information interferences of vehicles with different roads, designs to an implement quickly channel connection and an identify information for main slave communication modules. The communication slave module is assembled in special vehicles, which is connected with the communication main module in the height limit gantry. A main controller completes the feature recognition and the rise and fall of height limit gantry. The device improves the efficiency of emergency vehicles, with the rapidity, reliability and practicality.