A Variety Of Means Of Communication In A Wireless Monitoring System For Urban Lighting Applications

With the modernization of cities in China, the advanced City Lighting Monitor and Control System has become more and more important. In our vast country area a lot of big scale cities have potential need for this system. City Lighting Wireless Monitor and Control System is made up of control center, several scattering remote testing and controlling terminal and wireless communication nets. Control center has good human and machine interface, which control system element's running and send all kinds of commands to RTU (Remote Terminal Unit) also deal with data received from RTU. RTU in charge of collection and dealing with local data, management of local execute machine and communication with control center; Wireless communication net is the communicating bridge between control center and remote system, who will send and receive information according to some protocol. When one received the other's data, it will analyze them and get what it needed information according to the protocol. Only the smoothly communication nets could ensure whole system running well and arrive at advanced management of City Lighting Monitor and Control System. Usual wireless communication nets in City Lighting Wireless Monitor and Control System was built from special transmitter-receiver. In this method, the transmitter-receiver must apply to use special frequency. The communication scope will be limited by emit power of the transmitter-receiver. At the same time a high tower must be built in control center to ensure the intensity of signal. This method has expensive investment at the beginning, but since then it just need maintenance expense and have convenience utilization and simpleness expansion. With the popularize of common mobile net, City Lighting Wireless Monitor and Control System can also take the other more and more useful methods. Since utilizer tend to adopt common use nets GSM as the communication net of City Light Monitor and Control System. When you take GSM as the communication net, it still has several ways to choice, such as GPRS, Short Message Service (SMS), USSD. If you use GPRS or USSD, RTU must have GSM communication models. Control center can be connected with Mobile Servers by dedicated lines, which will have high communication speed. The two ways can be adopted by different utilizers, USSD has low running expense suite for communication requirement in industry environment; While, GPRS has broad band to carry data witch is needed by large amount of data...