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With the continuous development of communication technology , wireless communication , mobile communication has become the mainstream of the development direction of the communication . Short Message Service in mobile communications , has become widely accepted by virtue of its convenience , reliability , etc. , whether it is business support or network optimization , has been great development in recent years . In many industries , on the other hand , the need for monitoring the work environment , so as to ensure safe and orderly production monitoring system is essential . Monitoring system so it will have most of the monitoring information transmission , the transmission of the monitoring system are hosted by the wired network , cable network has many advantages , but it also has a lot of very difficult to overcome the shortcomings : for example, the large investment , network Networking complex scalability Poor . Public wireless network telecom operators responsible for the construction and maintenance of these shortcomings can be overcome . SMS wireless monitoring system , short message service through public wireless networks to transmit monitoring information , and has a very good practical value and economic benefits . This article describes the realization of a principle and design of GSM, CDMA , PHS network short message service (SMS) monitoring information transmission system (WSN) . The system contains three wireless terminal (GSM, CMDA, PHS three standard ) , the wireless terminal by the wireless module and the control unit . The wireless module is responsible for access to the public wireless network , the control unit via AT commands with the wireless module associated with the control unit software at the same time to provide a complete set of communication protocol , the wireless terminal and the monitoring equipment (peripheral equipment ) connected via this protocol ; the hardware connection to an RS232 interface, baud rate , default 9600bps . The sender of the user's own need to pass the information is passed to the radio terminal A , the terminal A via the short message information sent to the corresponding radio terminal B , the terminal B and then the recipient of the transmission of information of the user system . This starts a real-time , transparent information transmission channel .
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