The embedded alarm system based on the Public Switch Telephone Network

This paper elaborates the design and development of the embedded alarm system based on the public switch telephone network. The core of the system is Micro Control Unit (MCU), which, in coordination with other peripheral circuits, can implement the remote alarm through Public Switch Telephone Network (PSTN). The subscriber can easily modify telephone numbers pre-stored in the system. Compare with the other security products, this system has the advantages of low cost and alarms in time because it takes use of the telecom network nothing to be invested to the subscriber.