Intelligent Broadcasting System Based On Dual Audio Signal Transmission Security Technology Research

In recent years, frequent natural disasters and public events bring us economy immeasurable loss, and these events have alerted us to ponder how to deal with emergencies, for rapid and effective emergency treatment has become particularly important. In the case of emergencies coming, the emergency command can be subject to regional, environmental impact, command and broadcast long-distance to public, which has its irreplaceable effect for handling emergency incidents. This paper is based intelligent emergency broadcasting system that controlled dual tone multi-frequency signals,which can be set by the form of wired or wireless network as the controlling siginal, To achieve effective and reliable communications for remote control recognition.When the emergency is coming,the public emergency commanders can use the mobile phone to login in the system, after the password and ID are confirmed, the commander can continue to use the phone keys for remoting control, force to start all assigned target receivers to change into the dedicated channel of public emergency radio receiver, broadcast voice by phone to the receivers.This paper studies the communications security issues about the broadcasting system, which is on the basis of the DTMF and used specially for public emergency events.Firstly, I introduce the overall structure of the emergency broadcast system, then describe the working principle and working process of the system receiver and broadcast control center, and describe in detail the security of communications on the system design.The system use the dual tone multifrequency analog signal for the handshake signal as the receiver signal correspondence recognition and the control response.we add the dual-tone patrol inspection code generator which has patrol inspect function to prevent from interfere and attack of the extra DTMF signal;and we use the menthod of distinction address coding to istancely start-up the big proportion;and we use the hufu code distinguishing the DTMF controlling instruction and yalidate the distinction of the loginor. The control signals on the communication process encrypted by the DES encryption algorithm is modulated by the FM modulator and launched by the frequency transmitter mixer. the receiver decrypted and demodulated to get the original control signal, so that we can guarantee the security of communications. Finally, the tested platform is builded for verifying the security mechanism's valid character ,the laboratory equipment and test methods were described in detail, the experimental results were analyzed.The system's daily inspection can ensure the system in safe and reliable operation when any call comes. The authentication mechanism of hufu code ensure that the receiver can be safe and accurate when the system is in the active work state. The control signal automatically encryption and decryption mechanism makes it difficult to decipher the control signals . Resetting the hufu code mechanisms ,which are valid that the system prevent the evil attack, thereby ensuring the security of system operation.