In the last years, communication technology has developed tremendously .It has already proved its importance in sharing the information right from household to worldwide mediums. Besides sharing the information, it is also used for distant control of machines and electronic appliances. In our daily life, we use many appliances at home, office and other public places for our ease. Every device requires one or the other kind of operation control for which it has a HMI (humanmachine interface). Communication technology helps us to exchange information with human beings as well as it also allows us to carry out monitoring and controlling of DEVICES from remote locations. This remote control of appliances is possible among wired or wireless communication interfaces embedded in the machines. The use of “Embedded scheme in Communication” has given retort many interesting applications. One of such applications is public addressing system. Many companies are manufacturing audio / video systems like public notice system, CCTV, programmable signal boards etc. But all these systems are generally hardwired, complex in nature and difficult to expand. Thus ,by adding wireless communication interface such as GSM to these systems, we can overcome their restrictions.
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