The figure shows the block diagram of complete communication system, which can be divided into three main sections; namely a master unit, remote unit and signal transmission through free space optics. The remote unit is used to control the master unit. The hierarchy of operation is as follows.For Remote Module.: DTMF Keypad will provide control signal to DTMF Encoder; DTMF Encoder generates the tone frequency signal; IR Transmitter converts the above into a light signal.Free Space Optics: IR Signal generated by IR transmitter to Master Unit through Free space; IR Receiver reads the light signal and converts it into the tone frequency signal; DTMF to BCD decoder convert the above signal to BCD;De-multiplexer provides control signal for required switching.