Abstract: A receiving device and business methods to affect the private transmission of remote control messages and the synchronization of date and time to electrical appliances connected to the AC power grid.

Abstract: The invention describes a transmission system for transmitting digital information via a power supply network. The proposed transmission device comprises a generator (4a) for generating a simulated digital wave-form carrying the digital information to be transmitted, wherein the simulated digital wave-form is built of predetermined harmonic frequencies of a signal frequency, and a high-voltage injector (4b) to inject the generated simulated digital wave-form carrying the digital information into the power supply network. The proposed receiving device (6) comprises an analog detector (21) for detecting predetermined harmonic frequencies of a signal frequency, and a logic device (22) to output a logic signal corresponding to the output of the analog detector (21) as said digital information.