Intercom

The so-called intercom is defined as the simultaneous, two-sided exchange of information via a common medium in opposite directions. In communications technology, the term full-duplex transfer is often used for the intercom. Full-duplex is in contrast to simplex or half-duplex system, in which information is transferred either only in one direction or alternately, but never simultaneously in different directions. Typical areas of application for the intercom function are door communication systems or telephones.