Abstract: A communication system for a house, a flat or an office in a house or for separated blocks of buildings, so as to connect at least three terminal units within said house, flat, office or separated blocks of buildings, is based on a central data bus for transmitting data to be transmitted between the terminal units, wherein the data bus has no specific deterministic access control and a limited transmission capacity. A first intelligent network terminating device is provided in the first terminal unit and includes interfaces for communication devices which may be located in the first terminal unit. A second intelligent network terminating device is located in the second terminal unit and includes interfaces for communication devices which can be located in the second terminal unit.