An interface device for a communication network comprises a plurality of first communication nodes and a plurality of second communication nodes, wherein the interface device comprises a switching unit and a transmit-/receive aerial. The switching unit is capable of being coupled, so as to be able to communicate, to each of the first communication nodes and to each of the second communication nodes, and is configurable for transmitting a communication message between one of the first communication nodes and a second communication node, which may be unambiguously allocated to said first communication node. The switching unit may be coupled to the transmit-/receive aerial for wireless communication with each of the second communication nodes by way of the transmit-/receive aerial that may be shared for communicating with each of the second communication nodes.