Abstract: An ID transmitter for authentication on an access control unit of a physical unit. The ID transmitter may include an ID transmitter-BLE interface with an antenna, a microcontroller, a switching apparatus and a battery compartment to accommodate a battery. The microcontroller is arranged, in response to the receipt of the switching signal, to trigger the sending of an authentication signal that includes authentication information, and that is configured as a BLE beacon data packet. A set for assembling an ID transmitter and a system including an ID transmitter and a physical unit are disclosed.

Abstract: The disclosure relates to a method for authenticating a mobile ID transmitter, which has an ID transmitter/BLE interface, at an access control unit with an access control unit/BLE interface of a physical unit, wherein the method comprises the following steps: A) transmitting a beacon with a short beacon identifier in a first step; B) checking the short beacon identifier; C) performing a BLE communication sequence with steps; D) authenticating the ID transmitter. The disclosure also relates to an ID transmitter with an antenna, microcontroller, and sensor, wherein the ID transmitter forms a system with the physical unit, also having an antenna and control apparatus.