A system for implementing a control or access function is described. The system comprises a mobile device having a mobile identifier, a short range communication interface and a long range communication interface. The system also comprises a local device having a local identifier. The system also comprises a remote device comprising a long range communication interface and a controller. The mobile device is configured for short range communication with the local device for receiving the local identifier, and the remote device is configured for long range communication with the mobile device for receiving a communication comprising at least the local identifier and the mobile identifier. The controller of the remote device is configured to perform at least one control or access action in response to receiving the communication from the mobile device. A controller for implementing a control or access function is also described.