Abstract: In a stand-alone device arranged to transmit messages to mobile communication devices, the massages are transmitted without affecting the normal communication in the mobile communication networks. The system can be located at any suitable location where mobile telephone communication is not desired. The system is arranged to transfer a predefined message in form of text or voice to the mobile communications device. This is obtained in that the system is designed to detect and force the mobile to lock on to a control channel of the system. Thereafter the system transmits a predefined text or voice message to the mobile telephony device users within the coverage area of the system. An application area is to prevent mobile telephony device users to have the device switched on in radiosensitive areas such as hospitals and aeroplanes. The device could also suitably be located in libraries, churches and theatres where ring signals and conversation is of disturbing nature.