A telecommunications apparatus is provided which comprises a processing system, a cellular-network radio transceiver, a first radio module and a smart card. The smart card comprises a microcontroller, an electrical interface and a second radio module. The cellular-network radio transceiver and the first radio module are connected to the processing system by one or more electrical connections. The smart card is coupled to the cellular-network radio transceiver through the electrical interface and the processing system is arranged to use a radio communication link between the first radio module and the second radio module to communicate data with the microcontroller of the smart card. The smart card is configured to interrupt the processing system by sending data over the radio communication link.