| 摘要 |
PROBLEM TO BE SOLVED: To provide a door lock system, a radio transmission device and a radiocommunication device capable of preventing a vehicle theft by a relay attack, by enabling the radiocommunication device to prohibit transmission of a radio signal, when the radiocommunication device enters the inside of a building.SOLUTION: In a door lock system, a radio transmission device 3 comprises: an opening-closing detection part for detecting opening-closing operation of a door of a building 8; and a transmission part for alternately transmitting a prohibition signal and a permission signal of adding identification information when the opening-closing detection part detects the opening-closing operation of the door of the building 8, and the radiocommunication device 2 comprises: a determining part for determining whether or not the identification information added to the prohibition signal or the permission signal coincides with second identification signal stored in a storage part 22 when receiving the prohibition signal or the permission signal by an LF receiving part 23a; and a CPU 20 for prohibiting or permitting transmission of a response signal by a transmission-reception part 23 based on the prohibition signal or the permission signal when determining as coinciding by the determining part. |
