Non-reception-controlled area information is stored in the non-reception-controlled area storage section of the reception control device for each mobile device ID. When the reception control device receives the disconnection signal and position information from the mobile device in accordance with the mobile device moving away from the key terminal, the presence/absence determination section determines whether or not the mobile device is within the aforementioned area. As a result of the determination, if the current position of the mobile device is within the aforementioned area, control for enabling reception for the mobile device is performed, and if the current position is outside the aforementioned area, control for disabling reception for the mobile device is performed.