Status change notification method, subscriber authentication device, status change detection device, and mobile communication system

摘要

PROBLEM TO BE SOLVED: To enable secure notification of a status change in a user terminal, a subscriber authentication module and an attachment device to a network provider.SOLUTION: A status change notification method includes the steps of: receiving an authentication token (AUTN) transmitted from a VLR (40) connected to a user terminal (10); on detection of a status change of the user terminal (10), a subscriber authentication module (20) or an attachment device (80), transmitting a resynchronization token (AUTS) in response to the authentication token (AUTN) in place of an authentication response (RES) to the VLR (40).