Question: What action is mandated for the Mobile Equipment (ME) to perform immediately after a successful execution of the AUTHENTICATE command with a USIM application?
Option 1: Initiate a new session with the network using updated identifiers.
Option 2: Send a confirmation message to the user indicating successful authentication.
Option 3: Perform cipher and integrity key update procedure.
Option 4: Automatically select another USIM application for secondary authentication.
Explanation: After successfully authenticating with the USIM application via the AUTHENTICATE command, the Mobile Equipment (ME) is required to update its security parameters to ensure ongoing communication security. This involves refreshing the keys used for encrypting data (cipher key) and verifying data integrity (integrity key), hence the necessity of performing a cipher and integrity key update procedure. This action enhances the security posture of subsequent communications between the ME and the network.