Question: In the context of authentication re-synchronization in a 3GPP network, what is the primary purpose of setting the AMF (Authentication Management Field) to "1111 1111 1111 1111" (AMFRESYNCH) in an AUTN (Authentication Token)?
Option 1: To indicate a successful authentication outcome to the User Equipment (UE).
Option 2: To trigger a re-synchronization procedure when received by the test USIM.
Option 3: To encrypt the AK (Anonymity Key) for secure transmission.
Option 4: To signal the end of an authentication session to the Serving Network.
Explanation: Setting the AMF to AMFRESYNCH ("1111 1111 1111 1111") is a specific trigger for the test USIM to initiate an authentication re-synchronization procedure upon receiving this value in the AUTN. This mechanism ensures that both the network and the UE can synchronize their security parameters under certain conditions, maintaining the integrity of the authentication process.