Question: What action should a NB-IoT UE connected to EPC take if Access Barring (AB) is enabled, before initiating RRC connection establishment/resume for non-mobile terminating calls?
Option 1: Proceed with RRC connection establishment/resume without acquiring additional system information blocks.
Option 2: Acquire MasterInformationBlock-NB/MasterInformationBlock-TDD-NB but not SystemInformationBlockType14-NB.
Option 3: Wait for a random backoff timer before attempting RRC connection establishment/resume.
Option 4: Acquire SystemInformationBlockType14-NB to obtain updated AB parameters before initiating RRC connection establishment/resume.
Explanation: According to the access barring procedure, if access barring is enabled, the UE must acquire SystemInformationBlockType14-NB to get the latest AB parameters before initiating RRC connection establishment or resume for non-mobile terminating calls, ensuring compliance with the network's current access control settings.