Question: In an IMS (IP Multimedia Subsystem) emergency call setup, what happens if a UE (User Equipment) does not recognize a dialled number as an emergency call number but the IM CN (IP Multimedia Core Network) subsystem where the subscriber is located does?
Option 1: The call is automatically terminated by the network.
Option 2: The call shall be routed as an emergency call indicating the type of emergency service to the correct PSAP (Public Safety Answering Point), subject to national regulations.
Option 3: The UE is prompted to authenticate before proceeding with the call setup.
Option 4: The network requests the UE to switch to a different access network for emergency services.
Explanation: This correct answer reflects the protocol's emphasis on ensuring emergency calls are successfully connected, even if the UE is unaware of local emergency numbers. By routing the call to the correct PSAP with the emergency service type, the IM CN subsystem prioritizes emergency response accessibility, adhering to national regulations for subscriber location.