Question: In an IP Multimedia Subsystem (IMS), what information does a User Equipment (UE) provide to the network for a successful CS (Circuit Switched) to PS (Packet Switched) access transfer during SRVCC (Single Radio Voice Call Continuity)?
Option 1: Current operator policy and user preferences
Option 2: Local Operating Environment Information alone
Option 3: IMS registration status only
Option 4: Pre-allocated ports and codec information to be used during access transfer
Explanation: For a seamless CS to PS SRVCC access transfer, the UE must provide specific technical details to ensure compatibility and continuity of service. Among the given options, only pre-allocated ports and codec information directly pertain to the technical requirements necessary for the network to facilitate this transfer successfully, ensuring uninterrupted communication with adapted settings for packet-switched networks.