Question: When establishing a PDP context/EPS bearer for IMS (IP Multimedia Subsystem) related signaling over E-UTRAN access, what indicates to the radio and core network the requirement for enhanced handling over the radio interface?
Option 1: Requesting the appropriate QCI (QoS Class Identifier) for signaling traffic in the UE Requested Bearer Resource Modification procedure.
Option 2: Setting a specific APN (Access Point Name) in the Attach/UE Requested PDN connectivity Request.
Option 3: Including a general purpose PDP context activation without QoS IE.
Option 4: Modifying an existing EPS bearer to convert it for IMS signaling.
Explanation: For E-UTRAN access, requesting the appropriate QCI for signaling traffic in the UE Requested Bearer Resource Modification procedure is what indicates to both the radio and core networks the need for enhanced handling over the radio interface specifically for IMS related signaling. This aligns with the policy and charging control architecture as specified in relevant 3GPP standards (e.g., TS 23.203).