Question: In IMS Service Continuity, what information can a UE capable of Inter-UE Transfer (IUT) discover about an ongoing session on another UE under the same or different subscription of the same operator?
Option 1: Only the session identifier and source UE identifier (e.g., GRUU or IMPU)
Option 2: Session information (including identifiers for session, source UE, remote end, and Controller UE), media flow details (type, status, identifier), and Service Identifier
Option 3: Just the type of media flows (voice, video, etc.) without any session or service identifiers
Option 4: The availability and capabilities of other UEs but not specific ongoing session details
Explanation: This option is correct because, according to the IMS Service Continuity specifications for Session Discovery, a UE capable of IUT can indeed discover comprehensive information about an ongoing session on another UE. This includes detailed session information (session identifier, source and remote end identifiers, and the Controller UE for collaborative sessions), specific media flow details (type, status, and media flow identifier), and the Service Identifier related to the session. This extensive discovery capability is crucial for effective Inter-UE Transfer in maintaining service continuity across different UEs under the same operator.