Question: In UTRAN Iu interface RANAP signalling, under what condition is the "Last Known Service Area" information element reported by the RNC?
Option 1: When the UE initiates a new call setup in the current Service Area.
Option 2: Periodically, as part of routine location update procedures.
Option 3: When the current Service Area is unknown to the RNC.
Option 4: Upon handover completion to a new Service Area.
Explanation: The correct answer is Option 3 because, according to the specification, the "Last Known Service Area" is reported when the RNC lacks knowledge of the UE's current Service Area, indicating a scenario where the UE's latest location within a known Service Area is shared due to uncertainty about its present location. This highlights the importance of location management in maintaining connectivity and service continuity in telecom networks.