Question: What is the primary purpose of the Service Area Identifier (SAI) in UTRAN's Iur interface RNSAP signalling?
Option 1: To uniquely identify individual User Equipment (UE: User Equipment) within a cell.
Option 2: To differentiate between PS (Packet Switched) and CS (Circuit Switched) domains within a single Location Area.
Option 3: To indicate the location of a UE to the Core Network (CN), identifying an area consisting of one or more cells within the same Location Area.
Option 4: To manage handovers between different Radio Access Networks (RANs) in heterogeneous network deployments.
Explanation: The correct answer, Option 3, aligns with the provided context that explains the Service Area Identifier's role in identifying a service area (comprising one or more cells within the same Location Area) for locating a UE relative to the Core Network (CN), applicable to both PS and CS domains. This highlights its significance in location management and signaling within UTRAN architecture.