Question: What is the primary purpose of the Iur Invoke Trace procedure in UTRAN's Iur interface Radio Network Subsystem Application Part (RNSAP) signalling?
Option 1: To establish a new UE Context between the DRNC and SRNC for handover preparation.
Option 2: To modify existing QoS parameters for a UE already connected to the network.
Option 3: To initiate a Trace Session for a specific UE Context based on Trace Parameters provided by the SRNC.
Option 4: To terminate an ongoing call due to insufficient resources in the RAN.
Explanation: The correct answer accurately reflects the purpose of the Iur Invoke Trace procedure. This procedure informs the DRNC to start tracing a particular UE's context based on parameters set by the SRNC, crucial for network diagnostics and optimization, aligning with trace concepts in telecom management standards.