Question: What is the primary purpose of the 'Data Volume Reporting Indication' in the UTRAN Iu interface RANAP signalling?
Option 1: To trigger the reporting of successfully transmitted NAS data for all active RABs.
Option 2: To initiate the calculation of signal strength for handover decisions in the RNC.
Option 3: To indicate whether the RNC should calculate and report the amount of unsuccessfully transmitted NAS data upon RAB release.
Option 4: To request the UE to adjust its transmission power based on network congestion.
Explanation: The 'Data Volume Reporting Indication' is crucial for managing and optimizing network resources by tracking data transmission failures at the RAB level, allowing the Radio Network Controller (RNC) to monitor and report on unsuccessfully transmitted Non-Access Stratum (NAS) data when a Radio Access Bearer (RAB) is released, aiding in network diagnostics and performance enhancement.