Question: In a UTRAN network, what is the primary purpose of collecting 'UTRAN Cell Unavailable Time' measurements with various causes (e.g., manual intervention, fault, transport problem, energy saving)?
Option 1: To optimize packet switched traffic routing in real-time.
Option 2: To support the calculation of the Key Performance Indicator (KPI) 'UTRAN Cell Availability'.
Option 3: To automatically trigger corrective actions for cell faults.
Option 4: To compare energy consumption across different cell sites.
Explanation: The primary purpose of collecting 'UTRAN Cell Unavailable Time' measurements with specific causes is to accurately calculate the 'UTRAN Cell Availability' KPI. This KPI is crucial for assessing the reliability and uptime of UTRAN cells, which directly impacts network performance and user experience. By measuring unavailable time by cause, operators can identify areas for improvement to enhance overall cell availability.