Question: In a 5G network, when reporting usage information from the User Plane (UP) function to the Control Plane (CP) function, which of the following aggregation levels does NOT require the UP function to have knowledge of its granularity level?
Option 1: Cell Level Reporting
Option 2: Bearer/Traffic Flow Level Reporting
Option 3: Per-UE (User Equipment) Aggregate Reporting
Option 4: Network Slice Level Reporting
Explanation: According to telecom standards, the CP function ensures multiple granularity levels are satisfied without requiring the UP function to know these levels. Specifically, Bearer/Traffic Flow Level Reporting is defined by reporting keys in the Usage Reporting Rule, which doesn't necessitate the UP function's awareness of its granularity level, as this is managed by the CP function based on predefined rules and mappings.