Question: In a 5G network, which of the following components are included in the RAN part of Downlink (DL) packet delay measurement for a User Equipment (UE)?
Option 1: D1 (DL air-interface delay), D2 (DL delay on gNB-DU), D3 (DL delay on F1-U), and D5 (CN processing delay)
Option 2: D1 (DL air-interface delay), D2 (DL delay on gNB-DU), D3 (DL delay on F1-U), and D4 (DL delay in CU-UP)
Option 3: D1 (DL air-interface delay), D2.1 (average over-the-air interface packet delay), D2.2 (average RLC packet delay), and D2.3 (average delay UL on F1-U)
Option 4: D2 (DL delay on gNB-DU), D3 (DL delay on F1-U), D4 (DL delay in CU-UP), and D5 (UE processing delay)
Explanation: The RAN part of DL packet delay measurement comprises four components: D1 (average Downlink air-interface delay), D2 (average delay in the gNB-DU), D3 (average delay on the F1-U interface), and D4 (average delay in the CU-UP). Option 2 correctly lists all these components, excluding non-RAN or non-DL specific measurements.