Question: What is the primary criterion for a PDCP SDU packet to be considered in the UL PDCP SDU Success Rate measurement at the gNB?
Option 1: The packet must have been successfully decrypted and authenticated by the gNB's security layer.
Option 2: The packet must have entered the PDCP layer and been assigned a PDCP sequence number, and be part of user-plane traffic (DTCH).
Option 3: The packet must have originated from a specific QoS level (mapped 5QI or QCI in NR option 3) and been successfully routed through the S-NSSAI.
Option 4: The packet must have undergone a successful CRC check at the physical layer before being passed to the PDCP layer.
Explanation: This is because only user-plane traffic (DTCH) and PDCP SDUs that have entered the PDCP layer (and thus been given a PDCP sequence number) are considered for this measurement, reflecting the success rate of packets properly engaging with the PDCP protocol for assessing upper-layer packet delivery success in 5G performance measurements.