A.3 New QoS Flow with Explicit RRC Signalling

38.3003GPPNRNR and NG-RAN Overall descriptionRelease 17Stage 2TS

The following figure shows an example message flow when explicit RRC signalling is used for a new QoS flow. In this example, the gNB receives from UPF a first downlink packet associated with a QFI, for which the QoS parameters are already known from the PDU session establishment, but for which there is no association to any DRB yet in AS.

Figure A.3-1: DL data with new QFI sent over existing DRB

0. PDU session and DRB(s) have been already established.

1. gNB receives a downlink packet with a new QFI from UPF.

2. gNB decides to send the new QoS flow over an existing DRB using explicit RRC signalling for updating the AS mapping rules.

3. gNB sends an RRCReconfiguration message to UE with the new QFI to DRB mapping rule. gNB may also decide to update the DRB configuration if required to meet the QoS requirements for the new QoS Flow.

4. UE updates the QFI to DRB mapping rules and configuration (if received).

5. UE sends an RRCReconfigurationComplete message to gNB.

6. User Plane Data for the new QoS flow can then be exchanged between UE and gNB over the DRB according to the updated mapping rules and between UPF and gNB over the tunnel for the PDU session.