9.20 Monitoring and control of QoS for eV2X communications

23.2863GPPApplication layer support for Vehicle-to-Everything (V2X) servicesFunctional architecture and information flowsRelease 18TS

9.20.1 General

5GS supports eV2X communications with extended QoS monitoring and reporting.The VAE layer utilizes these monitoring and reporting mechanisms to support control of QoS for eV2X communications. The V2X application specific server subscribes to service adaptation and QoS control events from the VAE layer and receives notifications about the relevant service requirement adaptations and corresponding QoS changes.

9.20.2 Information flows

Editor’s note: The specification of information flows is FFS.

9.20.3 Subscription Procedure

Pre-conditions:

1. The VAE server includes an Application Function (AF) functionality, as defined in 3GPP TS 23.287 [8].

2. The VAE server has subscriptions with SEAL servers to receive V2X service-related information (e.g. UE IDs, location, group, configuration info, etc.).

Figure 9.20.3-1: Subscription for monitoring and control of QoS for eV2X communications

1. The V2X application specific server sends a service adaptation and QoS control subscription request to the VAE server.

2. The VAE server, who acts as an AF, subscribes to QoS monitoring service from 5GS (e.g. PCF/NWDAF). This subscription may be active for a certain period of time or a given geographical area. The monitoring may either include the request for QoS sustainability events as specified in 3GPP TS 23.288 [24], or can include a QoS change notification requests as provided by SMF and specified in 3GPP TS 23.287 [8]. The reporting may be configured by the application enabler layer for a given area, time, periodicity etc taking into account the service requirement and other parameters (e.g. expected congestion in certain area, time of the day, road conditions).

3. The VAE server sends a service adaptation and QoS control subscription response indicating success or failure of subscription.

9.20.4 Notification Procedure

Pre-condition:

1. The subscription procedure specified in clause 9.20.3 is performed.

Figure 9.20.3-1: Notification for monitoring and control of QoS for eV2X communications

1. Based on the subscription, as specified in 3GPP TS 23.287 [8], 5GS provides the extended QoS monitoring report, over N33 interface. This report may come either from NWDAF or SMF via PCF/NEF.

2 The VAE server, based on the monitoring events (step 1) for one or multiple V2X-UEs within one service or across multiple services, may trigger a service requirement adaptation (step 3) based on the actual or expected QoS change for one or more V2X services.

3. The VAE server sends a service requirement adaptation notification request to V2X application specific server to identify the action which is needed, based on the actual or expected QoS change. This could be the adaptation of the Level of Automation (LoA) for one or more V2X-UEs or V2X services.

4. The V2X application specific server decides whether to adapt the service requirement based on step 3.

5. The V2X application specific server sends a response to VAE server with a positive or negative acknowledgment. Optionally, this may include the list of a sub-set of V2X-UEs within a service for which the requirement change should be applied

6. If no QoS adaptation is required, V2X application layer may adapt based on the adapted service requirements; and steps 7-10 are optional.

7. If a QoS adaptation is required, the VAE server, triggers the adaptation of QoS for the affected V2X-UE(s) within the service or across multiple services in close vicinity.

8. The VAE server performs network resource adaptation by interacting with the NRM server as specified in the 3GPP TS 23.434 [10].

9. The VAE server also notifies about the QoS adaptation to the V2X application specific server.

10. The V2X application layer adapts based on the adapted service and QoS requirements.