9.7 Network monitoring by the V2X UE

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

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

9.7.1 General

The V2X UE subscribes for network monitoring information from the VAE server. Such network monitoring information may be used by the V2X UE for network connectivity adaptations (e.g. switching between different modes of operations for V2V communications).

9.7.2 Information flows

9.7.2.1 Network monitoring information subscription request

Table 9.7.2.1-1 describes the information flow network monitoring information subscription request from the VAE client to the VAE server.

Table 9.7.2.1-1: Network monitoring information subscription request

Information element	Status	Description
V2X UE ID	M	Identity of the V2X UE subscribing for the network monitoring information
Subscription event	M	Identify one or multiple network monitoring events (e.g. uplink degradation, congestion, overload, coverage)
Triggering criteria	M	Identify when the VAE server will send the monitoring reports to the VAE client.
Area information	O	Identify the area where the event is subscribed.
V2X UE ID(s)	O	Identify the V2X UE(s) to be monitored.
V2X service ID(s)	O	Identify the V2X service which is related with the event.

9.7.2.2 Network monitoring information subscription response

Table 9.7.2.2-1 describes the information flow network monitoring information subscription response from the VAE server to the VAE client.

Table 9.7.2.2-1: Network monitoring information subscription response

Information element	Status	Description
V2X UE ID	M	Identity of the V2X UE
Result	M	Indicates success or failure

9.7.2.3 Network monitoring information notification

Table 9.7.2.3-1 describes the information flow network monitoring information notification from the VAE server to the VAE client.

Table 9.7.2.3-1: Network monitoring information notification

Information element	Status	Description
V2X UE ID	M	Identity of the subscribed V2X UE
Network monitoring information (NOTE 2)	M	This includes information on network status for the triggering criteria, and may include the following parameters: – Uplink quality level – Congestion information (NOTE 1) – Geographical Area (cell area or TA for which the monitoring applies) – Time Validity (the period for which the monitoring applies) – Coverage level and bearer level events (optionally, for MBMS) – QoS Sustainability
V2X UE ID (NOTE 2)	O	Identify the V2X UE that the network monitoring information is related.
NOTE 1: With respect to the congestion information acquired from 5GC, it may be exact values for congestion status reported by NWDAF to NEF or abstracted values e.g. (High, Medium, Low) which can be reported by the NEF. NOTE 2: If subscription is for multiple V2X UE IDs, then multiple Network monitoring information IEs corresponding to V2X UE ID(s) can be present.

9.7.3 V2X UE subscription for network monitoring information

9.7.3.1 General

This subclause describes the procedure for V2X UE subscription for network monitoring information.

9.7.3.2 Procedure

Figure 9.7.3.2-1 illustrates the procedure where the V2X UE subscribes for the network monitoring information from the VAE server.

Pre-condition:

– The VAE client of the V2X UE is connected to the VAE server and is authorized to access the network monitoring information.

Figure 9.7.3.2-1: V2X UE subscription for network monitoring information

1. The VAE client sends a network monitoring information subscription request to the VAE server. The area information and/or the V2X UE ID(s) (e.g., the initiating V2X UE ID, the V2X UE ID(s)) is included to indicate whether per area or per UE(s) networking monitoring information is subscribed.

2. The VAE server checks for the authorization of the VAE client to access the network monitoring information and if allowed, stores the subscription information corresponding to the V2X UE.

3. The VAE server sends a network monitoring information subscription response to the VAE client including the result of the subscription (i.e. success or failure).

9.7.4 Notifications for network monitoring information

9.7.4.1 General

This subclause describes the procedure for notification of network monitoring information from the VAE server.

9.7.4.2 Procedure

Figure 9.7.4.2-1 illustrates the procedure where the VAE server sends notification of the network monitoring information to the V2X UEs.

Pre-conditions:

1. The VAE server acting as a SCS/AS is configured with the SCEF information and is authorized to exchange information with the SCEF as specified in subclause 4.9 in 3GPP TS 23.682 [8]. The VAE server has subscribed to QoS notification service from 5GS (e.g. PCF/NWDAF). The notification 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];

2. The V2X UE1 and V2X UE2 have subscribed for the network monitoring information at the VAE server.

3. The VAE server may be aware of the RAT type the V2X UE supports from the registration of VAE client.

Figure 9.7.4.2-1: Notifications for network monitoring information

1. The VAE server communicates with the SCEF to receive network monitoring information as per the procedure in subclause 4.9 of 3GPP TS 23.682 [8], and/or communicates with NEF or NWDAF to receive QoS monitoring information and/or data analytics information of 5GS as defined in 3GPP TS 23.288 [24] for the requesting area and/or the V2X UE(s). The VAE server may determine to receive network monitoring information from EPC or 5GC or both considerting the RAT type provided by the UE. The VAE server subscription to QoS monitoring service from 5GS (e.g. PCF/NWDAF) may be active for a certain period of time or a given geographical area and/or the V2X UE(s). 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, V2X UE(s), 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). 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 network monitoring information (e.g. uplink or downlink link degradations, congestions, etc.) available at the VAE server about the on-going V2V session(s) and the network status is based on the original network monitoring information provided by the SCEF in step 1, and/or based on QoS monitoring report or data analytics from 5GS as specified in step 1. The VAE server determines the network monitoring information to send to the UE.

3. The monitoring information is sent to the subscribed V2X UEs via network monitoring information notification.