Content for  TS 23.247  Word version:  18.4.0

Same as in Figure 7.1.1.2-1.

The NEF/MBSF may optionally, based on local configuration, decide to interact with the PCF. If the NEF/MBSF decided to interact with the PCF, steps 11 to 19 are performed, and in step 20 the MBS Service Information is not provided to the MB-SMF. If the NEF/MBSF decided not to interact with the PCF, steps 12 to 19 are skipped, and in step 20 the MBS Service Information is provided to the MB-SMF.

[Conditional] If the NEF/MBSF did not receive an MBS Session ID from the AF in step 8, the NEF/MBSF sends an Nmbsmf_TMGI_Allocate Request (1) message to the MB-SMF and the MB-SMF allocates a TMGI and returns the TMGI to the NEF/MBSF via the Nmbsmf_TMGI_Allocate response (TMGI, expiration time).

[Conditional] If the NEF/MBSF receives the Request for location-dependent session from the AF and if there is a need to select the same PCF for the location dependent MBS Sessions, the NEF/MBSF first uses the BSF Discovery service to discover whether there is a PCF serving the MBS session with the MBS Session ID by using Nbsf_management_Discovery operation. If there is a PCF registered for the MBS Session ID, the NEF/MBSF interacts with that PCF and skips the following step 13.

[Conditional] If step 12 was not executed or the interaction with the BSF revealed that no PCF is registered for the MBS Session ID, the NEF/MBSF discovers the PCF candidates by interacting with the NRF and selects a PCF, possibly based on MBS service area.

The NEF/MBSF sends an Npcf_MBSPolicy_Authorization_Create Request (MBS Session ID, [Area Session Policy ID], [Request for location dependent MBS session], MBS Service Information (as defined in clause 6.14)) to the PCF.

[Optional] The PCF may retrieve authorization information for the MBS session from the UDR (see clause 6.10.2) and takes it into account for the subsequent authorization and QoS allowance check.

The PCF determines whether the request is authorized and if the request is authorized, the PCF derives the required QoS parameters based on the received MBS Service Information and determines whether this QoS is allowed. If the required QoS is allowed, the PCF generates the policy information for the MBS session (as defined in clause 6.10) and stores it together with the MBS Session ID.

If the request is authorized and the required QoS is allowed, the PCF registers at the BSF that it handles the MBS session by using Nbsf_management_Register Request (MBS Session ID, PCF ID). It provides an identifier that the policy association is for MBS and the MBS Session ID, its own PCF ID and optionally its PCF set ID.

The PCF sends an Npcf_MBSPolicy_Authorization_Create Response (Result indication, [Area Session Policy ID]) to the NEF/MBSF.

• The request is authorized for a location dependent MBS Session, the PCF assigns Area Session Policy ID.
• If the request is not authorized or the required QoS is not allowed, the PCF indicates so in the response to the NEF/MBSF which in turn informs the AF about it (by sending the Nnef_MBSSession_Create Response) and ends this procedure.

Same as step 10 in Figure 7.1.1.2-1.

Same as step 11 in Figure 7.1.1.2-1 with the following differences:

• If the optional interaction between AF/NEF/MBSF and PCF has been performed:
• The MBS Service Information is not present (as it was already provided to the PCF in step 14).
• For location dependent MBS service, the AF/NEF/MBSF also includes Area Session Policy ID (which is assigned by the PCF in step 18) to the MB-SMF.

The MB-SMF discovers the PCF using NRF.

The MB-SMF sends an Npcf_MBSPolicyControl_Create Request (MBS Session ID, [Area Session policy ID], [MBS Service Information (as defined in clause 6.14)]) for the MBS session towards the PCF. The MB-SMF forwards the MBS Service Information to the PCF if received from the NEF/MBSF in the previous step 20. For location dependent MBS Session, the MB-SMF also sends Area Session Policy ID to the PCF as follows:

• If the AF/NEF/MBSF does not include Area Session policy ID, (i.e. the AF/NEF/MBSF has not interacted with PCF), the MB-SMF uses its assigned Area Session ID as Area Session Policy ID.
• If AF/NEF/MBSF includes Area Session Policy ID (i.e. AF/NEF/MBSF (i.e. the AF/NEF/MBSF has interacted with PCF), the MB-SMF provides that received Area Session Policy ID (received from AF/NEF/MBSF) as Area Session Policy ID.

If PCF receives MBS Service Information from the MB-SMF, the PCF performs the subsequent steps 23 to 26. If the PCF does not receive MBS Service Information from the MB-SMF, but has previously determined policy information for the MBS session (see step 16) corresponding to the MBS Session ID (and Area Session Policy ID for location dependent MBS) received from the MB-SMF, the PCF continues with step 27.

If the PCF is not handling the MBS Session ID, the PCF uses the BSF Register service to check whether there is already a PCF serving the MBS session. If so, the PCF skips steps 24 to 26 and indicates in step 27 that the PCF serving the MBS session shall be contacted.

[Optional] The PCF may retrieve authorization information for the MBS session from the UDR (see clause 6.10.2) and takes it into account for the subsequent authorization and QoS allowance check.

The PCF determines whether the request is authorized and if the request is authorized, the PCF derives the required QoS parameters based on the received MBS Service Information and determines whether this QoS is allowed. If the required QoS is allowed, the PCF generates the policy information for the MBS session (as defined in clause 6.10) and stores it together with the MBS Session ID.

If the request is authorized and the required QoS is allowed the PCF registers at the BSF that it handles the MBS session by using Nbsf_management_Register Request (MBS Session ID, PCF ID). It provides an identifier that the policy association is for MBS and the MBS Session ID, its own PCF ID and optionally its PCF set ID.

The PCF responds with Npcf_MBSPolicyControl_Create Response ([policy information for the MBS session (as defined in clause 6.10)], Result indication). If the request is not authorized or the required QoS is not allowed, the PCF indicates so in the response to the MB-SMF which in turn informs the AF about it (by sending the Nmbsmf_MBSSession_Create Response) and ends this procedure. If another PCF is serving the MBS session, the PCF indicates that another PCF serving the MBS session shall be contacted and provides an ID of that other PCF. The MB-SMF then repeats step 22 towards that other PCF.

Same as steps 14-22 in Figure 7.1.1.2-1.