Understanding MBS Frequency Identification in Broadcast Services

5MBS Pre 5MBS Pre- -meeting CC for meeting CC for 149E 149E LiMeng Raymond.limeng@Huawei.com

Agenda Agenda Identifier of the frequency (MBMS SAI-like); Session start response success/failure per gNB basis; MBS PCC; Secondary authorization; AoB; Click here to join the meeting

Identifier of the frequency Identifier of the frequency current status current status Status quo: Agreed: Usage of MBS XXX ID. MBS XXX ID/mapping frequencies are provided to RAN via OAM. RAN announces in SIBs about MBS XXX IDs and frequencies. MBS XXX ID will be included in Service announcement. Open issues: The terminology of MBS XXX ID. How could the AF know the MBS XXX ID for a certain broadcast service? How could RAN understand the MBS XXX ID used for a certain broadcast service? When will AF know the MBS XXX ID? Tdoc# Title Source 23.247 CR0080 (Rel-17, 'F'): MBS FAI S2-2200468 Ericsson 23.247 CR0082 (Rel-17, 'F'): MBS identifier for broadcast MBS session S2-2200527 CATT 23.247 CR0087 (Rel-17, 'F'): Discussion and proposals for MBS SAI Huawei, HiSilicon S2-2200595 23.247 CR0092 (Rel-17, 'F'): MBS Broadcast Frequency area Identifier Nokia, Nokia Shanghai-Bell S2-2200958 23.247 CR0094 (Rel-17, 'F'): Clarification on the MBS SAI S2-2201132 ZTE

Identifier of the frequency Identifier of the frequency contributions contributions S2-2200468 (Ericsson) S2-2200527 (CATT) S2-2200595 (Huawei) S2-2200958 (Nokia) S2-2201132 (ZTE) MBS FAI Broadcast Frequency area Identifier (BFA) Terminology of MBS XXX ID MBS Service Area ID MBS Frequency Area ID MBS Service Area ID (Frequency Area Identity) The MBS XXX ID(s) might be provided by MB-SMF to AF during MBS session Creation. The MB-SMF determines the MBS XXX ID(s) corresponding to the MBS service. If AF is in trust domain, then it knows the MBS FAI; If AF is not in trust domain, MB-SMF based on configuration provides MBS FAI to AF via NEF. When a broadcast session is created, BFA ID(s) are selected for that broadcast session by the MB-SMF and provided towards AF/MBSF. During the MBS Session Creation, MB-SMF determines the MBS xxx ID(s) returns the MBS xxx ID(s) to the AF via NEF/MBSF in the response. How could the AF know the MBS XXX ID? N/A During MBS Session Start for Broadcast, the MB-SMF may include the MBS XXX ID(s) in N2 message to the NG-RAN nodes. During the MBS session Start, the MB-SMF includes MBS XXX ID(s) to AMF. The AMF sends MBS XXX ID(s) to NG-RAN nodes. During MBS Session Start/Update, MB-SMF may include the MBS FAIs and sends them to the NG-RAN. How could RAN understand the MBS XXX ID? N/A N/A according to Service area (e.g. cell list, TAI or TAI list) configured in the MB-SMF How does MB- SMF determine MBS XXX ID Base on e.g., SLA, MBS service area, etc. Base on MBS service area and local configuration Pre-configuration at MB-SMF N/A

Identifier of the frequency Identifier of the frequency proposal proposal Way forward proposal: Open issue Way forward proposal Terminology of MBS XXX ID MBS Broadcast Frequency Area ID During MBS session Creation/Update (?). The MB-SMF determines the MBS Broadcast Frequency Area ID corresponding to the MBS service and provides to AF via NEF or to MBSF. How could the AF know the MBS XXX ID? AF may provide MBS Broadcast Frequency Area ID in MBS session creation procedure if it is in trust domain. How could RAN understand the MBS XXX ID? During MBS Session Start/Update (?); MB-SMF may include the MBS MBS Broadcast Frequency Area ID in N2 message to the NG-RAN. How does MB-SMF determine MBS XXX ID Pre-configuration at MB-SMF; Base on local configuration, MBS service area, etc.

Session start response success/failure per Session start response success/failure per gNB gNB basis basis Tdoc# Title Source LS from RAN WG3: LS on MBS Service Area Identity and start procedure for broadcast service S2-2200415 RAN WG3 (R3-221302) [DRAFT] Reply LS on MBS Service Area Identity and start procedure for broadcast service S2-2200996 Ericsson Inc. [Draft] Reply LS on MBS Service Area Identity and start procedure for broadcast service 23.247 CR0083 (Rel-17, 'F'): Corrections to MBS procedures for broadcast Session S2-2200526 CATT S2-2200528 CATT In the meanwhile, RAN3 also discussed on session start procedure for broadcast service and the view of majority is that indication of session start success or failure with cell accuracy is not needed. Instead, RAN3 is of the opinion that a success/failure on a per gNB basis may be sufficient and would like to know the views of SA2. Proposal 1: Get confirmation from SA6 (S2-2200996), and length is 3 octet. Proposal 2: Follow the request and update TS 23.247 directly (S2-2200526), and length is 2 octet.

MBS PCC MBS PCC Tdoc# Title Source 23.247 CR0004R2 (Rel-17, 'F'): Policy Control for MBS Session Ericsson, Huawei, HiSilicon S2-2200468 23.247 CR0095 (Rel-17, 'F'): Resolving the PCC related EN and issue S2-2200527 ZTE

Secondary authorization Secondary authorization Tdoc# Title Source LS from SA WG3: LS to SA2 on secondary authentication for multicast PDU session S2-2200069 SA WG3 (S3-214538) [Draft] Reply LS on secondary authentication for multicast PDU session S2-2200465 Ericsson S2-2200596 [Draft] Reply to SA WG3 on Secondary Authorization Huawei, HiSilicon S2-2200597 23.247 CR0088 (Rel-17, 'F'): Secondary authorization Huawei, HiSilicon

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