S4-260035 - AI Summary

[5MBUSA] MBSF notification event corrections

Back to Agenda Download Summary
AI-Generated Summary AI

3GPP TR 26.502 Change Request Summary

General Information

  • CR Number: 0047
  • Category: A (mirror corresponding to a change in an earlier release)
  • Release: Rel-18
  • Work Item: 5MBUSA (5G MBS User Service Architecture)
  • Source: BBC
  • Meeting: S4#135, Goa, India, 9th-13th February 2026

Reason for Change

This CR addresses two main issues:

  1. Misalignment between Stage-2 and Stage-3 specifications: Two notification events specified by CT3 in TS 29.580 are not properly motivated at stage-2 level in TR 26.502. This issue is tracked at https://github.com/5G-MAG/rt-mbs-function/issues/11

  2. Errors in notification event depiction: Figure 5.3-2 contains errors in the depiction of event notifications. This issue is tracked at https://github.com/5G-MAG/Standards/issues/188

Technical Changes

Section 4.6.2: Notification Events

Modifications to Table 4.6.2-1:

  • Column simplification: The final column of the notification events table has been simplified for improved clarity. The column header changed from "Applicable reference point(s)" to "Stimulating reference point(s)"

  • Added motivation for missing events: Two notification events that were previously not properly motivated have been updated:

  • User Service advertisement event: Now includes proper description and stimulating reference point (Nmb10/Nmb5)
  • User Data Ingest Session starting event: Clarified with appropriate reference point information

  • Clarification of event sources: The table now more clearly indicates which reference points stimulate each notification event, with brackets indicating intermediate reference points and explicit notation of the final delivery reference points (Nmb10/Nmb5)

Section 5.3: Procedures for User Service Provisioning

Corrections to Figure 5.3-2 Call Flow:

Three specific steps in the MBS User Service internal provisioning procedure have been corrected:

  • Step 14: Corrected the event notification from MBSTF to MBSF regarding content ingest establishment status using the Distribution Session established event

  • Step 15: Corrected the event notification from MBSF to MBS Application Provider regarding content ingest establishment, properly distinguishing between Distribution Session established event (success case) and Distribution Session establishment failure event (failure case)

  • Step 17: Corrected the final notification event from MBSF to MBS Application Provider regarding the overall MBS User Data Ingest Session status, properly distinguishing between User Data Ingest Session established event (success case) and User data ingest failure event (failure case)

Impact Assessment

Consequences if not approved:
- Continued misalignment between stage-2 (SA4) and stage-3 (CT3) normative specifications
- The MBSF cannot be implemented correctly as currently specified

Alignment impact:
- This CR aligns TS 26.502 with TS 29.580
- No impact on TS 29.580 is required

Document Information
Source:
BBC
Type:
CR
For:
Agreement
Original Document:
View on 3GPP
Title: [5MBUSA] MBSF notification event corrections
Agenda item: 8.4
Agenda item description: Release 19 and earlier matters
Doc type: CR
For action: Agreement
Abstract: Content already agreed at SWG level. Some of the notifications in the high-level procedures are incorrect.
Secretary remarks: Source modified on 2/3/2026. Original source : BBC
Release: Rel-18
Specification: 26.502
Version: 18.4.0
Related WIs: 5MBUSA
CR number: 47.0
CR category: A
TSG CR pack: SP-260117
Clauses affected: 4.6.2, 5.3
CN: True
CR: 47.0
Spec: 26.502
Contact: Richard Bradbury
Uploaded: 2026-02-03T15:18:15.433000
Contact ID: 82569
TDoc Status: agreed
TSG CR Pack: SP-260117
Clauses Affected: 4.6.2, 5.3
Reservation date: 29/01/2026 17:00:02
Secretary Remarks: Source modified on 2/3/2026. Original source : BBC
Agenda item sort order: 28