[5MBUSA] User Service Announcement parameters alignment and clarifications
Source: BBC | Work Item: 5MBUSA | Category: A (mirror to earlier release) | Affected spec: TS 26.502 v18.5.0
Addresses gaps and ambiguities found during 5G-MAG reference implementation of MBS User Services, where stage 3 (TS 26.517) was correct but stage 2 (TS 26.502) lacked corresponding definitions or was unclear.
Conformance profiles (Change #1): Added as a new parameter (cardinality 0..*) in the MBS Distribution Session entity (Table 4.5.6-1), assigned by the MBS Application Provider. Also added to MBS Distribution Session Announcement (Table 4.5.8-1).
Transport security protection (Change #2): Clarified in Table 4.5.6-1 that this flag is assigned by either the MBS Application Provider or the MBSF (the latter for the User Service Announcement Channel special case). Assigner column updated accordingly.
Object acquisition identifiers – MIME type (Change #3): Clarified in Table 4.5.6-2 that each identifier may be accompanied by a content type, and that this content type shall be present when the identifier is an Application Service Entry Point locator. Reflected in Table 4.5.8-2 (Application Service Entry Point locators always paired with MIME type).
Object repair back-off parameters (Change #4): Added as a new parameter (0..1, assigned by MBSF) in both Table 4.5.6-2 and Table 4.5.8-2. Clarified throughout (clauses 4.2.6, 4.5.6, 4.5.8) that Object Repair is enabled by the MBSF (not provisioned by the MBS Application Provider). Object repair base URL description updated to use "enabled" instead of "provisioned."
New reference point MBS-1 (Change #5): Formally defined in clause 4.4.1 as the interface for the MBS Application Provider to retrieve User Service Announcement bundles from the MBSF for private advertisement via MBS-8. Referenced in clauses 4.3.2, 5.2, and 5.4.
User Service Announcement bundle clarification (Change #6): Clause 5.4 (procedure C) updated to clarify that the full User Service Announcement exposed via the User Service advertisement notification and retrievable at MBS-1 is the User Service Announcement bundle (replacing "composite").