5.2 High-level baseline procedures

26.5023GPP5G Multicast-Broadcast User Service ArchitectureRelease 17TS

The high-level baseline procedures for MBS User Services are shown in figure 5.2-1.

NOTE: In the interests of brevity, the prefix MBS is omitted from the numbered steps in the figure.

Figure 5.2-1: MBS User Service high-level baseline procedures

The basic procedures are as follows:

1. The MBS Application Provider provisions an Application Service as an MBS User Service by invoking the Nmbsf service on the MBSF.

2. The MBSF provisions one or more MBS Distribution Session by invoking the Nmbstf on the MBSTF.

3. The MBSF creates a User Service Announcement that may be accessed by the MBS Client of interested UEs.

4. The MBS Application Provider informs the MBS-Aware Application via MBS-8 that the specific Application Service can be accessed via an MBS User Service by means of an Application Service Announcement.

[Alternatively, the MBSF Client synthesises the Application Service Announcement from the User Service Announcement received in step 3 and informs the MBS-Aware Application via MBS‑6 that the Application Service can be accessed via an MBS User Service.]

5. The MBS Application Provider creates an MBS User Data Ingest Session with the MBSTF (via the MBSF) and the latter ingests the user data via Nmb8.

6. The MBS-Aware Application requests the MBS Client to access a specific MBS User Service by invoking procedures at MBS-6.

7. Optional: If it has not already been received in step 3 above, the MBSF Client may discover additional access information about this MBS User Service by querying the MBSF via MBS-5.

8. The MBSF Client provides the MBS Distribution Session information acquired as part of the User Service Announcement information to the MBSTF Client via MBS-6′.

9. The MBSTF Client activates reception of the MBS Distribution Session.

10. The MBSF Client continuously handles the MBS Distribution Session data based on updates received via MBS‑5.

11. The MBSTF Client receives MBS Distribution Session data via MBS-4‑MC as part of the MBS Distribution Session.

12. The MBSTF provides the MBS Distribution Session data to the MBS-Aware Application via MBS-7 in an MBS Application Data Session.

13. The MBS-Aware Application controls the MBS User Service by invoking MBS Application Service Control procedures on the MBSF Client via MBS-6.