Content for  TS 26.502  Word version:  17.3.0

Interworking between MBS and eMBMS is described in clause 5.2 of TS 23.247 and applies at the service layer in cases where the same Multicast/Broadcast service is provided simultaneously via eMBMS and MBS. Figure 4.9-1 depicts a combined network architecture based on Figure 4.2.1-1 in the present document and Figure 5.2-1 in TS 23.247.

To support MBS-eMBMS interworking according to the description in clause 5.2 of TS 23.247, the MBS User Services architecture supports the following functionality:

1. MBS User Services are provisioned via reference point Nmb8 per the present document. eMBMS User Services are separately provisioned at xMB-C per TS 26.348 or MB2-C per TS 23.468. A common TMGI is used in the MBS System and in the eMBMS System. The two User Services should be provisioned to ingest the same content if service continuity between the MBS System and the eMBMS System is required.
2. Signalling from the MBSF to the MBS Client is present in the MBS User Service Announcement indicating that the equivalent User Service is also available via eMBMS. By this, a UE that implements both an MBS Client and an eMBMS Client may choose to receive the service from either network, and may dynamically switch between them according to varying reception conditions. Such an architecture is shown in Figure 4.9-2.
3. Content for the provisioned MBS User Service is ingested logically by the MBTSF at reference point Nmb8 per the present document. Content for the provisioned eMBMS User Service is ingested logically by the MBSTF at reference point xMB-U per TS 26.348 or MB-2 per TS 23.468. If these reference points are compatible, the content is ingested once to satisfy both logical ingests.
4. MBS User Services distribution methods are compatible with eMBMS delivery methods such that the same ingested content can be delivered to an MBS Client and to an eMBMS Client. UEs only supporting only eMBMS are served by this architecture as well.