5 Reference Client Architecture
26.3473GPPApplication Programming Interface and URLMultimedia Broadcast/Multicast Service (MBMS)Release 17TS
Figure 5.1 shows a general service architecture including a reference client. On the network side, an MAA and content provider provides media formats to a BM-SC, typically through the xMB interface and initiates services and sessions through the xMB interface. The BMSC establishes MBMS User Services and the lower layers support the delivery of the data through regular 3GPP unicast as well as MBMS broadcast bearers.
The MAA initiates the communication with the MBMS client using the MBMS-API. The MBMS client identifies the relevant services and provides the delivered user data to MAA. Typically, the media formats are provided through interfaces and to functions that conform to well-defined media delivery formats. The MAA controls the media client.
In TS 26.346 [5] the interface between the BMSC and the MBMS client for both unicast and broadcast related services and functions are defined. The interface between the MBMS client and the MAA is defined in the present document..
The focus of the present document is to define app-developer and web-friendly interfaces and programming structures to enable such an MAA to interact with the MBMS client.
An MAA that communicates with the MBMS client through APIs and possibly URL handlers as defined in the present document is referred to as MAA. The MBMS Client is a function that implements functionalities defined in TS 26.346 and provides APIs interfaces to expose relevant functionalities to an MAA.
Figure 5.1: General Reference Architecture for Client
Figure 5.2 shows a specific instantiation for the media streaming Application User Service using the Media Streaming MBMS-API. In this case the content formats conform to TS 26.247. The DASH client may be viewed as part of the MAA, and as 3GPP defines interfaces into a DASH client in TS 26.247 [7] also interfaces to the DASH client function are in focus of the present document.
Figure 5.2: Client Reference Architecture for DASH-over-MBMS Streaming
The control part of the MBMS-API are used for service discovery, registration, notifications, state changes and other control messages between the MAA and the MBMS client and for other control messages. The control part of the MBMS-APIs are defined in clause 6.
The data part interfaces are used to provide content delivered through MBMS User services to the MAA. However, the data is using formats and interfaces that are primarily MBMS independent such that for the MAA the delivery over MBMS is obscured. MBMS Client to application interfaces for data is primarily introduced in clause 7.