4 Classification of MBMS User Services
22.2463GPPMultimedia Broadcast/Multicast Service (MBMS) user servicesRelease 17Stage 1TS
There exist many services and applications that can be provided over the application independent MBMS transport [2]. It is not necessary to standardise specific end user services because the deployment of particular applications and services over the capabilities provided by the 3GPP system is operator specific and outside the scope of standardisation. However, it is possible to classify MBMS User Services according to the method used to distribute these services.
There are four types of MBMS User Service considered within this specification.
Streaming services
A continuous data flow providing a stream of continuous media (i.e. audio and video) is a basic MBMS User Service. Like digital video broadcasting, supplementary information of text and/or still images (static media) is also important. For example, if text includes URLs of some content on the Internet, a user can easily access the content without entering the URL for herself. Still images may also be used for banner images that advertise some product or service. These static media need to be synchronized and displayed with audio/video streams.
Note: Streaming in the context of MBMS User Services may not be the same as that described e.g. within PSS [4].
File download services
This service delivers binary data (file data) over an MBMS bearer. An MBMS client (i.e. UE) activates an appropriate application, and utilises the delivered data. The most important functionality for this service is reliability. In other words, it is necessary that the user receive all the data sent in order to experience the service.
Carousel services
Carousel is a service that combines aspects of both the Streaming and File download services described above. Similar to the streaming service this service includes time synchronisation. However, the target media of this service is only static media (e.g. text and/or still images). Time synchronization with other media is also required. For example, text objects are delivered and updated from time to time. Still images may also be collated to display low frame-rate video. In common with the download service this service also includes reliability (typically 100% reliability is not always necessary). The benefit of this service is that it is possible over a low bit-rate bearer.
An example of an application utilising the Carousel service is a ‘ticker-tape’ type service in which the data is provided to the user repetitively and updated at certain times to reflect changing circumstances.
Television (TV) service
The Television service is an MBMS service consisting of synchronised streaming audio and visual components.