- The below shows the MBMS user service entities and their inter-relations.
MBMS User Service à à à MBMS User Service Session à à à Unicast or MBMS Bearer
- An MBMS user service is an entity that is used in presenting a complete service offering to the end-user and allowing him to activate or deactivate the service.
- A single service entity can contain multiple distinct multimedia objects or streams, which may need to be provided over various MBMS download or MBMS streaming sessions.
- The MBMS User Service Session may be mapped either on MBMS Bearer Services or on unicast bearer services.
- A download session or a streaming session is associated with either an unicast bearer or one or more MBMS bearers and a set of delivery method parameters specifying how content is to be received on the mobile side.
- A set of one or more MBMS bearers can be used for delivering data as part of an MBMS download or streaming session. As an example, the audio and visual part of video stream can be carried on separate MBMS bearers. However, it is recommended to transfer MBMS download and/or streaming sessions, which belong to the same MBMS user service on the same MBMS bearer service.
- An MBMS bearer (identified by IP multicast address and APN) might be used in providing data to more than one MBMS download or streaming session (3GPP TS 22.246)
1.1. MBMS User services
MBMS User Service
- MBMS user services are services an operator may provide to subscribers. MBMS user services use the capabilities of MBMS. The operator may provide such services on his own or in collaboration with third party service providers.
- MBMS user services are based on broadcast- or multicast services, which are defined in TS 22.146. MBMS user services shall be bearer agnostic to enable access via generic IP access systems. An MBMS user service may use one or more broadcast- or multicast services at a time within the MBMS service area bound to this user service.
- It shall be possible for one application independent MBMS transport service to be used by more than one MBMS user service at a time. If an MBMS user service makes use of several application independent MBMS transport services then these may only consist of either broadcast or multicast services, but not of a combination of both. When necessary, within a single MBMS user service, it shall be possible to synchronize the media sessions.
- Service classes denote a classification of MBMS user services according to their usage.
1.2. Types of MBMS User services
Types of MBMS User Service
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
- File download services
- Carousel services
- Television (TV) service
MBMS Service classes (or types) in roaming:
In case of roaming a user shall be able to enjoy services as follows:
- A user shall be able to activate services that are provided locally in the visited network, as allowed by the user’s home environment (e.g. local tourist information).
- A user subscribed to a service class in the HPLMN shall be able to enjoy equivalent services in the same service class as provided by a visited PLMN without explicit subscription in the VPLMN (e.g. weather forecast).
- A user subscribed to a service class in the HPLMN shall be able to have access to home contents provided via a visited PLMN without explicit subscription in the VPLMN (e.g. enjoy subscribed service while roaming)
1.3. 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.
1.4. 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.
1.5. 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 (like Stock Market Information) service in which the data is provided to the user repetitively and updated at certain times to reflect changing circumstances.
1.6. Television (TV) service
- The Television service is an MBMS service consisting of synchronised streaming audio and visual components. It shall be possible for a user to select between different content within the MBMS Television Service.
- The MBMS service shall add no more than 1 second when switching between different TV streams to any delay introduced with regards to the coding of the TV stream.
- It shall be possible for an operator to configure the MBMS Television service so that the typical switching time, from the end user's perspective, does not exceed 2 seconds.
- Handover within the same radio access technology shall be transparent to the user.
- Handover between different radio access technologies should be performed without any user perceived interruption.
- Note: The quality of the MBMS Television service may change depending on the capabilities of the target network.
1.7. MBMS User Service examples
MBMS user services may be classified (below) into several service examples, which are characterized by
Service Example | Media Type | Distribution Scope (Operation Mode) | MBMS User Service Type | Application Bit rate |
Reliable text distribution (eg Local news) | Text | Multicast | 2-Download | Up to 10 kbps |
Unverified text distribution | Text | Multicast, Broadcast | 3-Carousel, 2-Download | Up to 10 kbps |
Secure data download | File; eg UE type specific and/or application specific software | Multicast | 3-Carousel, 2-Download | Up to 10 kbps |
Text distribution with still images and/or low quality video | Text, Still images, Video (e.g. 3fps) | Multicast, Broadcast | 3-Carousel, 2-Download | Up to 32 kbps |
Audio streaming | Stereo Audio | Multicast | 1-Streaming | Up to 48kbps |
Audio streaming | Stereo Audio | Broadcast | 1-Streaming | Up to 48kbps |
Audio download | Stereo Audio | Broadcast | 2-Download | Up to 48kbps |
Audio download | Stereo Audio | Multicast | 2-Download | Up to 48kbps |
Audio distribution with low quality video | Stereo Audio, Video (e.g. 3fps) | Broadcast | 1-Streaming | Up to 128kbps |
Audio distribution with low quality video | Stereo Audio, Video (e.g. 3fps) | Multicast | 1-Streaming | Up to 128kbps |
Audio distribution with low quality video | Stereo Audio, Video (e.g. 3fps) | Broadcast | 2-Download | Up to 128kbps |
Audio distribution with low quality video | Stereo Audio, Video (e.g. 3fps) | Multicast | 2-Download | Up to 128kbps |
Video streaming | Video & supplementary data (e.g. text, still images) | Broadcast | 1-Streaming | Up to 384 kbps |
Video streaming | Video & supplementary data (e.g. text, still images) | Multicast | 1-Streaming | Up to 384 kbps |
Video distribution | Video & supplementary data (e.g. text, still images) | Broadcast | 2-Download | Up to 384 kbps |
Video distribution | Video & supplementary data (e.g. text, still images) | Multicast | 2-Download | Up to 384 kbps |
General Content Distribution | Video, Audio, File Data (binary data) | Broadcast | 3-Carousel, 2-Download | Up to 384 kbps |
General Content Distribution | Video, Audio, File Data (binary data) | Multicast | 3-Carousel, 2-Download | Up to 384 kbps |
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