MBMS User Services are classified according to the method used to distribute these services. There are three types of MBMS User Service considered within 3GPP:
- 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.
- 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.
Some example service scenarios for MBMS User services are as follows:
Text notification service
Precondition: The user is a member of a MBMS Multicast group supplying text alerts.
Actions: At an appropriate time an alert is sent to the user's mobile handset using the MBMS Multicast service.
Post condition: The user receives the alert using her mobile handset and takes appropriate action.
Local Area Information distribution (Scenario 1)
Media: Text & Text with low quality video
Precondition: The user is a registered with an MBMS Broadcast service providing information to the local area such as local news and weather reports.
Actions: Information in the form of text & text with low quality video is distributed to the user's mobile handset by the MBMS Broadcast service. The text may be scrolled on the mobile handset. The information distributed by the MBMS Broadcast Service may be repeated periodically and updated at appropriate intervals.
Post condition: The user is aware of events that have taken place within the local area and can view appropriate images.
Local Area Information distribution (Scenario 2)
Media: Video & Audio
Precondition: The user is a registered with an MBMS Broadcast service providing streaming audio and/or visual content related to a local area, such as audio and visual guides to local attractions, traffic reports etc…
Actions: Audio and/or visual information is distributed to the user's mobile handset by the MBMS Broadcast service. The user is able experience the content on her mobile device. The user is able to receive the MBMS broadcast service continuously throughout the local area. At some points the user is able to interact with the content of the MBMS Broadcast service in order to access specific information regarding items being presented within the content. The user is able to activate/deactivate reception of the MBMS service at any time.
Post condition: The user experiences and interacts with the content provided and is therefore able to obtain information regarding the local area and act accordingly.
Media: Text & Text with still images
Precondition: The user is a member if a MBMS multicast group providing personally tailored content such as targeted advertising etc…
Actions: Information is provided by the MBMS Multicast service in the form of text & text with still images, to the user's mobile handset based on her subscription to the Multicast group and current location.
Post condition: The user receives tailored content and is able to utilize this as appropriate.
Media: Stereo Audio
Precondition: The user is registered with an MBMS Broadcast service providing stereo quality streaming audio content.
Actions: Audio content is distributed to the user's mobile handset by the MBMS Broadcast service. Whilst listening to the audio content the user is able to interact with the service using the capabilities of the mobile handset (e.g. messaging).
Post condition: The user is able to enjoy the stereo quality audio content and interacts with the service as appropriate.
Media : File
Preconditions :Need to update/download software in UE, the User is subscribed to MBMS User Service, OTA download is supported in UE
Actions: The operator compiles a list of affected users and sends them a text message (using MBMS) explaining the problem and that the user should select the MBMS application on their handset. The user sees a message inviting her to activate the Enable Upgrade, selects 'yes' and the software patch transferred by the MBMS User Service, including verification parameters.
Postcondition :The software once installed allows the user to view the MMs that she couldn't see before.