3G mobile systems, through the increase in available bandwidth, offer new possibilities and services. One of these new services will be the ability to stream sound and movies to mobile devices. Streaming is a mechanism whereby media content can be rendered at the same time that it is being transmitted to the client over the data network. Streaming services are required whenever instant access to multimedia information needs to be integrated into an interactive media application. This has to be seen in contrast to other multimedia services like for instance MMS where multimedia content is delivered to the user asynchronously by means of a "message". Interactive applications that use streaming services include on-demand and live information delivery applications. Examples of the first category are music, music videos and news-on-demand applications. Live delivery of radio and television programs are examples of the second category, this could e.g. make it possible to listen to domestic radio while abroad. A web server works with requests for information, it delivers that particular information as fast as possible, completes the transaction, disconnects and goes on to other requests. A client connects to a web server only when it needs information. This strategy works well as long as pictures and text are to be received. If a client wants to watch video or listen to audio, the entire file must be received before it can be played. The problem is that these kinds of files can be very large thus potentially causing storage problems in the client and resulting in long start-up latency. A streaming service improves this by allowing the media to be consumed as it is received, thereby reducing the latency and removing the need to store the media. In addition to providing the streaming mechanism the PSS also encompasses the composition of media objects thereby allowing compelling multimedia services to be provisioned. For instance, a mobile cinema ticketing application would allow the user to view the film trailers.

This Technical Specification defines the stage one description of the Packet-switched Streaming Service (PSS). Stage one is the set of requirements that shall be supported for the provision of a streaming service, seen primarily from the user's and service providers' points of view but also includes the service capabilities of the PSS itself This TS includes information applicable to network operators, service providers, terminal and network manufacturers. This TS contains the core requirements for the Packet-switched Streaming Service (PSS), which are sufficient to enable a range of services.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

• References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

The Figures 01 and 02 shows the basic entities involved in the Streaming service and how they connect. Clients initiate the service and connect to the selected content server. Content servers can generate live content e.g. video from a concert. User profile and terminal capability data can be stored on a network server and will be contacted at the initial set up. User Profile will provide the Streaming service with the user's preferences. Terminal capabilities will be used by the Streaming service to decide whether or not the client is capable of receiving the streamed content. Portals are servers allowing convenient access to streamed media content. For instance, a portal might offer content browse and search facilities. In the simplest case, it is simply a Web/WAP-page with a list of links to streaming content. The content itself is usually stored on content servers, which can be located elsewhere in the network.

The user shall be able to use the PSS in a secure manner. Mechanisms shall be provided to ensure that the media objects are only sent to and accessed by the intended end-user(s).

• PSS shall support end-to-end security (e.g. between the server and the Streaming client).

PSS should support various charging mechanisms, for example, time base charging, volume based charging, event based charging, content based charging. It shall be possible to include the following streaming specific data, as a minimum, in the CDRs as charging information:

• streaming type (e.g. real-time or non real-time),
• volume of streaming content delivered
• volume of data delivered
• time of start of delivery
• duration
• Qos, including transmission rate, packet loss ratio, transfer delay(latency ,jitter),
• Streaming service sender / -recipient
• number of Streaming events sent
• number of Streaming events received.
• Media type
• Content id (the particular content stream being accessed)

PSS shall support the 3GPP DRM mechanism (see ref [9])

The standard shall permit interworking with other streaming technologies.

 

• The PSS shall define a common file format (common to all download mechanisms) for easy service interaction with other multimedia delivery services defined in 3GPP (e.g. MMS).
• It shall be possible for the PSS to interact with the MMS and other 3GPP multimedia delivery services. The interfaces and protocols used between the PSS and other 3GPP multimedia delivery services shall be standardized.
• The PSS shall define a server file format to provide easy interoperability between Content Creators and Service Providers.

Some domains may benefit from the convenient, ubiquitous and more reachable mobile device. A second challenge for operators and service providers is to utilise the 'mobile' effect for providing value-added services. We believe successful wireless data services will exploit the unique mobile characteristics. A non-exhaustive list of these mobile service characteristics can be presented as follows:

• Content everywhere: Locally interactive content and remote interaction (back-channels) in relation to interactive streamed media, including rewind/pause functions will define the key features for providing attractive and friendly contents for distance learning applications and other information services (news, financial, etc). Scanning headlines of daily newspapers is already about to become a popular 'waiting time' activity. In the learning context, one may imagine that a student will be able to select on his portal page the school section from which he will be able to view a list of classes that will take place and to preview current live lectures, required readings, etc.
• Lifestyle facilitators: When discovering a tourism site one may want access to leisure and travel information (e.g., flight deals, package holidays, quality hotels, fun activities, etc). During weekend outings and holidays, a common use case will be the following: one uses the location finder to find the nearest shop where he can find the desired object at the desired price, a navigation guide helps him to determine how he will get to the shop or store.
• Entertainment services: Gaming is already being touted as the biggest generator of minutes of use for interactive cellular services in Asia and Europe. Features such as streamed 2D graphics, 3D objects, complex animations and multi-user technologies will attract more subscribers by allowing richer experiences with more fancy navigation schemes. As an example of future scenario, when online-games will become very popular, 3D-graphics of the new multimedia mobile phones allow a bunch of fancy games. Players can join multi-user games, some use a virtual location as well as the real location in a funny interactive way

This set of multimedia applications should be foreseen for the Release 5 and the future releases. Service Examples All these service examples could use or be enhanced by PSS. Infotainment Video on demand, including TV Audio on demand, including news, music, etc Multimedia Travel Guide Karaoke - song words change colour to indicate when to sing Multimedia information services:

• Sports
• News
• Stock quotes
• Traffic

Weather cams - gives information on other part of country or the world Edutainment Distance learning - video stream of teacher or learning material together with teacher's voice or audio track. How to? service - manufacturers show how to program the VCR at home Corporate Field engineering information - junior engineer gets access to on line manuals to show how to repair the central heating system Surveillance of business premises or private property (real-time and non real-time) M-commerce Multimedia Cinema ticketing application On line shopping - product presentations could be streamed to the user and then the user could buy on line.