9 Standardised Protocols and Capabilities
22.1053GPPRelease 17Services and service capabilitiesTS
This clause introduces a list of standardised protocols and capabilities that shall be supported for the control and creation of services. The access protocols and the execution environment described below are essential.
9.1 Access protocols
The access protocols shall allow the support of multimedia services. These services are characterised by the ability to dynamically change the number of participants and the number of connections during a call. The characteristics of the connections (confer the list of attributes used to describe a connection) may differ from one connection to another. They are negotiated during call set-up. They may be independently and dynamically re-negotiated on application (the telecommunication requirements of the application changes) or network initiative (change of network load conditions, during a handover procedure) during the call.
The application may require synchronisation between some of the connections. Later, this synchronisation shall not be lost during handover procedures.
Whenever a call is terminated in other types of networks, the negotiation shall take into account the limitations of these networks. Interworking shall be possible with PLMN, PSTN, ISDN and Internet networks. The access protocols shall allow a user equipment to have several calls active simultaneously.
9.2 Execution Environment
The execution environment is a set of standardised capabilities that shall allow the support of HE/SN specific services (i.e. both applications, teleservices and supplementary services). The execution environment shall be distributed between the IC card, terminal and network nodes. The terminal and the serving network capabilities shall be the only limiting factor for the support of the services designed to run on the execution environment. The execution environment is composed of the following building blocks;
– A standardised content description language for support of HE/SN specific user interfaces (both for information output and user input). This is intended only for platforms which are terminals.
– A standardised procedural language for support of HE/SN specific scripts. This language shall be common to all types of platforms. The scripts could be used for e.g. improving the user interface, adding new features to the terminal like the latest version of a codec, controlling the execution of a service.
– Standardised application programming interfaces for opening platform resources and capabilities to the scripts written with the standardised procedural language. These interfaces would be platform type dependent. The interfaces shall include primitives for accessing to the basic control functions, as illustrated on the figures 5 and 6 below.
Figure 5: Execution Environment in the User Equipment
Figure 6: Execution Environment in the Network
– Call states, messages, information elements, values of information elements shall serve as triggers for subsequent interaction with service logic. The list of triggers shall incorporate those provided by CAMEL, SIM Toolkit, MExE.
– Means to turn triggers on and off, and associate them with service logic will be standardised.
– A standardised certification scheme and security model with several levels of trusts in order to control the scripts access rights to the platform resources and capabilities. This would be used to allow e.g. the SP and the HE only to access to SIM/USIM data.
– Standardised protocols for allowing the download of content description pages and scripts in the platform.