This TS defines the service requirements from users' and operators' perspective for the support of IP multimedia applications through the IMS.
IP multimedia applications are supported by IP multimedia sessions in the IM CN Subsystem. IP multimedia sessions use IP connectivity bearers (e.g. GPRS as a bearer). Examples of IP multimedia applications include speech communication, real time multimedia applications, shared online whiteboards etc.
This TS, in general, does not standardise usage of IP multimedia applications, but instead identifies the requirements to enable their support.
In order to align IP multimedia applications wherever possible with non-3GPP IP applications, the general approach is to adopt non-3GPP IP based solutions.
The existing legacy tele- and supplementary services shall not be re-standardised as IP multimedia applications, and multimedia equivalent applications may be created with toolkits.
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.
ETSI TS 102 424: "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); Requirements of the NGN network to support Emergency Communication from Citizen to Authority"
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
the ability for the subscribers to access their IP Multimedia services over any access network capable of providing IP-connectivity, e.g. via:
3GPP accesses (e.g. E-UTRAN, UTRAN, GERAN)
Non 3GPP accesses with specified interworking (e.g. WLAN with 3GPP interworking, DOCSIS®, WiMAX™ and cdma2000® access)
Other non 3GPP accesses that are not within the current scope of 3GPP (e.g. xDSL, PSTN, satellite, WLAN without 3GPP interworking)
An IP multimedia session with two or more participants. Each conference has a "conference focus". A conference can be uniquely identified by a user. Examples for a conference could be a Telepresence or a multimedia game, in which the conference focus is located in a game server.
A conference with interactive audio-visual communications experience between remote locations, where the users enjoy a strong sense of realism and presence between all participants by optimizing a variety of attributes such as audio and video quality, eye contact, body language, spatial audio, coordinated environments and natural image size.
A set of functions, devices and network elements which are able to capture, deliver, manage and render multiple high quality interactive audio and video signals in a Telepresence conference. An appropriate number of devices (e.g. cameras, screens, loudspeakers, microphones, codecs) and environmental characteristics are used to establish Telepresence.
The conference focus is an entity which has abilities to host conferences including their creation, maintenance, and manipulation of the media. A conference focus implements the conference policy (e.g. rules for talk burst control, assign priorities and participant's rights).
Domain Name Owner:
The entity that is noted in the Internet (i.e. ICANN or one of its subsidiaries) as owning the Domain Name.
IM CN subsystem:
(IP Multimedia CN subsystem) comprises of all CN elements for the provision of IP multimedia applications over IP multimedia sessions
IMS Inter UE Transfer:
Transfer at the IMS-level of all or some of the media components of an IMS session between UEs under the control of the same end-user while maintaining service continuity.
IMS Network-Independent Public User Identity (INIPUI):
A Public User Identity in the form of a SIP URI where the Domain Name part is a Shared Domain Name.
IMS Network-Independent Public User Identity (INIPUI) User:
An entity that is identified by an IMS Network-Independent Public User Identity.
IMS Network-Independent Public User Identity (INIPUI) Host:
The entity that hosts and manages the INIPUIs.
IMS Network-Independent Public User Identity (INIPUI) Registry:
An entity that provides mapping of IMS Network-Independent Public User Identities and IMS NNI-Routable Identifiers.
IMS Network-Independent Public User Identity (INIPUI) Operator:
An IMS operator who provides IMS-based Services for a Shared Domain Name.
IP multimedia application:
an application that handles one or more media types simultaneously such as speech, audio, video and data (e.g. chat text, shared whiteboard) in a synchronised way from the user's point of view. A multimedia application may involve multiple media streams of the same or different types multiple parties, multiple connections, and the addition or deletion of resources within a single IP multimedia session. A user may invoke concurrent IP multimedia applications in an IP multimedia session.
IP multimedia service:
an IP multimedia service is the user experience provided by one or more IP multimedia applications.
IP multimedia session:
an IP multimedia session is a set of multimedia senders and receivers and the data streams flowing from senders to receivers. IP multimedia sessions are supported by the IP multimedia CN Subsystem and are enabled by IP connectivity bearers (e.g. GPRS as a bearer). A user may invoke concurrent IP multimedia sessions.
This is the mobility for those scenarios where the user changes the terminal used for network access at different locations. The ability of a user to access telecommunication services at any terminal on the basis of a personal identifier, and the capability of the network to provide those services delineated in the user's service profile.
Source: ITU-T NGN Focus Group.
Shared Domain Name:
The domain name in the IMS Network-Independent Public User Identity, and which is served by multiple IMS Operators.
A call where caller identity creation, modification or removal in call signalling results in an unauthorized or illegal use of this identity in the call., This typically occurs where the caller intends to defraud the called user or otherwise illegally obscure the real caller identity.
This is mobility for those scenarios where the same terminal equipment is moving or is used at different locations. The ability of a terminal to access telecommunication services from different locations or while in motion, and the capability of the network to identify and locate that terminal.
Source: ITU-T NGN Focus Group.
Unsolicited Communication (UC) denotes bulk communication in IMS where the benefit is weighted in favour of the sender. In general the receiver(s) of UC do not wish to receive such communication. UC may comprise of, e.g., "SPam over IP Telephony (SPIT)"  or "SPam over IP Messaging (SPIM)".
Web Real-Time Communications (WebRTC):
A set of browser extensions enabling web applications to define real-time services.
WebRTC IMS client:
A WebRTC client that allows a user to access IMS services from a device that supports a WebRTC-capable browser.
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
Data Over Cable Service Interface Specifications
IMS Network Independent Public User Identity
Web Real-Time Communications
Worldwide Interoperability for Microwave Access
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