A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number.
 GSM 01.04: "Digital cellular telecommunications system (Phase 2+); Abbreviations and acronyms".
 TR 21.905: "Vocabulary for 3GPP Specifications"
 TS 22.101: "Service principles"
 TS 22.105: "Services and Service Capabilities"
 TS 22.060: "General Packet Radio Service (GPRS) stage 1"
 TS 22.003: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Public Land Mobile Network (PLMN)"
Editor's note: Update spec name …
 TS 22.004: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General on supplementary services"
 TS 22.121: "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; The Virtual Home Environment"
 TS 22.057: ”; Mobile Station Application Execution Environment (MExE); Service description, Stage 1”
 TS 22.078: ”; Customised Applications for Mobile network Enhanced Logic (CAMEL); Service definition - Stage 1”
 GSM 11.14: ”Digital cellular telecommunication system (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity Module - Mobile Equipment; (SIM - ME) interface”
Editor's note: Stage 1 required
 > reference to 22.001…
 TR 21.978: Feasibility Technical Report - CAMEL Control of VoIP Services
3 Definitions and abbreviations
For the purposes of this TR the following definitions apply:
All IP network: an integrated telecommunications network that uses IP for the transport of all user data and signaling
Editor's note: may need this to elaborate from an IP services point of view (i.e. support of IP addresses and IP clients in the terminal)
Circuit switched (CS) domain: the CS domain comprises all network functionality for provision of bearer and teleservices in a circuit orientated manner
Circuit services: the services enabled by the circuit switched domain
Editor's note: CS domain and PS domain may require further elaboration
Emergency call: a mobile originated basic call that terminates at a national or local emergency center. Provision of location information to the emergency center is a mandatory feature in some countries
IP telephony: a voice call that uses IP for transport of all user data and signalling
Multimedia service: multimedia services are services that handle one or more media simultaneously such as speech (e.g. IP telephony), audio, video and data in a synchronised way from the user's point of view. A multimedia service may involve multiple parties, multiple connections, and the addition or deletion of resources within a single communication session
Operator specific service: any service offered to a mobile user that is not standardised by the 3GPP specifications
Packet switched domain: the PS domain comprises all network functionality for provision of bearers in a packet orientated manner
Release 99: 3GPP specified release of complete technical specifications for the definition and development of telecommunication services (including both CS and PS services) scheduled for completion in year 1999
Release 2000: 3GPP specified release of complete technical specifications for the definition and development of telecommunication services (including both CS and PS services) and also IP-based multimedia services (as defined in this TR) scheduled to be completed by the end of year 2000
Subscriber: a subscriber is an entity that has a subscription with an operator/service provider for the provisioning of specific services. The subscriber is also responsible for paying the bill for the services utilized
Supplementary service: a supplementary service modifies or supplements a basic telecommunication service (cf. 22.004 
Teleservice: the services identified in 22.003 .
User: a user is an entity associated with a subscriber that is capable of using the subscribed services
The communication industry is going through a period of explosive change, which is both enabling and driving the convergence of services. Data is becoming a more significant proportion of traffic compared to voice. Organisations and service providers are seeking ways to consolidate voice and data traffic platforms and services. With a number of technological solutions to choose from, the Internet Protocol (IP) is today considered the most promising platform on which to build the new integrated services.
The ease of developing new applications together with IP's ability to communicate between different networks has led to IP being seen as a convergence layer that promises to evolve from a mere data platform to a provider of a much larger variety of services. An increasing demand for bandwidth, connectivity features and economy that can not be supplied by the CS mobile networks in the present form, is leading the mobile telecommunications world to reinvent itself via IP.
The IP protocol has opened up a whole range of communication applications, which may allow operators to develop totally new value added services as well as to enhance their existing solutions. An example of this is currently being experienced on the Internet, where new services are developed and introduced at a pace never seen before in the telecommunications industry. The open architecture and platforms supported by the IP protocols and operating systems will lead to applications and new opportunities that are more difficult to replicate using a standard switched centralized solution. Thus, the main drivers for IP services are new services as the plain voice telephony is gradually moving to multimedia. IPT is seen as very important step forward to the mobile information society.
All IP offers the operators a complete solution for IP Telephony (IPT) and multimedia. The solution, based on the 3GPP Release 2000 standards, consists of terminals, GERAN or UTRAN radio access networks and PS domain evolved core network.
A major part of the evolution of new applications is foreseen to be in IP multimedia based services. One of the main objectives for 3GPP specifications is therefore is to ensure that the availability and behaviour of these applications when used via the 3GPP mobile access is at least as good as when used via other mobile access types.