UMTS Forum Report 20, May 2002

Overview

The introduction of multimedia elements into mobile voice telephony dramatically changes the technology, industry, and market dynamics of a previously "all voice" mobile world. New network and handset technical capabilities, additional licence areas, and partnership opportunities are creating new challenges for mobile operators in a potentially $320 billion market(1). The marriage of mobility with Internet content and voice with multimedia services introduces requirements for interoperability between mobile networks and Internet networks and higher levels of service integration. The concept of the IP Multimedia Subsystem (IMS) was developed to address the resulting network and end-user requirements.

The understanding of the term IMS has changed over time as the standardisation process has evolved(2). Although there is no widely agreed definition of IMS today, the vision of what the "IMS approach" is designed to achieve remains. It adds significant new dimensions to the communications process. To facilitate understanding of this report, the UMTS Forum has agreed on the following definition of IMS:

IMS is understood to be an evolution of 3G/UMTS technology, which brings:

• the ability to deliver person-to-person real-time IP-based multimedia communications (e.g., voice,)


• the ability to fully integrate real-time with non-real time multimedia and person-to-machine multimedia communications,


• the ability for different services and applications to interact, and


• the ability for the user to very easily set up multiple services in a single session or multiple simultaneous synchronised sessions.

In theory, IMS provides robust, highly valuable services that integrate multimedia activities and allow for service interact with each other, thus enhances the natural, intuitive process of the end user, in whatever network he is operating, whether fixed, mobile, or roaming. The resultant integration and interaction of media types opens up new possibilities for far richer services than are available today.

The power of this interaction and integration is significant. It is the integration and interaction of services that can turn a frustrated user attempting to manage multiple activities on a small device into a satisfied customer using mobile services involving multimedia activities in a seamless fashion, following a natural, intuitive process. This is the experience that end users want from mobile data services and for which they will be willing to pay.

Still, qualitative differences in user experiences are difficult to quantify. Since IMS deployment is an option for operators, the need for IMS is a subject of debate amongst industry players, especially since many services can be emulated to some extent without IMS. However, consumers have clearly demonstrated a willingness to pay for the integration of services(3). In the mobile environment, ease-of-use has always been highly valued, and users will expect mobile data services that offer comparable convenience. To obtain high adoption levels, the mobile industry must also make mobile data services natural, intuitive, convenient and easy-to-use.

For the mobile operator, IMS provides the potential for interoperability of mobile and fixed networks and a robust service creation platform, which in turn can be used to increase competitive advantage. Although the UMTS Forum has forecast 3G service revenues at $320 billion in 2010, this potential will only be fully achieved with the robustness and high end-user satisfaction that IMS can provide.

This report explains the IMS concept and illustrates the benefits of IMS to the end-user experience as well as to the mobile operator. It illustrates that IMS provides a standardized solution for enhancing the end-user experience that cannot be easily duplicated by any known technology today. In addition, a vision of IMS is portrayed that includes interoperability between fixed and mobile IP networks that will further the possibility of a common satisfactory end-user experience across services, networks and devices.

(1) See UMTS Forum worldwide estimates for 3G revenue in Report 17.
(2) The term IMS was at one stage synonymous with an "all-IP" solution but now more often just refers to the provision of IP in the core network.
(3) For example, consumers buy second dial-up lines and subscribe to cable modem service in part so that they do not need to suspend one activity (making and receiving phone calls) to begin another (accessing the Internet).