TABLE OF CONTENTS In Chapter 10, we discuss general trends in the convergence of wireless and IP. We have seen how, in moving towards all-IP networks, network providers would like to provide more than just IP connectivity. In versions of UMTS from Release 5 onwards, provision of basic multimedia over IP services will be handled by a new network subsystem, the IMS [sometimes also known as IP multimedia core network subsystem (IM CN SS)]. These basic multimedia over IP services include the establishment, management, and termination of voice, video, and other sessions carried over IP. Additionally, IMS takes a layered and flexible approach to service provision, by providing hooks for application servers to offer further services built upon the basic service capabilities.
This chapter provides a good example of how wireless and IP come together in a real telecommunications system, to provide basic and advanced telecommunications services. It ties together elements from all the other chapters in the book so far, and illustrates some of the system design choices involved in wireless IP telecommunication system design.
Since IMS is a new, evolving subsystem, we base this chapter on the UMTS Release 5 version of IMS.
In moving towards an all-IP network, the evolving releases of UMTS continue to provide voice services. One reason for this is that despite the growth in volume and diversity of data traffic, voice continues to be important for the foreseeable future because it supports such a basic and fundamental form of human communication.
