The IMS (IP Multimedia Subsystem) is the exciting new technology that will merge the Internet with the cellular world. It will make Internet technologies such as the web, email, instant messaging, presence, and videoconferencing available nearly everywhere.

The 3G IP Multimedia Subsystem (IMS) provides a thorough overview of the IMS and its technologies. Throughout, the authors first describe how each technology works on the Internet and then explain how the same technology is adapted to work in the IMS, enabling readers to take advantage of any current and future Internet service.

• Presents an introduction to the IMS - its goals, history, vision, the organizations involved in its standardization and architecture
• Discusses the signalling plane of the IMS including protocols, such as SIP and Diameter, used between the IMS architectural entities. Also describes how the IETF developed these protocols and how they are used in the IMS architecture
• Describes the media plane of the IMS and discusses Internet protocols that are not currently used in the IMS but may be in the future
• Provides SIP-based service examples such as presence, instant messaging and Push-to-Talk

Key features of the Second Edition include:

• New chapter on Next Generation Networks, including an overview on standardization, the architecture, and PSTN/ISDN simulation services.
• Fully updated chapter on the Push-to-talk over Cellular (PoC) service, covering the standardization in the Open Mobile Alliance (OMA), architecture, PoC session types, user plane, and the Talk Burst Control Protocol.
• Several expanded sections, including discussion of the role of the Open Mobile Alliance in the standardization process, IPv4 support in IMS, a description of the IMS Application Layer Gateway and the Transition Gateway, and a description of the presence data model.
• Updated material on the presence service, session-based instant messages with the Message Session Relay Protocol (MSRP), and the XML Configuration Access Protocol (XCAP).
• Supported by a companion website on which instructors and lecturers can find electronic versions of the figures.