Preface to the First Edition
The IMS (IP Multimedia Subsystem) is the 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. We have written this book to help engineers, programmers, business managers, marketing representatives, and technically aware users understand how the IMS works and the business model behind it.
We have distributed the topics in this book into four parts: an introduction, the signaling plane in the IMS, the media plane in the IMS, and IMS service examples. All four parts follow a similar structure; they provide both Internet and IMS perspectives on each topic.
First, we describe how each technology works on the Internet. Then, we see how the same technology is adapted to work in the IMS. Following these two steps for each technology provides the reader with a wider perspective. So, this book is not a commented version of the IMS specifications. It covers a much broader field.
Reading this book will improve anyone’s understanding of the Internet technologies used in the IMS. You will know how each technology is used on the Internet and which modifications are needed to make it work in the IMS. This way you will understand how the use of Internet technologies in the IMS will make it easy to take advantage of any current and future Internet service. Finally, you will appreciate how operators can reduce the operational ...
