This book is about the Universal Mobile Telecommunication System (UMTS). UMTS is the most important of the third generation (3G) mobile phone systems, which are gradually replacing the older second generation systems such as the Global System for Mobile Communications (GSM). 3G systems provide much faster communications than their predecessors, and this allows them to offer the user a wider range of services than before, such as high speed Internet access, video and interactive games.

My aim in this book has been to write a technical introduction to UMTS. As an important part of this, I have tried to give the reader a system level understanding of what all the different parts of UMTS are, and how they relate to each other. Such an understanding is hard to gain from the UMTS specifications or from the more specialised books on the subject, but is precisely what the newcomer to the system needs.

At the same time, I have kept the book short enough that it can be read cover to cover in a weekend. To do this, I have consciously left out many of the details that can be found in the specifications or in some of the other technical books on the subject. Accordingly, you won't find in this book an exhaustive description of issues such as the bit layouts in the physical channels, the contents of the system information blocks or the different types of measurement event.