In this chapter we describe the motivation for writing this book and explain its scope. Some remarks on nomenclature are given in order to help the reader with a fast and easy start. The concept and structure of the material compiled is p- sented, followed by some hints on how to make best use of it. Finally the status of standardization, on which this book is based, is described. 1. 1 Motivation Probably the main motivation for starting to draft the script for this book, and eventually to finish it, was the desire to have a more or less complete, up-to-date overview of mobile network technology for myself, not only when starting my work in 3GPP standardization, but also continuously afterwards. I realized that some of my colleagues were in search of the same, and I extrapolated to the point where, after 3G technology is in in the field for some time, the huge, new step of development would be implemented and finally exist in reality: a manifold of s- tem designers, SW engineers, solution consultants, test personnel, field tech- cians and service staff would have to deal with the underlying architecture, c- cepts and detailed procedures. Yet, I noticed in my roughly two decades of work as a engineer (in a few diverse fields) that compact, consistent, and balanced ov- view material, suitable for the wider audience is scarce.