We dedicate this book to students 0/ computer science who want to under stand why the radio channel is at the heart of mobile communications, be it data or voice, and to students 0/ communications engineering looking for an introduction to the structure of the Internet protocols, and their application to mobile radio. We also welcome the practicing engineer' working for mobile network operators and infrastructure suppliers, and the application program mer looking for the underlying reasons for the problems they encounter in their daily work. Given that convergence of the information...