This book is intended to provide detailed and relevant information on the technologies related to the deployment of 3G systems, and focuses on UMTS. It is designed to cover the requisite knowledge to a reader coming from either a telecommunications or a computer networking background, examining how the different technologies are implemented in a UMTS context, and how the system evolves to deliver the service model. Throughout the text, examples of procedures are illustrated using trace files captured from UMTS networks to demonstrate their operation in practice.