This book provides a complete and comprehensive picture of the 3G UMTS charging services Evolved from offline traditional telecom billing, charging for IP services in mobile networks challenge; convergence charging is one of the main trends in the telecommunications industry. Main features: Presenting a complete picture of telecommunications charging system, including the evolution from 2G to 3G and all-IP network charging Discussing all aspects of management frameworks associated with charging and billing processes, focusing on major trends and developments in the telecommunications industry provides an overview of telecommunication networks such as PSTN , GSM, UMTS and IMS Covers the concept of telecom charging on mobile services and new technologies to implement an online charging system, such as the GTP? and Diameter protocols Includes coverage on network nodes and data flows in relation to the charging of mobile applications, such as IMS calls and download content Explain IP-based charging system online, the details of the protocol and the latest trends in charging for the mobile telecommunications industry This book is an invaluable resource for graduate students, telecommunications and IP engineers, network service providers and systems architect.