illustrating how the aspects covered in the first three sections of the book can be put into practice. With his experience in delivering telecom projects, Jithesh has explained ele- ment management systems (EMS), network management systems (NMS), and operation/business support systems (OSS/BSS) through concepts, functionality descriptions, applicable protocols, and implementation guidelines. Each section touches upon definitions and models, explaining the complex concepts without losing simplicity or introducing technical jargon, and finally directing the user to further reading material to enable a better, more detailed understanding. I am honored to have had the opportunity to work directly with Jithesh in architectural design efforts for the telecom support systems and I am sure this Foreword book will be a valuable asset for academicians and professionals. It is with great pleasure that I introduce this book. I wish Jithesh all the success in this and future endeavors. Manesh Sadasivan Principal Architect, Product Engineering Infosys Technologies Limited (www.infosys.com) Preface The communication service industry is moving toward a converged world where services like data, voice, and value-added services are available anytime and any- where. The services are "always on," without the hassle of waiting or moving between locations to be connected or for continuity in services. The facilities offer easy and effortless communications, based on mobility and personalized services that increase quality of life and lead to more customer satisfaction. Service provid- ers will have much more effective channels to reach the customer base with new services and applications. With changes in services and underlying networks, the ease in managing the operations becomes critically important. The major chal- lenge is changing business logic and appropriate support systems for service deliv- ery, assurance, and billing. Even after much maturity of IMS technology, there has been a lag in the adoption of this service because of 