This fully revised, updated and expanded second edition covers all aspects of today's networks, including how they are planned, formed and operated. After an introductory chapter on telephony, the book describes all of today's networks and considers how they link. Individual chapters then consider the principles, technologies and network structures relating to network components; transmission systems and networks; circuit switching systems and networks; signalling and control; data (packet) switching and routeing; and mobile systems and networks. The book concludes with a chapter designed to pull everything together, considering architecture, quality of service and performance, operations, network evolution and next generation networks. This is a companion volume to authored by Andy Valdar & Ian Morfett (ISBN: 9781849197458).