A telecommunications network is an electronic system of links, nodes and the controls that govern their operations to allow voice and data transfer among users and devices. This fully revised, updated and expanded second edition covers all aspects of today's networks, including how they are planned, formed and operated.

Andy Valdar has covered many aspects of telecommunications over his career, including network planning, international standards, training, marketing and product management, advising on the network and technical aspects of regulation, and developing network and technology strategy. He worked at BT for 30 years, spent 3 years in India working for the ITU, and 15 years at University College London, where he is currently a visiting Professor. He is also the co-author of the companion book Understanding Telecommunications Business and the earlier textbook: SPC Digital Telephone Exchanges.

• Chapter 1: An introduction to telephony


• Chapter 2: The many networks and how they link


• Chapter 3: Network components


• Chapter 4: Transmission systems


• Chapter 5: Transmission networks


• Chapter 6: Circuit-switching systems and networks


• Chapter 7: Signalling and control


• Chapter 8: Data (packet) switching and routeing


• Chapter 9: Mobile systems and networks


• Chapter 10: Numbering and addressing


• Chapter 11: Putting it all together


• Appendix 1: Standards organisations


• Appendix 2: List of ITU-T recommendation E.164 assigned country codes