The rapid expansion of the field of telecommunication networks call for a new edition to assist the readers with development of understanding towards new telecommunication technologies. This well-accepted textbook, now in its Second Edition, is designed for the final-year undergraduate and the first-year graduate students in electronics and communication engineering and allied subjects. It fulfils the need for a suitable textbook in the area of telecommunication switching systems and networks. The text covers, in a single volume, both switching systems and telecommunications networks. The book begins with a brief discussion on the evolution of telecommunication. It then goes on to give a classification scheme for switching systems, and describes the basic components of a switching system and the fundamental concepts of network structures. It provides an in-depth coverage of fibre optic communication system and the traffic engineering concepts. A distinguishing feature of the book is the thorough treatment of the most important telecommunication networks, viz. the public switched telephone network (PSTN), the public data network (PDN), and the integrated services digital network (ISDN). Worked-out examples and exercises would be of considerable assistance to the reader in understanding all aspects of telecommunication engineering. NEW TO THIS EDITION • Sections on SONET, WDM, and DWDM in Chapter 7 • New section on Broadband ISDN and related technologies in Chapter 11 • A new chapter on Mobile Communication which covers almost all aspects of the cell planning and mobile channels • A new chapter on Satellite Communication which gives sufficient introductory knowledge of the satellites, satellite orbits, and orbital theory • Satellite link budget analysis (with examples) in Chapter 13.