duce broadband services, Northern Telecom Europe Ltd. Preface 'Time and technology wait for no man.' So goes the old saying and tions industry; telecommunication standards; the open system inter- this is certainly true in telecommunications where the past decade connect reference model; multiple access techniques, which are has seen technology advance at breakneck speed. Spurred on by used in a variety of telecommunication systems; network manage- international standardisation and the incentive of increased compe- ment; analogue and digital modulation; time division multiplexing; tition, changes have occurred which impact the environment of radio spectrum management; and digital transmission. every individual both at home and in the work-place. The final path describes telecommunication applications and rep- Against this background the task of producing a single volume resents the largest section of the book. The topics have been selected which covers the whole field of telecommunications seems Hercu- and grouped SO as to cover all the major areas within telecommuni- lean! How successful I have been in my particular labours only the cations, spanning the field of transmission and switching, the trans- reader can judge! mission media being copper, fibre optic or wireless. Both the public The book has been written by engineers for engineers. The prime and private networks are described. Some of the topics in this readership is practising engineers within industry and research section are: synchronous digital hierarchy; asynchronous transfer establishments. It will also be useful as a supplementary text for mode; the integrated services digital network; switching systems; undergraduate courses in telecommunications centrex; call management; voice processing; electronic data inter- The book aims to maintain a balance between new developments change; radio systems, such as paging, PMR, cellular, personal and established technology since, especially in telecommunications communication networks and microwaves; local and