 (1990) Digital Communications, Kluwer Academic Narrowband gaussian noise is called Rayleigh noise and it is defined Publications. as narrowband if the noise bandwidth is small compared to the midband frequency. It has the appearance of a sinusoidal carrier at Slater, J.N. (1988) Cable Television Technology, John Wiley. This page intentionally left blank telecommunications industry Fraidoon Mazda MPhil DFH DMS MBIM CEng FIEE Northern Telecom Contents 11.1 Introduction 11/3 The telecommunications model 11/3 11.3 The key players 11/4 11.4 Economic considerations 11/10 Services and technology 11/13 References 11/18 This page intentionally left blank Introduction 11/3 11.1 Introduction Telepoint (mobile public telephony) licences were granted to several operators in the UK in 1989, but the service failed to catch It has long been recognised that availability of information is crucial on immediately. The technology was available to provide the ser- if a country is to be globally competitive. Telecommunications is the vice but there was no customer demand for it. Similarly ISDN was method for transmission of this information. In fact the word tele- developed as a technology long before its widespread acceptance by matics is derived from a contraction of the French words for tele- users, primarily because of lack of suitable services. However communications and computing. personal global communications, also known as 'any' communica- The requirements placed on a telecommunications system are: tions (anyone, anytime, any place) was in demand as a supplement or even replacement for fixed networks, but the technology to 1. A modern infrastructure to support the economic growth of the deliver the service at an economic price (facilities for global roam- nation. ing and compact handsets) were to come much later. 2. Availability of a range of services at prices which the user can Technology is subject to frequent change or evolution (Gilhooly, afford. 1990) which means that: 3. Continual investment in the infrastructure, whic