987) Radio Handbook, 23rd Edition, Sama. the land mobile services, Department of Trade and Industry, Parsons, J.D. and Gardiner, J.G. (1989) Mobile Communications London, MPT1315, March. Systems, 1st Edition, Blackie and Sons Ltd., Glasgow and Lon- DTI (1981b) Code of practice for selective signalling for use in the private mobile radio services, Department of Trade and Indus- Pascoe, R. (1989) The manufacturer's viewpoint, IBC Trunked try, London, MPT1316, January. Private Mobile Radio Conference, November. DTI (1987) Code of practice for radio site engineering, Department Philips (1980) Quasi-synchronous operation of two or more trans- of Trade and Industry, London, MPT1331, April. mitters, Philips Radio Communications Systems Ltd. publica- DTI (1988b) A signalling standard for trunked private land mobile tion ref. TSP361/2, April. radio systems, Department of Trade and Industry, London, Radiocom. (1990) Mobile Radio, U.K. Radiocommunications MPT1327, January. Agency, Annual Report 1990-1991, pp. 30-31. Erlang, A.K. (1918) Solution of some problems in the theory of probabilities of significance in automatic telephone exchanges, Post Office Electrical Engineers Journal, January. Cellular radio systems Malcolm Appleby Cellnet (Sections 47.1-47.4,47.6) Fred Harrison BSc CEng MIEE Cellnet (Sections 47.3,47.5,47.7) Contents Introduction 47/3 Principles of operation 47/3 Radio planning 47/5 Overview of systems 47/7 Detailed description of GSM 47/9 Services 47/14 Future developments 47/16 Conclusion 47/17 References 47/17 This page intentionally left blank Introduction 47/3 47.1 Introduction A cellular network will be allocated a number of radio frequen- cies, or channels, for use across its coverage area, this number being Cellular radio systems are by far the most common of all public dependent upon the amount of spectrum made available by the mobile telephone networks, the earlier (pre-cellular) networks now licensing authority and the channel spacing of the technical standard all being in decline. The basic princi