14.1 Introduction

The introduction of cellular telephony in the UK in 1985 opened a window of opportunity to people in the business sector to communicate on the move. The system was based on analogue technology suited to speech and, although the coverage was not very good, the gradual increase in demand made it financially viable for the operators to expand the coverage area. There were a number of problems with this cellular system, including interference, low security and lack of common standards, even within European countries. The operators, in spite of low traffic, kept the quality of service acceptable by charging premium rates. Mobile telephone users could sometimes hear other users and it was possible to eavesdrop on users with cheap scanners. The result of non-standard cellular telephones even within European countries made roaming impossible. Higher call tariffs and the prices of handsets kept the mobile telephones beyond the reach of most people. A common cellular mobile system, at least within Europe, was needed.

To harmonise cellular mobile service within Europe a new cellular system, GSM (global system for mobile communications), was developed. This is a second generation system and is still in use across Europe and many other parts of the world. Unlike the first generation system it is digital, and as well as good speech quality, it can also provide data at 9.6 kbit/s, or at 40 kbit/s [1] using general packet radio service (GPRS). Recently some mobile handsets have become available with WAP (wireless application...