nsatlantic pictures relayed by satellite. After the success of Telstar developments progressed at a rapid rate and many more satellites were launched. Soon they were providing an enormous variety of services from communications to weather monitor- ing, and direct broadcasting to navigation. Satellites were by no means the only improvement for communica- tions. With electronic technology progressing at an ever increasing rate the need for personal communications was seen as the next major goal. As a result the idea of a truly mobile phone developed. The basic idea appeared at Bell Laboratories in the USA in the early 1970s but they were An introduction to radio 15 Figure 1.7 Telstar (courtesy NASA) not available for use until the 1980s. In fact the first systems were introduced in the UK in 1984. During the 1980s these first generation analogue systems experienced rapid growth. In view of the limitations of the analogue systems digital systems were envisaged. The most widely used digital system, GSM, was first introduced for commercial use in 1991 and its use spread rapidly. The GSM system was intended as a pan- European system, although its use spread beyond Europe. The acronym GSM initially stood for Groupe Spécial Mobile, but later this changed Global System for Mobile Communications. In the USA the first CDMA system was launched with the introduction of cdmaOne. With the success of the second generation systems, third generation systems capable of high data rate transmissions were devised. Since the first radio or wireless transmissions were made the field of radio has grown by enormous proportions. Now, more than ever, it is a cornerstone to our everyday life, both at home and at work. With technology progressing as it is, radio is likely to become even more important in the years to come, giving more flexibility and higher quality services. It is also likely to find an even greater variety of uses, many of which have not even been conceived yet. Radio tomorrow There is a very large amount of development bein