eneration of computer is faster and more cost and energy efficient than its predecessor. Similarly, it might be assumed that each new generation of cellular network provides faster connection speeds at lower cost with ever better energy efficiency and that this provides the basis for an improved financial return. Both of these assumptions are unproven. 2http://www.makingthemodernworld.org.uk/icons_of_invention/technology/1968-2000/IC.110/ Wireless Radio Access Network Hardware Figure seum/SSPL 12.1 10303264, 1832 Babbage difference engine. Reproduced with the permission of the Science Mu- introduced The first by practical Almon automatic telephone exchange based on electromechanical exchanges similar to Strowger in 1888 and was first introduced to the UK in 1912. switching was proving the the one illustrated in Figure 12.2 remained in use until the Strowger life cycle, point that telecoms equipment when fit for purpose can have a remarkably mid-1990s, long The development of electronic computing life cycles. particularly when compared to modern-day the US and rather experience practical deployment only being realised through painful and expensive with switching in the 1950s proved to be a surprisingly the world and every telecommunications network including cellular however, remain today at the heart later of in Europe and the rest of the world. These exchanges, the 1960s in up, maintaining are and completely fit for purpose for the job that they were every intended to network in manufactured clearing down telephone calls. Figure 12.3 shows an AXE digital do, setting switch by Ericsson. Making Telecoms Work Figure 12.2 Strowger exchange. Reproduced with the permission of the Science Museum. forget that exchanges have also been efficient at generating still and works distribut- in a ing power many provides a curious comfort. However, there is now a general from cen- We sometimes and for people the idea that an old-fashioned fixed phone assumption tralised that switching and transitioning to distributed architectur