From GSM to LTE-Advanced Pro and 5G, 3rd Edition

1Global System for Mobile Communications (GSM)

At the beginning of the 1990s, GSM, the Global System for Mobile Communications, triggered an unprecedented change in the way people communicate with each other. While earlier analog wireless systems were used only by a few, GSM is used worldwide by billions of people today. This has mostly been achieved by steady improvements in all areas of telecommunication technology and the resulting steady price reductions for both infrastructure equipment and mobile devices. This chapter discusses the architecture of this system, which also forms the basis for the packet‐switched extension called General Packet Radio Service (GPRS), discussed in Chapter 2, for the Universal Mobile Telecommunications System (UMTS), which is described in Chapter 3 and Long‐Term Evolution (LTE), which is discussed in Chapter 4.

Although the first standardization activities for GSM date back to the middle of the 1980s, GSM is still the most widely used wireless technology worldwide. In recent years, however, 4G LTE networks have become tremendously popular and a new service was standardized to support voice calls via the LTE radio network. This service is referred to as Voice over LTE (VoLTE) and is discussed separately in Chapter 5. Although efforts to roll out VoLTE are significant, a large percentage of mobile voice calls are still handled by GSM and UMTS networks to which devices without VoLTE support fall back for this service. In addition, even if a device ...