From GSM to LTE-Advanced Pro and 5G, 4th Edition

1Global System for Mobile Communications (GSM)

At the beginning of the 1990s, the Global System for Mobile Communications (GSM), triggered an unprecedented change in the way people communicated with each other. While earlier analog wireless telephony systems were country specific and used only by a few, GSM was adopted around the globe and was used by billions of people during its peak years. This was mostly 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 the chapter on GPRS and EDGE, and for the Universal Mobile Telecommunications System (UMTS), which we describe in the chapter on UTMS and HSPA.

Although the first standardization activities for GSM date back to the middle of the 1980s, GSM is still widely used today. In recent years however, 4G LTE networks have become tremendously popular and a new service was standardized to support voice calls over the LTE radio network. This service is referred to as Voice over LTE (VoLTE) and is discussed in a separate chapter. Although efforts to roll out VoLTE are significant, many 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 ...