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General Packet Radio Service (GPRS) and EDGE

In the mid‐1980s voice calls were the most important service in fixed and wireless networks.
This is the reason why GSM was initially designed and optimized for voice transmis-
sion. Since the mid‐1990s, however, the importance of the Internet has been constantly
increasing. GPRS, the General Packet Radio Service, enhanced the GSM standard to
transport data in an efficient manner and enabled wireless devices to access the Internet.
With Enhanced Datarates for GSM Evolution (EDGE), further additions were specified
to improve speed and latency.
While GPRS and EDGE were initially well suited for applications such as web browsing,
the complexity of web pages and the resulting amount of data grew considerably over time.
In addition, the number of devices on the network increased significantly over time as well
and network overload in areas not covered by LTE or UMTS are now commonplace. As a
consequence, the system is no longer suitable even for small‐screen web browsing in most
circumstances today and has become a niche technology, mainly useful for legacy applica-
tions such as embedded devices that only transfer small amounts of data by today’s standards.
As many embedded devices are only replaced or upgraded after a long usage period, how-
ever, it is likely that many EDGE networks will remain in service for quite some time to come.
The following overview of GPRS and EDGE is structured as follows: In the first part,
the advantages and disadvantages of GPRS and EDGE compared to data transmission
in classic GSM and fixed‐line networks are discussed. The second part of the chapter
then focuses on how GPRS and EDGE have been standardized and implemented.

2.1 Circuit‐Switched Data Transmission over GSM

As discussed in Chapter 1, the GSM network was initially designed as a circuit‐switched
network. All resources for a voice or data session are set up at the beginning of the call
and are reserved for the user until the end of the call, as shown in Figure 2.1. The dedicated
resources assure a constant bandwidth and end‐to‐end delay time. This has a number
of advantages:
Data that is sent does not need to contain any signaling information such as information
●
about the destination. Every bit simply passes through the established channel to the
receiver. Once the connection is established, no overhead, for example, addressing
information, is necessary to send and receive the information.

From GSM to LTE-Advanced Pro and 5G: An Introduction to Mobile Networks and Mobile Broadband,
Third Edition. Martin Sauter.
© 2017 John Wiley & Sons Ltd. Published 2017 by John Wiley & Sons Ltd.