User's Manual Part 1

Product Overview — Introduction to GSM and GPRS 3
P/N 9002363 Revision 1.8
GPRS (General Packet Radio Service) is a digital, packet-switched, data extension to the
GSM voice and circuit-switched data network. In short, it substitutes binary data for the
voice data, which is subsequently routed to a data network, the Internet, rather than the
public switched telephone network. This enables high-speed data communication on a
global wireless standard, using the same frequency bands as the underlying GSM
network.
Advantages of GPRS
The advantage of a packet-based approach is that GPRS only uses the medium, in this
case the radio link, for the duration of time that data is being sent or received. GPRS has
one distinct advantage over the traditional GSM in that a channel is not dedicated to one
user. Communication channels are being used on a “shared-use as packets are needed”
basis rather than dedicated to one user at a time. This means that multiple users can
share the same radio channel. In contrast, with current circuit-switched connections,
users have dedicated connections during their entire call, whether they are sending data
or not. Many applications have idle periods during a session, with packet data, users will
only pay for the amount of data they actually communicate, and not the idle time.
Figure 2 GSM Vs. GPRS Data Transfer