Chapter 24: GPRS

General Packet Radio Services (GPRS) is a packet-based wireless communication service that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users. The higher data rates allow users to take part in video conferences and interact with multimedia Web sites and similar applications using mobile handheld devices as well as notebook computers. GPRS is based on Global System for Mobile (GSM) communication and complements existing services such circuit-switched cellular phone connections and the Short Message Service (SMS)

In theory, GPRS packet-based services cost users less than circuit-switched services since communication channels are being used on a shared-use, as-packets-are-needed basis rather than dedicated to only one user at a time. It is also easier to make applications available to mobile users because the faster data rate means that middleware currently needed to adapt applications to the slower speed of wireless systems are no longer be needed. As GPRS has become more widely available, along with other 2.5G and 3G services, mobile users of virtual private networks (VPNs) have been able to access the private network continuously over wireless rather than through a rooted dial-up connection.
GPRS also complements Bluetooth, a standard for replacing wired connections between devices with wireless radio connections. In addition to the Internet Protocol (IP), GPRS supports X.25, a packet-based protocol that is used mainly in Europe. GPRS is an evolutionary step toward Enhanced Data GSM Environment (EDGE) and Universal Mobile Telephone Service (UMTS).


Advantages of GPRS

GPRS brought mobile phone users out from the world of WAP, and into a world where Internet was finally available on mobiles. This in itself was a monumental feat, and hence GPRS took off with quite a bang. With GPRS, large amounts of data can be transferred to and from the mobile device over the Internet

Drawbacks

Since GPRS uses the cellular network’s GSM band to transmit data, more often than not, when a connection is active, calls and other network-related functions cannot be used. The data session will go on standby. This is a characteristic typical of the Class B GPRS device. There are Class A devices as well, where there are two radios incorporated into the device, allowing both features to run simultaneously. However, Class A devices tend to be more expensive, and by extension, less popular. Most mobile phones fall in the Class B category.
GPRS is usually billed per megabyte or kilobyte, depending on the individual service provider. However, this has changed in many places, where GPRS downloads are no longer charged as per usage, but are unlimited, and there is merely a flat fee to be paid every month.


EDGE

Enhanced GPRS goes by many monikers, but is essentially the next generation GPRS. It employs much the same technology from the user’s end; however it requires some basic modification at the transmitter’s base stations. Theoretically, EDGE can transmit and receive data three times as fast as a normal GPRS connection, subject of course to ideal conditions.
EDGE and GPRS are still used in lesser developed countries across the globe, mainly because hotspots are not as prolific as other more developed nations. Additionally, 3G technology has not spread across the globe, making GPRS a very viable option as of now

Sources: http://www.brighthub.com/mobile/symbian-platform/articles/16995.aspx
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