GENERAL PACKET RADIO SERVICE (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.

The key drivers for operators to evolve to GPRS networks are to:

Ø  Increase revenues by moving into the mobile data market, especially since the voice market has had profit margins squeezed with the commoditization of voice services.

Ø  Gain new subscribers who require mobile data services or do not want to invest in a PC to gain internet access.

Ø  Retain current subscribers by offering new services.

Ø  Reduce costs due to the efficient use of network resources.

Ø  Ease of adapting applications for mobile users because high data speeds mean that middleware is no longer required to convert fixed applications for mobile use.

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.

Applications for GPRS

Ø  Chat

Ø  Textual and Visual Information

Ø  Moving Images

Ø  Web Browsing

Ø  Document Sharing/Collaborative Working

Ø  Audio

Ø  Job Dispatch

Ø  Corporate E−mail

Ø  Internet E−mail

Ø  Vehicle Positioning

Ø  Remote LAN Access

Ø  File Transfer

Ø  Home Automation

Disadvantages:

Ø  GPRS packet loss phenomena occur. As the packet 
switching connection is worse than the number of circuit-switched connection, 
therefore, use the GPRS packet loss phenomena will occur. 

Ø   The actual rate lower than the theoretical value, GPRS 
data transfer rate to achieve the theoretical maximum 172.2kbps, must be only 
one user occupy all eight time slots, and no protection against mistakes. 

Ø   Termination of the Terminal does not 
support wireless functions, the absence of any declared a major handset 
manufacturer to support its GPRS wireless terminal to receive calls termination 
functions, this would be whether the market can successfully GPRS from other 
non-voice services market, grab the user's core problem.

Ø   Modulation is not optimal, GPRS-based GMSK (Gaussian 
Minimum-Shift Keying) modulation technique, compared to, EDGE modulation method 
based on a new 8PSK (eight-phase-shift keying), which allows wireless interface 
to support higher rates.

Ø  There is switching delay, GPRS packet data sent by different 
directions and eventually reach the same destination, then the data is 
transmitted via wireless link may occur during one or several packet loss or 
error situation.

References:


http://searchmobilecomputing.techtarget.com/definition/GPRS
http://www.mobilein.com/GPRS.pdf
http://www.brighthub.com/mobile/symbian-platform/articles/16995.aspx
http://www.blurtit.com/q3456268.html