Wednesday, March 7, 2012

General Packet Radio Service (GPRS)

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.

GPRS (General Packet Radio Service) offers high speed data services in GSM network. It uses Packet Mode Technique to transfer data and provides connectivity to Internet. Users will be able to browse Internet using handsets supporting Internet browsing. They will also be able use their e-mail accounts as is being done through landline Internet access. Also browsing of Internet from Laptops and Desktop computers is possible by connecting the computer with the GPRS enabled mobile handset through a data cable or Infrared connectivity.

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 middle-ware 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).

Services offered
GPRS extends the GSM Packet circuit switched data capabilities and makes the following services possible:
  • SMS messaging and broadcasting
  •  "Always on" internet access
  •  Multimedia messaging service (MMS)
  • Push to talk over cellular (PoC)
  • Instant messaging and presence—wireless village
  • Internet applications for smart devices through wireless application protocol (WAP)
  • Point-to-point (P2P) service: inter-networking with the Internet (IP)
  • Point-to-Multipoint (P2M) service: point-to-multipoint multicast and point-to-multipoint group calls.
If SMS over GPRS is used, an SMS transmission speed of about 30 SMS messages per minute may be achieved. This is much faster than using the ordinary SMS over GSM, whose SMS transmission speed is about 6 to 10 SMS messages per minute.

Protocols supported
GPRS supports the following protocols:
  • Internet protocol (IP). In practice, built-in mobile browsers use IPv4 since IPv6 was not yet popular.
  • Point-to-point protocol (PPP). In this mode PPP is often not supported by the mobile phone operator but if the mobile is used as a modem to the connected computer, PPP is used to tunnel IP to the phone. This allows an IP address to be assigned dynamically to the mobile equipment.
  • X.25 connections. This is typically used for applications like wireless payment terminals, although it has been removed from the standard. X.25 can still be supported over PPP, or even over IP, but doing this requires either a network based router to perform encapsulation or intelligence built in to the end-device/terminal; e.g., user equipment (UE).
When TCP/IP is used, each phone can have one or more IP addresses allocated. GPRS will store and forward the IP packets to the phone even during handover. The TCP handles any packet loss.

GPRS/GSM mobile classes

ETSI defines three different classes of mobiles for the hybrid GPRS/GSM network:

  • Class A (GSM/GPRS)

     Class A mobiles can attach to the GPRS and GSM network simultaneously. They can receive GSM voice/data/SMS calls and GPRS data calls. For this to happen, the mobiles must monitor both the GSM and GPRS networks for incoming calls. Class A mobiles also can make and receive GPRS and GSM calls simultaneously. Operational requirements of this class include an additional receiver in the mobile phone for neighbor cell measurements.

  • Class B (GSM/GPRS)

     This class is similar to class A with the exception that Class B mobile phones will not support simultaneous traffic. If a GPRS call is ON, the phone cannot receive GSM calls and vice versa.

  • Class C (GSM or GPRS) 

       This class of mobile phones will have both GSM and GPRS functionality but will attach to only one network at a time. Thus, if the phone is attached to the GPRS network, it will be detached from the GSM network and will not be able to make or receive GSM calls. Conversely, if it is attached to the GSM network, it will not be able to make or receive GPRS calls. Today most manufacturers are building Class B phones.
In the GPRS architecture, the fundamental cause of security threats to an operator’s network is the inherent lack of security in GPRS tunneling protocol (GTP). GTP is the protocol used between GPRS support nodes (GSNs). Communication between different GPRS networks is not secure because GTP does not provide any authentication, data integrity, or confidentiality protection. Implementing Internet Protocol security (IPsec) for connections between roaming partners, setting traffic rate limits, and using stateful inspection can eliminate a majority of the GTP’s security risks. Juniper Networks security devices mitigate a wide variety of attacks on the Gp, Gn, and Gi interfaces.




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4 comments:

  1. RaysunMarch 7, 2012 at 8:40 AM

    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.

    ReplyDelete
  2. ronronMarch 8, 2012 at 5:23 AM

    GPRS use Packet Mode Technique to transfer data and provides connectivity to Internet.

    ReplyDelete
  3. kingMarch 8, 2012 at 7:59 AM

    other advantage of using GPRS is that the Internet is access even in remote areas and can down load games, ring tones, images by visiting different web sites.

    ReplyDelete
  4. RhoneilLuayon(Gothic)March 8, 2012 at 11:41 PM

    GPRS packet based services should cost users less than circuit switched services since communication channels are being shared and are on as packets are needed basis rather than dedicated to only one user at a time. It should also be easier to make applications available to mobile users because the faster data rate means that middleware currently needed to adapt applications from fixed lines rates to the slower speed of wireless systems will no longer be needed.

    ReplyDelete

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