HOW THE STUFF

WORKs : GPRS

Under the guidance of:Prof. Pramod Kadam

INTRODUCTION

The General Packet Radio Service (GPRS) is an enhancement to the existing GSM network infrastructure and provides a connectionless packet data service.

GPRS is based on Internet Protocols (IP) and enables users to utilise a wide range of applications - email and internet or Intranet resources for instance, with throughput rates up to 40 Kbit/s.

The GPRS specifications are written by the European Telecommunications Standard Institute (ETSI), the European counterpart of the American National Standard Institute (ANSI).

HISTORY

• Like the GSM standard itself, GPRS will be introduced in phases.

Phase 1 became available commercially in the year 2000/2001.Point to Point GPRS, which is sending information to a single GPRS user, was supported, but not Point to Multipoint which is sending the same information to several GPRS users at the same time.

Phase 2 is not yet fully defined, but is expected to support higher data rates through the possible incorporation of techniques such as EDGE (Enhanced Data rates for GSM Evolution), in addition to Point-to-Multipoint support.

See below for a timeline history of GPRS.

HISTORY(contd.)Throughout 1999-2000

Network operators place trial and commercial contracts for GPRS infrastructure.Incorporation of GPRS infrastructure into GSM networks.

Summer of 2000 First trial GPRS services become available.Typical single user throughput is likely to be 28 kbps. For example, T-Mobil is planning a GPRS trial at Expo2000 in Hanover in the Summer of 2000.

Start of 2001 Basic GPRS capable terminals begin to be available in commercial quantities.

Throughout 2001 Network operators launch GPRS services commercially an roll out GPRS.Vertical market and executive GPRS early adopters begin using it regularly for nonvoice mobile communications.

2001/2002 Typical single user throughput is likely to be 56 kbps. New GPRS specific applications, higher bitrates, greater network capacity solutions, more capable terminals become available, fueling GPRS usage.

2002 Typical single user throughput is likely to be 112 kbps.GPRS Phase 2/EDGE begins to emerge in practice.

2002 GPRS is routinely incorporated into GSM mobile phones and has reached critical mass in terms of usage. (This is the equivalent to the status of SMS in 1999)

2002/2003 3GSM arrives commercially.Source: An Introduction to the General Packet Radio Service, January 2000

AppLications Of GPRSIn general, applications can be separated into two high-level categories: corporate and consumer. These include:

• Communications- E-mail, fax, unified messaging, intranet/Internet access

• Value-added services (VAS) -Information services, games• E-commerce - Retail, ticket purchasing, banking, financial trading• Location-based applications - Navigation, traffic conditions,

airline/rail schedules, location finder• Vertical applications - Freight delivery, fleet management, sales- force

automation• Advertising - Advertising may be location sensitive. For example, a user

entering a mall can receive advertisements specific to the stores in that mall.

GPRS ArchitectureGPRS is a data network that overlays a second-generation GSM network. This

data overlay network provides packet data transport at rates from 9.6 to 171 kbps. Additionally, multiple users can share the same air-interface resources simultaneously.

GPRS Network Element Defination

Mobile Station (MS) New Mobile Station is required to access GPRS services. These new terminals will be backward compatible with GSM for voice calls.

GPRS Base Station Subsystem(BSS)Each BSC requires the installation of one or more Packet Control Units (PCUs) and a software upgrade. The PCU provides a physical and logical data interface to the base station subsystem (BSS) for packet data traffic.

Gateway GPRS support node (GGSN)The Gateway GPRS Support Node acts as an interface and a router to external networks. The GGSN contains routing information for GPRS mobiles, which is used to tunnel packets through the IP based internal backbone to the correct Serving GPRS Support Node.

GPRS Support Nodes (SGSNs) The deployment of GPRS requires the installation of new core network elements called the serving GPRS support node (SGSN) and gateway GPRS support node (GGSN).

Databases (HLR, VLR, etc.) All the databases involved in the network will require software upgrades to handle the new call models and functions introduced by GPRS.

Internal Backbone

The internal backbone is an IP based network used to carry packets between different GSNs. Tunneling is used between SGSNs and GGSNs, so the internal backbone does not need any information about domains outside the GPRS network.

What’s Next?

We have now seen that GPRS is a crucial step in the mobile evolution, and it opens endless possibilities for application developers and users. The next step after GPRS can be either EDGE or UMTS (or both).• Enhanced Data rate for GSM Evolution (EDGE):

using a new modulation scheme to provide up to three times higher throughput (for HSCSD and GPRS)• Universal Mobile Telecommunication System

(UMTS): a new wireless technology using new infrastructure deployment.

Advantages

• Higher Data Rate: Users of GPRS benefit from shorter access times and higher data rates. In conventional GSM, the connection setup takes several seconds and rates for data transmission are restricted to 9.6 kilobits p/s.

• Easy Billing: In contrast to this, with packet switched services, billing can be based on the amount of transmitted data. The advantage for the user is that he or she can be "online" over a long period of time but will be billed based on the transmitted data volume.

To sum up, GPRS improves the utilization of the radio resources, offers volume-based billing, higher transfer rates, shorter access times, and simplifies the access to packet data networks.

DisAdvantages• LIMITED RADIO RESOURCES

There are only limited radio resources that can be deployed for different uses – use for one purpose precludes simultaneous use for another. For example, voice and GPRS calls both use the same network resources.

• SPEEDS MUCH LOWER IN REALITY Attaining the highest GPRS data transmission speed of 171.2 kbps would require a single user taking over all eight

timeslots; therefore, maximum GPRS speeds should be compared against constraints in the GPRS terminals and networks. It is highly unlikely that a GSM network operator would allow all timeslots to be used by a single GPRS user. The initial GPRS terminals are expected to only support one to three timeslots, which will be severely limiting to users. The reality is that mobile networks are always likely to have lower data transmission speeds than fixed networks. Mobile cellular subscribers often like to jump on the fact that a certain technology has high data transmission speeds, when the figure in all reality could be a theoretical number that is based on the perfect situation. Consumers should, therefore, compare all available mobile services and use the one that bests suits their needs. • NO SUPPORT OF MOBILE TERMINATED CALLS

There has been no confirmation by any mobile phone provider that initial GPRS terminals will support mobile terminated GPRS calls (receipt of GPRS calls on the mobile phone).When a mobile phone user initiates a GPRS session, they are agreeing to pay for the content to be delivered by the GPRS service. Internet sources originating unsolicited content may not be chargeable. A worse case scenario would be that a mobile user would then be made responsible for paying for the unsolicited junk content that they received. This is one main reason why mobile vendors are not willing to support mobile terminated GPRS calls in their terminals.

Conclusion

In my opinion, I feel that Nokia has the safest approach to GPRS. Instead of trying to perform so much at once, they offer consumers such things as web access. Once GPRS is made available, I think that it will really add to the reliability and mobility of cellular phones. Until then, consumers will have to wait until Verizon or Pacific Bell announce a deal on GPRS. The GPRS-enabled phones are not going to be great on their own; it is going to take service providers and operators to make them great. So, until then, even the most hopeful company won’t put a GPRS phone out on the market.

THANK YOU

Vinay SoniRoll No. 60