final gprs edited

7/31/2019 Final GPRS Edited

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INTRODUCTION

GPRS stands for General Packet Radio

Service, and is a relatively low cost

technology that offers packet-based

radio service and allows data orinformation to be sent and received

across mobile telephone networks.

Designed to supplement the existingmobile technologies, like GSM, CDMA,

TDMA etc.


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It is a packet oriented mobile data service

It is available to all users having 2G communication system,as well as inthe 3G systems.

In 2G systems, GPRS provides data rates of 56- 114 kbit/second.

GPRS data transfer is typically charged per megabyte of traffic transferred.

2G cellular systems combined with GPRS are often described as 2.5G, thatis, a technology between the second (2G) and third (3G) generations ofmobile telephony.

GPRS is classified as a 2.5G technology because it builds upon existingnetwork infrastructure whereas with 3G networks it normally requires buildingan entirely new network.


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WHAT DOES GPRS DO?

GPRS provides a permanent connectionwhere information can be sent or receivedimmediately as the need arises, subject toradio coverage.

No dial-up modem connection isnecessary. This is why GPRS users are sometimes

referred to be as being anytime-anywhere"always connected".

The GPRS traffic structure is based on afixed cost, dependent on the quantity ofdata required.


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Services offered

"Always on" internet access

Multimedia messaging service (MMS)

Instant messaging

Internet applications for smart devices

through wireless application protocol

(WAP)

Point-to-point (P2P) service: inter-

networking with the Internet (IP)


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GPRS TERMINALS

Class A

MS supports simultaneous operation of GPRS andGSM services

Class A terminal can make or receive calls on twoservices simultaneously

Class B

MS able to register with the n/w for both GPRS &GSM services simultaneously. It can only use one ofthe two services at a given time.

Users can make or receive calls on either a packet ora switched call type sequentially, but notsimultaneously.


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Class C

MS can attach for either GPRS or

GSM services

a Class C terminal can make or

receive calls from only the manually

(or default) selected service


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GPRS ARCHITECTURE

GPRS Subscriber Terminals

GPRS BSS

GPRS Networks Node

GPRS Mobility Management


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GPRS SUBSCIBER TERMINALS

New terminals are required because existingGSM phones do not handle the enhanced airinterface, nor do they have the ability topacketize traffic directly.

A variety of terminals will exist, including ahigh-speed version of current phones tosupport high-speed data access.


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GPRS BSS

Each BSC will require the installation of oneor more PCUs (packet control unit) and asoftware upgrade. The PCU provides aphysical and logical data interface out of thebase station system (BSS) for packet data

traffic. The BTS (base transceiver site) may also

require a software upgrade, but typically willnot require hardware enhancement.


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GPRS NETWORKS NODE

In the core network, the existing MSCs arebased upon circuit-switched central-officetechnology, and they cannot handle packettraffic.

Thus two new components, called GPRSSupport Nodes, are added:

Serving GPRS Support Node (SGSN)

Gateway GPRS Support Node (GGSN)

BACK


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SGSN The SGSN can be viewed as a "packet-

switched MSC;" it delivers packets to mobilestations (MSs) within its service area

SGSN performs mobility managementfunctions such as mobile subscriber

attach/detach and location managementGGSN GGSNs are used as interfaces to external IP

networks such as the public Internet

GGSNs maintain routing information that isnecessary to tunnel the protocol data units(PDUs) to the SGSNs that service particularMSs


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GPRS MOBILITY MANAGEMENT

Mobility management within GPRS builds on the

mechanisms used in GSM networks.

As a MS moves from one area to another,

mobility management functions are used to track

its location within each mobile network.


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OTHER ELEMENTS

BG (Border Gateway) (Not defined within GPRS) Routes packets from SGSN/GGSN of one

operator to a SGSN/GGSN of an otheroperator

Provides protection against intruders fromexternal networks

DNS (Domain Name Server) Translates addresses from ggsn1.oper1.fi -

format to 123.45.67.89 format (i.e. as usedin Internet)


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OTHER ELEMENTS

Charging Gateway

Collects charging information from SGSNsand GGSNs

PTM-SC (Point to Multipoint -ServiceCenter)

PTM Multicast (PTM-M): Downlinkbroadcast; no subscription; no ciphering

PTM Group call (PTM-G): Closed or opengroups; Down/up -link; ciphered

Geographical area limitation


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HOW GPRS WORKS

GPRS provides packet data services (similar to the

Internet) using the GSM digital radio network. Eachvoice circuit in GSM transmits the speech on a secure

14kbps digital radio link between the mobile phone and

a nearby GSM transceiver station.

RADIO INTERFACE


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RADIO INTERFACE

Each transceiver uses TDM to deliver eightvoice circuits on one radio channel

The GPRS service joins together multiplespeech channels to provide higher bandwidth

data connections The radio bandwidth remains the same, it is

just shared between the voice users and thedata users

higher the data rate, the more power the

mobile device will use and the shorter thebattery life and the higher the transmitted RFpower


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GPRS ROAMING

Home Network Roaming - Here alldata is transmitted from wherever you

connect to a GPRS network to your

home GPRS network Local Network Roaming - Data is just

transmitted to a local Internet connection

point and will be subject to localconditions for security and performance.


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GPRS MOBILE DEVICES

The key use for GPRS is to send andreceive data to a computer application

To use GPRS, the service is 'dialed' at

which point the user is 'attached' and an IPaddress is allocated

The three standard methods to connectyour computer to GPRS mobile phone are:

1 Infrared2 Data-cable

3 Bluetooth


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GPRS SECURITY

The radio interface is considered to be

relatively secure being controlled by the GSM

network's security - (SIM card + HLR).

Security issues arise when data needs to

leave the GPRS network to be delivered to

either the Internet or a company LAN.

Internet connectivity is the cheapest andmost common - and here you can take charge

of security by encrypting sensitive data.


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NETWORK CONNECTIVITY

Three ways to connect to GPRS network

1. Internet

2. Leased Lines

3. Frame Relay


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NETWORK

CONNECTIVITY LEASED LINES

Leased lines provide the most securemethod of connecting to GPRS but are

traditionally expensive FRAME RELAY

If a frame relay connection is availablewith network suppliers then adding anaddition PVC (Private Virtual Circuit) toone of the GPRS networks will make acost effective solution


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DATA PACKET ROUTING


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Data Packet Routing

GGSN handles interaction with the external datanetwork.

routes external data packets to the SGSN

Three different routing schemes arepossible:

Mobile-originated message.

Network-initiated messages when the MSis in its home network.

Network-initiated messages when the MS has

roamed to another GPRS operators network.


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Data Packet Routing

GPRS operators will allow roaming through aninter-operator backbone network

GPRS operators connect to the inter-operatornetwork by a border Gateway (BG)

The main benefits of the architecture are itsflexibility, scalablity, interoperability androaming

The GPRS network encapsulates all data

network protocols into its own encapsulationprotocol, called the GPRS Tunning Procotocol(GTP).


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Data Packet Routing

The operation of GPRS is partlyindependent of the GSM network.However, some procedures share the

network elements with current GSMfunctions.

A mobile station has three states in theGPRS system:

Idle Standby

Active


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KEY USER FEATURES OF

GPRS

SpeedTheoretical maximum speeds of up to

171.2 kilobits per second are achievablewith GPRS

ImmediacyGPRS facilitates instant connections

whereby information can be sent orreceived immediately as the need arises

New applications, betterapplications


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KEY NETWORK FEATURES OF

GPRS

Packet SwitchingGPRS involves overlaying a packet based air

interface on the existing circuit switched GSMnetwork With GPRS, the information is split intoseparate but related "packets" before beingtransmitted and reassembled at the receivingend

Spectrum EfficiencyThe available radio resource can be concurrently

shared between several users. This efficient use ofscarce radio resource means that large numbers ofGPRS users can potentially share the samebandwidth and be served from a single cell.


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KEY NETWORK FEATURES OF

GPRS

Internet aware

File Transfer Protocol (FTP), web

browsing, chat, email, telnet- will be as

available over the mobile network

because of GPRS. Hence, web

browsing is a very important application

for GPRS. Supports TDMA and GSM


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THANK YOU

final gprs edited

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