UNIT - 3

GPRS

Prepared By:- NITIN PANDYA

Assistant Professor,

SVBIT.

“ GPRS “

GPRS- General Packet Radio Service provides a direct link into the Internet from a GSM phone

2 NITIN PANDYA

INTRODUCTION TO GPRS GPRS will undoubtedly speed up a handset's

Internet connection - but it remains to be seen exactly how much speed can be achieved out of the system

GPRS works by aggregating a number of separate data channels. This is possible because data is being broken down into small 'packets' which are re-assembled by the receiving handset back into their original format.

3 NITIN PANDYA

INTRODUCTION (cont…)

GPRS stands for General Packet Radio Service , and is a relatively low cost technology that offers packet-based radio service and allows data or information to be sent and received across mobile telephone networks.

GPRS provides a permanent connection where information can be sent or received immediately as the need arises, subject to radio coverage.

4 NITIN PANDYA

GPRS and Packet Data N/W

Capacity and other end user aspects : It has ability to offer

data speeds of 14.1 Kbps to 17.2 Kbps, which allow easy

Internet access.

QoS (Quality of Service) : Service precedence, Reliability,

Delay and Throughput.

Integral Part of the future 3G Systems : the use of GPRS in

GSM n/w is known as 2.5G with limited Internet

accessibility speed.

5 NITIN PANDYA

GPRS ARCHITECTURE & n/w enhancement

GPRS Subscriber Terminals

GPRS BSS

GPRS Networks Node

GPRS Mobility Management

6 NITIN PANDYA

7 NITIN PANDYA

8 NITIN PANDYA

GPRS BSS Each BSC will require the installation of one or

more PCUs and a software upgrade. The PCU provides a physical and logical data interface out of the base station system (BSS) for packet data traffic.

The BTS may also require a software upgrade, but typically will not require hardware enhancement.

9 NITIN PANDYA

GPRS NETWORKS NODE

In the core network, the existing MSCs are based upon circuit-switched central-office technology, and they cannot handle packet traffic.

Thus two new components, called GPRS Support Nodes, are added:

Serving GPRS Support Node (SGSN)

Gateway GPRS Support Node (GGSN)

10 NITIN PANDYA

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.

The GGSN also collects charging information connected to the

use of the external data networks and can act as a packet filter for

incoming traffic.

11 NITIN PANDYA

Serving GPRS support node (SGSN):

The Serving GPRS Support Node is responsible for

authentication of GPRS mobiles, registration of mobiles in the

network, mobility management, and collecting information for

charging for the use of the air interface.

12 NITIN PANDYA

Transmission Plane & Protocol Architecture

13 NITIN PANDYA

Information transfer control procedures (e.g., flow control, error detection, error correction and error recovery), see Figure . The needed protocols are

SNDCP Subnetwork Dependent Convergence Protocol

LLC Logical Link Control

RLC Radio Link Control

MAC Medium Access Control

PLL Physical Link Layer

RFL Physical RF Layer

BSSGP Base Station System GPRS Protocol

IP Internet Protocol

TCP Transmission Control Protocol

UDP User Datagram Protocol

GTP GPRS Tunneling Protocol

14 NITIN PANDYA

The physical layer GPRS is compatible with GSM.

At the link layer of the air interface the GSM system uses

LAPDm whereas GPRS uses a Logical Link Control (LLC) and

Radio Link Control (RLC)/Medium Access Control (MAC).

The Radio Link Control function, which provides a radio-solution-

dependent reliable link.

The Medium Access Control function, which controls the access

signaling (request and grant) procedures for the radio channel,

and the mapping of LLC frames onto the GSM physical channel.

15 NITIN PANDYA

GPRS Network Operations

Attachment and De-attachment procedure

APN- Access Point Name

Mobility Management

Routing

Communicating with IP N/W

16 NITIN PANDYA

1.Attachment and De-attachment

procedure

17 NITIN PANDYA

Session Management in Attachment

procedure

18 NITIN PANDYA

2. Access Point Name

Access Point Name (APN) is a configurable network

identifier used by a mobile device when connecting to a GSM

carrier.

The carrier will then examine this identifier to determine

what type of network connection should be created,

for example: what IP addresses should be assigned to the

wireless device, what security methods should be used, and

how or if, it should be connected to some private customer

network.

19 NITIN PANDYA

Structure of APN Network Identifier: Defines the external network to which the

Gateway GPRS Support Node (GGSN) is connected. Optionally,

it may also include the service requested by the user. This part of

the APN is mandatory

Operator Identifier: Defines the specific operator’s packet

domain network in which the GGSN is located. This part of the

APN is optional. The MCC is the Mobile Country Code and the

MNC is the Mobile Network Code which together uniquely

identify a mobile network operator.

20 NITIN PANDYA

3. Mobility Management

GPRS Mobility Management (GMM) is a GPRS signaling

protocol that handles mobility issues such as roaming,

authentication, and selection of encryption algorithms.

GPRS Mobility Management, together with Session

Management (GMM/SM) protocol support the mobility of

user terminal so that the SGSN can know the location of a

mobile station (MS) at any time and to activate, modify and

deactivate the PDP sessions required by the MS for the user

data transfer.

21 NITIN PANDYA

If the MS moves to a new Location Area, it also moves to a new Routing Area.

Each RA is identified by a routing area identifier (RAI). This is made up of a

location area identifier (LAI) and a routing area code (RAC).

22 NITIN PANDYA

4.Routing

There are three important routing schemes:

Mobile-originated message: This path begins at the

GPRS mobile and ends at the host

Network-initiated message when the MS is in its

home network: This path begins at the host and ends at the

GPRS mobile

Network-initiated message when the MS roams to

another GPRS network: This path begins at the host of

visited network and ends at the GPRS mobile

23 NITIN PANDYA

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.

24 NITIN PANDYA

WORKING OF GPRS

Each voice circuit in GSM transmits the speech on a secure 14kbps digital radio link between the mobile phone and a nearby GSM transceiver station.

The GPRS service joins together multiple speech channels to provide higher bandwidth data connections for GPRS data users. The radio bandwidth remains the same, it is just shared between the voice users and the data users.

25 NITIN PANDYA

GPRS MOBILE DEVICES

The key use for GPRS is to send and receive data to a computer application such as Email, web browsing or even telemetry.

To use GPRS the service is 'dialed' in a similar manner to a standard data call at which point the user is 'attached' and an IP address is allocated.

26 NITIN PANDYA

GPRS MOBILE DEVICES(cont…)

The three standard methods to connect your computer to GPRS mobile phone are:

1… Infrared

2… Data-cable

3… Bluetooth

27 NITIN PANDYA

GPRS Roaming

In the short term don't expect to be able to roam to many countries with GPRS, many networks are still negotiating to set up roaming agreements. Technically there are two type of GPRS Roaming

1… Home Network Roaming

2… Local Network Roaming

28 NITIN PANDYA

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 and most common - and here you can take charge of security by encrypting sensitive data.

29 NITIN PANDYA

FEATURES OF GPRS

Key User Features of GPRS

Key Network Features of GPRS

30 NITIN PANDYA

KEY USER FEATURES OF GPRS

Speed…

Immediacy…

New and Better Applications…

Service Access…

31 NITIN PANDYA

KEY NETWORK FEATURES OF GPRS

Packet Switching…

Spectrum Efficiency…

Internet Aware…

Supports TDMA and GSM…

32 NITIN PANDYA

APPLICATIONS OF GPRS E-Commerce

Banking

Financial Trading

Unified Messaging

33 NITIN PANDYA

GENERAL APPLICATIONS OF GPRS

Communications—E-mail and fax; 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

34 NITIN PANDYA

ADVANTAGES OF GPRS

GPRS will enable a variety of new and unique services to the mobile wireless subscriber. These mobile applications contain several unique characteristics that enhance the value to the customers.

First among them is mobility—the ability to maintain constant voice and data communications while on the move.

Second is immediacy, which allows subscribers to obtain connectivity when needed, regardless of location and without a lengthy login session.

Finally, localization allows subscribers to obtain information relevant to their current location

35 NITIN PANDYA

LIMITATIONS OF GPRS

Limited Cell Capacity for All Users

Speeds Much Lower in Reality

Support of GPRS Mobile Terminate by Terminals is Not Ensured

Suboptimal Modulation

Transit Delays

No Store and Forward

36 NITIN PANDYA