GENERAL PACKET RADIO SERVICE(GPRS)
A new dimension to wireless communication….
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INTRODUCTION
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INTRODUCTION CONTD…….
GSM-
• maximum speed 9.6 kbps
• Based on circuit switching technology.
HSCSD-
• 1st step towards faster data speeds on GSM
• Allows data speed of 64 kbps
• Used for notebooks with data cards
GPRS-
• Introduces packet switching to GSM,CDMA,TDMA
• Provides easier integration with packet based protocols.
EDGE-
• 2nd step towards 3G for GSM/GPRS networks
• Increases data rates on GSM to 384 kbps 3
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WIRELESS ROADMAP
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GPRS (General Packet Radio Service) is a packet based
communication service for mobile devices .
It allows data to be sent and received across a mobile
telephone network.
GPRS is a step towards 3G and is often referred to as
2.5G.
GPRS provides a permanent connection where
information can be sent or received immediately as the
need arises, subject to radio coverage.
Provides connections to external packet data networks
(Internet, X.25).
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• Circuit switched service provide maximum data
rate 9.6 kbps.
• Customer pays for connection time and not for
the volume transferred.
• GPRS provides high data rates from 14.4 to 115
kbps.
• Requires little modification in existing GSM
components.
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BPL Mobile
Bharti Cellular
Hutchison Max
Hutchison Essar
Idea Cellular
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GPRS REQUIREMENTS
GPRS Subscriber Terminals
GPRS BSS
GPRS Networks Node
GPRS Mobility Management
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GPRS SUBSCIBER TERMINALS
New terminals are required because existing GSM
phones do not have the ability to packetize traffic
directly.
A variety of terminals exists, including a high-speed
version of current phones to support high-speed data
access.
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GPRS BSS
Stands for Base station subsystem
Comprises of BTS & BSC
Performs the necessary functions for monitoring radio connections
to the MS, coding and decoding voice, and rate adaptation to and
from the wireless network.
The BTS includes all the radio equipment (i.e., antennas, signal
processing devices, and amplifiers) necessary for radio transmission
within a geographical area .
The base station controller (BSC) is the controlling component of
the radio network, and it manages the BTSs
The BTS is responsible for establishing the link to the MS and for
modulating and demodulating radio signals between the MS and the
BTS. 12
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GPRS NETWORK NODE
In GSM 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)
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SERVING GPRS SUPPORT NODE(SGSN)
SGSN has a logical connection to the GPRS
device & delivers data to mobile stations(MS)
Main functions
• Authenticates GPRS mobiles
• Handles mobile’s registration in GPRS network
• Handles mobile’s mobility management
• TCP/IP header compression
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GATEWAY GPRS SUPPORT NODE (GGSN)
It is basically a gateway, router and firewall
rolled into one.
Main functions
• Interface to external data network
• Forwards end user data to right SGSN
• Routes mobile originated packets to right destination
• Filters end user traffic
• Collects charging information for data network usage
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GPRS NETWORK
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CONTINUED BY AJIT
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A main issues in the GPRS network is the routing of
data packets to/from a mobile user.
It is divided into two areas:
Data packet routing
Mobility management
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DATA PACKET ROUTING
GGSN
Handles interaction with the external data
network.
Routes external data packets to the SGSN
Three different routing schemes are possible:
Mobile-originated message.
Network-initiated messages when the MS is in
its home network.
Network-initiated messages when the MS has
roamed to another 19
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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MOBILITY MANAGEMENT CONTD….
MS(Mobile Station) has three states in the GPRS system
• Active or Ready
• Standby
• Idle
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ACTIVE
• Data is transmitted between an MS and the GPRS network only
when the MS is in the active state. In the active state, the SGSN
knows the cell location of the MS.
• Packet transmission to an active MS is initiated by packet paging.
• When an MS has a packet to transmit, it must access the uplink
channel .The uplink channel is shared by a number of MSs.
• The MS requests use of the channel in a random access
message. The BSS allocates an unused channel to the MS and
sends an access grant message in reply to the random access
message
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STANDBY STATE
• In the standby state, only the routing area of the MS is
known.
• When the SGSN sends a packet to an MS that is in the
standby state, the MS must be paged because the SGSN
knows the routing area of the MS.
• On receiving the packet-paging message, the MS relays its
cell location to the SGSN to establish the active state.
• The main reason for the standby state is to reduce the load
in the GPRS network caused by cell-based routing update
messages and to conserve the MS battery.
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IDLE STATE
• In the idle state, the MS does not have a logical GPRS
context activated.
• In this state, the MS can receive only those multicast
messages that can be received by any GPRS MS.
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MOBILITY MANAGEMENT
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IP ADDRESSING
Allocating Addresses
There are 2 different ways in which a device can
be assigned an IP address.
Fixed IP addressing
Dynamic IP addressing
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FIXED IP ADDRESSING
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DYNAMIC IP ADDRESSING
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GPRS MOBILE DEVICES
The key use of GPRS is to send and receive data to a
computer application such as Email, web browsing or
even telemetry.
The three standard methods to connect our computer to
GPRS mobile phone are:
1… Infrared
2… Data-cable
3… Bluetooth
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GPRS MOBILE CONNECTION
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GPRS HANDSET CLASSES
Class A:
• Simultaneous GPRS and conventional GSM operation
• Supports simultaneous circuit switched and GPRS data
transfer
Class B:
• Can be attached to both GPRS and conventional GSM
services simultaneously
• Can listen circuit switched and GPRS pages (via GPRS)
• Supports either circuit switched calls or GPRS data transfer
but not simultaneous communication
Class C:
• Alternatively attached in GPRS or conventional GSM
• No simultaneous operation
• ‘GPRS only’ mobiles also possible (e.g. for telemetric
applications)
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PROTOCOLS SUPPORTED
Internet Protocol
Mobile built-in browsers use IPv4 since IPv6 is not yet
popular.
Point to point protocol
PPP is used to tunnel IP to the phone. This allows an IP
address to be assigned dynamically to the mobile
equipment.
X.25
Used for applications like wireless payment terminals
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CONTINUED BY IRFAN
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COMPARISON BETWEEN GSM & GPRS
GSM GPRS
Data Rates 9.6 Kbps 56 to 171.2
Kbps
Modulation GMSK GMSK
Technique
Billing Duration of Amount of
connection data
transferred
Type of Circuit – Packet -
Connection Switched Switched 35
Technology Technology
GPRS CHARACTERISTICS & FEATURES
GPRS uses packet switched resource allocation
• resources allocated only when data is to be sent/received
Flexible channel allocation
• one to eight time slots
• available resources shared by active users
• up and down link channels reserved separately
• GPRS and circuit switched GSM services can use same
time slots alternatively
Traffic characteristics suitable for GPRS
• Bursty data transmissions
• Frequent transmissions of small volumes of data
• Infrequent transmission of larger volumes of data 36
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HIGH DATA RATE
GPRS uses radio channel i.e. 200 kHz wide
Radio channel carries digital data stream of 271
kbps
This rate is divided into 8 time slots each carrying
34 kbps per time slot
Data rate 14 kbps per time slot achieved after error
corrections
GPRS can combine upto 8 time slots giving data
rate of 171 kbps 37
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COMPARISON OF DATA TRANSFER RATE
(IN KBPS)
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NETWORK FEATURES
• Packet switching
• Spectrum efficiency
• Internet aware
• Support TDMA & GSM
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Packet Switching
1. GPRS involves overlaying a packet based air interface
on the existing circuit
switched GSM network.
2. In GPRS, the information is split into separate but
related "packets" before
being transmitted and reassembled at the receiving
end
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PACKET SWITCHING
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SPECTRUM EFFICIENCY
Packet switching means that GPRS
radio resources are used only when
users are actually sending or receiving
data.
This efficient use of scarce radio
resources means that large numbers
of GPRS users can potentially share
the bandwidth and be served from a
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single cell..
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Internet Aware
1. GPRS fully enables Mobile Internet functionality by
allowing inter-working
between the existing Internet and the new GPRS network.
2. It Provide any service that is used over the fixed
Internet today- File Transfer
Protocol (FTP), web browsing, chat, email, telnet,
etc.
Supports TDMA & GSM
1. It Support both GSM and TDMA (Time Division Multiple
Access) standard popular
in North and South America.
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USER FEATURE OF GPRS
1. SPEED.
2. IMMEDIACY.
3. BETTER APPLICATION.
1. SERVICE ACCESS
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BETTER APPLICATION
1. Fully Internet application such as web browsing and
chatting.
2. File Transfer.
3. Home Automation (the ability to remotely access and
control in-house appliances and machines).
Service Access
1. To use GPRS, users specifically need’s mobile phone or terminal
that supports GPRS.
2. A subscription to a mobile telephone network that supports GPRS,
use of GPRS must be enabled for that user.
3. Automatic access to the GPRS may be allowed by some mobile
network operators, others will require a specific opt-in knowledge of
how to send and/ or receive GPRS information using their specific
model of mobile phone.
4. GPRS users can access any web page or other Internet applications 45
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WEB BROWSING.
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GPRS ATTACHMENT
GPRS Attach function
• Authenticate the mobile
• Generate the ciphering key
• Enable the ciphering
• Allocate temporary identity
• Copy subscriber profile from HLR to SGSN
After GPRS attach
• The location of the mobile is tracked
• Communication between MS and SGSN is secured
• Charging information is collected
• SGSN knows what the subscriber is allowed to do
• HLR knows the location of the MS in accuracy of SGSN
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SERVICES FROM GPRS
"Always on" internet access
Multimedia messaging service (MMS)
Push to talk over cellular (PTT)
Instant messaging
Internet applications for smart devices
through wireless application
protocol (WAP)
Point-to-point (P2P) service: inter-
networking with the Internet Protocol (IP)
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LIST OF PARTICIPANTS
The following companies and organizations have been
participating in GPRS work in last 3 years
Some of the manufacturers, operators and others
participating GPRS standardization:
Alcatel, BT, CNET, CSELT, Detemobil, Eplus,
Ericsson, France Telecom, IBM, Inmarsat, Lucent,
Mannesmann, Motorola, NEC, Nokia, Nortel/Matra,
Omnipoint, OPI, Philips, SFR, Siemens, Telecom
Finland, Telia, UIC, Vodafone
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CONTINUED BY MITHILESH
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APPLICATIONS OF GPRS
• Chat
• Information services
• Still Image
• Moving Image
• Web browsing
• Document sharing
• Audio Reports
• Corporate emails
• Vehicle Positioning
• File Transfer 51
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ADVANTAGES
1. SPEED
2. ALWAYS ON CONNECTIVITY.
3. COST.
4. MOBILITY.
5. GSM OPERATOR COST
6. SIMULTANEOUS USE.
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SPEED
1. Theoretical Maximum Speed Of up to 172.2 kbps.
2. It is about ten times as fast as current Circuit Switched Data services
on GSM networks
3. It is less costly mobile data service compared to SMS and Circuit
switched Data
ALWAYS ON CONNECTIVITY
1. It facilitates instant connections.
2. It is also referred as "always connected".
3. It is always on service which makes constant connection with internet.
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COST.
1. Communication via GPRS is cheaper than through the regular GSM
Network.
2. Customer only pay for the amount of data transported,and not for the
duration of the internet connection.
MOBILITY.
1. GPRS provides wireless acces to the internet from any location where there
is a network signal.
2. This enables you to surf the internet on your laptop or phone,even in remote
areas.
3. GPRS users can access any web page or other Internet applications
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Home automation
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GSM OPERATOR COST
• As GPRS is an upgrade to the existing GSM network .So to implement
GPRS most updates in the existing GSM network are software that can be
administered easily.
• It allows the GSM providers to add value at relatively at smaller cost.
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Simultaneous use
1.When you acces the internet through
GPRS, it does not block incomming calls
through the GSM network.
2.This enables you to make or receive voice
calls while you are browsing the internet
or downloading.
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LIMITATION OF THE GPRS
• Limited Cell Capacity: There are limited radio resources and
voice and GPRS both uses same network resources hence they
impact the existing cell capacity.
• Speeds Much Lower In Reality: The total bandwidth is divided
among different user. Hence a single user cannot get the
transmission speed up to 172.1 kbps.
. GPRS roaming has not been implemented in many countries on
a lot of network .This limits its use in these network.
• Transit Delays: GPRS packets are sent in all different directions
to reach the same destination. Hence one or some of those
packets to be lost or corrupted during the data transmission over
the radio link.
• No Store And Forward: There is no storage mechanism 58
incorporated into the GPRS standard as compare to SMS.
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WHAT MUST BE INVESTED TO GET
GPRS UP AND RUNNING?
Updates on existing network elements
BTS, BSC, MSC/HLR, billing system, network planning
New network elements
Totally new network for GPRS backbone, based on IP
New packet network nodes
A lot of Internet "stuff" (routers, DNS servers, firewalls, …)
Totally new skills needed
"Internet way" of thinking
New mobiles and new type of users
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HOW TO LAUNCH GPRS WITH
MINIMISED INCREMENTAL COST
A single SGSN/GGSN combined functional unit
BTSs support basic GPRS services with software
update only, BSCs need HW upgrade to add
connection to SGSN
Use existing paging and control channels for
GPRS
Limit the number of radio channels available for
GPRS
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GPRS promotes integrated and seamless advanced
services & enables mobile operators to combine
wireless networks with public & private/corporate
networks.Thus it paves the way for migration to 3G
thus enabling to high speed,universal communication
services.
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Technology /White paper/GPRS/26 JUNE
2000.
www.wikipedia.com
GSM world http://www.gsmworld.com
GPRS Tutorial from morgandoyle.co.uk
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Thank you
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