GSM Overview

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BSNL

ANANT KUMAR RAI

REG. NO.- U05EC005

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BSNL OBJECTIVESOBJECTIVES

Describe the Cellular Concept

Explain the GSM Access Network

Explain the GSM Core Network

Explain the GPRS Core Network

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BSNL Communication - Mobile

TelephoneExchange

SubscriberLine (2W)

Inter-ExchangeJunction

Mobile SwitchingCentre (MSC)

BSC BTSMS

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BSNL

CELLULAR MOBILE CONCEPTS

WHAT IS A CELL ?

• A base station (transmitter) having a number of RF channels is called a cell

• Each cell covers a a limited number of mobile subscribers within the cell boundaries ( Coverage area)

• Typical Cell Radius Aprrox = 30 Km (Start up), 1 KM (Mature)

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Voice Channels Coverage area

Forward path

Reverse path

Or control

channels

Lines toBSC

MS

A RADIO CELL

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BSNL Fundamental problems

• Radio range, or coverage

• No. of channels, or voice circuits

• Full, seamless service coverage

• Large no. of subscribers in the range of millions

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BSNL

FERQUENCY SCARCITY PROBLEM

TelEx.

WIRED NETWORK

100,000 50 Khz = 5 Ghz (NOT POSSIBLE)

Hence Individual RF Loop is not extended

But a Common group of channels is shared

CELLULAR MOBILE CONCEPTS

BW for Telephony speech: 3KHz increases to 25 KHz with FM for Radio Trans.

BSNL

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GSM Specifications

Carrier Separation - 200 kHz

No. of RF Carriers - 124

Access Method - TDMA/FDMA

Modulation Method - GMSK

Transmission Rate - 270.833 Kbps

Speech Coding - Full rate 13 Kbps Half rate 6.5 Kbps

Duplex Distance - 45 MHz

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GSM FDMA(Frequency Division Multiple Access

25 MHz 25 MHz

Mobile to Base

0 1 2

890.2 890.4 890.6(MHz)

Base to Mobile

0 1 2

935.2 935.4 935.6

200 kHz45MHz

Channel layout and frequency bands of operation

890 935 960915

200 kHz

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GSM TDMA(Time Division Multiple Access)

8765

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8765

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21

45 MHz

Frequency

F2’F1’(Cell transmit)

F2F1(Cell Rx)

Amplitude

Typical TDMA/ FDMA frame structure

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FDMA/TDMA Scheme

BP1

BP2

BP3

BP4

BP5

BP6

BP7

BP8

BP1

BP2

TIME

890.0

890.2890.4

890.6890.8

891.0891.2 915.8

FREQ

MHz

BURSTF

R

A

M

E

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LOGICAL CHANNELS• USER INFORMATION( TRAFFIC)• SIGNALLING INFORMATION (CONTROL)

GSM RF CHANNELS

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BSNL OPERATIONAL CONCEPTS

• Subscribers are not allocated dedicated channels

• TCH Allocated to users only when needed

• Hence IDLE MODE & DEDICATED MODE

• DEDICATED MODE -- When a full Bi -directional P to P CHL has been allocated during an established call • IDLE MODE MODE

-- When MS is powered on (active) without being in dedicated mode

BSNL

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Network Architecture

BTS

MSC VLR

HLR

PSTNISDN

DataNetworks

Air interface

OSS

BTS

BTS

MSC VLR

BSCBSC

1 MSC=16 BSC

1 BSC=1024 TRU

A Interface

A-bis interface

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BSNL GSM Network Structure• GSM Service Area: Total area served by the

combination of all member countries where a mobile can be served.

• PLMN Service Area: It is one N/W area.

• MSC Service Area: There can many MSC/VLR in one PLMN area.It is one Mobile Exch. Area.

• GMSC: All I/C calls for PLMN N/W will be routed through GMSC. In a GSM/PLMN N/W all mobile terminated calls will be routed to a Gateway MSC. Call connections between PLMNs , or to fixed N/Ws must be routed to a GMSC.The GMSC contains the Inter working functions to make these connections.

• Location Area• Cells

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LOCATION AREA : There are several LA in a MSC/VLR combination. A LA is a part of the MSC/VLR service area in which a MS may move freely without updating location information to the MSC/VLR exchange that control the LA. Within a LA a paging message is broadcast in order to find the called mobile subs. LA can be identified by system using the LAI.

CELL : A cell is an identity served by one BTS. The MS distinguishes between cells using the BASE STATION IDENTIFICATION CODE(BSIC) that the cell site broadcast over the air.

GSM Network Structure

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MSC/VLR

MSC/VLR

MSC/VLR

MSC/VLR

II

I

IIIIV

GSMPLMN Service Area

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MSC/VLR

LA 1 LA 2

LA 6

LA 3

LA 4

LA 5

GSMMSC Service Area

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MSC/VLR

LA 1 LA 2

LA 6

LA 3

LA 4

LA 5

C1

C5C4

C7

C2

C3

C6

GSMCells

C = Cell

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GSMRelation between areas in GSM

Location AreaCellArea served by a BTS

Location AreaMSC Service AreaPLMN Service Area

GSM Service Area

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GSMFunctions of Mobile Station

• Voice and data transmission

• Frequency and time synchronization

• Monitoring of power and signal quality of the surrounding cells

• Provision of location updates even during inactive state

• Equalization of multi path distortions

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GSMMobile Station

• Portable, vehicle mounted, hand held• MS identified by unique IMEI(International Mobile Equipment

Identity)

• Shall display at least last ten received, dialled and missed calls

• Minimum talk time of 1hr 30 min. and standby time of 80 hrs

• 160 characters long SMS

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GSMMobile Identification Numbers

IMEI

MSISDN

IMSI

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BSNLGSMIMSI

• International mobile subscriber’s Identity

• The IMSI is an unique identity which is used internationally and used within the network to identify the mobile subscribers.

• The IMSI is stored on the subscriber identity module (SIM), the HLR, VLR and AC database.

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RSSRSS

n BTS n BTS

BSC

BSC

BSC

MSC/VLR

RADIO SUB SYSTEM (RSS)

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GSMFUNCTION OF BTS -I

• Encodes, encrypts, multiplexes, modulates and feeds the RF signals to the antenna

• Transcoding and rate adaption Functionality• Time and frequency synchronisation signals

transmission.• 11 power classes from .01 watts to 320 watts

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GSMFUNCTION OF BTS -II

• Frequency hopping

• Random access detection

• Uplink radio channel measurements

• BTS mainly consists of a set of transceivers (TRX).

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GSMFUNCTIONS OF BSC-I

• It is connected to BTS and offloads MSC

• Radio resource management

• Inter-cell handover

• Reallocation of frequencies

• Power control

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GSMFUNCTIONS OF BSC-II

• Time delay measurement of the received signals from MS with respect to BTS clock.

• Performs traffic concentration to reduce the number of lines from BSC to MSC.

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GSMMSC-BSS Configurations

BTSBTS

BTS

A-bisBSC

BSS

Configuration -6 Multi - cell site = multi--BTS site

Many single cell sites

BSS

MSC

BTS

AA

A

Single - cell siteConfiguration -1

Multi - cell site (sector CellsConfiguration -5

MCC: Mobile Switching Centre

BSS: Base Station System

BSC: Base Station Controller

BTS: Base Transceiver Station

A-bis

BTS BTS

BTS

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BSNLGSMMSC ( MOBILE SWITCHING CENTRE)

Manages communication between GSM & other network

Call setup functions, basic switching are done

MSC takes into account the RR allocation in addition to normal exchange functions

MSC does gateway function while its customers roams to other network by using HLR /VLR

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GSMMSC Functions - I

Paging, specifically call handling

Location updation

Handover management

Billing for all subscribers based in its area

Reallocation of frequencies to BTSs in its area to meet

heavy demands

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GSMMSC Functions - II

Echo canceller operation control Signaling interface to databases like HLR, VLR. Gateway to SMS between SMS centers and subscribers Handle interworking function while working as GMSC

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GSMVISITOR LOCATION REGISTER (VLR)-I

It controls those mobiles roaming in its area.

VLR reduces the number of queries to HLR

One VLR may be incharge of one or more LA.

VLR is updated by HLR on entry of MS its area.

VLR assigns TMSI which keeps on changing.

IMSI detach and attach operation

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GSMData in VLR

IMSI & TMSI

MSISDN

MSRN.

Location Area

Supplementary service parameters

MS category

Authentication Key

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GSM Home Location Register(HLR)-I

• Reference store for subscriber’s parameters, numbers, authentication & Encryption values.

• Current subscriber status and associated VLR.

• Both VLR and HLR can be implemented in the same equipment in an MSC.

• one PLMN may contain one or several HLR.

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GSM Home Location Register(HLR)-II

Data stored is changed only by man-machine.

IMSI, MS-ISDN number.

Category of MS ( whether pay phone or not )

Roaming restriction ( allowed or not ).

Supplementary services like call forwarding

Permanent data in HLR

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Temporary data in HLR The data changes from call to call & is

dynamic

MSRN

RAND /SRES and Kc

VLR address, MSC address.

Messages waiting data used for SMS

GSM Home Location Register(HLR)-II

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GSM SERVICES

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GSM Services

Services are defined as anything the end user explicitly sees as worth paying for.

The primary objective of a mobile telephony system is to allow mobile subscribers to communicate effectively.

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SERVICE CATEGORIESMain type of telecommunication services:

☻ Basic services: Available to all subscribers to a mobile network. e.g. voice telephone calls.

☻ Supplementary services: Additional services that are available by subscription only. e.g. Call forwarding.

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Basic Telecommunication Services

Two main categories:

Teleservices

Bearer Services

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Basic Telecommunication Services

Teleservices

Teleservice allows the subscriber to communicate (usually via voice, fax, data or SMS) with another subscriber.

It is a complete system including necessary terminal equipment.

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Basic Telecommunication Services

Bearer services

It transports speech and data as digital information within the network between user interfaces.

e.g.- a bearer service associated with the speech telephony teleservice is the timeslot assigned to a call on a TDMA frame over the air interface.

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TELESERVICES

Emergency calls

The emergency call function enables a subscriber to make an emergency call by pressing a predefined button or by using the emergency number. (like 112 , 911).

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SMS Cell Broadcast (SMSCB)

A text message with a maximum length of 93 characters can be broadcast to all mobiles within a certain geographic area.

traffic congestion warnings

accident reports,

weather announcements and

advertisements.

TELESERVICES

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Calling line identification services:These cover both the presentation and restriction of the calling line identity.

The presentation part of the service supplies the called party with the ISDN or MSISDN number of the calling party. The restriction service enables calling parties to restrict the presentation of their number on the MSs of called parties

SUPPLEMENTARY SERVICES

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Value Added Services

Mobile Messaging

Mobile internet

Mobile intelligent Network Services

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Some Applications

•Internet e.g. WAP•E-mail•Messaging Services e.g. MMS•Telemetery•M-Commerce•Location Based Service•Games

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Mobile

internet

Sports MTV

Jokes

Grocery

Prepaid,

messaging

GamblingCompany

data

Customer data

Banking data

Financial/

Stock news

Other news

Young people

Middle aged

Financial community/trader

Traveling sales/-business man

Anybody else

Wireless World - there’s something for everyone

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Unified Messaging

Mobile Positioning

Multimedia Messaging

Mobile Banking

Bluetooth:

Location based

Mobile E-mail:

Corporate Lan Access

Wireless World

bring in New Services Mobile Trading

Mobile Shopping

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Mobile Applications

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Mobile Messaging

SMS

EMS

MMS

Instant Messaging

Streaming

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Short Message Services (SMS)

The service allows simple text message consisting of a maximum of 160 alphanumeric characters to be sent to or from an MS.

If the MS is switched off, or has left the coverage area, the message is stores in a Short Message Service Center (SMS-C).

When the mobile is switched on again or has re-entered the network coverage area, the subscriber is informed that there is a message.

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Enhanced Messaging System (EMS)

• EMS can support relatively simple pictures,sounds and animation.

• EMS messages that are sent to devices that do not support it will be displayed as SMS transmissions.

• It is a 3GPP standard.

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• MMS means a multimedia presentation which consists of music, voice, image, text, video and graphics all synchronized across a common timeline.

• “Synchronized Power Point Presentations”.

MULTIMEDIA MESSAGE SERVICE

(MMS)

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• MMS-enabled mobile phones enable subscribers to compose and send messages with one or more multimedia parts. Mobile phones with built-in or attached cameras, or with built-in MP3 players are very likely to also have an MMS messaging client -- a software program that interacts with the mobile subscriber to compose, address, send, receive, and view MMS messages.

MULTIMEDIA MESSAGE SERVICE

(MMS)

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Multimedia Messaging - Any combination of media types

Hi Grandma!

Babysitting

tomorrow?

Video and

Audio

Images

Graphics

Music

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rich content to encourage usageCartoons, Dating, Pop stars, Sports stars, Pets,

Special occasions, Hobbies, Sports results, TV programmes, News, Weather, Holidays, Timetables, Family...

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SMS MMS

Text Based Messagingrich content including text, graphic, photos etc.

Proprietary Standard Based upon 3 GPP & WAP standards.

Store & Forward system Store & Forward system

Uses signaling links MMS uses main data channel.

SMS & MMS

** 3rd Generation Partnership Project (3GPP) **

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Instant Messaging

It enables to communicate with another individual in real time, analogous to a telephone conversation but using text based communication instead of voice-based communication.

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Streaming

• It enables real time or on demand distribution of audio, video and multimedia on the internet.

• It is simultaneous transfer of digital media (video,voice and data) so that it is received as a continuous real-time stream.

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Movies

Video-clips

Photos

Pictures

Applications Evolution – user perspective

SMS

EMS

MMSText

Streaming

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Where do we fit in ???

• Ringtones and Images over SMS, EMS and MMS

• Games over SMS for single, multi player and as a team

• Gaming servers handling SMS, WAP and Java games

• MMS applications for Imaging and Melodies

• Java applications on handsets

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Content & Application

Fun: Cartoon of the day, Tarot cards, Cocktail recipes, Alcometer, Daily Horoscope, Personality Test,

Games: Hangman, Puzzles & Riddles, Cute’n’clever, Lifestyler, Friends PopStar, PopQuiz, Jewel & Rubin, Amour

Photo & Film: PhotoGallery, Mobile Greeting Card, My SoapOpera,

Chat & date: Mobile Chat, Love Horoscope, Love Matcher

Music: Karaoke, Fan Packages, Hit Lists, Music News

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The Greeting Card solution:

• Send Messages to your friends, family and loved ones: - Via the web to the mobile phone

• Ease of use– self instructing -Drag ‘n’ drop

• Animations, Sounds, Pictures & Text

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BSNL MESSAGING TYPE

STREAMING

INSTANT

MESSAGING

CONTENT CARRIED

REAL TIME DISTRIBUTION OF AUDIO, VIDEO AND MULTIMEDIA

REAL TIME TEXT BASED COMMUNICATION

MMS PICTURES, SOUNDS AND ANIMATIONS

EMS RELATIVELY SIMPLE PICTURES, SOUNDS AND ANIMATIONS

SMS SIMPLE TEXT

WIRELESS MESSAGING LADDER

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Location Based Applications

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Location Based Services

Positioning application

Where am I

Yellow Pages

Tracking

Fleet management

Brand Finder

Geo Coding, Content,

Application Integration

Positioning methods:– Cell/Sector , Time of Arrival-- Network Based AGPS – Terminal Based EOTD

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• Stickiness : Daily traffic info. pushed during rush hours via SMS/MMS

• Most people need to know the current traffic sitution on their route.

• Hosting: Operator / ISP

• WAP/Web/MMS/SMS: yes/yes/yes/yes

• Devices supported: - All devices

• Commerically used worldwide

This service both collects and distributes traffic information. Traffic information is very important need for city dwellers. Systems can estimate traffic information by sampling mobiles in automobiles on freeways anonymously to determine average velocity of vehicles. If this is not possible in locataion more static information can be collected from city authorities. All this information is mapped and sent to mobile users who request it.

This service both collects and distributes traffic information. Traffic information is very important need for city dwellers. Systems can estimate traffic information by sampling mobiles in automobiles on freeways anonymously to determine average velocity of vehicles. If this is not possible in locataion more static information can be collected from city authorities. All this information is mapped and sent to mobile users who request it.

APPLICATION OVERVIEWAPPLICATION OVERVIEW

Traffic Information

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Positioning based information,

advertisements... Telecom & backhand IT infrastructure makes it

possible!

All Trademarks and Registered Trademarks are of respective holders

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Operations• Dispatch

operations interconnected:

– Taxi– Field services– Parcel services

• Emergency services

Automation

• Vending machines

• Lottery machines

• Automatic ticket machines

M2M – Services

• Alarm & supervision

• Point of sales

• Telemetry

• Financial services

M2M – Vehicle

• Vehicle tracking

• Electronic maps

• Traffic telematics

• Car tolls

Vertical applicationsIts all about Imagination……...

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Machine to Machine communication (M2M)

Some key technologies for M2M

• Bluetooth

• GSM/GPRS

• GSM/SMS

• WiFi

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NewNewapplicationsapplications

I don’t need wiresI don’t need wiresto connect anymoreto connect anymore

Help! I’m almost outHelp! I’m almost outof coke bottles…….of coke bottles…….

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age/status?attitude?culture?interests?financial situation?location?time?behaviour/mood?

Who are your customers?

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Thanks