mobile communications sajay k r

25 th Faculty Development Programme

08 October 2012

Department of Computer ApplicationsVidya Academy of Science & TechnologyThrissur – 680501, INDIA

Agenda

History of Mobile Communication

Fundamental Principles of Mobile Communication

Cellular Mobile Communication

GSM- Global System for Mobile Communication

History of Mobile Communication

BRIEF HISTORY OF MOBILE COMMUNICATIONS

1973 - Dr. Martin Kooper

Father of Mobile Phones

Technology uses Simple Receiver & Transmitter

1978- Bahrain Telephone Company -1G( Ist Generation)

Commercial Cellular Telephone System

only 250 Subscribers

1980- NTT-Nippon Telegraph & Telephone

Company ( Ist Generation(1G))

New Cellular Technology in Japan

1981- Nordic Mobile Phone ( Ist Generation(1G))

Used in Northern European Countries

Offers Speech only

First Generation (1G) mobile systems were designed to

offer a single service, i.e., speech.

1983- AMPS-Advanced Mobile Phone System(IInd Generation(2G))

Developed in US

1991-DECT-Digital Enhanced Cordless Telephone(IInd

Generation(2G))

Developed by ETSI(European Technical Standard Institute)

1982- GSM -Group Speciale Mobile (IInd

Generation(2G))

Global System for Mobile Communication

Fully Digital Technology

Offers Speech & Data Service

Most successful DIGITAL MOBILE

COMUNICATION SYSTEM

Second Generation (2G)

Second Generation (2G) mobile systems were also

designed primarily to offer speech with a limited capability to

offer data at low rates.(max 9.6kbits/s)

GSM (Global System for Mobile comm)can only offer a data

rate of 9.6 kbps

2.5G-GPRS General packet Radio Service

GPRS allows simultaneous voice and data communication

Increase data transmission speeds from the current 9.6 Kbps to over 100 Kbps

2.75G- EDGE -Enhanced Data rates for GSM Evolution

Supports High-speed data applications such as video services

384 kbps data transfer rate

2001-3G Mobile Systems

IMTS -International Mobile Telecomm. System

THIRD GENERATION(3G)

1998-Satellite Mobile Communication System

Using in Europe

2 Satellite systems are used

1. Iridium-66 satellites

2.Globalstar-less than 35

System is now called UMTS

Universal Mobile Telephone System

Third Generation (3G) mobile systems are expected to

offer high-quality multi-media services and operate in different

environments

3G systems are referred to as Universal Mobile

Telecommunications System (UMTS) in Europe and

International Mobile Telecommunications 2000

(IMT2000) worldwide.

Frequency band 1.8 -2.5 GHz

2Mbps data transfer rate.4G SYSTEMS

Frequency band (2 – 8 GHz)

Expecting- 20 Mbps-100Mbps Data

Transfer Rate

11

Wireless Comm. Systems- Overview

Conventional Telecom systems

Broadcast systems

Satellitesystems

WirelessNetworks

GSM-1900Cdma2000W-CDMA3G

DABDVB

LEO

MEOGEO

Wireless PANWireless LANWireless ATM

Fundamental Principles

of

Mobile Communication

Defining Mobility ..

Reachability (anywhere)

Accessibility (any device)

Service portability

From the Latin word “Mobilis” = “to move” able to move freely or easily

Properties

2 Different Kinds of Mobility

User MobilityUser accessing the telecomm. services at different

places.

ie the User can be mobile and services will follow him…..

Device Portability

Communication Device Moves(with or without a

user)

eg. Mobile phone system

2 types of Voice & Data Communication

1. Wired Communication

2. Wireless Communication

Wired Communication

Base Station

R2

R1

R3

R4

Wireless TransmissionWithout wire communicating

Base

Station

R4

R2

R3

R1

signals

Downlink Freq.

In Mobile communication

R4

R2

R3

R1

signals

Downlink Freq.

Uplink Freq.

Downlink Freq- From Base station To Receiver

Uplink Freq - From Receiver to Base station

GSM Mobile Communication Frequency range in

India

890-915 MHz- Uplink Freq

935-960 MHz - Downlink Freq.

Signal propagation ranges

distance

sender

transmission

detection

interference

Transmission range

– communication possible

– low error rate

Detection range

– detection of the signal possible

– no communication possible

Interference range

– signal may not be detected

– signal adds to the background noise

These transmitting stations or Base stations are called Antennas

In Mobile comm. They are called BTS -Base Transceiver Station

BTS -Base Transceiver Station

CELLULAR

MOBILE COMMUNICATION

For Each BTS only one cell

Cell-A basic geographic unit of a cellular system

Each Base Station covers a certain area called a CELL

Maximum Cell Radii is

100 of metres in cities

35 kms in Open space

Radio stations use powerful transmitters with huge cells

Mobile Base stations generate very small cells why?

2. Less Transmission power

3. Local Interference only

1. Frequency Reusef4

f5

f1f3

f2

f6

f7

f3f2

f4

f5

f1

890-915 MHz- Uplink Freq

935-960 MHz - Downlink Freq.

Components in Cellular System Architecture

1. Cell-A basic geographic unit of a cellular system

2. Cluster(Cell Site) -Group of Cells

f4

f5

f1

f3

f2

f6

f7

f4

f5

f1

f3

f2

f6

f7

f3

f2

f4

f5

f1

Cells with the same no. have the same set of

frequencies

7 cells in one cluster

Coverage area of Cells are called

FOOTPRINT

No Channels are reused within a cluster

3. Cell Splitting

Cities contain large number of low power BTS

Handle heavy traffic & Less Interference

Produce large no. of cells

3. Cell Splitting

Rural areas contain only one high power BTS

Covers more area,

Interference will be very high

Produce only one cell

Some Figures

No. of Cells in one cluster or cellsite = 3

Subscribers supported per cell = 596

Total No. of Subscribers /Cluster or cellsite =1788

POPULAR TECHNOLOGY

USED IN

MOBILE

COMMUNICATION

GSM

Global system for

Mobile communication

GSM - Group speciale Mobile

Global system for Mobile Communication

2nd Generation system

Formed in 1982

Initially Implemented in Europe

Using 10 billion People in 212 countries

Technology that widely used in India-700

million customers

9.6 Kbits/sec DTR(Data Transf. Rate)

Major Companies dealing GSM Technology in

India

Primary Objective of GSM

GSM phone is compatible with

Fixed Landline Networks

GSM Mile Stones

Year Mile Stone

1982

1986

1987

1988

1989

1990

1989

1991

1993

1995

GSM Formed

Field Test

Access Methods Chosen

MOU Signed

Validation of GSM System

Preoperation System

Validation of GSM System

Commercial System Startup

Coverage of Main Roads/Cities

Coverage of Rural areas

GSM -900 MHz

890-915 MHz- Uplink Freq

935-960 MHz - Downlink Freq.

GSM 1800 MHz

1710-1785 MHz -Uplink Freq.

1930-1990 MHz- Downlink Freq

Used In

India

DCS-1800

Digital

Comm.

Service

GSM 1900 MHz

1850-1910MHz- Uplink Freq

1930-1990MHz- Downlink Freq

PCS-1900

Personal Comm.

Service

GSM in 3 Frequencies

Cellular growth in India(2009-2014)

GSM

NETWORK

ARCHITECTURE

Major Ingredients in a

GSM network

Ingredients 1: Mobile Phones, PDAs etc

The visible but smallest

part of the network!

Ingredients 2: Antennas

Another visible part

Ingredients 3: Infrastructure 1

Cabling

Microwave links

Ingredients 3: Infrastructure 2

Switching units

Data bases

Management

Monitoring

Not „visible“, but

comprise the major

part of the network

(also from an

investment point of

view…)

GSM network is mainly divided in to 3 Major Systems

1. Switching System (SS)

2. Base Station System(BSS)

3. Operation & Support System(OSS)

Switching

system

Base Station

SystemBSC

BTS

VLR

HLR

AUC

MSC

EIRGMSC

GIWU

PSTN

PLMN

Other

OSS

Mobile

Station

Operation &

Support

System

1. Switching System(SS)

Heart of GSM

Performs Call Processing and Subscriber related functions

Functional Units in SS

1. MSC- Mobile Service Switching Centre

High Performance Digital Switch

Fixed Backbone

Complete Connection Setup & Release

IWF - Connects to other Networks

2. HLR - Home Location Register

Most Important Database

Stores Permanent Data about the subscriber

Location Information

MSIN no. ,IMSI no. MSRN no.

Eg:-IMSI(MCC+MNC+MSIN)3. VLR- Visitor Location Register

Database

Stores temporary data about subscriber

4. AUC- Authentication Centre

Provides Security

User Authentication & Data Encryption

5. EIR- Equipment Identity Register

Database contains the information about the identity of mobile

equipment- Unique identity number for mobile devices

IMEI- International Mobile Equipment Identity NO.

*#06# -Shows a 17 digit No.

In Nokia Phones

#92702689# Shows

Slno

Mfg date

Purchase date……..

2. BSS- Base station System

All Radio related functions

Consists of 2 Components

1. BSC- Base Station Controller

High Capacity Switch

Call Configuration

Handover

Freq. Distribution

2. BTS- Base Transciever Station

Handles Connection to the MS

Generate Cells

3. OSS- Operation & Support System

Functions for network operations & Management

Consists of one important functional unit

OMC-Operation & Maintenance Center

Monitor & Controls the System

A/C & Billing

Subscriber & Security Management

Additional Functional Elements

1. MXE -Message Center

Provides SMS, Voicemail,Fax, E-mail etc

2. MSN -Mobile Service Node

Provides Intelligent Network Services

3. GMSC- Gateway Mobile Service Switching Centre

A gateway that interconnects two networks: the cellular network and the PSTN.

GSM Services

1. SMS - Short Message Service -160 alphanumeric characters

2.EMS- Extended Message Service -760 alphanumeric characters

3.MMS-Multimedia Message Service

4. Cell Broadcast

5. Call forwarding

6.Barring of Incoming Calls

7. Barring of Outgoing Calls

8.AOC- Advice of Charge

9. Call hold

10. Call waiting

11. CLIP- Call Line Identification Presentation

12. CUG - Closed user Group

Evolution Path for GSM

Newspectrum

Existingspectrum

2G evolved 2G 3G

14.4 kbps 64–115 kbps 0.384–2 mbps115–384 kbps

IMT-2000Capable Systems

GSM GPRS EDGE

3G

Key Feature of GSM

SIM- Subscriber Identity Module

Detachable Smart Card

User Subscribed Information

Phone Book

PIN- Personal Ident. No.

Size-16KB,64 KB,512 KB

2 Types of Calling In GSM

1. Calling to Mobile (Mobile Terminated Call)

2. Mobile to Fixed Telephone Network (Mobile Originated Call)

GSM

Mobile Terminated Call

PSTNcalling

stationGMSC

HLR VLR

BSSBSSBSS

MSC

MS

1 2

3

4

5

6

7

8 9

10

11 12

1316

10 10

11 11 11

14 15

17

1: calling a GSM subscriber

2: forwarding call to GMSC

3: signal call setup to HLR

4, 5: request MSRN from VLR

6: forward responsible MSC to GMSC

7: forward call to

current MSC

8, 9: get current status of MS

10, 11: paging of MS

12, 13: MS answers

14, 15: security checks

16, 17: set up connection

Mobile Originated Call

PSTN GMSC

VLR

BSS

MSC

MS1

2

6 5

3 4

9

10

7 8

1, 2: connection request

3, 4: security check

5-8: check resources (free circuit)

9-10: set up call

Advantages of GSM

Less signal deterioration inside buildings.

Ability to use repeaters

The availability of Subscriber Identity Module allows users to switch networks and handsets.

GSM covers virtually all parts of the world so international roaming is not a problem.

The much bigger number of subscribers globally creates a better network effect for GSM handset makers, carriers and end users.

Thanks