| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Introduction to Wireless Communications

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 1/13 |

Communications

Introduction

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Introduction Outline

• What is Wireless Communications

• The Evolution of Wireless Communications

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 2/13 |

• Broadband Wireless Technology

• Limitations and Difficulties of Wireless Technologies

• Wireless Communications in Tanzania

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

What is Wireless Communications?

• Communication System– A system over which information is transmitted from point A

to point B

• where the distance between them is beyond usual

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 3/13 |

• where the distance between them is beyond usual voice or visual communication.

• Wireless Communications– Communicating information without wires

• using electromagnetic waves.

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Wireless Communications

• Freedom from wires– No wires to install (cost), no bundles of wires around

• Global coverage

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 4/13 |

– Can reach where wiring cannot go (not feasible / cost), can stay connected (roaming allows flexibility anywhere and any time)

• Flexibility– Mobility, multiple connections

Any time, Any where, Any device

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Wireless vs. Mobile

• Wireless does not necessarily mean mobile• Fixed (e.g., IEEE 802.16 WirelessMAN)

• Portable (e.g., IEEE 802.11 WiFi, IEEE 802.15.3 UWB)

• Mobile (e.g., GSM, cdma2000)

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 5/13 |

• Mobile (e.g., GSM, cdma2000)

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

The Evolution of Wireless Communications

• 1896: Guglielmo Marconi invented the wireless telegraph.– Communication by encoding alphanumeric characters in analogue signal– Sent telegraphic signals across the Atlantic Ocean

• 1940’s (late): Terrestrial fixed wireless links routinely providing phone service.

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 6/13 |

phone service.

• 1960’s: Satellite links used for geostationary intercontinental communications.

• 1980’s: Cellular systems are introduced– 1990’s: Cellular industry becomes amongst fastest growing of all time.

• More advances in : – Radio, television, cellular technology, satellite communications, wireless

networking, etc.

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

The Evolution of Wireless Communications

• Joseph Henry

• James Clerk Maxwell

• Heinrich Hertz

• Ferdinand Braun

• Alexander Stepanovich Popov

• Julio Cervera Baviera

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 7/13 |

• Édouard Branly

• Nikola Tesla

• Roberto Landell de Moura

• Oliver Joseph Lodge

• Jagadish Chandra Bose

• Ernest Rutherford

• Julio Cervera Baviera

• Guglielmo Marconi

• John Stone Stone

• Reginald Fessenden

• John Ambrose Fleming

• Lee De Forest

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Broadband Wireless Technology

• Higher data rates obtainable with broadband wireless technology.– Graphics, video, audio

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 8/13 |

• Shares same advantages of all wireless services: convenience and reduced cost.– Service can be deployed faster than fixed service

– No cost of cable plant

– Service is mobile, deployed almost anywhere

• Many initiatives developing broadband wireless standards around many different applications.

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Limitations and Difficulties of Wireless Technologies

• Wireless is convenient and less expensive but there are limitations and political and technical difficulties inhibiting wireless technologies.

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• Lack of an industry-wide standard– slows technology growth

• Device limitations– size, power, etc

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

• Efficient Hardware– low power transmitters, receivers, signal processing tools

• Efficient use of finite radio spectrum

Limitations and Difficulties of Wireless TechnologiesLimitations and Difficulties of Wireless Technologies

-----------------------------------------------------------------------------------------------------------------------------| TE 412 Introduction to Wireless Communications | Christine Mwase | 10/03/2014 | Slide 10/13 |

– frequency reuse, MAC protocols,...

• Integrated services– voice, data, multimedia over a single network

– service differentiation, priorities, resource sharing,...

• Network support for user mobility (mobile scenarios)– location identification, handover,...

– �maintaining quality of service over unreliable links

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Wireless Communication System Classifications

• Analogue - e.g. AM radio, FM radio, television, and 1G cellular systems.

• Digital (the source is assumed to be digital) - Every major

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• Digital (the source is assumed to be digital) - Every major wireless system being developed and deployed is built around digital communication e.g. cellular communication, WLANs, personal area networks, and high-definition television.

The focus of this class will be on digital wireless communication.

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Wireless Technologies

TVFM radio

AM radioBroadcast systems

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Wireless Local Area Networks

Bluetooth

Adhoc

Cellular systems

| University of Dar es Salaam | Department of Electronics and Telecommunications Engineering |__________________________________________________________________________________

Wireless Communications in Tanzania

• The evolution of wireless communications in Tanzania– History and evolution

– Key organisations and authorities

– Status of providers, consumers, standards, devices, applications

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– Status of providers, consumers, standards, devices, applications

• Mobile vs. fixed wireless communications in Tanzania – Penetration of devices

– Cost of devices and services

– Urban-rural coverage

– National strategies push, and international forces