cellular networks

CELLULAR NETWORKS

Guided By :- Mrs. Baljeet kaur (lecturer)

Name:-Kumar GauravRoll No:-26

HISTORY OF MOBILE PHONES Two-way radios (known as mobile rigs) were

used in vehicle. During the early 1940s, Motorola developed

a backpacked two-way radio, the Walkie-Talkie and later developed a large hand-held two-way radio for the US military. This battery powered "Handie-Talkie" (HT) was about the size of a man's forearm.

Later radio telephony was introduced on a large scale in German tanks during the Second World War.

EARLY YEARS.. In 1910 Lars Magnus Ericsson installed a

telephone in his car, although this was not a radio telephone. While travelling across the country, he would stop at a place where telephone lines were accessible and using a pair of long electric wires he could connect to the national telephone network.

1946 soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version

of a radio mobile phone mounted inside a car. The device could connect to local telephone network on a range up to 20 kilometers.

Contd…

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EARLY YEARS.. In1945

The first mobile-radio-telephone service is established in St. Louis, Miss. The system is comprised of six channels that add up to 150 MHz. The project is approved by the FCC, but due to massive interference, the equipment barely works.

In 1947 AT&T comes out with the first radio-car-

phones that can be used only on the highway between New York and Boston; they are known as push-to-talk phones. The system operates at frequencies of about 35 to 44 MHz, but once again there is a massive amount of interference in the system. AT&T declares the project a failure.

EARLY YEARS…. In 1973

Dr. Martin Cooper invents the first personal handset while working for Motorola. He takes his new invention, the Motorola Dyna-Tac., to New York City and shows it to the public. His is credited with being the first person to make a call on a portable mobile-phone.

EARLY YEARS…….

Top of cellular telephone tower

Dr. Martin Cooper of Motorola, made the first US analogue mobile phone call on a larger prototype model in 1973.

PICTURE GALLRY

The First Mobile Phone: Motorola DynaTAC 8000X (1983)Motorola's DynaTAC 8000X wasn't commercially available until 1983, but its beginnings can be tracked back to 1973 when the company showed off a prototype of what would become the world's first mobile phone. The DynaTAC weighed almost a kilogram, provided one hour of battery life and stored 30 phone numbers in its phonebook. The Motorola DynaTAC is best known for bring used in the 1987 movie Wall Street, starring Michael Douglas as corporate raider Gordon Gecko.

PICTURE

First Car Phone: Nokia Mobira Senator (1982)In the early 1980's, the mobile phone was best known for its in-car use. Nokia's Mobira Senator, released in 1982, was the first of its kind. A car phone that weighed almost 10 kilograms, the Nokia Mobira Senator resembled a large radio rather than a conventional mobile phone.

FIRST GSM PHONE: NOKIA 101 (1992)

First GSM Phone: Nokia 101 (1992)Nokia's 101 was the world's first commercially available GSM mobile phone. Paving the way for future "candy-bar" designs, the 101 had a monochrome display, an extendable antenna and a phonebook that could store 99 phone numbers. It did however lack Nokia's famous "Nokia tune" ringtone — this wasn't introduced until the next model in 1994.

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EARLY YEARS…. In 1981

The FCC makes firm rules about the growing cell phone industry in dealing with manufactures. It finally rules that Western Electric can manufacture products for both cellular and terminal use. (Basically they admit that they put the phone companies about 7 years behind)

In 1988 One of the most important years in cell

phone evolution. The Cellular Technology Industry Association is created and helps to make the industry into an empire. One of its biggest contributions is when it helped create TDMA phone technology, the most evolved cell phone yet. It becomes available to the public in 1991.

TOUCH SCREEN: IBM SIMON PERSONAL COMMUNICATOR (1993)

Touch Screen: IBM Simon Personal Communicator (1993)The IBM Simon Personal Communicator was one of the first attempts at a commercially viable smartphone. A joint venture between IBM and Bellsouth, the Simon was only sold into the US and was best known for having no physical keys. It used a touch screen and optional stylus to perform the majority of its functions, which included dialling phone numbers, sending faxes and writing memos. It was priced at $899 when it launched.

GENERATIONS OF MOBILE PHONES

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INTRODUCTION OF MOBILE TECHNOLOGY First Generation (1G)

Analog system designed for voice only communication. 1G systems are almost extinct now,

Second Generation (2G) Use GSM and IS-95 CDMA technologies CDMA

Allows users to communicate with different codes

Still designed for voice communication

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INTRODUCTION OF MOBILE TECHNOLOGY 2.5 and 2.75 Generation

General Packet Radio Service(GPRS )and CDMA2000 (Phase 1) are belonged to 2.5 G

Enhanced Data Rates for GSM Evolution(EDGE) is belonged to 2.75G

As higher data rate is provided, allows some data transmission

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INTRODUCTION OF MOBILE TECHNOLOGY Third Generation (3G)

Two 3G, Universal Mobile Telecommunication system(UMTS )and CDMA-2000, are used. UMTS is broadly deployed in Europe and CDMA-2000 is being deployed in North American and parts in Asia

Higher data transmission rate (up to 2Mbps) which allows video conferencing

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INTRODUCTION OF MOBILE TECHNOLOGY Forth Generation (4G)

Combined the technologies of Wireless local area network (will be introduced soon) and 3G

THE CELLULAR CONCEPT

BASIC CONCEPT

Cellular system developed to provide mobile telephony: telephone access “anytime, anywhere.”

First mobile telephone system was developed and inaugurated in the U.S. in 1945 in St. Louis, MO.

This was a simplified version of the system used today.

SYSTEM ARCHITECTURE

A base station provides coverage (communication capabilities) to users on mobile phones within its coverage area.

Users outside the coverage area receive/transmit signals with too low amplitude for reliable communications.

Users within the coverage area transmit and receive signals from the base station.

The base station itself is connected to the wired telephone network.

FIRST MOBILE TELEPHONE SYSTEM

One and only onehigh power base station with which allusers communicate.

Entire Coverage Area

NormalTelephone

System

Wired connection

CELLULAR GEOMETRIES

Rd 3

• The most common model used for wireless networks is uniform hexagonal shape areas– A base station with omni-directional antenna is placed in

the middle of the cell

PROBLEM WITH ORIGINAL DESIGN

Original mobile telephone system could only support a handful of users at a time…over an entire city!

With only one high power base station, users phones also needed to be able to transmit at high powers (to reliably transmit signals to the distant base station).

Car phones were therefore much more feasible than handheld phones, e.g., police car phones.

IMPROVED DESIGN

Over the next few decades, researchers at AT&T Bell Labs developed the core ideas for today’s cellular systems.

Although these core ideas existed since the 60’s, it was not until the 80’s that electronic equipment became available to realize a cellular system.

In the mid 80’s the first generation of cellular systems was developed and deployed.

THE CORE IDEA: CELLULAR CONCEPT

The core idea that led to today’s system was the cellular concept.

The cellular concept: multiple lower-power base stations that service mobile users within their coverage area and handoff users to neighboring base stations as users move. Together base stations tessellate the system coverage area.

CELLULAR CONCEPT

Thus, instead of one base station covering an entire city, the city was broken up into cells, or smaller coverage areas.

Each of these smaller coverage areas had its own lower-power base station.

User phones in one cell communicate with the base station in that cell.

3 CORE PRINCIPLES

Small cells tessellate overall coverage area.

Users handoff as they move from one cell to another.

Frequency reuse.

SUMMARIZATION

1G 2G 2.5G 3G 3.5G 4GSpeeds n/a <20Kbps 30Kbps to

90Kbps144Kbps to 2Mbps

384Kbps to 14.4Mbps

100Mbps to 1Gbps

Features Analog (voice only)

Voice; SMS; conference calls; caller ID; PTT

MMS; Images; Web browsing; Short audio video clips; games; apps; Ring tone downloads

Full motion video; streaming music; 3D gaming; faster Web browsing

On-demand video; video conferencing

High-quality streaming video, HQ video conferencing; VOIP telephony

Technology

AMPS GSM CDMA iDen

GPRS 1xRTT EDGE

UMTS 1xEV-DO

HSPDA 1x-EV-DV

WiMax

Time 1980 1990 – 1995 1995 – 2000 2000 – 2005 2005 + TBA

TECHNOLOGY USED IN CELLULAR NETWORK

WHAT IS GSM ?

Global System for Mobile (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation

GSM: HISTORY• Developed by Group Spéciale Mobile (founded 1982) which was an

initiative of CEPT ( Conference of European Post and Telecommunication )

• Aim : to replace the incompatible analog system

• Presently the responsibility of GSM standardization resides with special mobile group under ETSI ( European telecommunication Standards Institute )

• Full set of specifications phase-I became available in 1990

• Under ETSI, GSM is named as “ Global System for Mobile communication “

• Today many providers all over the world use GSM (more than 135

countries in Asia, Africa, Europe, Australia, America)

• More than 1300 million subscribers in world and 45 million subscriber in India.

6: Wireless and Mobile Networks

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CODE DIVISION MULTIPLE ACCESS (CDMA)

used in several wireless broadcast channels (cellular, satellite, etc) standards

unique “code” assigned to each user; i.e., code set partitioning

all users share same frequency, but each user has own “chipping” sequence (i.e., code) to encode data

encoded signal = (original data) X (chipping sequence)

decoding: inner-product of encoded signal and chipping sequence

allows multiple users to “coexist” and transmit simultaneously with minimal interference (if codes are “orthogonal”)

CDMA THE MOST ADVANCED WIRELESS DIGITAL TECHNOLOGY

. . . . . . . . . . . . . .

1G Analog

2G Time Division

(TDMA & GSM)3 – 7x Analog Capacity

3G Code Division

(CDMA2000®, WCDMA)20 – 26x Analog Capacity

CDMA2000 BENEFITS FOR OPERATORS, SUBSCRIBERS AND GOVERNMENTS

CDMA is a high-speed wireless data and voice network solution for low-cost, easy to deploy, high-performance services, that address the needs of governments, operators and subscribers CDMA can support high volumes of voice traffic

and high-speed data traffic;

Contd.

.Contd

Instead of being limited to a narrow channel structure in a given frequency, CDMA spreads signal across 1.25 MHz of the spectrum, and simultaneously transmits unique, digitally encoded and encrypted signals over the same radio frequency (RF) carrier;

CDMA2000 technology can be configured for data and/or voice, as well as for fixed or mobile services.

Due to its efficient use of the spectrum to provide high-quality voice and high-speed data services, CDMA can be utilized for fixed voice and data services, delivering end-users the richness and variety of the Internet with the quality and reliability of the traditional phone network.

OFDM

Divides the spectrum into a number of equally spaced tones. Each tone carries a portion of data. A kind of FDMA, but each tone is orthogonal with every other

tone. Tones can overlap each other. Example: 802.11a WLAN

3G WIRELESS SYSTEMS

3G Wireless Systems are the new generation of systems that offer high bandwidth and support digital voice along with multimedia and global roaming.

Globally, different systems are being used, so, to migrate to globally acceptable systems, numerous standardization activities were carried out and three systems emerged: W-CDMA, CDMA2000, and TD-SCDMA

Communication services

•Video telephony

•Video conference

•Personal location (GPS)

Education

• Virtual schools

• On-line science lab

• On-line library

• On-line language labs

• Training

Applications Using 3G

Finance services

•Virtual banking

•On-line billing

•Universal USIM and credit card

Business services

• Mobile office

•Narrowcast business TV

•Virtual workgroups

•Expertise on tap

Entertainment

•Audio on demand

•Games

•Video clips

•Virtual sightseeing

Applications Using 3G…

3G CONCLUSION

3G technologies promise to deliver a lot and are slowly being put into effect.

We have already started seeing the early features of 3G technologies being implemented in our phones, i.e., the video phones in the market.

It remains to be seen how much of the promised features and applications are actually implemented in today’s economy.

However, they have been slow in coming in. Let’s see what the future holds…

THANK YOU