History of Telecom & Electronics

7/30/2019 History of Telecom & Electronics

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Broadcasting , Switching and Transmission

Evolution of Telephone system- Xbar Exchange Electronics Switching - SPC Analog

Software Architecture Of switching

Time Division Switching - TST Concepts Introduction of Transmission-Mode & Standards

Introduction to SONET/SDH

ISDN - standards, DSL & Cable TV

Television - Concepts ,Technology and Standards


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Module I

Evolution of Telephone system

&

Crossbar Exchange


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All revolutionary advances in science may consist less

of sudden and dramatic revelations

than a series of transformations,

of which the revolutionary significance may not be seen

(except afterwards, by historians) until the last great step.

-Bernard Cohen -1980

To understand a science it is necessary to know its history

-Auguste Comte (1798-1857)


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Communication-History

Communication is a process that started perhaps evenbefore we knew how to write or spell the word

"communication".Communication probably dates back to the advent of

life itself. What evolved from simple body language or ancientpictorial messages carved on rocks, metamorphosed

That evolved channels of communication like thetelephone, television and of course the World WideWeb that has evidently brought the world closer.


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Although various complex theories and principles exist,communication can be simply

Defined as a process by which information is exchangedbetween individuals through a common system of symbols,

signs, or behavior Obviously the term is not limited to human beings because

animals have their own way of communicating too.


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Technological History of Media

The first one-to-one communication was thehuman body.

When a person tried to show a necessity he justgot his hands, facial expression or gesture.

Since those days the body language was theoldest and important language that human beinghad.

The people want to abet there body language atone time and started using there voice withsounds and express there necessity much more.


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Technological History of Media The language development is not natural.

The people developed there mind to make feelings, emotionsand necessities clearer to each other.

And so they start to develop language.

We can divide the basic communication elements in two maingroups.

Verbal communication Non-Verbal communicationelements elementsLanguage Body

Writing Signs

Sounds Symbols


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Tele-communication:

The Semaphore or the optical telegraph system was an apparatus forconveying information by means of visual signals.

Claude Chappe (1763-1805)

Could Have Been Built Earlier

Lacked Telescope First Stations

Menilmontant

Saint-Martin-du-Tertre (21 Miles)

First Line Paris to Lille


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Semaphore System

Wooden T Horizontal Beam (Regulator)

Jointed Arms (Indicator)

196 Different Positions

Chappe Code - 92 Positions

Diplomatic Dictionary

92 Pages - First Signal

92 Words/Page - 2nd Signal Second Dictionary - Phrases


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Significance of

Human Communication

Communication is the process of exchanginginformation.

Main barriers are language and distance.

Emphasis is now the accumulation,packaging, and exchange of information.


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COMMUNICATIONS & TELECOMUNICATIONS

COMMUNICATIONS

Process of conveying information

Telecommunications

the transmission of information over significantdistances to communicate.

In earlier times, telecommunications involved the use

of visual signals, such as beacons, smoke signals,semaphore telegraphs, signal flags,
http://en.wikipedia.org/wiki/Transmission_(telecommunications)http://en.wikipedia.org/wiki/Beaconhttp://en.wikipedia.org/wiki/Smoke_signalhttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/Signal_flaghttp://en.wikipedia.org/wiki/Signal_flaghttp://en.wikipedia.org/wiki/Semaphore_linehttp://en.wikipedia.org/wiki/Smoke_signalhttp://en.wikipedia.org/wiki/Beaconhttp://en.wikipedia.org/wiki/Transmission_(telecommunications)


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Telephone system components

microphone

receiver

Transmission

system

Signaling and

switching system


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History of Communications

Charles Wheatstone reproduces

sound in a primitive sound box -

the first speaker.

Joseph Henry invents the first

electric telegraph.

Samuel Morse invents Morse

code.

1821

1831

1835


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Samuel Morse creates the first

long distance electric telegraph

line.

Alexander Bain patents the first

fax machine.

United States starts the Pony

Express for mail delivery.

1843

1861


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Coleman Sellers invents the

Kinematoscope - a machine that

flashed a series of still

photographs onto a screen.

Christopher Shoales creates the

first successful modern

typewriter.

1861

1867


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Thomas Edison patents the

mimeograph - an office copying

machine.

Alexander Graham Bell patents

the electric telephone.

Melvyl Dewey writes the Dewey

Decimal System for orderinglibrary books.

1876


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Thomas Edison patents the

phonograph - with a wax cylinder

as recording medium.

Eadweard Muybridge invents

high speed photography -

creating first moving pictures that

captured motion.

1877


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Emile Berliner invents the

gramophone - a system of

recording which could be used

over and over again.

George Eastman patents Kodak

roll film camera.

Almon Strowger patents the

direct dial telephone.

1887

1889


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Guglielmo Marconi improves

wireless telegraphy.

First telephone answering

machines appear.

Valdemar Poulsen invents the

first magnetic recording device

using magnetized steel tape.

Loudspeakers invented.

1894

1899


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Marconi transmits radio signals

from Cornwall to Newfoundland -

the first radio signal to cross the

Atlantic Ocean

First regular comic books.

Lee Deforest invents an electronic

amplifying tube improving radios

and telephones

1902

1904


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Thomas Edison demonstrates

the first talking motion picture. It

will be 17 years until talkies

First cross country telephone call

made.

First radios with tuners begin to

broadcast different stations

1910

1914

1916


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The television or iconoscope

(cathode-ray tube) invented by

Vladimir Kosma Zworykin - first

television camera.

John Logie Baird transmits the

first experimental television

signal.

1923

1925


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Warner Brothers Studios invents

a way to record sound separately

from the film on large disks and to

synchronize the sound andmotion picture tracks upon

playback - an improvement on

Thomas Edison's work.

1926


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NBC starts two radio networks.

CBS founded.

First television broadcast inEngland.

Warner Brothers releases The

Jazz Singer the first successful

talking motion picture.

1927


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Radio popularity spreads with the

"Golden Age" of radio.

First television broadcasts in the

United States.

Movietone system of recording

film sound on an audio track right

on the film invented.

1930


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Joseph Begun invents the first

magnetic tape recorder for

recording location audio. Television broadcasts are now

able to be taped and edited -

rather than only live or on film. Scheduled regular television

broadcasts begin.

1934

1938

1939


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Computers like Harvard's Mark I

put into public service - the age

of Information Science begins Long playing record invented -

vinyl and played at 33 rpm.

Transistor invented - enablingthe miniaturization of electronic

devices.

1944

1948


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Network television starts in U.S.

and NBC is the First Network

45 rpm record invented

Computers are first sold

commercially.

Chester Carlson invents thephotocopier or Xerox machine.

1949

1951

1958


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Integrated Circuit invented

enabling the further

miniaturization of electronicdevices and computers.

Zip codes invented in the US

Xerox invents the Telecopier -the first successful fax machine.

1958

1963

1966


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ARPANET - the first Internet -

started by MIT.

The floppy disc is invented.

The microprocessor is invented

- called a computer on a chip

HBO invents pay-TV service forcable.

1969

1971

1972


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First Apple home computer

invented.

First nationwide programming via

satellite - implemented by Ted

Turner.

First cellular phone communi-

cation network started in Japan.

1976

1979


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Sony Walkman invented.

First IBM PC sold.

First laptop computers sold topublic.

Computer mouse becomes

regular part of computer.

1980

1981


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Time magazines names the

computer as "Man of the Year."

First cellular phone network

started in the United States.

Apple Macintosh released.

IBM PC AT released.

1983

1984


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Cellular telephones in cars

become wide-spread.

CD-ROMs in computers.

American government releases

control of internet and WWW is

born - making communication

at lightspeed.

1985

1994


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History of Electronics

The is a story of the twentieth century three key componentsthevacuum

tube, the transistor, and theintegrated circuit.

1883, Thomas Alva Edisondiscovered that electrons will flowfrom one metal conductor to anotherthrough avacuum. ( Edisoneffect)

In 1904, John Fleming applied the

Edison effect in inventing a two-element electron tube called a diode,

Lee De Forest followed in 1906 withthe three-element tube, the triode.
http://science.jrank.org/pages/7139/Vacuum-Tube.htmlhttp://science.jrank.org/pages/7139/Vacuum-Tube.htmlhttp://science.jrank.org/pages/6925/Transistor.htmlhttp://science.jrank.org/pages/3619/Integrated-Circuit.htmlhttp://science.jrank.org/pages/7137/Vacuum.htmlhttp://science.jrank.org/pages/2374/Electron.htmlhttp://science.jrank.org/pages/2101/Diode.htmlhttp://science.jrank.org/pages/2101/Diode.htmlhttp://science.jrank.org/pages/2374/Electron.htmlhttp://science.jrank.org/pages/7137/Vacuum.htmlhttp://science.jrank.org/pages/3619/Integrated-Circuit.htmlhttp://science.jrank.org/pages/6925/Transistor.htmlhttp://science.jrank.org/pages/7139/Vacuum-Tube.htmlhttp://science.jrank.org/pages/7139/Vacuum-Tube.html


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History of Electronics

In 1947, the transistor was invented by a team ofengineers from Bell Laboratories. (Nobel prize)

The transistor functions like the vacuum tube, butit is tiny by comparison, weighs less, consumes lesspower, is much more reliable, and is cheaper to

manufacture with its combination of metalcontacts and semiconductor materials.


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Integrated circuit was proposed in 1952 by Geoffrey W.A. Dummer, Throughout the 1950s, transistors weremass produced on single wafers and cut apart.

By 1961, integrated circuits were in full production at anumber of firms, and designs of equipment changedrapidly and in several directions to adapt to the

technology. Bipolar transistors and digital integrated circuits were

made first, but analog ICs, large-scale integration (LSI),and very-large-scale integration (VLSI) followed by the

mid-1970s. VLSI consists of thousands of circuits withon-and-off switches or gates between them on a singlechip.


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Small Scale Integrated Circuits (SSI): Less than 100 Transistorsper Integrated Circuit or chipMedium Scale Integrated Circuits (MSI): 100 to 1000 Transistorsper Integrated Circuit or chip


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Large Scale IntegratedCircuits (LSI): 1000 to

10000 Transistors perIntegrated Circuit orchip

Very Large ScaleIntegrated Circuits(VLSI): 10000 to 1million Transistors perIntegrated Circuit orchip


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Ultra Large Scale Integrated Circuits (ULSI):over 1 million Transistors per Integrated Circuit

or Chip


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Digital Communication history

Foundation of digital communication is thework of Nyquist(1924)

Problem:how to telegraph fastest on a channelof bandwidth W?

Ironically, the original model forcommunications was digital! (Morse code)

First telegraph link was established betweenBaltimore and Washington in 1844


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Shannon channel capacity

Claude Shannon, a Bell Labs Mathematician,proved in 1948 that a communicationchannel is fundamentally speed-limited. Thislimit is given by

C=Wlog2(1+P/NoW) bits/sec

Where W is channels bandwidth, P signalpower and No is noise spectral density

Digital Communications History


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Digital Communications -History

1958, (Bell Lab.) First call through a stored-program system

1960, (Morris, Illinois)

The first commercial telephone service with digitalswitching begin.

1962, (Bell Lab.)

The first T-1 carrier system transmission was installed

Historical Background- Computers

C t N t k


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Historical Background Computers Computer Networks 1943~1946, (Moore School of Electrical Engineering of the Univ. of

Pennsylvania)

ENIAC : first electronic digital computer

1950s Computers and terminals started communicating with each other

1965, Robert Lucky

Idea of adaptive equalization

1982, G. Ungerboeck

Efficient modulation techniques

1950~1970 Various studies were made on computer networks

1971

Advanced Research Project Agency Network(ARPANET) first putinto service; Packet switched Network. 1985,

ARPANET was renamed the Internet

1990, Tim Berners-Lee

Proposed a hypermedia software interface to internetWorld Wide Web -WWW

Historical Background- SATCOM


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Historical Background SATCOM

Satellite Communications

1945, C. Clark

Studied the use of satellite for communications

1955, John R. Pierce

Proposed the use of satellite for communications1957, (Soviet Union)

Launched Sputnik I

1958, (United States)

Launched Explorer I

1962, (Bell Lab.)

Launched Telstar I


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Historical Background-

Optical Communications

Optical Communications

1966, K.C. Kao, G. A. Hockham

Proposed the use of a clad glass fiber as a dielectric

waveguide1959~1960

The laser had been invented and developed

Consider


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Consider

Non-scientists inventions! Examples

MorseArt teacher

BellTeaching deaf studentswanting to become rich

Strowgerundertaker

Josephine Cochranerich partylady! (Dish Washer)

Characteristics

1. Visionary2. Ignoring the complexity

3. Strong will

4. Lucky

Lack of support! Telegraph system not

practical!

Telephone system is

useless!

Continues battle to gain powerand control!

Establishing monopoly!

Bell refusal to connect!

ATT refusal to useothers phones

People seeking profit

C i i S


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Communication Systems

Noise degrades or interferes with transmitted information.

Noise is random, undesirable electronic energy that enters thecommunication system via the communicating medium and

interferes with the transmitted message.


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Broadcasting

Broadcasting

Which involves the use of a single powerful transmitterand numerous receivers that are relatively inexpensive tobuild

point-to-point communications

In which the communication process takes place over alink between a single transmitter and a single receiver.

B d i & P i P i


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Broadcasting & Point to Point

Communication

Radio

Broadcasting

AM and FM radio

The voices are transmitted from broadcasting stations thatoperate in our neighborhood

Television

Transmits visual images and voice

Point-to-point communication Satellite communication

Built around a satellite in geostationary orbit, relies on line-of-sight radio propagation for the operation of an uplink and adownlink


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omputers- pp cat on


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omputers pp cat on Communication Networks

Consists of the interconnection of a number of

routers that are made up of intelligent processorsCircuit switching

Is usually controlled by a centralized hierarchical controlmechanism with knowledge of the networks entire

organizationPacket switching

Store and forward

Any message longer than a specified size is subdivided prior to

transmission into segmentsThe original message is reassembled at the destination on a

packet-by-packet basis

Advantage

When a link has traffic to sent, the link tends to be more fullyutilized.


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Information & Communication

Generation and transfer of information is criticalto todays businesses and social life.

Flow of information both mirror and shape

organizational structures.

Networks are the enabling technology for thisprocess.


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Alexander Graham Bell

Inventor of the Telephone



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*Born: March 3, 1847

*Parents: Alexander Melville Bell and Elisa GraceSymonds

*Siblings: 2 brothers, Melville and Edward


E l Lif


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Early Life

At the Age of16, Graham beganto teach musicand speech at a

boys school.Years later, Bellstarted teachinghis fathers visualspeech to deafand hearingimpaired children.

Bell at age 29

B t U i it


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While Bell was in Massachusetts, he invented theharmonic telegraph, an instrument that makes it

possible to send multiple telegraphs on one line.

Boston University


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On March 7, 1876,Bell received hispatent for the

telephone.

The Telephoneis Patented

Mr Watson come here I want you


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Mr.Watson, come here, I want you.

On March 10, 1876, Alexander Graham Bell was

in his testing room with his partner, Watson.

R d


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The experiment they were working with hadreeds that were thin and steel.One of the reeds

was stuck so Watson plucked it to try to fix it.

Reeds

Successful!


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When he did, Graham heard the vibration

clearly through the newly invented telephone.

Successful!


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Bells Invention

Models of the first electric telephone liquid transmitter (left)and tuned-reed receiver (right)

1876 Patent Issued for Telephone


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1876 Patent Issued for Telephone

to Alexander Graham Bell

RecognizedAlexander

Graham Bell asinventor ofTelephone


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A telephone is an instrument that sends and receivesinformation, usually by means of electricity.

The word telephone comes from Greek words

meaning far and sound. The telephone is one of our best ways to

communicate.

In an emergency a telephone can save your life.

You can make a telephone call almost anywhere inthe world.

Telephones are even used in cars, planes, ships, and

on lots of different mechanical machines.


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While Alexander Graham Bell wasexperimenting with telegraph instruments in theearly 1870s, he realized it might be possible to

transmit the human voice over a wire by usingelectricity

Bell's interest in electricity continued and he

attempted to send several telegraph messagesover a single wire at one time.


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Lacking the time and skill to make theequipment for these experiments he enlisted thehelp of Thomas A. Watson. The two became fast

friends and worked together on the tediousexperimentation to produce sounds over the"harmonic telegraph."

It was on June 2, 1875, while Bell was at one end

of the line and Watson worked on the reeds ofthe telegraph in another room that he heard thesound of a plucked reed coming to him over the

wire.


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The next day, after much tinkering, the instrument

transmitted the sound of Bell's voice to Watson.The instrument transmitted recognizable voice sound,

not words.

Bell and Watson experimented all summer and inSeptember, 1875,

Bell began to write the specifications for his first

telephone patent. By March 1876 he managed to make a transmission,

but the sound was very faint.


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The patent was issued on March 7, 1876.

The telephone carried its first intelligiblesentence three days later in the rented top floor

of a Boston boarding house at 109 Court Street,Boston

By the summer of 1877, the telephone had

become a business. The first private lines, whichtypically connected a businessman's home andhis office, had been placed in service


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From the telephone's earliest days, Bellunderstood his invention's vast potential. Hewrote in 1878:

"I believe in the future, wires will unite

the head offices of telephone companies in

different cities, and a man in one part of thecountry may communicate by word of mouthwith another in a distant place."


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Movies 1 & 2

Elisha Gray and Alexander


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yBell Telephone Controversy

Elisha Gray


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y

Elisha Gray was an American electrical

engineer who developed a telephoneprototype in 1874, in Highland Park, Illinoisand had 70 patents for his own inventions.

Grays patents were financed by Dr. Samuel

White, a prominent Philadelphia dentist,who made his fortune on producingporcelain teeth. He believed that their wasno profit in the telephone, so Grayabandoned his plans.

Many believe Gray to be the true inventor ofthe telephone, only to be cheated out of

credit by history.

So, who got to the patent


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office first?

According to Gray, he had submitted hispatent caveat first thing in the morning onFebruary 14, 1876, in Washington DC and

remained near the bottom of the in-basketuntil late in the afternoon.

Bells application, was submitted by his

lawyer, shortly before noon and insisted onthe Patent Clerk receipting the filing feeimmediately, thus Bells application was

entered first.

Lawsuits


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From 1878-1888, Bell was accused ofpatent fraud. The patent examiner, ZenasWilber, was accused of revealinginformation to Bells lawyer that Gray had

submitted an identical patent earlier in themorning.

Evidence was introduced to the court thatBells 1876 US patent, had a specific 7

sentence claim that did not appear on anyof patent drawings, or earlier drafts, but did

appear on Grays.


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Lawsuits (Contd)

After numerous appeals, Wilber admittedunder oath to taking a $100 bribe from

Bells patent attorney and in fact hadallowed Bells lawyers to see Grays patent

application and make the necessarycorrections in Bells name. Bell countered

under oath that no such thing occurred andWilber was an alcoholic.


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Impact

Even though Bell is still accused in somecircles, history has long forgotten Grays

contribution to the invention of thetelephone.

Bell in fact did end up using Grays

transmitter design after his own patent wasaccepted, but quickly abandoned it.

Commercial Use

Bell's greatest success was achieved on March 10 1876


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Bell s greatest success was achieved on March 10, 1876,marked not only the birth of the telephone but the death ofthe multiple telegraph as well.

By the end of 1880, there were 47,900 telephones in theUnited States.

The following year telephone service between Boston and

Providence had been established 1892:Service between New York and Chicago started

1894:Service between New York and Boston started

1915:Transcontinental service by overhead wire started 1889:Almon B. Strowger invented a switch that could connect

one line to any of 100 lines by using relays and sliders.

1989: These switches were in use till then.


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Dr. Martin

Cooper ofMotorola, madethe first private

handheld mobilephone call on alarger prototype

model in 1973.
http://en.wikipedia.org/wiki/Martin_Cooper_(inventor)http://en.wikipedia.org/wiki/Martin_Cooper_(inventor)http://en.wikipedia.org/wiki/File:2007Computex_e21Forum-MartinCooper.jpghttp://en.wikipedia.org/wiki/Martin_Cooper_(inventor)http://en.wikipedia.org/wiki/Martin_Cooper_(inventor)


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The Telephone


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p

The telephone may seemlike a complicated machine,but it really is one of the

simplest devices that youmay find in your home, oranywhere else you can

imagine.


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A Sad day inHistoryOn August 2, 1922,

Alexander Graham Belldied at his home inBaddek Nova Scotia.

Documents

History of Telecom & Electronics