Download - 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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Communication-History
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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Communication-History
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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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History of Communications
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
Alexander Graham Bell
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*Born: March 3, 1847
*Parents: Alexander Melville Bell and Elisa GraceSymonds
*Siblings: 2 brothers, Melville and Edward
Alexander Graham Bell
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.