History of Telecommunications

PRESENTED BY:CHETAN KHADTARESY DIPLOMA

Outline• What is Telecommunications?• The time before phones• Who actually invented the telephone?• 1900 – 1982 – Regulated AT & T Monopoly• 1982 – Long Distance Competition• 1996 – Local dial tone competition• 2000 and Beyond – WWW, internet phones

Telecomm. Definition• Transmission of signals over a distance for the

purpose of communication.– The word telecommunication is adapted from a

French word. It is a compound of the Greek prefix tele, meaning 'far off', and communication, meaning 'to transfer information'.

• 3 parts:– Transmitter– Medium– Receiver

Telecomm. Definition• What are some

examples of Telecommunication systems?– Name the mediums for

each.

Time before Phones• 1831 – Professor Joseph

Henry, Albany, NY – Ring a bell at a distance by connecting and disconnecting wires.

• May 24, 1844 -- Samuel Morse sends from Baltimore to Washington, D.C. “What hath God wrought.”– Numbers 22:23– Morse code

Time before Phones• 1854 – 25,000 miles of telegraph wires have

been laid across the US.– Train schedules, weather, important news

• 1864 – A telegraph line spans the entire continental US– Western Union is formed.

• 1866 – Trans Atlantic telegraph– 8 words a minute

• Very costly

Who invented the Phone?• 1871 – Antonio Meucci, an Italian immigrant living

in New York, files a caveat (an announcement of invention) of a talking telegraph. However, due to financial hardships, he is unable to pay for a full patent when the caveat is due 3 months later.– Had a working prototype.– Honored in 2002 by Congress.

Who invented the Phone?

Alexander Graham Bell (1867)Elisha Gray (1878)

Who invented the Phone?• US Patent 174,465

– Said to be the most valuable patent ever• Over 600 lawsuits were filed in the 1800’s over it.• Awarded to:

– Bell in 1876

Bell tried to sell the patent rights to

Western Union in 1876 for $100,000.

Western Union said the patent was

worthless; who’d want voice when the

telegraph still work?

Who invented the Phone?• Bell’s first phone used a metal disk attached to a

rod floating in acid to create a variable resistance.– A change in intensity made the disk vibrate differently.

• 1877 – Thomas Edison invents the carbon microphone.– Used in phones until late 1970’s

• A phone produced from around 1900 on will still work on today’s phone network.

Who invented the Phone?• Alexander Graham Bell was awarded the

first US patent for a device which ultimately became the telephone.

• Who invented the telephone is very debatable.

1877 - 1900• 1877 – Bell telephone company formed.• 1877 – Western Union forms the American Speaking

Telephone Company using Gray’s invention.– All phones are party lines initially.

• 1877 – In July, a druggist in New Hartford, Connecticut invents the switchboard.

1877 - 1900

1877 - 1900• Ringers:

– Thumper (pre switchboard)– 1878: Thomas Watson

invents the ‘Magneto’• An AC current sent down the

line that would make a hammer move back and forth between 2 bells.

– The first non-voice signal that the telephone system used.

1877 - 1900

Strowger’s Phone

1877 - 1900• 1896 – Invention of the rotary dial phone.

– Less wiring and cheaper.

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