Invention and applicaion of telephone

Probably no means of communication has revolutionized the daily lives of ordinary people more than the telephone. The actual history of the telephone is a subject of complex dispute. The controversy began with the success of the invention and continues today. Some of the inventors credited with inventing the telephone include Antonio Meucci, Philip Reis, Elisha Gray and Alexander Graham Bell. Bell's experiments with his assistant Thomas Watson finally proved successful on March 10, 1876, when the first complete sentence was transmitted: "Watson, come here; I want you."

The

modern telephone is the culmination of work done by many individuals. Alexander Graham Bell was the first to patent the telephone, an "apparatus for transmitting vocal or other sounds telegraphically", after experimenting with many primitive sound

transmitters and receivers. However, the history of the invention of the

telephone is a confusing collection of claims and counterclaims, made no less confusing by the many lawsuits which attempted to resolve the patent claims of several individuals.

1831 Michael Faraday proved that vibrations of metal could be converted to electrical impulses.

1861 Johann Philip Reis built a apparatus that changed sound to electricity and back again to sound

1871 Antonio Meucci filed his patent caveat (notice of intention to take out a patent)

1874 A. G. Bell while working on a multiple telegraph, developed the basic ideas for the telephon

1875 Bell files first patent for improved telegraphy

1876 Bell and Watson transmit the first complete sentence

1876 Bell files patent application on February 14,. patent issues March 7

1876 Elisha Gray filed his patent caveat (notice of intention to take out a patent) on February 14,

1877 formed Bell Telephone Company to operate local telephone exchange operation

1877 first city exchange installed in Hartford, Connecticut

1879 irst exchange outside the United States was built in London, England

1880 invented the photophone, which transmits speech by light rays

1882 acquired a controlling interest in the Western Electric Company, Elisha Gray's company

1883 irst exchange linking two major cities was established between New York and Boston

1885 formed American Telephone and Telegraph Company to operate the long distance network.

1888 coin operated pay telephone was patented by William Gray of Hartford, Connecticut

1891 first automatic telephone exchange was patented by Almon Strowger of Kansas City

1921 The Detroit Police Department, began experimentation with one-way vehicular mobile service.

1928 Detroit Police commenced regular one-way radio communication with all its patrol cars.

1933 Bayonne, NJ Police Department initiated regular two-way communications with its patrol cars

1936 Alton Dickieson, H.I. Romnes and D. Mitchell begin design of AT&T's mobile phone system

1940 Connecticut State Police began statewide two-way, on the frequency modulated (FM)

1941 FM mobile radio became standard throughout the country following the success in Connecticut

1946 A driver in St. Louis, Mo., placed a phone call,it was the first AT&T mobile telephone call.

1948 wireless telephone service was available in almost 100 cities and highway corridors.

1947 cellular telephone service conceived by D.H. Ring at Bell Labs, but the technology didn't exist

1962 The first commercial touch-tone phones were a big hit in their preview at Seattle World's Fair.

1970 commercial Picture phone service debuted in downtown Pittsburgh, Pennsylvania.

1971 Richard Frenkiel and Joel Engel of AT&T applied computers and electronics to make it work.

1973 Martin Cooper of Motorola made the first cellphone call to his rival Joe Engel of AT&T Bell Labs

1978 AT&T conducted FCC-authorized field trials in Chicago and Newark, N.J.

1979 the first cellular network was launched in Japan.

1982 FCC granted commercial licenses to an AT&T subsidiary, Advanced Mobile Phone Service

1983 AMPS was then divided among the local companies as part of the planning for divestiture

1983 Illinois Bell opened the first commercial cellular system in October.

Simply described, it is a system which converts sound, specifically the human voice, to electrical impulses of various frequencies and then back to a tone that sounds like the original voice. In 1831, Englishman Michael Faraday (1791-1867) proved that vibrations of metal could be converted to electrical impulses. This was the technological basis

of the telephone, but no one actually used this system to transmit sound until 1861. In that year, Johann Philip Reis (1834-1874) in Germany is said to have built a simple apparatus that changed sound to electricity and back again to sound. A crude device, it was incapable of transmitting most frequencies, and it was never fully developed.

A practical telephone was actually invented independently by two men working in the United States, Elisha Gray and Scottish-born Alexander Graham Bell. Incredibly, both men filed for a patent on their designs at the New York patent office on February 14, 1876, with Bell beating Gray by only two hours! Although Gray had built the first steel diaphragm / electromagnet receiver in 1874, he wasn’t able to master the design of a workable transmitter until after Bell had. Bell had worked tirelessly, experimenting with various types of mechanisms, while Gray had become discouraged.

According to the famous story, the first fully intelligible telephone call occurred on March 6, 1876, when Bell, in one room, called to his assistant in another room. "Come here, Watson, I want you."

Watson heard the request through a receiver connected to the transmitter that Bell had designed, and what followed after that is a history of the founding of the Bell Telephone Company (later AT&T), which grew to be the largest telephone company in the world.

The first telephone system, known as an exchange, which is a practical means of communicating between many people who have telephones, was installed in Hartford, Connecticut in 1877, and the first exchange linking two major cities was established between New York and Boston in 1883. The first exchange outside the United States was built in London in 1879. The exchange involved a group of operators working at a large switchboard. The operators would answer an incoming telephone call and connect it manually to the party being called. The first automatic telephone exchange was patented by Almon Strowger of Kansas City in 1891 and installed in 1892, but manual switchboards remained in common use until the middle of the twentieth century.

The coin operated pay telephone was patented by William Gray of Hartford in 1889. The first rotary dial telephone was developed in 1923 by Antoine Barnay in France. The mobile telephone was invented by Bell Telephone Company and introduced into New York City police cars in 1924. Although the first commercial mobile telephone service became available in St. Louis, Missouri in 1946, the mobile telephone would not become common for another four decades.

The first touch-tone system - which used tones in the voice frequency range rather than pulses generated by rotary dials - was installed in Baltimore, MD, in 1941. Operators in a central switching office pushed the buttons; it was much too expensive for general use. However, the Bell System was intrigued by touch-tone because it increased the speed of dialing.

By the early 1960s, low-cost transistors and associated circuit components made the introduction of touch-tone into home telephones possible. Extensive human factors tests determined the position of the buttons to limit errors and increase dialing speed even further. The first commercial touch-tone phones were a big hit in their preview at the 1962 Seattle World's Fair.

The first Picturephone test system, built in 1956, was crude—it transmitted an image only once every two seconds. But by 1964 a complete experimental system, the "Mod 1," had been developed. To test it, the public was invited to place calls between special exhibits at Disneyland and the New York World’s Fair. In both locations, visitors were carefully interviewed afterward by a market research agency.

People, it turned out, didn’t like Picturephone. The equipment was too bulky, the controls too unfriendly, and the picture too small. But the Bell System was convinced that Picturephone was viable. Trials went on for six more years. In 1970, commercial Picturephone service debuted in downtown Pittsburgh and AT&T executives confidently predicted that a million Picturephone sets would be in use by 1980.

What happened? Despite its improvements, Picturephone was still big, expensive, and uncomfortably intrusive. It was only two decades later, with improvements in speed, resolution, miniaturization, and the incorporation of Picturephone into another piece of desktop equipment, the computer, that the promise of a personal video communication system was realized.

In 1978, American Telephone and Telegraph’s (AT&T) Bell Laboratories began testing a mobile telephone system based on hexagonal geographical regions called cells. As the caller’s vehicle passed from one cell to another, an automatic switching system would transfer the telephone call to another cell without interruption. The cellular telephone system began nationwide usage in the United States in 1983.