Sunday, February 11, 2007

Timeline of the telephone (1849-1875)

1849 Antonio Meucci demonstrates a device later called a telephone to individuals in Havana. (It is disputed if this is an electric telephone, but is said to involve direct transmission into the body.)
1854 Charles Bourseul publishes a description of a make-break telephone transmitter and receiver but does not construct a working instrument.
1854 Antonio Meucci demonstrates an electric voice operated device in New York, but it is not clear what kind of device he demonstrated.
1860 Johann Philipp Reis demonstrates a make-break transmitter after the design of Bourseul and a knitting needle receiver. Witnesses said they heard human voices being transmitted.
1861 The German Philipp Reis manages transfer voice electrically over a distance of 340 feet, see Reis' telephone.
1864 In an attempt to give his musical automaton a voice, Innocenzo Manzetti invents the 'Speaking telegraph'. He shows no interest in patenting his device, but it is reported in newspapers.
1865 Meucci reads of Manzetti's invention and writes to the editors of two newspapers claiming priority and quoting his first experiment in 1849. He writes "I do not wish to deny Mr. Manzetti his invention, I only wish to observe that two thoughts could be found to contain the same discovery, and that by uniting the two ideas one can more easily reach the certainty about a thing this important." If he reads Meucci's offer of collaboration, Manzetti does not respond.
1871 Antonio Meucci files a patent caveat (a statement of intention to patent).
1872 Elisha Gray founds Western Electric Manufacturing Company.
1872 Prof Vanderwyde demonstrated Reis's telephone in New York.
July 1873 Thomas Edison notes variable resistance in carbon grains due to pressure, builds a rheostat based on the principle but abandons it because of its sensitivity to vibration.
May 1874 Gray invents electromagnet device for transmitting musical tones. Some of his receivers use a metallic diaphragm.
December 29, 1874 Gray demonstrates his musical tones device and transmitted "familiar melodies through telegraph wire" at the Presbyterian Church in Highland Park, Illinois.
2 June 1875 Alexander Graham Bell transmits the sound of a plucked steel reed using electromagnet instruments.
1 July 1875 Bell uses a bi-directional "gallows" telephone that was able to transmit "indistinct but voicelike sounds" but not clear speech. Both the transmitter and the receiver were identical membrane electromagnet instruments.
1875 Thomas Edison experiments with acoustic telegraphy and in November builds an electro-dynamic receiver but does not exploit it.

Thursday, February 08, 2007

Timeline of the telephone (1927-2007)

1927 First public trans-atlantic phone call (via radio)
1935 First telephone call around the world.
1941 Touch Tone dialing introduced for operators in Baltimore, Maryland
1946 National numbering plan (area codes)
1946 First commercial mobile phone call
1946 Bell Labs develops the germanium point contact transistor
1947 December, D. H. Ring, a Bell Labs engineer, proposed hexagonal cells for mobile phones.
1948 Phil Porter, a Bell Labs engineer, proposed that cell towers be at the corners of the hexagons rather than the centers and have directional antennas pointing in 3 directions.
1951 Direct Distance Dialing (DDD) first offered at Englewood, New Jersey, to 11 selected major cities across the United States; this service grew rapidly across major cities during the 1950s
1955 The laying of trans-Atlantic cables began
1958 Modems used for direct connection via voice phone lines
1960 ESS-1
1961 Touch-tone released to public
1962 T-1 service in Skokie, Illinois
1960's Bell Labs developed the electronics for cellular phones.
1970 ESS-2 electronic switch.
1970 Modular telephone cords and jacks introduced
1970 Amos Joel of Bell Labs invented the "call handoff" system for "cellular mobile communication system"
1971 AT&T submitted a proposal for cellular phone service to the FCC.
1973 April 3, Motorola employee Martin Cooper placed the first hand-held cell phone call to rival Joel Engel, head of research at AT&T's Bell Labs, while talking on the first Motorola DynaTAC prototype.
1975 Last manual telephone switchboard in Maine is retired
1978 Bell Labs launched a trial of the first commercial cellular network in Chicago using AMPS.
1982 FCC approved AT&T proposal for Advanced Mobile Phone Service (AMPS) and allocated frequencies in the 824-894 MHz band.
1982 Caller ID patented by Carolyn Doughty, Bell Labs
1987 ADSL introduced
1990 Analog AMPS was superseded by Digital AMPS.
1993 Telecom Relay Service available for the disabled
1995 Caller ID implemented nationally in USA
2002 Antonio Meucci was recognized as the first inventor of the telephone by the United States House of Representatives, in House Resolution 269, dated 11 June. The Parliament of Canada retaliated by passing a bill recognizing Canadian immigrant Alexander Graham Bell as the only inventor of the telephone.
2005 Mink, Louisiana gets phone service (Last in the USA)
2004 VoIP created