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Telecom Timeline
1900-1949
1950-2000
2000- Present

1900-1949

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The period between 1900 and 1949 saw tremendous advances in telecommunications with the coming of the rotary dial phone and the earliest mobile telephones were used in New York City police cars in 1924. AT&T is already becoming a monopoly and many spin off companies sprout up along the way.

1900
676,733 Bell telephone stations owned and connected. #TelecomTimeline
1900
Basic trunking principles established for large exchanges. Bank terminals molded in plaster of Paris. #TelecomTimeline
1900
First telephone derivative paths (by Carter's idea 1886). #TelecomTimeline
1900
John J. Carty installs loading coils to extend range and reduce crosstalk an inductive pickup from ac transmission lines.
1900
There are now about 20,000 telcos in business. There are now 856,000 telephones in service. #TelecomTimeline
1901
Formation of Automatic Electric Company to take over Strowger Automatic Telephone Exchange. #TelecomTimeline
1901
Guglielmo Marconi sends first transatlantic wireless signals, 12 December. #TelecomTimeline
1901
Installation at Fall River, Mass., used line banks with fiber insulators and aluminum fillers. First use of “slip multiple.”
1901
Marconi transmits first trans-Atlantic radio message (from Cape Cod). #TelecomTimeline
1902
First conversation by long distance underground cable, 10 miles. New York to Newark. #TelecomTimeline
1902
First installation in Chicago begun. Earliest use of measured service in automatic exchanges. #TelecomTimeline
1902
Krarup (Denmark) Invention of krarupization. #TelecomTimeline
1902
Poulsen-Arc Radio Transmitter invented. #TelecomTimeline
1903
AIEE Committee on Telegraphy and Telephony formed. #TelecomTimeline
1903
Large Strowger installations placed in service in Grand Rapids, Dayton, Akron, Columbus. #TelecomTimeline
1904
First use of multi-office trunking, and connections between automatic and manual offices (Los Angeles, Califonia). #TelecomTimeline
1904
John Ambrose Fleming invents the two-element "Fleming Valve". #TelecomTimeline
1905
Earliest extended use of party lines and reverting calls. First system using common battery talking (South Bend, Indiana).
1905
Marconi patents his directive horizontal antenna. #TelecomTimeline
1906
Conversation by underground cable, 90 miles-New York to Philadelphia. #TelecomTimeline
1906
Dr. Lee de Forest reads paper before AIEE meeting on first of the vacuum tubes that would make long distance radiotelephony possible.
1906
Invention of Keith Line Switch, resulting in enormous reduction in cost of automatic boards. First used at Wilmington, Delaware.
1906
Lee deForest invents the vacuum tube. #TelecomTimeline
1906
Molina from American Telephone and Telegraph Company (USA) invention of registry. #TelecomTimeline
1906
Reginald Fessenden broadcasts Christmas Carols on Christmas Eve from Brant Rock, MA. #TelecomTimeline
1907
"Common carrier" regulation refers to approval of tariffs which provide terms and conditions whereby the public can use their services
1907
First installation in Canada. Invention of small dial and two-wire system eliminating ground at subscriber’s station. #TelecomTimeline
1907
States start to regulate telcos. Mississippi was among the first. #TelecomTimeline
1907
Theodore Vail returns as President of AT&T (and Western Union). He is responsible for the concept of "end-to-end" service.
1907
World's first transatlantic commercial wireless services is established by Marconi with stations at Clifden, Ireland & Nova Scotia.
1908
AT&T President Theodore Vail sets a goal of Universal Service. providing high-quality telephone service to any American who wants it.
1908
Earliest use of automatic, intermittent ringing. Installation at Lansing, MI. Features use of small dial, secondary line switch.
1908
First two-wire system (large dial) installed at Pontiac, Illinois. #TelecomTimeline
1909
Invention of out-going secondary line switch, resulting in economy of inter-office trunks. First used at San Francisco.
1909
Marconi shares the Nobel Prize in Physics, with Karl Ferdinand Braun for their work in the development of wireless telegraphy.
1909
Western Union and AT&T are closely locked. #TelecomTimeline
1910
5,142,692 Bell telephone stations owned and connected. #TelecomTimeline
1910
Interstate Commerce Commission starts to regulate telcos. #TelecomTimeline
1910
Peter DeBye in Holland, develops theory for optical waveguides. He was a few years ahead of his time. #TelecomTimeline
1910
Strowger system introduced in Hawaii and Cuba. Earliest use of dialing over toll lines. Introduction of revertive ringing tone.
1910
The first commercial radios are sold by Lee de Forest's Radio Telephone Company. #TelecomTimeline
1910
The Mann-Elkins Act enacted, putting interstate communications under the purview of the Interstate Commerce commission (ICC)
1911
Conversation by overhead line., 2,100 miles — New York to Denver. #TelecomTimeline
1911
Formation of Automatic Telephone Manufacturing Co., Ltd. For production of Strowger system in England. #TelecomTimeline
1911
Using loading coils properly spaced in the line, the transmission distance for telephone reaches from New York to Denver.
1912
First Strowger installation in England (Epsom “Official Switch”). #TelecomTimeline
1912
Palmgren and Betulander (Sweden) Invention of marker. #TelecomTimeline
1913
AT&T agrees to divest its holdings of Western Union, stop acquisition of other telcos, and permit other telcos to interconnect.
1913
Conversation by overhead line, 2,600 miles—New York to Salt Lake City. Conversation by underground cable, 455 miles-Boston to WashDC.
1913
Pupinization of air lines (range to 3000 km) USA. #TelecomTimeline
1913
Pupinization of telephone wire from Washington. New York
1913
Roberts and Reynolds (USA)Invention of multiswitch (crossbar) by idea of Roberts 1901. #TelecomTimeline
1913
Strowger system introduced in Australia and New Zealand. Development of key-type impulse sender, and Simplex dialing on toll lines.
1913
The Kingsbury Commitment precludes un-approved expansion, and permits connections to network. #TelecomTimeline
1913
US Justice Department filed its first antitrust suit against Bell, charging unlawful combination to monopolize the Pacific Northwest.
1914 (February 26)
Boston-Washington under-ground telephone cable placed in commercial service. #TelecomTimeline
1914
Automatic Switches used as traffic distributors in manual exchanges (Indianapolis, Indiana and Defiance, Ohio). #TelecomTimeline
1914
First launch of telephone exchange with automatic switch indirectly controlled (rotary system Great Britain). #TelecomTimeline
1914
The last pole of the transcontinental telephone line is placed in Wendover, Utah, on the Nevada-Utah state line. #TelecomTimeline
1914
Underground cables link Boston, NYC and Washington. #TelecomTimeline
1915 (January 25)
Opening of First Trans-continental telephone line, New York to San Francisco, 3600 miles. #TelecomTimeline
1915 (October 21)
First transmission of speech across the Atlantic by radiotelephone, Arlington, Va., to Paris. #TelecomTimeline
1915
AT&T engineers transmit speech across the Atlantic Ocean by wireless radio. #TelecomTimeline
1915
Development of modern covered switch with horizontal relays. used at St. Paul and Minneapolis. #TelecomTimeline
1915
Direct telephone communications opened for service at 4pm, EST. #TelecomTimeline
1915
E.T. Whitaker develops the sampling theorem that forms the basis of today's PCM and TCM technologies. #TelecomTimeline
1915
first conversation by transcontinental line, 3,650 miles-Boston to San Francisco. #TelecomTimeline
1915
First launch of telephone exchange with automatic switch indirectly controlled (Panel system, USA). #TelecomTimeline
1915
First use of cast iron switch frame at Hazelton, Pennsylvania. #TelecomTimeline
1915
Speed transmitted for the first time by radio telephone from Arlington, Va. across the Atlantic to Paris. #TelecomTimeline
1915
Vacuum tube amplifiers used the first time in coast-to-coast telco circuits. #TelecomTimeline
1916
Earliest community automatic exchange network installed in Wisconsin. #TelecomTimeline
1917
Bell System engineers demonstrate oneway radiotelephone transmission from airplane to ground. #TelecomTimeline
1917
Rapid expansion in the use of private automatic branch exchanges. Development of remote alarm equipment for unattended exchanges.
1918
Edwin Armstrong develops a receiving circuit. the superheterodyne. #TelecomTimeline
1918
First installation using rotary primary line switches (Elyria, Ohio). #TelecomTimeline
1919
AT&T introduces dial telephones. #TelecomTimeline
1919
First Strowger board manufactured for Bell System (Norfolk, Virginia). #TelecomTimeline
1919
Palmgren and Betulander (Sweden)Improvement of crossbar. #TelecomTimeline
1919
Radio Corporation of America (RCA) is formed. #TelecomTimeline
1920 (July 16)
World's first radiotelephone service, between Los Angeles and Santa Catalina Island, opened to the public. #TelecomTimeline
1920
11,795,747 Bell telephone stations owned and connected. #TelecomTimeline
1920
Beginning of wide-spread adoption of Strowger equipment for metropolitan areas both in the U.S. and abroad. #TelecomTimeline
1920
Bell introduces its own step-by-step offices previously acquired from Automatic Electric. #TelecomTimeline
1920
First installation of call-indicator equipment for automatic-manual connections in multi-office areas. #TelecomTimeline
1920
First regular commercial radio broadcasts begin when AM station KDKA of Pittsburgh delivers results of the Harding-Cox election.
1920
G. Valensi develops the time domain multiplexing concept. #TelecomTimeline
1920
Radio experiences immediate success—. by the end of 1922, 563 other licensed stations will join KDKA. #TelecomTimeline
1920
Westinghouse Radio Station KDKA is established (2 November). #TelecomTimeline
1921 (April 11)
Opening of deep sea cable, Key West to Havana, Cuba, 115 miles. #TelecomTimeline
1921
Conversation by deep sea cable, 115 miles— Key West, Fla., to Havana, Cuba. #TelecomTimeline
1921
First radio broadcast of a sporting event (Dempsey/Carpentier Heavyweight Championship Prize Fight, 2 July). #TelecomTimeline
1921
The idea for a facsimile transmission was first proposed by Scottish clockmaker Alexander Bain in 1843. #TelecomTimeline
1921
The Willis-Graham Act allows telcos to merge with permission of the States and the Interstate Commerce Commission. #TelecomTimeline
1921
Wirephoto. The first electronically-transmitted photograph is sent by Western Union. #TelecomTimeline
1922 (August 2)
Alexander Graham Bell dies at his summer home in Beinn Breagh, near Baddeck, Cape Breton Island, Nova Scotia.
1922
British Broadcasting Corporation (BBC) is formed. (It would receive it's Royal Charter in 1927). #TelecomTimeline
1922
Introduction of improved steel wall telephones and improved desk stands (Type 21). #TelecomTimeline
1922
Phone service is suspended for one minute (6. 25pm-6
1922
Ship-to-shore conversation by wire and wireless between Bell telephones in homes and offices and the SS America 400 miles at sea.
1923 (December 22)
Opening of Second Trans-continental telephone line, southern route. #TelecomTimeline
1923 (June 7)
Radio broadcasting networks had their beginning with a hook-up of four radio stations by long distance telephone lines.
1923
14,050,565 Bell telephone stations owned and connected. #TelecomTimeline
1923
Antoine Barnay (France)First rotary dial telephone was developed. #TelecomTimeline
1923
AT&T longdistance lines connect stations in the first network-radio broadcast. #TelecomTimeline
1923
First British Post Office announces adoption of Strowger system (with Director) for London. #TelecomTimeline
1923
New York & Chicago meetings of the American Institute of Electrical Engineers linked by long distance so both could follow program.
1923
Successful demonstration of transoceanic radio telephony from a Bell telephone station in New York City to New Southgate, England.
1924
Bell Telephone Company (USA)The mobile telephone was invented and introduced into New York City police cars. #TelecomTimeline
1924
Directive short wave antenna is developed by Professor Hidetsugu Yagi and his assistant, Shintaro Uda. #TelecomTimeline
1924
Strowger exchange installed throughout Canal Zone. First Strowger “Directors” installed in Havana. #TelecomTimeline
1925 (October 1)
Opening of long distance telephone cable, New York to Chicago. #TelecomTimeline
1925
Bell Telephone Laboratories founded. 1.5 million dial telephones in service out of 12 million phones in service. #TelecomTimeline
1925
Introduction of the Monophone. first hand set telephone of modern type. #TelecomTimeline
1925
The Combined Line and Recording (CLR) method of handling toll calls over long distances introduced experimentally by Bell Systems.
1925
The Research and Engineering Departments of AT&T and the Western Electric Company are incorporated as ell Telephone Laboratories.
1926
Baird in Scotland and Jenkins in the U.S. demonstrate TV using neon bulbs and mechanical scanning disks. #TelecomTimeline
1926
First crossbar switch indirectly controlled (Sweden). #TelecomTimeline
1926
Introduction of the Type 24 Dial. modern, quiet-running, long-life calling device. Strowger system adopted by Japan. #TelecomTimeline
1926
P.M. Rainey at Western Electric patents the PCM methodology. #TelecomTimeline
1926
The first public test of radiotelephone service from New York to London. #TelecomTimeline
1927 (April 7)
First public demonstration of television by Bell System engineers, by wire and radio. #TelecomTimeline
1927 (January 17)
Opening of Third Trans-continental telephone line, northern route. #TelecomTimeline
1927 (January 7)
Opening of transatlantic telephone service between New York and London, 3500 miles. #TelecomTimeline
1927
Don Juan, the first full length movie with sound uses AT&T equipment. The next year, Warner Bros produces The Jazz Singer w/AT&T equip
1927
First “Director” installation in London. Introduction of line switch with self-aligning plunger. #TelecomTimeline
1927
First public demonstration of long distance transmission of television. #TelecomTimeline
1927
Formal opening of telephone service between the US and Mexico, and also, Mexico- London, via New York. #TelecomTimeline
1927
Television. Philo Farnsworth demonstrates the first television for potential investors by broadcasting the image of a dollar sign.
1927
Wireless telephone service between New York and London. #TelecomTimeline
1928
A joint meeting of the AIEE and the British IEE is held over radiotelephone channels, with the respective groups in New York & London.
1928
First extended use of Strowger 200-point Line finder. Introduction of improved Monophone designs. #TelecomTimeline
1928
Zworykin files patents on electronic scanning TV using the iconoscope. #TelecomTimeline
1929 (December 8)
Commercial ship-to-shore telephone service opened. #TelecomTimeline
1929
U.S. Navy begins use of Strowger equipment. Monophones made available in color. #TelecomTimeline
1930 (April 3)
Opening of transoceanic telephone service to Argentina, Chile & Uruguay & subsequently to all other South American countries
1930
AT&T introduces much higher quality insulated wire. #TelecomTimeline
1930
Development of new small switchboards of unit type. Networks of small Strowger exchanges installed in Italy. #TelecomTimeline
1931
AT&T inaugurates the Teletypewriter Exchange Service (TWX) November 21. #TelecomTimeline
1931
Development of Strowger Remote Toll Board. First installed in Elyria, Ohio. #TelecomTimeline
1931
While tracking down source of electrical interference on telephone transmissions, Bell Labs discovers radio waves from outer space.
1932
Development of unattended private automatic branch exchanges. Two-line Monophones introduced. #TelecomTimeline
1933
Edwin Armstrong demonstrates frequency modulation (FM) to Sarnoff. #TelecomTimeline
1933
New small private automatic exchanges introduced. #TelecomTimeline
1934
"value-of-service" pricing required subsidization of residential subscribers to speed availability of nationwide telephone service.
1934
Congress passes Communications Act of 1934, with a goal of universal service at reasonable charges. The FCC was formed.
1934
Federal Communications Commission founded. #TelecomTimeline
1934
Introduction of new self-contained desk Monophone molded in bakelite (Type 34A3). #TelecomTimeline
1935 (April 25)
First around-the-world telephone conversation by wire and radio. #TelecomTimeline
1935
First telephone call around the world. About 6700 telcos in operation. #TelecomTimeline
1935
New “all positions” transmitter. New bakelite wall Monophone (Type 35A5). #TelecomTimeline
1935
The first around-the-world telephone conversation takes place. (April 25) #TelecomTimeline
1936
BBC begins regular television service. #TelecomTimeline
1936
Invention of coaxial cable is announced at a joint meeting of the American Physical Society and the IRE (April 30). #TelecomTimeline
1936
Small, compact community automatic exchanges introduced. #TelecomTimeline
1937 (December 8)
Opening of Fourth Transcontinental telephone line. #TelecomTimeline
1937
Bell introduces the Model 300 improved handset. #TelecomTimeline
1937
Seven-hour radio broadcast of the coronation of King George VI and Queen Elizabeth of England. #TelecomTimeline
1938
Application of multiswitches with electric motor drive. #TelecomTimeline
1938
Bell introduces crossbar central office switches. #TelecomTimeline
1938
ErwinInvention of automatic switch "walk round" system. #TelecomTimeline
1938
Orsen Wells with the broadcast of "War of the Worlds" and causes telephone traffic to peak in nearly all cities long distance lines.
1939
FM is used by Bell Laboratories in a radio altimeter that uses signal reflections from the surface of the earth. #TelecomTimeline
1939
John Atanasoff and Clifford Berry invent the first electronic computer at the University of Iowa. #TelecomTimeline
1939
The Golden Gate Exposition (San Francisco) & New York Worlds Fair exhibit the newest technologies, including the Voder and television.
1939
WU introduces coast-to-coast fax service. #TelecomTimeline
1940 (June 24)
Television transmitted over coaxial cable from Convention Hall in Philadelphia to television studio in Radio City, New York.
1940
FM Police Radio Communications begin in Hartford, CT. #TelecomTimeline
1941
Introduction of touch-tone system. #TelecomTimeline
1941
Konrad Zuse in Germany develops the first programmable calculator using binary numbers and boolean logic. #TelecomTimeline
1941
The Japanese attack on Pearl Harbor affects the telephone system of the USA by causing tremendous traffic peaks in all cities.
1942 (December 21)
First all-cable transcontinental telephone line with completion of buried cable, connecting systems of East and West.
1942
The Alcan Highway begins at Dawson Creek. #TelecomTimeline
1942
The first section of telephone line is completed along the Alcan Highway, from Edmonton, Alberta, to Dawson Creek, British Columbia.
1943 (August 22)
First equipment for the dialing of called telephone numbers in distant cities directly by the operator in Philadelphia.
1943
Construction of a telephone line from Calcutta, India to Kunming, China, along Stilwell Road, begins at Ledo, Assam. #TelecomTimeline
1943
First interstate automatic telephone exchange in Philadelphia (USA). #TelecomTimeline
1943
Philadelphia is the last city to have telephone service supplied by different local carriers. #TelecomTimeline
1943
Western Union and Postal Telegraph permitted to merge. #TelecomTimeline
1944
A telephone submarine cable is laid across the English Channel. #TelecomTimeline
1945
AT&T lays 2000 miles of coax cable. Arthur C. Clarke proposes communications satellites. #TelecomTimeline
1945
Western Union installs the first commercial radio beam system. #TelecomTimeline
1946 (February 12)
New York-Washington co-axial cable circuits opened for television transmission on an experimental basis.
1946 (June 17)
Opening of experimental mobile radiotelephone service in St. Louis. #TelecomTimeline
1946
AT&T has 8 VF channels on microwave from Catalina Island to LA. Raytheon has a microwave link transmitting from WQXR in NYC to Boston.
1946
AT&T televises Army-Navy game in Philadelphia and transmits it to NYC #TelecomTimeline
1946
Beam traveling-wave tube announced by Bell Telephone Laboratories. This tube is an important amplifier for broadband communication.
1946
FCC's Recording Devices Docket required telcos to furnish connecting arrangements for conversation recorders. #TelecomTimeline
1946
First commercial mobile telephone service became available in St. Louis, Missouri (USA). #TelecomTimeline
1946
Mobile telephone service is placed into commercial use in St. Louis, Missouri. #TelecomTimeline
1946
The use of "beep tones" required when conversations are recorded. #TelecomTimeline
1947 (August 15)
Opening of commercial telephone service for passengers on certain trains running between New York and Washington, D.C.
1947 (December 23)
Bell Labs introduces germanium point contact transistor & in the following year the alloy junction germanium transistor.
1947 (December 23)
Demonstration of mobile telephone equipment from a United Airlines plane to ground stations. #TelecomTimeline
1947 (Nov. 13)
Opening of New York-Boston radio relay system for experimental service. #TelecomTimeline
1947
Invention of the point contact transistor by Brattain and Bardeen. #TelecomTimeline
1947
Bell Labs scientists Shockley, Bardeen and Brattain invent the transistor. #TelecomTimeline
1947
Bell Telephone Laboratories has a 96-channel PCM experimental system working between Murray Hill, N.J. and NYC. #TelecomTimeline
1947
Telcos install nationwide numbering plan. #TelecomTimeline
1948
Hush-A-Phone Corp. developed a cup-like device placed on a phone's mouthpiece to increase privacy. Bell complains about it to FCC.
1948
Invention of the junction transistor. #TelecomTimeline
1949 (October 17)
Transcontinental telephone calls by operators started with the joining of toll dialing networks on East & West coasts.
1949
AT&T introduces the famous black rotary Model 500 telephone. #TelecomTimeline
1949
Bell Labs publishes Shannon's seminal theory of relay logic so important in the development of modern computers. #TelecomTimeline
1949
Jordaphone and three other manufacturers of answering machines sought FCC approval for their use on telco lines. #TelecomTimeline
1949
Justice Department files antitrust suit against AT&T. The Department wanted Bell to divest Western Electric among other actions.
1949
The volume of telephone calls reaches 180 million a day! #TelecomTimeline