1947 Telephone strike(1 link)The 1947 Telephone strike was a five-week long, nation-wide labor stoppage in the United States by the National Federation of Telephone Workers (NFTW) and other smaller unions that started on… [see Wikipedia article]
1983 AT&T strike(1 link)The 1983 AT&T strike was a nationwide strike of 675,000 telephone workers across the United States that followed a breakdown in contract negotiations with the American telecommunications company AT&T. [see Wikipedia article]
9 Evenings: Theatre and Engineering(2 links)9 Evenings: Theatre and Engineering was a series of performances from October 13–23, 1966, where artists and engineers from Bell Laboratories in Murray Hill, New Jersey collaborated on what was… [see Wikipedia article]See also:Billy Klüver · Fred Waldhauer
911 (emergency telephone number)911, sometimes written 9-1-1, is an emergency telephone number in Canada and the United States, one of eight N11 codes of the North American Numbering Plan (NANP). Dialing 911 from… [see Wikipedia article]
A
Acoustic telegraphy(4 links)Acoustic telegraphy (also known as harmonic telegraphy) was a name for various methods of multiplexing (transmitting more than one) telegraph messages simultaneously over a single telegraph wire by using different… [see Wikipedia article]See also:Alexander Graham Bell · Thomas Edison · Elisha Gray
Adaptive equalizer(2 links)An adaptive equalizer is an equalizer that automatically adapts to time-varying properties of the communication channel. It is frequently used with coherent modulations such as phase-shift keying, mitigating the effects… [see Wikipedia article]See also:Robert W. Lucky
Adaptive predictive coding(1 link)Adaptive predictive coding (APC) is a narrowband analog-to-digital conversion that uses a one-level or multilevel sampling system in which the value of the signal at each sampling instant is predicted… [see Wikipedia article]See also:Bishnu S. Atal
Advanced Mobile Phone System(3 links)Advanced Mobile Phone System (AMPS) was an analog mobile phone system standard originally developed by Bell Labs and later modified in a cooperative effort between Bell Labs and Motorola. It… [see Wikipedia article]See also:Richard H. Frenkiel
Amplitude modulation(1 link)Amplitude modulation (AM) is a signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave… [see Wikipedia article]See also:Reginald Fessenden
Anderson impurity model(1 link)The Anderson impurity model, named after Philip Warren Anderson, is a Hamiltonian that is used to describe magnetic impurities embedded in metals. It is often applied to the description of… [see Wikipedia article]See also:Philip W. Anderson
Anderson localization(1 link)In condensed matter physics, Anderson localization is the absence of diffusion of waves in a disordered medium. In other words, disordered media are good at trapping waves. This phenomenon is… [see Wikipedia article]See also:Philip W. Anderson
Answering machine(1 link)An answering machine, answerphone, or message machine, also known as telephone messaging machine in the UK and some Commonwealth countries, ansaphone or ansafone, or telephone answering device (TAD), is used… [see Wikipedia article]
Arc converter(1 link)The arc converter, sometimes called the arc transmitter, or Poulsen arc after Danish engineer Valdemar Poulsen who invented it in 1903, was a variety of spark transmitter used in early… [see Wikipedia article]See also:Valdemar Poulsen
Audion(5 links)The Audion is an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest as a diode in 1906. Improved, it was patented as the first… [see Wikipedia article]See also:Harold D. Arnold · Lee de Forest
AWK(1 link)AWK is a scripting language designed for text processing and typically used as a data extraction and reporting tool. Like sed and grep, it is a filter, and it is… [see Wikipedia article]See also:Brian Kernighan
BCS theory(1 link)In physics, the Bardeen–Cooper–Schrieffer (BCS) theory is a microscopic theory of superconductivity which explains many thermodynamic and electromagnetic properties of superconductors. The theory describes superconductivity as a microscopic effect caused… [see Wikipedia article]See also:John Bardeen
Beat frequency oscillator(1 link)In a radio receiver, a beat frequency oscillator or BFO is a dedicated oscillator used to create an audio frequency signal from Morse code radiotelegraphy (CW) transmissions to make them… [see Wikipedia article]See also:Reginald Fessenden
Belle (chess machine)(1 link)Belle is a chess computer that was developed by Joe Condon (hardware) and Ken Thompson (software) at Bell Labs. In 1983, it was the first machine to achieve master-level play,… [see Wikipedia article]See also:Ken Thompson
Bipolar junction transistor(1 link)A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor… [see Wikipedia article]See also:William Shockley
Bit(1 link)The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one… [see Wikipedia article]See also:John Tukey
Blue box(4 links)A blue box is an electronic device that produces tones used to generate the in-band signaling tones formerly used within the North American long-distance telephone network to send line status… [see Wikipedia article]See also:John Draper · Steve Jobs · Joybubbles · Steve Wozniak
Bode plot(1 link)In electrical engineering and control theory, a Bode plot is a graph of the frequency response of a system. It is usually a combination of a Bode magnitude plot, expressing… [see Wikipedia article]See also:Hendrik Wade Bode
Bode's sensitivity integral(1 link)Bode's sensitivity integral, discovered by Hendrik Wade Bode, is a formula that quantifies some of the limitations in feedback control of linear parameter-invariant systems. Let L be the loop transfer… [see Wikipedia article]See also:Hendrik Wade Bode
Bohlen–Pierce scale(1 link)The Bohlen–Pierce scale is a musical tuning and scale, first described in the 1970s, that offers an alternative to the octave-repeating scales typical in Western and other musics, specifically the… [see Wikipedia article]See also:John R. Pierce
Breakup of the Bell System(3 links)The Bell System held a virtual monopoly over telephone infrastructure in the United States from around the early 20th century until January 8, 1982. It consisted of the parent American… [see Wikipedia article]See also:Harold H. Greene · William G. McGowan
Brus equation(1 link)The Brus equation or confinement energy equation can be used to describe the emission energy of quantum dot semiconductor nanocrystals in terms of the band gap energy Egap, the Planck… [see Wikipedia article]See also:Louis E. Brus
C
C (programming language)(4 links)C is a general-purpose programming language created in the 1970s by Dennis Ritchie. By design, C gives the programmer relatively direct access to the features of the typical CPU architecture,… [see Wikipedia article]See also:Brian Kernighan · Dennis Ritchie · Ken Thompson
C++(1 link)C++ is a high-level, general-purpose programming language created by Danish computer scientist Bjarne Stroustrup. First released in 1985 as an extension of the C programming language, adding object-oriented (OOP) features,… [see Wikipedia article]See also:Bjarne Stroustrup
Caller ID(1 link)Caller identification is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment… [see Wikipedia article]
Candlestick telephoneThe candlestick telephone is a style of telephone that was common from the late 1890s to the 1940s. A candlestick telephone is also often referred to as a desk stand,… [see Wikipedia article]
Carbon microphone(8 links)The carbon microphone, also known as carbon button microphone, button microphone, or carbon transmitter, is a type of microphone, a transducer that converts sound to an electrical audio signal. It… [see Wikipedia article]See also:Emile Berliner · Francis Blake · Thomas Edison
Carson bandwidth rule(1 link)In telecommunications, the Carson's bandwidth rule defines the approximate bandwidth requirements of communications system components for a carrier signal that is frequency modulated by a continuous or broad spectrum of… [see Wikipedia article]See also:John Renshaw Carson
Carterfone(1 link)The Carterfone is a device invented by Thomas Carter. It connects a two-way radio system to the telephone system, allowing someone on the radio to talk to someone on the… [see Wikipedia article]
Cellular network(1 link)A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells,… [see Wikipedia article]See also:Richard H. Frenkiel
Charge-coupled device(3 links)A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge… [see Wikipedia article]See also:Willard Boyle · George E. Smith
Code-excited linear prediction(2 links)Code-excited linear prediction (CELP) is a linear predictive speech coding algorithm originally proposed by Manfred R. Schroeder and Bishnu S. Atal in 1985. At the time, it provided significantly better… [see Wikipedia article]See also:Bishnu S. Atal · Manfred R. Schroeder
Common battery(1 link)In telecommunications, a common battery is a single electrical power source used to energize more than one circuit, electronic component, equipment, or system. [see Wikipedia article]
Common-channel signalingIn telecommunications, common-channel signaling (CCS), or common-channel interoffice signaling (CCIS), is the transmission of control information (signaling) via a separate channel than that used for the messages, The signaling channel… [see Wikipedia article]
Communications Act of 1934(1 link)The Communications Act of 1934 is a United States federal law signed by President Franklin D. Roosevelt on June 19, 1934, and codified as Chapter 5 of Title 47 of… [see Wikipedia article]
Communications Workers of America(1 link)The Communications Workers of America (CWA) is the largest communications and media labor union in the United States, representing about 700,000 members in both the private and public sectors. The… [see Wikipedia article]
Composite image filter(1 link)A composite image filter is an electronic filter consisting of multiple image filter sections of two or more different types. [see Wikipedia article]See also:Otto Julius Zobel
Constant k filter(1 link)Constant k filters, also k-type filters, are a type of electronic filter designed using the image method. They are the original and simplest filters produced by this methodology and consist… [see Wikipedia article]See also:George Ashley Campbell
Cooley–Tukey FFT algorithm(1 link)The Cooley–Tukey algorithm, named after J. W. Cooley and John Tukey, is the most common fast Fourier transform (FFT) algorithm. It re-expresses the discrete Fourier transform (DFT) of an arbitrary… [see Wikipedia article]See also:John Tukey
Cosmic microwave background(3 links)The cosmic microwave background, or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies… [see Wikipedia article]See also:Arno Allan Penzias · Robert Woodrow Wilson
Courtesy telephoneA courtesy telephone is a telephone located in airport terminals, large train stations, hotel lobbies, and other places where many travellers are expected, which is used to relay messages to… [see Wikipedia article]
Critical band(1 link)In audiology and psychoacoustics the concept of critical bands, introduced by Harvey Fletcher in 1933 and refined in 1940, describes the frequency bandwidth of the "auditory filter" created by the… [see Wikipedia article]See also:Harvey Fletcher
Crossbar switch(1 link)In electronics and telecommunications, a crossbar switch is a collection of switches arranged in a matrix configuration. A crossbar switch has multiple input and output lines that form a crossed… [see Wikipedia article]
Crystal filter(1 link)A crystal filter is an electronic filter that uses the mechanical resonance of piezoelectric crystals, usually quartz, to shape a circuit's frequency response. Its early development was driven by carrier… [see Wikipedia article]See also:Warren P. Mason
D
Davisson–Germer experiment(2 links)The Davisson–Germer experiment was conducted from 1923 to 1927 by Clinton Davisson and Lester Germer at Western Electric. Electrons, scattered by the surface of a crystal of nickel metal, displayed… [see Wikipedia article]See also:Clinton Davisson · Lester Germer
Diffused junction transistor(1 link)A diffused junction transistor is a transistor formed by diffusing dopants into a semiconductor substrate. The diffusion process was developed later than the alloy-junction and grown junction processes for making… [see Wikipedia article]See also:Calvin Souther Fuller
Direct distance dialing(1 link)Direct distance dialing (DDD) is a telecommunications service in North America by which a caller may call any other subscriber outside the local calling area without operator assistance, DDD was… [see Wikipedia article]
Distributed-element circuit(1 link)Distributed-element circuits are electrical circuits composed of lengths of transmission lines or other distributed components. These circuits perform the same functions as conventional circuits composed of passive components, such as… [see Wikipedia article]See also:Warren P. Mason
DjVu(1 link)DjVu is a computer file format designed primarily to store scanned documents, especially those containing a combination of text, line drawings, indexed color images, and photographs. It uses technologies such… [see Wikipedia article]See also:Yann LeCun
DMS-100(1 link)The DMS-100 is a member of the Digital Multiplex System (DMS) product line of telephone exchange switches manufactured by Northern Telecom. Designed during the 1970s and released in 1979, it… [see Wikipedia article]
Dry cell(1 link)A dry cell is a type of electric battery, commonly used for portable electrical devices. Unlike wet cell batteries, which have a liquid electrolyte, dry cells use an electrolyte in… [see Wikipedia article]
DTMF signaling(1 link)Dual-tone multi-frequency (DTMF) signaling is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed… [see Wikipedia article]
DynaTAC(1 link)The DynaTAC is a series of cellular telephones manufactured by Motorola from 1983 to 1994. Unveiled on March 6, 1983, the DynaTAC was the first commercially available handheld cellular phone.… [see Wikipedia article]See also:Martin Cooper
E
Echo suppression and cancellation(1 link)Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition… [see Wikipedia article]
Electret microphone(1 link)An electret microphone is a microphone whose diaphragm forms a capacitor that incorporates an electret. The electret's permanent electric dipole provides a constant charge Q on the capacitor. Sound waves… [see Wikipedia article]See also:James West
Electrical telegraph(1 link)Electrical telegraphy is point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications… [see Wikipedia article]See also:George May Phelps
Electronic switching system(4 links)In telecommunications, an electronic switching system (ESS) is a telephone switch that uses solid-state electronics, such as digital electronics and computerized common control, to interconnect telephone circuits for the purpose… [see Wikipedia article]See also:Erna Schneider Hoover · Amos E. Joel Jr. · Raymond W. Ketchledge
Elisha Gray and Alexander Bell telephone controversy(1 link)The Elisha Gray and Alexander Graham Bell controversy concerns the question of whether Elisha Gray and Alexander Graham Bell invented the telephone independently. This issue is narrower than the question… [see Wikipedia article]See also:Elisha Gray
Entropy (information theory)(1 link)In information theory, the entropy of a random variable quantifies the average level of uncertainty or information associated with the variable's potential states or possible outcomes. This measures the expected… [see Wikipedia article]See also:Claude Shannon
Equal-loudness contour(1 link)An equal-loudness contour is a measure of sound pressure level, over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit… [see Wikipedia article]See also:Harvey Fletcher
Ethernet(2 links)Ethernet ( EE-thər-net) is a family of wired computer networking standards designed for (but not limited to) local area networks (LAN), access networks, and metropolitan area networks (MAN). It was… [see Wikipedia article]See also:Robert Metcalfe
Experiments in Art and Technology(2 links)Experiments in Art and Technology (E.A.T.), a non-profit and tax-exempt organization, was established in 1967 to develop collaborations between artists and engineers. The group operated by facilitating person-to-person contacts between… [see Wikipedia article]See also:Billy Klüver · Fred Waldhauer
F
Fast Fourier transform(1 link)A fast Fourier transform (FFT) is an algorithm that computes the discrete Fourier transform (DFT), or its inverse (IDFT), of a sequence. A Fourier transform converts a signal from its… [see Wikipedia article]See also:John Tukey
Fessenden oscillator(1 link)A Fessenden oscillator is an electro-acoustic transducer invented by Reginald Fessenden, with development starting in 1912 at the Submarine Signal Company of Boston. It was the first successful acoustical echo… [see Wikipedia article]See also:Reginald Fessenden
Fiber-optic communication(1 link)Fiber-optic communication is a form of optical communication for transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. The light… [see Wikipedia article]See also:Charles K. Kao
First transcontinental telephone call(5 links)A telephone call, which for marketing purposes is claimed to be the first transcontinental telephone call, occurred on January 25, 1915, a day timed to coincide with the Panama–Pacific International… [see Wikipedia article]See also:Alexander Graham Bell · John J. Carty · Theodore Vail · Thomas A. Watson
Floating-gate MOSFET(2 links)The floating-gate MOSFET (FGMOS), also known as a floating-gate MOS transistor or floating-gate transistor, is a type of metal–oxide–semiconductor field-effect transistor (MOSFET) where the gate is electrically isolated, creating a… [see Wikipedia article]See also:Dawon Kahng · Simon Sze
Frequency-hopping spread spectrum(2 links)Frequency-hopping spread spectrum (FHSS) is a method of transmitting radio signals by rapidly changing the carrier frequency among many frequencies occupying a large spectral band. The changes are controlled by… [see Wikipedia article]See also:Hedy Lamarr
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Graphophone(1 link)The Graphophone was the name and trademark of an improved version of the phonograph. It was initially designed at the Volta Laboratory established by Alexander Graham Bell in Washington, D.C.,… [see Wikipedia article]See also:Alexander Graham Bell
Gray graph(1 link)In the mathematical field of graph theory, the Gray graph is an undirected bipartite graph with 54 vertices and 81 edges. It is a cubic graph: every vertex touches exactly… [see Wikipedia article]See also:Marion Cameron Gray
Grep(1 link)grep is a command-line utility for searching text for lines that match a regular expression. Its name comes from the ed command g/re/p, which has the same effect. grep was… [see Wikipedia article]See also:Ken Thompson
GSM(1 link)The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile… [see Wikipedia article]
H
Hamming bound(1 link)In mathematics and computer science, in the field of coding theory, the Hamming bound is a limit on the parameters of an arbitrary block code: it is also known as… [see Wikipedia article]See also:Richard Hamming
Hamming code(1 link)In computer science and telecommunications, Hamming codes are a family of linear error-correcting codes. Hamming codes can detect one-bit and two-bit errors, or correct one-bit errors without detection of uncorrected… [see Wikipedia article]See also:Richard Hamming
Hamming distance(1 link)In information theory, the Hamming distance between two strings or vectors of equal length is the number of positions at which the corresponding symbols are different. In other words, it… [see Wikipedia article]See also:Richard Hamming
Hamming weight(1 link)The Hamming weight of a string is the number of symbols that are different from the zero-symbol of the alphabet used. It is thus equivalent to the Hamming distance from… [see Wikipedia article]See also:Richard Hamming
Handover(2 links)In cellular telecommunications, handover, or handoff, is the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. In satellite… [see Wikipedia article]See also:Amos E. Joel Jr.
Hartley (unit)(1 link)The hartley, also called a ban, or a dit, is a logarithmic unit that measures information or entropy, based on base 10 logarithms and powers of 10. One hartley is… [see Wikipedia article]See also:Ralph Hartley
Hartley function(1 link)The Hartley function is a measure of uncertainty, introduced by Ralph Hartley in 1928. If a sample from a finite set A uniformly at random is picked, the amount of… [see Wikipedia article]See also:Ralph Hartley
Hartley oscillator(1 link)The Hartley oscillator is an electronic oscillator circuit in which the oscillation frequency is determined by a tuned circuit consisting of capacitors and inductors, that is, an LC oscillator. The… [see Wikipedia article]See also:Ralph Hartley
Hartley transform(1 link)In mathematics, the Hartley transform (HT) is an integral transform closely related to the Fourier transform (FT), but which transforms real-valued functions to real-valued functions. It was proposed as an… [see Wikipedia article]See also:Ralph Hartley
Hawthorne Works(1 link)The Hawthorne Works was a large factory complex of the Western Electric Company in Cicero, Illinois. In addition to industrial plants, several on-site community amenities were provided to workers. Named… [see Wikipedia article]
Hayes AT command set(1 link)The Hayes command set is a specific command language originally developed by Dale Heatherington and Dennis Hayes for the Hayes Smartmodem in 1981. [see Wikipedia article]See also:Dennis Hayes
Haynes–Shockley experiment(1 link)In semiconductor physics, the Haynes–Shockley experiment was an experiment that demonstrated that diffusion of minority carriers in a semiconductor could result in a current. The experiment was reported in a… [see Wikipedia article]See also:William Shockley
Heaviside condition(1 link)A transmission line which meets the Heaviside condition, named for Oliver Heaviside (1850–1925), and certain other conditions can transmit signals without dispersion and without distortion. The importance of the Heaviside… [see Wikipedia article]See also:Oliver Heaviside
Heterodyne(1 link)A heterodyne is the result of mixing two signals in a nonlinear device to produce new frequency components, notably sum and difference frequencies of the original signals. This process, called… [see Wikipedia article]See also:Reginald Fessenden
Hidden-line removal(1 link)In 3D computer graphics, solid objects are usually modeled by polyhedra. A face of a polyhedron is a planar polygon bounded by straight line segments, called edges. Curved surfaces are… [see Wikipedia article]See also:Ruth A. Weiss
Holmdel Horn Antenna(2 links)The Holmdel Horn Antenna is a large microwave horn antenna that was used as a satellite communication antenna and radio telescope during the 1960s at the Bell Telephone Laboratories facility… [see Wikipedia article]See also:Arno Allan Penzias · Robert Woodrow Wilson
I
In-band signalingIn telecommunications, in-band signaling is the sending of control information within the same band or channel used for data such as voice or video. This is in contrast to out-of-band… [see Wikipedia article]
Independent telephone company(1 link)An independent telephone company was a telephone company providing local service in the United States or Canada that was not part of the Bell System organized by American Telephone and… [see Wikipedia article]
Information theory(1 link)Information theory is the mathematical study of the quantification, storage, and communication of a particular type of mathematically defined information. The field was established and formalized by Claude Shannon in… [see Wikipedia article]See also:Claude Shannon
Integrated Services Digital Network(1 link)Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public… [see Wikipedia article]
Intelsat(1 link)Intelsat S.A. is a Luxembourgish-American multinational satellite services provider with corporate headquarters in Luxembourg and administrative headquarters in Tysons, Virginia, United States. Originally formed as International Telecommunications Satellite Organization, from… [see Wikipedia article]
Intelsat I(1 link)Intelsat I (nicknamed Early Bird for the proverb "The early bird catches the worm") was the first commercial communications satellite to be placed in geosynchronous orbit, on April 6, 1965.… [see Wikipedia article]
Internet protocol suite(3 links)The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational… [see Wikipedia article]See also:Vint Cerf · Robert Kahn
Invention of the telephone(1 link)The invention of the telephone was the culmination of work done by many different people, and led to an array of lawsuits relating to the conflicting patent claims made by… [see Wikipedia article]See also:Antonio Meucci
J
Johnson–Nyquist noise(2 links)Johnson–Nyquist noise is the voltage or current noise generated by the thermal agitation of the charge carriers inside an electrical conductor at equilibrium, which happens regardless of any applied voltage.… [see Wikipedia article]See also:Harry Nyquist · John Bertrand Johnson
K
Karnaugh map(1 link)A Karnaugh map is a diagram that can be used to simplify a Boolean algebra expression. Maurice Karnaugh introduced the technique in 1953 as a refinement of Edward W. Veitch's… [see Wikipedia article]See also:Maurice Karnaugh
Kennelly–Heaviside layer(1 link)The Heaviside layer, sometimes called the Kennelly–Heaviside layer, named after Arthur E. Kennelly and Oliver Heaviside, is a layer of ionised gas occurring roughly between 90 and 150 km above the… [see Wikipedia article]See also:Oliver Heaviside
Kernighan–Lin algorithm(1 link)The Kernighan–Lin algorithm is a heuristic algorithm for finding partitions of graphs. The algorithm has important practical application in the layout of digital circuits and components in electronic design automation… [see Wikipedia article]See also:Brian Kernighan
Kingsbury Commitment(2 links)The Kingsbury Commitment is a 1913 out-of-court settlement of the United States government's antitrust challenge against the American Telephone and Telegraph Company (AT&T) for the company's then-growing vertical monopoly in… [see Wikipedia article]See also:Theodore Vail
L
LandlineA landline, or fixed line, is telephone service provided to a subscriber via cable or wire, i.e. metal conductors or optical fiber. The term differentiates a telephone service from the… [see Wikipedia article]
Laser(2 links)A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser originated as an acronym for… [see Wikipedia article]See also:Arthur Leonard Schawlow · Charles H. Townes
Laser cooling(2 links)Laser cooling includes several techniques where atoms, molecules, and small mechanical systems are cooled with laser light. The directed energy of lasers is often associated with heating materials, e.g. laser… [see Wikipedia article]See also:Steven Chu · Arthur Leonard Schawlow
Lattice phase equaliser(1 link)A lattice phase equaliser or lattice filter is an example of an all-pass filter. That is, the attenuation of the filter is constant at all frequencies but the relative phase… [see Wikipedia article]See also:Otto Julius Zobel
LeNet(1 link)LeNet is a series of convolutional neural network architectures created by a research group at AT&T Bell Laboratories between of the period of 1988 to 1998, centered around Yann LeCun.… [see Wikipedia article]See also:Yann LeCun
Lin–Kernighan heuristic(1 link)In combinatorial optimization, Lin–Kernighan is one of the best heuristics for solving the symmetric travelling salesman problem. It belongs to the class of local search algorithms, which take a tour… [see Wikipedia article]See also:Brian Kernighan
Linear predictive coding(2 links)Linear predictive coding (LPC) is a method used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form,… [see Wikipedia article]See also:Bishnu S. Atal · Manfred R. Schroeder
Local loopIn telephony, the local loop (also referred to as the local tail, subscriber line, or in the aggregate as the last mile) is the physical link or circuit that connects… [see Wikipedia article]
Local number portabilityLocal number portability (LNP) for fixed lines, and full mobile number portability (FMNP) for mobile phone lines, refers to the ability of a "customer of record" of an existing fixed-line… [see Wikipedia article]
Long-distance calling(4 links)In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the UK ) is a telephone call made to a location outside a defined… [see Wikipedia article]
M
m-derived filter(2 links)m-derived filters or m-type filters are a type of electronic filter designed using the image method. They were invented by Otto Zobel in the early 1920s. This filter type was… [see Wikipedia article]See also:Otto Julius Zobel
Maser(3 links)A maser is a device that produces coherent electromagnetic waves (microwaves), through amplification by stimulated emission. The term is an acronym for microwave amplification by stimulated emission of radiation. Nikolay… [see Wikipedia article]See also:Charles H. Townes · Arthur Leonard Schawlow
Metcalfe's law(1 link)Metcalfe's law states that the financial value or influence of a telecommunications network is proportional to the square of the number of connected users of the system. The law is… [see Wikipedia article]See also:Robert Metcalfe
Microphone(1 link)A microphone, colloquially called a mic, or mike, is a transducer that converts sound into an electrical signal. Microphones are used in telecommunication, sound recording, broadcasting, and consumer electronics, including… [see Wikipedia article]See also:Emile Berliner
Microwave transmissionMicrowave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300 MHz to 300 GHz of the electromagnetic spectrum. Microwave signals are normally limited… [see Wikipedia article]
Minitel(1 link)Minitel, officially known as TELETEL, was an interactive videotex online service accessible through telephone lines. It was the world's first and most successful mass-market online service prior to the World… [see Wikipedia article]
Mobile phone(1 link)A mobile phone or cell phone is a portable wireless telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone… [see Wikipedia article]See also:Martin Cooper
Mobile Telephone Service(1 link)The Mobile Telephone Service (MTS) was a pre-cellular VHF radio system that linked to the Public Switched Telephone Network (PSTN). MTS was the radiotelephone equivalent of land dial phone service. [see Wikipedia article]
Model 500 telephone(1 link)The Western Electric model 500 telephone series was the standard domestic desk telephone set issued by the Bell System in North America from 1950 through the 1984 Bell System divestiture.… [see Wikipedia article]See also:Henry Dreyfuss
Model K (calculator)(1 link)The Model K was an early 1-bit electromechanical binary adder built in November 1937 by Bell Labs scientist George Stibitz as a proof of concept, using scrap relays and metal… [see Wikipedia article]See also:George Stibitz
Modem(2 links)A modulator-demodulator, commonly referred to as a modem, is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such… [see Wikipedia article]See also:Dennis Hayes · Robert W. Lucky
Modular connectorA modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. [see Wikipedia article]
MOSFET(2 links)In electronics, the metal–oxide–semiconductor field-effect transistor is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of… [see Wikipedia article]See also:Mohamed M. Atalla · Dawon Kahng
Multi-frequency signalingIn telephony, multi-frequency signaling (MF) is a type of signaling that was introduced by the Bell System after World War II. It was in use since before 1949. It uses… [see Wikipedia article]
Multiplexing(1 link)In telecommunications and computer networking, multiplexing is a method by which multiple analog or digital signals are combined into one signal over a transmission medium. It allows the same medium… [see Wikipedia article]
Music Mouse(1 link)Music Mouse is an algorithmic musical composition software developed by Laurie Spiegel. [see Wikipedia article]See also:Laurie Spiegel
MUSIC-N(1 link)MUSIC-N refers to a family of computer music programs and programming languages descended from or influenced by MUSIC, a program written by Max Mathews in 1957 at Bell Labs. MUSIC… [see Wikipedia article]See also:Max Mathews
N
Negative-feedback amplifier(3 links)A negative-feedback amplifier is an electronic amplifier that subtracts a fraction of its output from its input, so that negative feedback opposes the original signal. The applied negative feedback can… [see Wikipedia article]See also:Harold Stephen Black · Harry Nyquist
Noisy-channel coding theorem(1 link)In information theory, the noisy-channel coding theorem, establishes that for any given degree of noise contamination of a communication channel, it is possible to communicate discrete data nearly error-free up… [see Wikipedia article]See also:Claude Shannon
Nordic Mobile Telephone(1 link)NMT is an automatic cellular phone system specified by Nordic telecommunications administrations (PTTs) and opened for service on 1 October 1981. NMT is based on analogue technology and two variants… [see Wikipedia article]
Number 4ESS switch(1 link)The No. 4 Electronic Switching System (4ESS) is a class 4 telephone electronic switching system that was the first digital electronic toll switch introduced by Western Electric for long-distance switching.… [see Wikipedia article]
Number Five Crossbar Switching SystemThe Number Five Crossbar Switching System is a telephone switch for telephone exchanges designed by Bell Labs and manufactured by Western Electric starting in 1947. It was used in the… [see Wikipedia article]
Number One Electronic Switching System(4 links)The Number One Electronic Switching System (1ESS) was the first large-scale stored program control (SPC) telephone exchange or electronic switching system in the Bell System. It was manufactured by Western… [see Wikipedia article]See also:Erna Schneider Hoover · Amos E. Joel Jr. · Raymond W. Ketchledge
Nyquist frequency(1 link)In signal processing, the Nyquist frequency is a characteristic of a sampler, which converts a continuous function or signal into a discrete sequence. It is named after Harry Nyquist. For… [see Wikipedia article]See also:Harry Nyquist
Nyquist ISI criterion(1 link)In communications, the Nyquist ISI criterion describes the conditions which, when satisfied by a communication channel, result in no intersymbol interference or ISI. It provides a method for constructing band-limited… [see Wikipedia article]See also:Harry Nyquist
Nyquist rate(1 link)In signal processing, the Nyquist rate is a value equal to twice the highest frequency (bandwidth) of a given function or signal. It is named after Harry Nyquist. It has… [see Wikipedia article]See also:Harry Nyquist
Nyquist stability criterion(1 link)In control theory and stability theory, the Nyquist stability criterion or Strecker–Nyquist stability criterion, independently discovered by the German electrical engineer Felix Strecker at Siemens in 1930 and the Swedish-American… [see Wikipedia article]See also:Harry Nyquist
Nyquist–Shannon sampling theorem(2 links)The Nyquist–Shannon sampling theorem is a theorem in the field of signal processing which serves as a fundamental bridge between continuous-time signals and discrete-time signals. In the case of uniformly… [see Wikipedia article]See also:Harry Nyquist · Claude Shannon
O
On-Line Encyclopedia of Integer Sequences(1 link)The On-Line Encyclopedia of Integer Sequences (OEIS) is an online database of integer sequences. It was created and maintained by Neil Sloane while researching at AT&T Labs. He transferred the… [see Wikipedia article]See also:Neil Sloane
Operational calculus(1 link)Operational calculus, also known as operational analysis, is a technique by which problems in analysis, in particular differential equations, are transformed into algebraic problems, usually the problem of solving a… [see Wikipedia article]See also:Oliver Heaviside
Optical fiber(2 links)An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers are widely used in fiber-optic… [see Wikipedia article]See also:Charles K. Kao
Optical molasses(1 link)Optical molasses (OM) is a laser cooling configuration that can produce extremely cold ensembles of neutral atoms. The temperatures can reach as low as a few microkelvins, depending on the… [see Wikipedia article]See also:Steven Chu
P
P–n junction(1 link)A p–n junction is a combination of two types of semiconductor materials, p-type and n-type, in a single crystal. The "n" (negative) side contains freely-moving electrons, while the "p" (positive)… [see Wikipedia article]See also:Russell Ohl
Panic of 1907(2 links)The Panic of 1907, also known as the 1907 Bankers' Panic or Knickerbocker Crisis, was a financial crisis that took place in the United States over a three-week period starting… [see Wikipedia article]See also:J. P. Morgan
Party line (telephony)A party line (multiparty line, shared service line, party wire) is a local loop telephone circuit that is shared by multiple telephone service subscribers. Party line systems were widely used… [see Wikipedia article]
Payphone(4 links)A payphone (alternative spelling: pay phone or pay telephone or public phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic public areas. Prepayment… [see Wikipedia article]See also:William Gray
Phantom circuit(1 link)In telecommunications and electrical engineering, a phantom circuit is an electrical circuit derived from suitably arranged wires with one or more conductive paths being a circuit in itself and at… [see Wikipedia article]See also:John J. Carty
Photophone(2 links)The photophone is a telecommunications device that allows transmission of speech on a beam of light. It was invented jointly by Alexander Graham Bell and his assistant Charles Sumner Tainter… [see Wikipedia article]See also:Alexander Graham Bell
Phreaking(6 links)Phreaking is a slang term coined to describe the activity of a culture of people who study, experiment with, or explore telecommunication systems, such as equipment and systems connected to… [see Wikipedia article]See also:John Draper · Steve Jobs · Joybubbles · Steve Wozniak
Picturephone(1 link)The Picturephone is an early commercial videophone produced by Western Electric for the Bell System under the AT&T brand. Picturephones had a vidicon camera tube to capture black and white… [see Wikipedia article]
Plain old telephone servicePlain old telephone service (POTS), or rarely publicly offered telephone service, is a retronym for voice-grade telephone service that employs analog signal transmission over copper loops. [see Wikipedia article]
Plan 9 from Bell Labs(1 link)Plan 9 from Bell Labs is an operating system designed by the Computing Science Research Center (CSRC) at Bell Labs in the mid-1980s, built on the UNIX concepts first developed… [see Wikipedia article]See also:Ken Thompson
Point-contact transistor(3 links)The point-contact transistor was the first type of transistor to be successfully demonstrated. It was developed by research scientists John Bardeen and Walter Brattain at Bell Laboratories in December 1947.… [see Wikipedia article]See also:John Bardeen · Walter Brattain · William Gardner Pfann
Polymer stabilizer(1 link)Polymer stabilizers are chemical additives which may be added to polymeric materials to inhibit or retard their degradation. Mainly they protect plastic and rubber products against heat, oxidation, and UV… [see Wikipedia article]See also:Walter Lincoln Hawkins
Princess telephone(1 link)The Princess telephone was introduced by the Bell System in 1959. It was a compact telephone designed for convenient use in the bedroom, and contained a light-up dial for use… [see Wikipedia article]See also:Henry Dreyfuss
Printing telegraph(1 link)The printing telegraph is a device for sending and receiving telegraph messages. The sending operator uses a piano-style keyboard to directly input the text of the message, and the receiver… [see Wikipedia article]See also:George May Phelps
Project Echo(2 links)Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft, launched in 1960 and 1964, were metalized balloon satellites acting as passive reflectors of microwave… [see Wikipedia article]See also:Rudolf Kompfner · John R. Pierce
Public switched telephone networkThe public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for… [see Wikipedia article]
Pulse dialingPulse dialing is a signaling technology in telecommunications in which the direct current flowing in the telephone local loop circuit is interrupted in a pattern according to a coding system… [see Wikipedia article]
Push-button telephoneA push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to a rotary dial used in earlier telephones. [see Wikipedia article]
Q
Quadruplex telegraph(3 links)The Quadruplex telegraph is a type of electrical telegraph which allows a total of four separate signals to be transmitted and received on a single wire at the same time.… [see Wikipedia article]See also:Thomas Edison · William Orton
Quantum dot(1 link)Quantum dots (QDs) or semiconductor nanocrystals are semiconductor particles a few nanometres in size with optical and electronic properties that differ from those of larger particles via quantum mechanical effects.… [see Wikipedia article]See also:Louis E. Brus
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Radio(1 link)Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called… [see Wikipedia article]See also:Guglielmo Marconi
Random dot stereogram(1 link)A random-dot stereogram (RDS) is stereo pair of images of random dots that, when viewed with the aid of a stereoscope, or with the eyes focused on a point in… [see Wikipedia article]See also:Béla Julesz
Red telephone box(1 link)The red telephone box is a telephone kiosk for a public telephone designed by Sir Giles Gilbert Scott, the architect responsible for famous sites like Liverpool Cathedral and Battersea Power… [see Wikipedia article]See also:Giles Gilbert Scott
Reis telephone(2 links)The Reis telephone was an early sound transmitting device, invented by Philipp Reis in 1857. Reis's first successful work is dated to October 1861. When properly set up, it would… [see Wikipedia article]See also:Johann Philipp Reis
Resonating valence bond theory(1 link)In condensed matter physics, the resonating valence bond theory (RVB) is a theoretical model that attempts to describe high-temperature superconductivity, and in particular the superconductivity in cuprate compounds. It was… [see Wikipedia article]See also:Philip W. Anderson
Ringer boxA ringer box is a telephone signaling device, similar to a bell box. It usually contains an electromechanical gong and was used with most early desk stand telephones, such as… [see Wikipedia article]
Rotary dial(2 links)A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing. It is used when initiating a… [see Wikipedia article]
Ruby laser(1 link)A ruby laser is a solid-state laser that uses a synthetic ruby crystal as its gain medium. The first working laser was a ruby laser made by Theodore H. Maiman… [see Wikipedia article]See also:Willard Boyle
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Shannon–Fano coding(1 link)In the field of data compression, Shannon–Fano coding, named after Claude Shannon and Robert Fano, is one of two related techniques for constructing a prefix code based on a set… [see Wikipedia article]See also:Claude Shannon
Shannon–Hartley theorem(2 links)In information theory, the Shannon–Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. It… [see Wikipedia article]See also:Ralph Hartley · Claude Shannon
Shannon's source coding theorem(1 link)In information theory, Shannon's source coding theorem establishes the statistical limits to possible data compression for data whose source is an independent identically-distributed random variable, and the operational meaning of… [see Wikipedia article]See also:Claude Shannon
Shockley diode(1 link)The Shockley diode is a four-layer semiconductor diode. It is a PNPN diode with alternating layers of P-type and N-type material. It is equivalent to a thyristor with a disconnected… [see Wikipedia article]See also:William Shockley
Shockley diode equation(1 link)The Shockley diode equation, or the diode law, named after transistor co-inventor William Shockley of Bell Labs, models the exponential current–voltage (I–V) relationship of semiconductor diodes in moderate constant current… [see Wikipedia article]See also:William Shockley
Sidetone(1 link)Sidetone is audible feedback to someone speaking or otherwise producing sound as an indication of active transmission. Sidetone is introduced by some communications circuits and anti-sidetone circuitry is used to… [see Wikipedia article]
Signal-flow graph(1 link)A signal-flow graph or signal-flowgraph (SFG), invented by Claude Shannon, but often called a Mason graph after Samuel Jefferson Mason who coined the term, is a specialized flow graph, a… [see Wikipedia article]See also:Claude Shannon
Signalling System No. 7(1 link)Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in the 1970s that is used to setup and teardown telephone calls on most parts of the… [see Wikipedia article]
SIGSALY(1 link)SIGSALY was a secure speech system used in World War II for the highest-level Allied communications. It pioneered a number of digital communications concepts, including the first transmission of speech… [see Wikipedia article]See also:Homer Dudley
Single-sideband modulation(1 link)In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of signal modulation used to transmit information, such as an audio signal, by radio waves. A… [see Wikipedia article]See also:John Renshaw Carson
SMS(1 link)Short Message Service (SMS) is a text messaging service component of most telephone, Internet and mobile device systems. It uses standardized communication protocols that let mobile phones exchange short text… [see Wikipedia article]
Sound-powered telephoneA sound-powered telephone is a communication device that allows users to talk to each other with the use of a handset, similar to a conventional telephone, but without the use… [see Wikipedia article]
Space weather(1 link)Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the varying conditions within the Solar System and its heliosphere. This includes the effects of the… [see Wikipedia article]See also:Louis J. Lanzerotti
Speaking tubeA speaking tube or voicepipe is a device based on two cones connected by an air pipe through which speech can be transmitted over an extended distance. [see Wikipedia article]
Speech coding(1 link)Speech coding is an application of data compression to digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal,… [see Wikipedia article]See also:Bishnu S. Atal
Spread spectrum(1 link)In telecommunications, especially radio communication, spread spectrum are techniques by which a signal generated with a particular bandwidth is deliberately spread in the frequency domain over a wider frequency band.… [see Wikipedia article]See also:Hedy Lamarr
SS Eastland(1 link)SS Eastland was an American Great Lakes passenger ship. On July 24, 1915, the ship capsized while tied to a dock in the Chicago River. In total, 844 passengers and… [see Wikipedia article]See also:Helen Repa
Stereophonic sound(1 link)Stereophonic sound, commonly shortened to stereo, is a method of sound reproduction that recreates a multi-directional, three-dimensional audible perspective. This is usually achieved by using two independent audio channels through… [see Wikipedia article]See also:Harvey Fletcher
Stored program control(1 link)Stored program control (SPC) is a telecommunications technology for telephone exchanges. Its characteristic is that the switching system is controlled by a computer program stored in a memory in the… [see Wikipedia article]See also:Erna Schneider Hoover
Strowger switch(5 links)The Strowger switch is the first commercially successful electromechanical stepping switch telephone exchange system. It was developed by the Strowger Automatic Telephone Exchange Company founded in 1891 by Almon Brown… [see Wikipedia article]See also:Almon Strowger
Submarine communications cableA submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. [see Wikipedia article]
Superexchange(1 link)Superexchange or Kramers–Anderson superexchange interaction, is a prototypical indirect exchange coupling between neighboring magnetic moments by virtue of exchanging electrons through a non-magnetic anion known as the superexchange center. In… [see Wikipedia article]See also:Philip W. Anderson
Surface equivalence principle(1 link)In electromagnetism, surface equivalence principle or surface equivalence theorem relates an arbitrary current distribution within an imaginary closed surface with an equivalent source on the surface. It is also known… [see Wikipedia article]See also:Sergei Alexander Schelkunoff
Switchboard operator(3 links)In the early days of telephony, companies used manual telephone switchboards, and switchboard operators connected calls by inserting a pair of phone plugs into the appropriate jacks. They were gradually… [see Wikipedia article]See also:Emma Nutt · Julia O'Connor
Switching circuit theory(1 link)Switching circuit theory is the mathematical study of the properties of networks of idealized switches. Such networks may be strictly combinational logic, in which their output state is only a… [see Wikipedia article]See also:Claude Shannon
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T-carrier(1 link)The T-carrier system is a member of the series of data-multiplexing carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls. [see Wikipedia article]
TAT-1(1 link)TAT-1 was the first submarine transatlantic telephone cable system. It was laid between Kerrera, Oban, Scotland, and Clarenville, Newfoundland. Two cables were laid between 1955 and 1956 with one cable… [see Wikipedia article]
TAT-8(1 link)TAT-8 was the 8th transatlantic communications cable and first transatlantic fiber-optic cable, carrying 280 Mbit/s between the United States, United Kingdom and France. It was constructed in 1988 by a consortium… [see Wikipedia article]
Telautograph(1 link)The telautograph is an ancestor of the modern fax machine. It transmits electrical signals representing the position of a pen or tracer at the sending station to repeating mechanisms attached… [see Wikipedia article]See also:Elisha Gray
Telecommunications Act of 1996(1 link)The Telecommunications Act of 1996 is a United States federal law enacted by the 104th United States Congress on January 3, 1996, and signed into law on February 8, 1996… [see Wikipedia article]
Telefon Hírmondó(1 link)The Telefon Hírmondó was a "telephone newspaper" located in Budapest, Hungary, which, beginning in 1893, provided news and entertainment to subscribers over telephone lines. It was both the first and… [see Wikipedia article]See also:Tivadar Puskás
Telegrapher's equations(1 link)The telegrapher's equations are a set of two coupled, linear partial differential equations that model voltage and current along a linear electrical transmission line. The equations are important because they… [see Wikipedia article]See also:Oliver Heaviside
TelephoneA telephone, commonly shortened to phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard… [see Wikipedia article]
Telephone booth(1 link)A telephone booth, phone booth, telephone kiosk, telephone call box, telephone box or public call box is a tiny structure furnished with a payphone and designed for a telephone user's… [see Wikipedia article]See also:Giles Gilbert Scott
Telephone directory(3 links)A telephone directory, commonly called a telephone book, telephone address book or phonebook, is a listing of telephone subscribers in a geographical area or subscribers to services provided by the… [see Wikipedia article]See also:George Willard Coy
Telephone exchange(7 links)A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the… [see Wikipedia article]See also:George Willard Coy · Tivadar Puskás · Almon Strowger
Telephone exchange namesA telephone exchange name or central office name was a distinguishing and memorable name assigned to a central office. It identified the switching system to which a telephone was connected,… [see Wikipedia article]
Telephone magnetoA telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature. In early telegraphy, magnetos were used to power instruments, while… [see Wikipedia article]
Telephone number(1 link)A telephone number is the address of a telecommunication endpoint, such as a telephone, in a telephone network, such as the public switched telephone network (PSTN). A telephone number typically… [see Wikipedia article]See also:Moses Greeley Parker
Telephone numbering planA telephone numbering plan is a type of numbering scheme used in a telecommunications network to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the… [see Wikipedia article]
Telephone switchboard(3 links)A telephone switchboard is a device used to connect circuits of telephones to establish telephone calls between users or other switchboards. The switchboard is an essential component of a manual… [see Wikipedia article]See also:George Willard Coy · Ezra Gilliland · Milo G. Kellogg
Telex(2 links)Telex is a telecommunication system that allows text-based messages to be sent and received by teleprinter over telephone lines. The term "telex" may refer to the service, the network, the… [see Wikipedia article]
Telstar(3 links)Telstar is a series of communications satellites. The first two, Telstar 1 and Telstar 2, were experimental and nearly identical. Telstar 1 was launched atop a Thor-Delta rocket on July… [see Wikipedia article]See also:John R. Pierce · Rudolf Kompfner
The C Programming Language(1 link)The C Programming Language is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the C programming language, as well… [see Wikipedia article]See also:Brian Kernighan
The Telephone Cases(2 links)The Telephone Cases, 126 U.S. 1 (1888), were a series of U.S. court cases in the 1870s and the 1880s related to the invention of the telephone, which culminated in… [see Wikipedia article]See also:Amos Dolbear · James J. Storrow
Thermionic emission(1 link)Thermionic emission is the liberation of charged particles from a hot electrode whose thermal energy gives some particles enough kinetic energy to escape the material's surface. The particles, sometimes called… [see Wikipedia article]See also:Thomas Edison
Thermistor(1 link)A thermistor is a semiconductor type of resistor in which the resistance is strongly dependent on temperature. The word thermistor is a portmanteau of thermal and resistor. The varying resistance… [see Wikipedia article]See also:Gerald Pearson
Thompson's construction(1 link)In computer science, Thompson's construction algorithm, also called the McNaughton–Yamada–Thompson algorithm, is a method of transforming a regular expression into an equivalent nondeterministic finite automaton (NFA). This NFA can be… [see Wikipedia article]See also:Ken Thompson
Ticker tape(1 link)Ticker tape was the earliest electrical dedicated financial communications medium, transmitting stock price information over telegraph lines, in use from around 1870 to 1970. It consisted of a paper strip… [see Wikipedia article]See also:Thomas Edison
Tin-can telephoneA tin-can telephone is a type of acoustic (non-electrical) speech-transmitting device made up of two tin cans, paper cups or similarly shaped items attached to either end of a taut… [see Wikipedia article]
Traffic Service Position System(2 links)The Traffic Service Position System (TSPS) was developed by Bell Labs in Columbus, Ohio to replace traditional cord switchboards. The first TSPS was deployed in Morristown, New Jersey in 1969… [see Wikipedia article]See also:Amos E. Joel Jr.
Transmission Control Protocol(1 link)The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite, providing reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications… [see Wikipedia article]See also:Robert Kahn
Traveling-wave tube(2 links)A traveling-wave tube or traveling-wave tube amplifier is a specialized vacuum tube that is used in electronics to amplify radio frequency (RF) signals in the microwave range. It was invented… [see Wikipedia article]See also:Rudolf Kompfner · John R. Pierce
Trimline telephone(1 link)The Trimline telephone is a series of telephones that was produced by Western Electric, the manufacturing unit of the Bell System. These telephones were first introduced in 1965 and are… [see Wikipedia article]See also:Donald Genaro
Triode(1 link)A triode is an electronic amplifying vacuum tube consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). [see Wikipedia article]See also:Lee de Forest
Twisted pairTwisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a… [see Wikipedia article]
U
United States v. AT&T (1982)(4 links)United States v. AT&T, 552 F.Supp. 131 (1982), was a ruling of the United States District Court for the District of Columbia, that led to the 1984 Bell System divestiture,… [see Wikipedia article]See also:Harold H. Greene · William G. McGowan
Universal service(1 link)Universal service is an economic, legal and business term used mostly in regulated industries, referring to the practice of providing a baseline level of services to every resident of a… [see Wikipedia article]See also:Theodore Vail
Unix(4 links)Unix is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, the development of which started in 1969 at the Bell Labs research center… [see Wikipedia article]See also:Brian Kernighan · Dennis Ritchie · Ken Thompson
UTF-8(1 link)UTF-8 is a character encoding standard used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode Transformation Format – 8-bit. As of 2026, almost every webpage… [see Wikipedia article]See also:Ken Thompson
VideotexVideotex was one of the earliest implementations of an end-user information system. From the late 1970s to early 2010s, it was used to deliver information to a user in computer-like… [see Wikipedia article]
Visible Speech(1 link)Visible Speech is a system of phonetic symbols developed by British linguist Alexander Melville Bell in 1867 to represent the position of the speech organs in articulating sounds. Bell was… [see Wikipedia article]See also:Alexander Melville Bell
Vocoder(2 links)A vocoder (, a portmanteau of voice and encoder) is a category of speech coding that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption… [see Wikipedia article]See also:Homer Dudley
Voder(2 links)The Bell Telephone Laboratory's voder (abbreviation of voice operating demonstrator) was the first attempt to electronically synthesize human speech by breaking it down into its acoustic components. It was invented… [see Wikipedia article]See also:Homer Dudley
Voice over IP(3 links)Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet.… [see Wikipedia article]See also:Marian Croak
W
Water microphone(2 links)A water microphone or water transmitter is based on Ohm's law that current in a wire varies inversely with the resistance of the circuit. The sound waves from a human… [see Wikipedia article]See also:Alexander Graham Bell · Elisha Gray
Wire recording(1 link)Wire recording, also known as magnetic wire recording, was the first magnetic recording technology, an analog type of audio storage. It recorded sound signals on a thin steel wire using… [see Wikipedia article]See also:Valdemar Poulsen
Wireless telegraphy(1 link)Wireless telegraphy or radiotelegraphy is the transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term wireless telegraphy was also used for… [see Wikipedia article]See also:Guglielmo Marconi
Z
Zobel network(1 link)Zobel networks are a type of filter section based on the image-impedance design principle. They are named after Otto Zobel of Bell Labs, who published a much-referenced paper on image… [see Wikipedia article]See also:Otto Julius Zobel
Zone melting(1 link)Zone melting is a group of similar methods of purifying crystals, in which a narrow region of a crystal is melted, and this molten zone is moved through the crystal.… [see Wikipedia article]See also:William Gardner Pfann
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