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Encyclopedia > Telephone
Look up Telephone in
Wiktionary, the free dictionary.
Touch Tone® single line business telephone with message waiting lamp
Touch Tone® single line business telephone with message waiting lamp

The telephone (from the Greek words tele (τηλέ) = far and phone (φωνή) = voice) is a telecommunications device that is used to transmit and receive sound (most commonly speech), usually two people conversing but occasionally three or more. It is one of the most common household appliances in the world today. Most telephones operate through transmission of electric signals over a complex telephone network which allows almost any phone user to communicate with almost anyone. Look up telephone in Wiktionary, the free dictionary. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... Conventional telephone from AT&T. Photo by Dante Alighieri | Talk. ... Conventional telephone from AT&T. Photo by Dante Alighieri | Talk. ... Copy of the original phone of Alexander Graham Bell at the Musée des Arts et Métiers in Paris Telecommunication is the assisted transmission of signals over a distance for the purpose of communication. ... Antenna tower of Crystal Palace transmitter, London A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. ... This article is about audible acoustic waves. ... The human voice consists of sound made by a human using the vocal folds for talking, singing, laughing, crying and screaming. ... In information theory, a signal is the sequence of states of a communications channel that encodes a message. ... The public switched telephone network (PSTN) is the network of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the network of the worlds public IP-based packet-switched networks. ...

Contents

Basic principle

1896 Telephone (Sweden)
1896 Telephone (Sweden)

A traditional landline telephone system, or "plain old telephone service" (POTS), commonly handles both signaling and audio information on the same twisted pair of insulated wires: the telephone line. Although originally designed for voice communication, the system has been adapted for data communication such as Telex, Fax and Internet communication. The signaling equipment consists of a bell, beeper, light or other device to alert the user to incoming calls, and number buttons or a rotary dial to enter a telephone number for outgoing calls. A twisted pair line is preferred as it is more effective at rejecting electromagnetic interference (EMI) and crosstalk than an untwisted pair. Image File history File links 1896_telephone. ... Image File history File links 1896_telephone. ... Plain old telephone service, or POTS, are the services available from analogue telephones prior to the introduction of electronic telephone exchanges into the public switched telephone network. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ... A telephone line (or just line) is a single-user circuit on a telephone communications system. ... Telegraph and Telegram redirect here. ... For other uses, see Fax (disambiguation). ... A telephone number is a sequence of decimal digits that uniquely indicates the network termination point. ... Electromagnetic interference (or EMI, also called radio frequency interference or RFI) is a (usually undesirable) disturbance caused in a radio receiver or other electrical circuit by electromagnetic radiation emitted from an external source. ... In telecommunication, the term crosstalk (XT) has the following meanings: 1. ...


A calling party wishing to speak to another party will pick up the telephone's handset, thus operating a button switch or "switchhook", which puts the telephone into an active state or "off hook" by connecting the transmitter (microphone), receiver (speaker) and related audio components to the line. This circuitry has a low resistance (less than 300 Ohms) which causes DC current (48 volts, nominal) from the telephone exchange to flow through the line. The exchange detects this DC current, attaches a digit receiver circuit to the line, and sends a dial tone to indicate readiness. On a modern telephone, the calling party then presses the number buttons in a sequence corresponding to the telephone number of the called party. The buttons are connected to a tone generator that produces DTMF tones which are sent to the exchange. A rotary dial telephone employs pulse dialing, sending electrical pulses corresponding to the telephone number to the exchange. (Most exchanges are still equipped to handle pulse dialing.) Provided the called party's line is not already active or "busy", the exchange sends an intermittent ringing signal (generally over 100 volts AC) to alert the called party to an incoming call. If the called party's line is active, the exchange sends a busy signal to the calling party. However, if the called party's line is active but has call waiting installed, the exchange sends an intermittent audible tone to the called party to indicate an incoming call. The person who (or device that) initiates a telephone call over the public switched telephone network is the calling party. ... A transceiver is a device that has a transmitter and receiver which is combined into a one unit. ... In telephony, the term off-hook has the following meanings: The condition that exists when a telephone or other user instrument is in use, , during dialing or communicating. ... Microphones redirects here. ... An inexpensive low fidelity 3. ... A multimeter can be used to measure resistance in ohms. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... Josephson junction array chip developed by NIST as a standard volt. ... For other uses, see Switch (disambiguation). ... For the G.I. Joe character, see List of G.I. Joe ARAH characters. ... Dual-tone multi-frequency (DTMF), also known as Touch Tone® is used for telephone signaling over the line in the voice frequency band to the call switching center. ... Pulse dialing, dial pulse, or loop disconnect dialing, also called Rotary or Decadic dialling in the United Kingdom (because up to 10 pulses are sent), and IKZ Impulskennzeichen in German, is pulsing in which a direct-current pulse train is produced by interrupting a steady signal according to a fixed... It has been suggested that this article or section be merged with ring tone, ring (telephone), polyphonic ringtone and Mobile music (Discuss) A ringing signal is an electronic telephony signal that causes a telephone to alert the user to an incoming call. ... City lights viewed in a motion blurred exposure. ... A busy signal is information communicated to a user or apparatus attempting a connection, indicating the requested connection cannot be completed. ... Call waiting, in telephony, is a feature on some telephone networks. ...


When a landline phone is inactive or "on hook", its alerting device is connected across the line through a capacitor, which prevents DC current from flowing through the line. The circuitry at the telephone exchange detects the absence of DC current flow and thus that the phone is on hook with only the alerting device electrically connected to the line. When a party initiates a call to this line, the ringing signal transmitted by the telephone exchange activates the alerting device on the line. When the called party picks up the handset, the switchhook disconnects the alerting device and connects the audio circuitry to the line. The resulting low resistance now causes DC current to flow through this line, confirming that the called phone is now active. Both phones being active and connected through the exchange, the parties may now converse as long as both phones remain off hook. When a party "hangs up", placing the handset back on the cradle or hook, DC current ceases to flow in that line, signaling the exchange to disconnect the call. In telecommunication, the term on-hook has the following meanings: 1. ... See Capacitor (component) for a discussion of specific types. ... This article does not adequately cite its references or sources. ...


Calls to parties beyond the local exchange are carried over "trunk" lines which establish connections between exchanges. In modern telephone networks, fiber-optic cable and digital technology are often employed in such connections. Satellite technology may be used for communication over very long distances. Fiber-optic communication is a method of transmitting information from one place to another by sending light through an optical fiber. ... Digital Multiplex System (DMS) is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators. ... U.S. military MILSTAR communications satellite A communications satellite (sometimes abbreviated to comsat) is an artificial satellite stationed in space for the purposes of telecommunications. ...


In most telephones, the transmitter and receiver (microphone and speaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure. Powered by the line, the transmitter produces an electric current which varies in response to the sound waves arriving at its diaphragm. The resulting electric current is transmitted along the telephone line to the local exchange and then to the other phone (via the local exchange or a larger network), where it passes through the coil of the receiver. The varying electric current in the coil causes the receiver's diaphragm to move in and out, reproducing the sound waves present at the transmitter. A transceiver is a device that has a transmitter and receiver which is combined into a one unit. ... A Speakerphone is a telephone with a microphone and loudspeaker provided separately from those in the handset. ... This article is about audible acoustic waves. ... In a loudspeaker, a diaphragm is the thin, semi-rigid membrane attached to the central magnet. ... A voice coil is the coil of wire attached to the apex of the moving cone of a loudspeaker. ...


A Lineman's handset is a telephone designed for testing the telephone network, and may be attached directly to aerial lines and other infrastructure components. A linemans handset, also called a test set or a butt set, is typically a very durable one-piece telephone that integrates an earpiece, a mouthpiece, and a dialing interface (originally a rotary dial, but now more commonly, a 12-button DTMF keypad). ...


History

Credit for inventing the electric telephone remains in dispute. As with other great inventions such as radio, television, light bulb, and computer, there were several inventors who did pioneer experimental work on voice transmission over a wire and improved on each other's ideas. Innocenzo Manzetti, Antonio Meucci, Johann Philipp Reis, Elisha Gray, Alexander Graham Bell, and Thomas Edison, among others, have all been credited with pioneer work on the telephone. The pre-history and early history of the telephone is the history of telephonic technology that produced instruments to transfer information through a medium, electrically or mechanically. ... Below is a Timeline of the telephone that covers important dates in the history of the telephone. ... For the musical form, see Invention (music). ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... Antonio Meucci. ... Johann Philipp Reis (January 7, 1834 – January 24, 1874), was born in Gelnhausen, Germany, as son to a poor Portuguese-Jewish baker. ... Elisha Gray (August 2, 1835 – January 21, 1901) was an electrical engineer and is best known for his development of a telephone prototype in 1876 in Highland Park, Illinois, U.S.A.. // Born into a Quaker family in Barnesville, Ohio, Gray was brought up on a farm. ... Alexander Graham Bell (3 March 1847 – 2 August 1922) was an eminent scientist, inventor and innovator who is credited with the invention of the telephone. ... Edison redirects here. ...


The early history of the telephone is a confusing morass of claim and counterclaim, which was not clarified by the huge mass of lawsuits which hoped to resolve the patent claims of individuals. The Bell and Edison patents, however, were forensically victorious and commercially decisive.

Further information: Invention of the telephone and Elisha Gray and Alexander Bell Controversy

Bell speaking into prototype model of the telephone The history of the invention of the telephone is a confusing claim and counterclaim, further worsened by the lawsuits which hoped to resolve the patent claims of individuals. ... The Elisha Gray and Alexander Graham Bell Controversy revolves around the question of whether Bell and Gray invented the telephone independently and, if not, whether one stole the invention from the other. ...

Early development

  • 1844Innocenzo Manzetti first mooted the idea of a “speaking telegraph” (telephone).
  • 26 August 1854Charles Bourseul publishes an article in a magazine L'Illustration (Paris) : "Transmission électrique de la parole".
  • 22 August 1865, La Feuille d'Aoste reported “It is rumored that English technicians to whom Mr. Manzetti illustrated his method for transmitting spoken words on the telegraph wire intend to apply said invention in England on several private telegraph lines.”
  • 28 December 1871Antonio Meucci files a patent caveat (n.3335) in the U.S. Patent Office titled "Sound Telegraph", describing communication of voice between two people by wire.
  • 1874 — Meucci, after having renewed the caveat for two years, fails to find the money to renew it. The caveat lapses.
  • 6 April 1875 — Bell's U.S. Patent 161,739 "Transmitters and Receivers for Electric Telegraphs" is granted. This uses multiple vibrating steel reeds in make-break circuits.
  • 11 February 1876 — Gray invents a liquid transmitter for use with a telephone but does not build one.
  • 14 February 1876 — Elisha Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.
  • 14 February 1876 — Alexander Bell applies for the patent "Improvements in Telegraphy", for electromagnetic telephones using undulating currents.
  • 19 February 1876 — Gray is notified by the U.S. Patent Office of an interference between his caveat and Bell's patent application. Gray decides to abandon his caveat.
  • 7 March 1876 — Bell's U.S. patent 174,465 "Improvement in Telegraphy" is granted, covering "the method of, and apparatus for, transmitting vocal or other sounds telegraphically … by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound."
  • 10 March 1876 — The first successful telephone transmission of clear speech using a liquid transmitter when Bell spoke into his device, “Mr. Watson, come here, I want to see you.” and Watson heard each word distinctly.
  • 30 January 1877 — Bell's U.S. patent 186,787 is granted for an electromagnetic telephone using permanent magnets, iron diaphragms, and a call bell.
  • 27 April 1877 — Edison files for a patent on a carbon (graphite) transmitter. The patent 474,230 was granted 3 May 1892, after a 15 year delay because of litigation. Edison was granted patent 222,390 for a carbon granules transmitter in 1879.

Jan. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... is the 238th day of the year (239th in leap years) in the Gregorian calendar. ... 1854 (MDCCCLIV) was a common year starting on Sunday (see link for calendar). ... Charles Bourseul was born in Brussels, Belgium on the 28th of April 1829, and grew up in Douai, France. ... is the 234th day of the year (235th in leap years) in the Gregorian calendar. ... Year 1865 (MDCCLXV) was a common year starting on Sunday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Friday of the 12-day slower Julian calendar). ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... is the 362nd day of the year (363rd in leap years) in the Gregorian calendar. ... 1871 (MDCCCLXXI) was a common year starting on Sunday (see link for calendar). ... Antonio Meucci. ... A patent caveat was a legal document filed with the United States Patent Office. ... Year 1874 (MDCCCLXXIV) was a common year starting on Thursday (link with display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ... is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... 1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ... is the 42nd day of the year in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... is the 45th day of the year in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... A patent caveat was a legal document filed with the United States Patent Office. ... is the 45th day of the year in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... [[Media:Italic text]]{| style=float:right; |- | |- | |} is the 50th day of the year in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... is the 66th day of the year (67th in leap years) in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... Year 1876 (MDCCCLXXVI) // January 31 - United States orders all Indigenous peoples in the United States to move onto reservations February 2 - The National League of Professional Baseball Clubs of Major League Baseball is formed. ... is the 30th day of the year in the Gregorian calendar. ... 1877 (MDCCCLXXVII) was a common year starting on Monday (see link for calendar). ... is the 117th day of the year (118th in leap years) in the Gregorian calendar. ... 1877 (MDCCCLXXVII) was a common year starting on Monday (see link for calendar). ... is the 123rd day of the year (124th in leap years) in the Gregorian calendar. ... Year 1892 (MDCCCXCII) was a leap year starting on Friday (link will display the full calendar) of the Gregorian Calendar (or a leap year starting on Wednesday of the 12-day slower Julian calendar). ...

Early commercial instruments

Early telephones were technically diverse. Some used a liquid transmitter, some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were "dynamic" - their diaphragm vibrated a coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. This dynamic kind survived in small numbers through the 20th century in military and maritime applications where its ability to create its own electrical power was crucial. Most, however, used the Edison/Berliner carbon transmitter, which was much louder than the other kinds, even though it required an induction coil, actually acting as an impedance matching transformer to make it compatible to the impedance of the line. The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument. An induction coil or spark coil (archaically known as a Ruhmkorff coil) is a type of disruptive discharge coil. ... Impedance matching is the practice of attempting to make the output impedance of a source equal to the input impedance of the load to which it is ultimately connected, usually in order to maximize the power transfer and minimize reflections from the load. ...


Early telephones were locally powered, using either a dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel was to visit each telephone periodically to inspect the battery. During the 20th century, "common battery" operation came to dominate, powered by "talk battery" from the telephone exchange over the same wires that carried the voice signals. Late in the century, wireless handsets brought a revival of local battery power. In telecommunication, the term outside plant has the following meanings: 1. ... For other uses, see Switch (disambiguation). ...


Early telephones had one wire for both transmitting and receiving of audio, with ground return as used in telegraphs. The earliest dynamic telephones also had only one opening for sound, and the user alternately listened and spoke (rather, shouted) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but were more expensive. Single wire earth return (SWER) or single wire ground return is a single-wire transmission line for supplying single-phase electrical power to remote areas at low cost. ... Telegraphy (from the Greek words tele = far away and grapho = write) is the long distance transmission of written messages without physical transport of letters, originally over wire. ...


At first, the benefits of an exchange were not exploited. Telephones instead were leased in pairs to the subscriber, who had to arrange telegraph contractors to construct a line between them, for example between his home and his shop. Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones. Western Union, already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco, and Bell was not slow in appreciating the potential. Subscriber: In a public switched telecommunications network such as the common telephone system, the ultimate user, customer, of a communications service. ... Western Union (NYSE: WU) is a financial services and communications company based in the United States. ... New York, New York and NYC redirect here. ... This page is a candidate for speedy deletion. ...


Signalling began in an appropriately primitive manner. The user alerted the other end, or the exchange operator, by whistling into the transmitter. Exchange operation soon resulted in telephones being equipped with a bell, first operated over a second wire and later with the same wire using a condenser (capacitor). Telephones connected to the earliest Strowger automatic exchanges had seven wires, one for the knife switch, one for each telegraph key, one for the bell, one for the push button and two for speaking. See Capacitor (component) for a discussion of specific types. ... Almon Brown Strowger (1839 – May 26, 1902) gave his name to the electromechanical telephone exchange technology that his invention and patent inspired. ... For other uses, see Switch (disambiguation). ... Electrical switches. ... Telegraph key Telegraph key (also known as the Morse key) is a generic term for any switching device used primarily to send Morse code. ...


Rural and other telephones that were not on a common battery exchange had a magneto or hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator. This article is about the engine component. ...


In the 1890s a new smaller style of telephone was introduced, packaged in three parts. The transmitter stood on a stand, known as a "candlestick" for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a "switchhook." Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone "off the hook". In phones connected to magneto exchanges, the bell, induction coil, battery and magneto were in a separate "bell box." In phones connected to common battery exchanges, the bell box was installed under a desk, or other out of the way place, since it did not need a battery or magneto.


Cradle designs were also used at this time, having a handle with the receiver and transmitter attached, separate from the cradle base that housed the magneto crank and other parts. They were larger than the "candlestick" and more popular.


Disadvantages of single wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long distance telephones, four-wire circuits. Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special sound proofed long distance telephone booth furnished with the latest technology. In telecommunication, the term crosstalk (XT) has the following meanings: 1. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ... In telecommunication, a four-wire circuit is a two-way circuit using two paths so arranged that the respective signals are transmitted in one direction only by one path and in the other direction by the other path. ... Long distance in telecommunications, refers to telephone calls made outside a certain area, usually characterized by an area code outside of a local call area. ...


What turned out to be the most popular and longest lasting physical style of telephone was introduced in the early 20th century, including Bell's Model 102. A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use sat in a cradle in the base unit. The circuit diagram of the Model 102 shows the direct connection of the receiver to the line, while the transmitter was induction coupled, with energy supplied by a local battery. The coupling transformer, battery, and ringer were in a separate enclosure. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line 1-10 times for each digit, and the hook switch (in the center of the circuit diagram) permanently disconnected the line and the transmitter battery while the handset was on the cradle. The Model 102 telephone was Western Electrics first widely distributed telephone set to feature the transmitter and receiver in a common handset. ... Carbon microphone from Western Electric telephone. ... A German Fe TAp 615, a widespread rotary dial telephone of the 1960s to the 1980s The rotary dial is a device mounted on or in a telephone or switchboard that is designed to send interrupted electrical pulses, known as pulse dialing, corresponding to the number dialed. ...


After the 1930s, the base also enclosed the bell and induction coil, obviating the old separate bell box. Power was supplied to each subscriber line by central office batteries instead of a local battery, which required periodic service. For the next half century, the network behind the telephone became progressively larger and much more efficient, but after the dial was added the instrument itself changed little until touch tone replaced the dial in the 1960s.


Digital telephony

Main article: Digital Telephony

The Public Switched Telephone Network (PSTN) has gradually evolved towards digital telephony which has improved the capacity and quality of the network. End-to-end analog telephone networks were first modified in the early 1960s by upgrading transmission networks with T1 carrier systems. Later technologies such as SONET and fiber optic transmission methods further advanced digital transmission. Although analog carrier systems existed, digital transmission made it possible to significantly increase the number of channels multiplexed on a single transmission medium. While today the end instrument remains analog, the analog signals reaching the aggregation point (Serving Area Interface (SAI) or the central office (CO) ) are typically converted to digital signals. Digital loop carriers (DLC) are often used, placing the digital network ever closer to the customer premises, relegating the analog local loop to legacy status. Digital telephony is a technology used in the provision of digital telephone services and systems. ... The public switched telephone network (PSTN) is the network of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the network of the worlds public IP-based packet-switched networks. ... An analog or analogue signal is any time continuous signal where some time varying feature of the signal is a representation of some other time varying quantity. ... For the guitar distortion pedal, see BOSS DS-1. ... Synchronous Optical Networking, commonly known as SONET, is a standard for communicating digital information over optical fiber. ... Fiber Optic strands An optical fiber in American English or fibre in British English is a transparent thin fiber for transmitting light. ... In telecommunications, multiplexing (also muxing or MUXing) is the combining of two or more information channels onto a common transmission medium using hardware called a multiplexer or (MUX). ... The serving area interface or SAI often called B-Box, cross-connect box, or Access Point (AP) is an outdoor telecommunications cabinet usually mounted on the ground on cable right-of-ways but can also be located on poles. ... In the field of telecommunications, a central office or telephone exchange houses equipment that is commonly known as simply a switch, which is a piece of equipment that connects phone calls. ... A digital signal is a signal that is both discrete and quantized. ... The local loop is the physical connection between the main distribution frame in the users premises to the telecommunications network provider. ... In telecommunications, the local loop is the wiring between the central office (telephone exchange in British English) and the customers premises demarcation point. ...


IP telephony

A WiFi-based VoIP phone

Internet Protocol (IP) telephony (also known as Internet telephony) is a service based on Voice over IP (VoIP), a disruptive technology that is rapidly gaining ground against traditional telephone network technologies. In Japan and South Korea up to 10% of subscribers, as of January 2005, have switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing." [1] As of 2006 many VoIP companies offer service to consumers and businesses. Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Wi-Fi (or Wi-fi, WiFi, Wifi, wifi), short for Wireless Fidelity, is a set of standards for wireless local area networks (WLAN) currently based on the IEEE 802. ... IP Telephony, also called Internet telephony, is the technology that makes it possible to have a telephone conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. ... An overview of how VoIP works A typical analog telephone adapter for connecting an ordinary phone to a VoIP network Ciscos implementation of VoIP - IP Phone Voice over Internet Protocol, also called VoIP (pronounced voyp), IP Telephony, Internet telephony, Broadband telephony, Broadband Phone and Voice over Broadband is the... A disruptive technology or disruptive innovation is a technological innovation, product, or service that eventually overturns the existing dominant technology or product in the market. ... The Newsweek logo Newsweek is a weekly news magazine published in New York City and distributed throughout the United States and internationally. ... This is a list of commercial voice over IP network providers, arranged alphabetically with no restriction to region. ... Consumers refers to individuals or households that use goods and services generated within the economy. ... In economics, a business (also called firm or enterprise) is a legally recognized organizational entity designed to provide goods and/or services to consumers or corporate entities such as governments, charities or other businesses. ...


IP telephony uses a broadband Internet connection and IP Phones to transmit conversations as data packets. In addition to replacing POTS(plain old telephone service), IP telephony is also competing with mobile phone networks by offering free or lower cost connections via WiFi hotspots. VoIP is also used on private wireless networks which may or may not have a connection to the outside telephone network. Broadband in telecommunications is a term that refers to a signaling method that includes or handles a relatively wide range of frequencies, which may be divided into channels or frequency bins. ... What to say? Its a phone, but it encodes voice and transmits it via IP, using one of several CODECs, including G.711, G.728, and G.729. ... In computer networking and telecommunications, packet switching is a communications paradigm in which packets (messages or fragments of messages) are individually routed between nodes, with no previously established communication path. ... Wi-Fi (or Wi-fi, WiFi, Wifi, wifi), short for Wireless Fidelity, is a set of standards for wireless local area networks (WLAN) currently based on the IEEE 802. ... Hotspots are venues that offer Wi-Fi access. ...


IP telephony technology transforms many non-telephone electronics devices into unified communications devices which simulate telephone usage, such as adding telephone-like features to portable game devices, digital picture frames, or handheld GPS receivers, typically by incorporating a voice engine. When used on a personal computer, an IP telephone is referred to as a soft phone. In computing, a softphone is a software program for making telephone calls over the Internet using a general purpose computer, rather than using dedicated hardware. ...


Usage

By the end of 2006, there were a total of nearly 4 billion mobile and fixed line subscribers and over 1 billion Internet users worldwide. This included 1.27 billion fixed line subscribers and 2.68 billion mobile subscribers. [2]


Telephone operating companies

In some countries, many telephone operating companies (commonly abbreviated to telco in American English) are in competition to provide telephone services. Some of them are included in the following list. However, the list only includes facilities based providers and not companies which lease services from facilities based providers in order to serve their customers. This list is incomplete; you can help by expanding it. ... A telephone company (or telco) provides telecommunications services such as telephony and data communications. ...


Patents

  • US 174,465 -- Telegraphy (Bell's first telephone patent) -- Alexander Graham Bell
  • US 186,787 -- Electric Telegraphy (permanent magnet receiver) -- Alexander Graham Bell
  • US 474,230 -- Speaking Telegraph (graphite transmitter) -- Thomas Edison
  • US 203,016 -- Speaking Telephone (carbon button transmitter) -- Thomas Edison
  • US 222,390 -- Carbon Telephone (carbon granules transmitter) -- Thomas Edison
Look up cordless telephone in Wiktionary, the free dictionary.
  • US 485,311 -- Telephone (solid back carbon transmitter) -- Anthony C. White (Bell engineer) This design was used until 1925 and installed phones were used until the 1940s.
  • US 3,449,750 -- Duplex Radio Communication and Signalling Appartus -- G. H. Sweigert
  • US 3,663,762 -- Cellular Mobile Communication System -- Amos Edward Joel (Bell Labs)
  • US 3,906,166 -- Radio Telephone System (DynaTAC cell phone) -- Martin Cooper et al. (Motorola)

Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... Cell phone redirects here. ...

See also

Look up telephone in Wiktionary, the free dictionary.

Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... ... Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... The Bell System was a trademark and service mark used by the United States telecommunications company American Telephone & Telegraph Company (AT&T) and its affiliated companies to co-brand their extensive circuit-switched telephone network and their affiliations with each other. ... This is a device which was invented by Thomas Carter. ... For the G.I. Joe character, see List of G.I. Joe ARAH characters. ... The Elisha Gray and Alexander Graham Bell controversy considers the question of whether Bell and Gray invented the telephone independently and, if not, whether one stole the invention from the other. ... Emergency telephone on a beach at Trefor in North Wales An Emergency telephone is a phone specifically provided for making calls to emergency services and are most often found in places of special danger or where it is likely that there will only be a need to make emergency calls. ... The telephone newspaper was a system, based largely in major cities of Europe, of distributing newspaper content via the telephone in the late 19th Century. ... A telephone numbering plan is a plan for allocating telephone number ranges to countries, regions, areas and exchanges and to non-fixed telephone networks such as mobile phone networks. ... Telecommunication involves the transmission of signals over a distance for the purpose of communication. ... Telephone switchboard, 1974 A switchboard (also called a manual branch exchange) is a device used to manually connect a group of telephones from one to another or to an outside connection. ... In telecommunication, Telephony encompasses the general use of equipment to provide voice communication over distances. ... In telecommunications, the local loop is the wiring between the central office (telephone exchange in British English) and the customers premises demarcation point. ... This article does not cite any references or sources. ... For other uses, see Fax (disambiguation). ... A satellite telephone, satellite phone, or satphone is a mobile phone that communicates directly with orbiting communications satellites. ... Top of a cellular radio tower In the beginning, two-way radios (known as mobile rigs) were used in vehicles such as taxicabs, police cruisers, ambulances, and the like, but were not mobile phones because they were not normally connected to the telephone network. ... The federal telephone excise tax is a statutory Federal Excise Tax imposed under the Internal Revenue Code in the United States under 26 U.S.C. Â§ 4251 on amounts paid for certain communications services. ... Below is a Timeline of the telephone that covers important dates in the history of the telephone. ... Bell speaking into prototype model of the telephone The history of the invention of the telephone is a confusing claim and counterclaim, further worsened by the lawsuits which hoped to resolve the patent claims of individuals. ... The pre-history and early history of the telephone is the history of telephonic technology that produced instruments to transfer information through a medium, electrically or mechanically. ... For other uses, see Switch (disambiguation). ... A telephone number is a sequence of decimal digits that uniquely indicates the network termination point. ... Telephone tapping (or wire tapping/wiretapping in the US) is the monitoring of telephone and Internet conversations by a third party, often by covert means. ... Moscow phone book, 1930. ... A modern GE cordless telephone, model 26930 A cordless telephone or portable telephone is a telephone with a wireless handset which communicates via radio waves with a base station connected to a fixed telephone line (POTS) and can only be operated near (typically less than 100 meters) its base station... Plain old telephone service, or POTS, are the services available from analogue telephones prior to the introduction of electronic telephone exchanges into the public switched telephone network. ... The public switched telephone network (PSTN) is the network of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the network of the worlds public IP-based packet-switched networks. ... A telephone line (or just line) is a single-user circuit on a telephone communications system. ... This article does not adequately cite its references or sources. ...

References

  • Coe, Lewis (1995), The Telephone and Its Several Inventors: A History, McFarland, North Carolina, 1995. ISBN 0-7864-0138-9
  • Evenson, A. Edward (2000), The Telephone Patent Conspiracy of 1876: The Elisha Gray - Alexander Bell Controversy, McFarland, North Carolina, 2000. ISBN 0-7864-0883-9
  • Baker, Burton H. (2000), The Gray Matter: The Forgotten Story of the Telephone, Telepress, St. Joseph, MI, 2000. ISBN 0-615-11329-X
  • Huurdeman, Anton A. (2003), The Worldwide History of Telecommunications, IEEE Press and J. Wiley & Sons, 2003. ISBN 0-471-20505-2
  • Josephson, Matthew (1992), Edison: A Biography, Wiley, 1992. ISBN 0-471-54806-5
  • Bruce, Robert V. (1990), Alexander Graham Bell and the Conquest of Solitude, Cornell University Press, Ithaca, 1990.

Further reading

Robert Sobel in a promotional photo for his publisher. ...

External links

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  Results from FactBites:
 
Business Phones: Office Phones, Speaker Phones | Business.com (897 words)
Some of the larger vendors of business telephone systems include Avaya, Cisco, Nortel, Vertical (which owns the Comdial and Vodavi brands), and NEC.
Some users of your office telephones will need headsets Receptionists, salespeople, technical support, billing -- many modern office workers are on the phone constantly as part of the job.
Consider headsets made for business telephone use by Plantronics and Logitech.
Howstuffworks "How Telephones Work" (383 words)
Although most of us take it completely for granted, the telephone you have in your house is one of the most amazing devices ever created.
Surprisingly, a telephone is one of the simplest devices you have in your house.
It is so simple because the telephone connection to your house has not changed in nearly a century.
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