Telephone

phonetelephonesLocal Telephone Servicefixed telephonyphonestelephonyFixed-Line TelephonyTelephone numbertelephone receiverfixed
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.wikipedia
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Charles Bourseul

Bourseul, Charles
Charles Bourseul, Antonio Meucci, Johann Philipp Reis, Alexander Graham Bell, and Elisha Gray, amongst others, have all been credited with the invention of the telephone.
Charles Bourseul (28 April 1829 – 23 November 1912) was a pioneer in development of the "make and break" telephone about 20 years before Bell made a practical telephone.

Microphone

microphonescondenser microphonedynamic microphone
The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice in a distant location.
Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, radio and television broadcasting, and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic sensors or knock sensors.

Trunking

trunktrunk linetrunks
Calls to parties beyond the local exchange are carried over trunk lines which establish connections between exchanges.
A trunk line is a circuit connecting telephone switchboards (or other switching equipment), as distinguished from local loop circuit which extends from telephone exchange switching equipment to individual telephones or information origination/termination equipment.

Tivadar Puskás

Puskás, Tivadar
In 1876, shortly after the telephone was invented, Hungarian engineer Tivadar Puskás invented the telephone switch, which allowed for the formation of telephone exchanges, and eventually networks.
Tivadar Puskás de Ditró (English: Theodore Puskás b. 17 September 1844, Pest – d. 16 March 1893, Budapest) was a Hungarian inventor, telephone pioneer, and inventor of the telephone exchange.

Ringer box

bell-setsubscriber set
Exchange operation soon resulted in telephones being equipped with a bell in a ringer box, first operated over a second wire, and later over the same wire, but with a condenser (capacitor) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone "on hook").
A ringer box is a telephone signaling device, similar to a bell box.

Hybrid coil

hybrid transformerhybridhybrid transformers
The strong outgoing speech signal from the microphone (transmitter) does not overpower the weaker incoming speaker (receiver) signal with sidetone because a hybrid coil (A3) and other components compensate the imbalance.
Telephone hybrids are used in telephone exchanges to convert the 4-wire appearance to the 2-wire last mile connection to the subscriber's telephone.

Alternating current

ACalternating-currentalternating
Exchange operation soon resulted in telephones being equipped with a bell in a ringer box, first operated over a second wire, and later over the same wire, but with a condenser (capacitor) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone "on hook"). If the called party's line is available, the exchange sends an intermittent ringing signal (about 75 volts alternating current (AC) in North America and UK and 60 volts in Germany) to alert the called party to an incoming call.
Alternating current is used to transmit information, as in the cases of telephone and cable television.

Western Union

Western Union Telegraph CompanyWestern Union TelegraphWestern Union Company
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.
In 1879, Western Union left the telephone business, settling a patent lawsuit with Bell Telephone Company.

Candlestick telephone

candlestickcandlestick phonecontemporary telephone
The transmitter stood on a stand, known as a "candlestick" for its shape.
The candlestick telephone is a style of telephone that was common from the late 1890s to the 1940s.

Invention of radio

inventor of radioinventors of radiodevelopment of radio
As with other influential inventions such as radio, television, the light bulb, and the computer, several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas.
In 1899, Bose announced the development of an "iron-mercury-iron coherer with telephone detector" in a paper presented at the Royal Society, London.

Telephone booth

phone boothtelephone boxtelephone kiosk
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 soundproofed long distance telephone booth furnished with the latest technology.
A telephone booth, telephone kiosk, telephone call box, telephone box or public call box is a small structure furnished with a payphone and designed for a telephone user's convenience.

Telephone exchange

exchangescentral officeexchange
In 1876, shortly after the telephone was invented, Hungarian engineer Tivadar Puskás invented the telephone switch, which allowed for the formation of telephone exchanges, and eventually networks.
A telephone exchange automatically senses an off-hook condition of the telephone when the user removes the handset from the switchhook or cradle.

Telephony

digital telephonytelephonedigital
With the development of electronic switching systems in the 1960s, telephony gradually evolved towards digital telephony which improved the capacity, quality, and cost of the network.
The history of telephony is intimately linked to the invention and development of the telephone.

Model 500 telephone

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After World War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as the model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices.
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.

Telephone magneto

magnetocrank telephoneDachshund
When there is no automatic exchange, telephones have hand-cranked magnetos to generate a ringing voltage back to the exchange or any other telephone on the same line.
Many early manual telephones had an attached hand-cranked magneto that produced an alternating current (AC) at 50-100V for signaling to ring the bells of other telephones on the same (party) line and to alert an operator at the local telephone exchange.

AT&T Corporation

AT&TAmerican Telephone & Telegraph CompanyAmerican Telephone and Telegraph Company
A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963.
During its long history, AT&T was at times the world's largest telephone company, the world's largest cable television operator, and a regulated monopoly.

Computer network

networknetworkingcomputer networking
The development of digital data communications method, such as the protocols used for the Internet, it became possible to digitize voice and transmit it as real-time data across computer networks, giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP), a term that reflects the methodology memorably.
Nodes are identified by network addresses, and can include hosts such as personal computers, phones, and servers, as well as networking hardware such as routers and switches.

Sidetone

The strong outgoing speech signal from the microphone (transmitter) does not overpower the weaker incoming speaker (receiver) signal with sidetone because a hybrid coil (A3) and other components compensate the imbalance.
Telephone

Innocenzo Manzetti

Innocent ManzettiManzettiManzetti, Innocenzo
1844: Innocenzo Manzetti first mooted the idea of a "speaking telegraph" or telephone. Use of the "speaking telegraph" and "sound telegraph" monikers would eventually be replaced by the newer, distinct name, "telephone".
In 1843 Manzetti first mooted the idea of a "speaking telegraph", or telephone, but didn't pursue the idea at the time.

Public switched telephone network

PSTNtelephone networkpublic telephone network
This gave rise to landline telephone service in which each telephone is connected by a pair of dedicated wires to a local central office switching system, which developed into fully automated systems starting in the early 1900s, and eventually into a worldwide public switched telephone network.
The public switched telephone network (PSTN) is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators, providing infrastructure and services for public telecommunication.

Direct current

DCdirect-currentD.C.
Exchange operation soon resulted in telephones being equipped with a bell in a ringer box, first operated over a second wire, and later over the same wire, but with a condenser (capacitor) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone "on hook"). The off-hook circuitry has a low resistance (less than 300 ohms) which causes a direct current (DC), which comes down the line (C) from the telephone exchange.
Many telephones connect to a twisted pair of wires, and use a bias tee to internally separate the AC component of the voltage between the two wires (the audio signal) from the DC component of the voltage between the two wires (used to power the phone).

VoIP phone

IP PhoneIP PhonesEthernet-based phone
The customer equipment may be an analog telephone adapter (ATA) which interfaces a conventional analog telephone to the IP networking equipment, or it may be an IP Phone that has the networking and interface technology built into the desk-top set and provides the traditional, familiar parts of a telephone, the handset, the dial or keypad, and a ringer in a package that usually resembles a standard telephone set.
VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone.

Cordless telephone

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Cordless telephone
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.

Loudspeaker

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The transmitter converts the sound waves to electrical signals which are sent through a telephone network to the receiving telephone, which converts the signals into audible sound in the receiver or sometimes a loudspeaker. In addition, many computer software vendors and telephony operators provide softphone application software that emulates a telephone by use of an attached microphone and audio headset, or loud speaker.
Johann Philipp Reis installed an electric loudspeaker in his telephone in 1861; it was capable of reproducing clear tones, but also could reproduce muffled speech after a few revisions.

Softphone

soft phonePC-to-PC calling
In addition, many computer software vendors and telephony operators provide softphone application software that emulates a telephone by use of an attached microphone and audio headset, or loud speaker.
Often, a softphone is designed to behave like a traditional telephone, sometimes appearing as an image of a handset, with a display panel and buttons with which the user can interact.