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73-406: In the same manner that early telephone users developed an increasing desire to talk to each other, and expected the service to reach farther out and increase the number of participating private and business customers locally, so did users in different towns and cities desire to call each other. However, the state of the technology initially had limitation in distance. Telephone companies developed on

146-604: A Primary Outlet . The Primary Outlet was responsible for establishing an optimal route either to another Primary Outlet or to a Regional Center . Regional Centers were toll-switches responsible for a yet larger geographic region each. The Regional Centers were strategically located across the nation and each maintained cable routes to all other Regional Centers. In addition, they connected to some Primary Outlets in other regions as well, as traffic demanded, or for alternate routing in case of congestion or technical failures. Telephone A telephone , colloquially referred to as

219-606: A disruptive technology that is rapidly replacing traditional telephone network infrastructure. By January 2005, up to 10% of telephone subscribers in Japan and South Korea had switched to this digital telephone service. A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing." The technology has spawned a new industry comprising many VoIP companies that offer services to consumers and businesses . The reported global VoIP market in October 2021

292-412: A phone , is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound , typically and most efficiently the human voice , into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term

365-483: A subscriber , who had to arrange for a telegraph contractor to construct a line between them, for example, between a home and a 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

438-437: A water microphone , 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. The sound-powered dynamic variants survived in small numbers through the 20th century in military and maritime applications, where its ability to create its own electrical power

511-479: A DC transformer which plugs into a wall AC power outlet. A mobile phone or cellphone or hand phone is a handheld telephone which connects via radio transmissions to a cellular telephone network . The cellular network consists of a network of ground based transmitter/receiver stations with antennas – which are usually located on towers or on buildings – and infrastructure connecting to land-based telephone lines. Analog cellular networks first appeared in 1979, with

584-439: A computer softphone application, utilizing the microphone and headset devices of a personal computer or smartphone. While traditional analog telephones are typically powered from the central office through the telephone line, digital telephones require a local power supply. Internet-based digital service also requires special provisions to provide the service location to the emergency services when an emergency telephone number

657-413: A display for caller ID . In addition, answering machine function may be built in. The cordless handset contains a rechargeable battery , which the base station recharges when the handset rests in its cradle. Muilt-handset systems generally also have additional charging stands. A cordless telephone typically requires a constant electricity supply to power the base station and charger units by means of

730-430: 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, telephones powered from the telephone exchange over the same wires that carried the voice signals became common. Early telephones used a single wire for the subscriber's line, with ground return used to complete

803-417: A handle with the receiver and transmitter attached, now called a handset , 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

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876-400: A local basis, usually one company for each community. As the technology of telephones and of line construction improved, logistical problems stood in the way of rapid expansion. Solutions had to be found for organizational structure, management, business relationships, collaboration, to operate telephone services between or across multiple communities. Theodore Newton Vail , General Manager of

949-591: A satellite phone is that it can be used in such regions where local terrestrial communication infrastructures, such as landline and cellular networks, are not available. Satellite phones are popular on expeditions into remote locations, hunting, fishing, maritime sector, humanitarian missions, business trips, and mining in hard-to-reach areas, where there is no reliable cellular service. Satellite telephones rarely get disrupted by natural disasters on Earth or human actions such as war, so they have proven to be dependable communication tools in emergency situations, when

1022-404: A short distance from the base station. Base stations include a radio transceiver which enables full-duplex, outgoing and incoming signals and speech with the handsets. The base station often includes a microphone, audio amplifier , and a loudspeaker to enable hands-free speakerphone conversations, without needing to use a handset. The base station may also have a numeric keypad for dialing, and

1095-429: A single molded plastic handle, which when not in use was secured in a cradle in the base unit. The circuit diagram of the model 202 shows the direct connection of the transmitter to the line, while the receiver was inductively coupled. In local battery configurations, when the local loop was too long to provide sufficient current from the exchange, the transmitter was powered by a local battery and inductively coupled, while

1168-428: A telephone are a microphone ( transmitter ) to speak into and an earphone ( receiver ) which reproduces the voice at a distant location. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The transmitter converts the sound waves to electrical signals which are sent through the telecommunications system to the receiving telephone, which converts

1241-514: A wired interface, such as USB or Lightning connectors. Smartphones, being able to run apps , have vastly expanded functionality compared to previous mobile phones. Having internet access and built in cameras, smartphones have made video calling readily accessible via IP connections. Smartphones also have access to a large number of web services and web apps, giving them functionality similar to traditional computers, although smartphones are often limited by their relatively small screen size and

1314-400: Is called. A cordless telephone or portable telephone consists of a base station unit and one or more portable cordless handsets . The base station connects to a telephone line, or provides service by voice over IP (VOIP). The handset communicates with the base station via radio frequency signals. A handset's operational range is limited, usually to within the same building or within

1387-529: Is derived from Ancient Greek : τῆλε , romanized :  tēle , lit.   'far' and φωνή ( phōnē , voice ), together meaning distant voice . In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business , government , and in households . The essential elements of

1460-606: Is the address of the call recipient's telephone in the telecommunications system, but other methods existed in the early history of the telephone. The first telephones were directly connected to each other from one customer's office or residence to another customer's location. Being impractical beyond just a few customers, these systems were quickly replaced by manually operated centrally located switchboards . These exchanges were soon connected together, eventually forming an automated, worldwide public switched telephone network . For greater mobility, various radio systems were developed in

1533-612: The American Bell Telephone Company , created the vision for this endeavor. The first long-distance experiment was the Boston–New York telephone line. Vail suggested that a company separate from the four or five affected local telephone companies should be responsible for the construction and operation of the line. Approved in 1880, he directed American Bell Telephone to incorporate a new entity in New York,

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1606-663: The Earth instead of terrestrial cell sites , as cellphones do. Therefore, they can work in most geographic locations on the Earth's surface, as long as open sky and the line-of-sight between the phone and the satellite is provided. Depending on the architecture of a particular system, coverage may include the entire Earth or only specific regions. Satellite phones provide similar functionality to terrestrial mobile telephones; voice calling , text messaging , and low-bandwidth Internet access are supported through most systems. The advantage of

1679-573: The Kingsbury Commitment . On December 19, 1913, in a letter by Nathan C. Kingsbury to the U.S. Attorney General, AT&T conceded to restrictions in the acquisition of independent companies, and agreed to the divestiture of Western Union . AT&T's telephone operations thereby essentially became a government-sanctioned natural monopoly , because an essential feature of this commitment was that independent telephony operators were permitted to "secure for their subscribers toll service over

1752-572: The Reis telephone , in c. 1860. His device appears to be the first device based on the conversion of sound into electrical impulses. The term telephone was adopted into the vocabulary of many languages. It is derived from the Greek : τῆλε , tēle , "far" and φωνή, phōnē , "voice", together meaning "distant voice". Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio , television ,

1825-426: The light bulb , and the computer , several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas. New controversies over the issue still arise from time to time. 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. Alexander Graham Bell

1898-483: The model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963. The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in

1971-447: The smartphone , the dominant type of telephone in the world today. Before the development of the electric telephone, the term telephone was applied to other inventions, and not all early researchers of the electrical device used the term. Perhaps the earliest use of the word for a communications system was the telephon created by Gottfried Huth in 1796. Huth proposed an alternative to the optical telegraph of Claude Chappe in which

2044-429: The 1890s to reduce electrical resistance substantially. Copper wire was drawn to a diameter of up to 1/6 inch (165 mils). The glass insulators on the pole cross-arms were spaced at about 12 inches (30cm) apart. Typically up to five wire pairs were installed on each crossarm , and multiple cross-arms could be installed on each pole. The practical limit in distance of telephone communication via open-wire transmission

2117-658: The 1990s, mobile phones have gained other features which are not directly related to their primary function as telephones. These include text messaging, calendars, alarm clocks, personal schedulers, cameras, music players, games and later, internet access and smartphone functionality. Nearly all mobile phones have the ability to send text messages to other users via the SMS (Short Message Service) protocol. The multimedia messaging service (MMS) protocol enables users to send and receive multimedia content, such as photos, audio files and video files. As their functionality has increased over

2190-695: The Atlantic Ocean and the Pacific Ocean. This connected a large customer base in the far west beyond the Rocky Mountains to the AT&;T Long Lines network. Open wire , while marginally increasing in installations in the 1920s, was increasingly supplemented with cable routes, experiencing dramatic growth, but also with carrier transmission, a new development which multiplexed multiple communication channels, at times 200 or 300 circuits, on

2263-691: The Inter-State Telephone Company for the construction of the first section starting in Boston, with the grant of a license by American Bell. An additional company was formed in Connecticut to complete the line to New York. The Boston–New York toll line opened in 1884, Building additional long-distance lines would require enormous amounts of financing. However, the Massachusetts legislature rejected an application to increase

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2336-565: The Trans-Canada Telephone System, having been planned immediately after the formation of the Telephone Association of Canada in 1921. A systematic approach was needed to limit the number of intermediate toll offices that relayed the calls across the country, to further reduce set-up time, and to establish technical parameters for interchange points to assure a certain level of circuit quality. In 1929,

2409-493: The advent of smartphones, mobile phone manufacturers have also included consumer electronics companies, such as Apple , Samsung and Xiaomi . As of 2022, most mobile phones are smartphones, being a combination of a mobile phone and a personal computing device in the same unit. Most smartphones are primarily operated using a graphical user interface and a touch screen. Many phones have a secondary voice user interface, such as Siri on Apple iPhones , which can operate many of

2482-426: The beginning of the 20th century did not place long-distance calls from their own telephones but made an appointment and were connected with the assistance of a telephone operator. 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 202-type desk set. A carbon granule transmitter and electromagnetic receiver were united in

2555-513: The bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone " on hook "). Telephones connected to the earliest Strowger switch 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. Large wall telephones in the early 20th century usually incorporated the bell, and separate bell boxes for desk phones dwindled away in

2628-439: The circuit (as used in telegraphs ). The earliest dynamic telephones also had only one port opening for sound, with the user alternately listening and speaking (or rather, shouting) into the same hole. Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive. At first, the benefits of a telephone exchange were not exploited. Instead, telephones were leased in pairs to

2701-589: The corporate capitalization of American Bell. With the experience of incorporating Inter-State Telephone in New York, the company formed a new subsidiary in New York City, the American Telephone and Telegraph Company , on March 3, 1885, with Theodore Vail as its first president. The new company had the mandate to construct and operate long-distance telephone lines, and would negotiate and facilitate inter-connections to local telephones companies under

2774-420: The device's functions, as well as enabling users to use spoken commands to interact with the internet. Typically alphanumeric text input is accomplished via an on-screen virtual keyboard, although some smartphones have a small physical keyboard. Smartphones offer the ability to access internet data through the cellular network and via wi-fi, and usually allow direct connectivity to other devices via Bluetooth or

2847-524: The first digital cellular networks appearing in the early 1990s. Mobile phones require a SIM card to be inserted into the phone. The SIM card is a small PVC card containing a small integrated circuit which stores the user's international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers to the cellular network. Mobile phones generally incorporate an LCD or OLED display, with some types, such as smartphones, having touch screens. Since

2920-582: The general market, so that independent operators could buy compatible apparatus. Vail organized a distinct research division within Western Electric, the later Bell Laboratories , to focus on basic research and development to solve the problems encountered in improving the technology of telephony. These efforts and this vision were communicated to the public by marketing campaigns under the slogan One System — One Policy — Universal Service . In 1913, AT&T settled pending anti-trust challenges in

2993-430: The handset was on the cradle. In the 1930s, telephone sets were developed that combined the bell and induction coil with the desk set, obviating a separate ringer box. The rotary dial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems remained even into the 1960s. After World War II, the telephone networks saw rapid expansion and more efficient telephone sets, such as

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3066-476: The lead of American Telephone and Telegraph. Such a nationwide network required technical standards that were understood and accepted by all cooperating participants in the industry. The Western Electric Company , the Bell System's sole and dedicated manufacturing unit, which was previously not permitted by company policy to sell outside the Bell System, was now directed to advertise and sell its products to

3139-477: The lines of the companies in the Bell System." removing the barriers to a nationwide telephone system that would have no competitors. While the Bell System had a specialized division, Long Lines , to interconnect the local telephone networks of its Associated Companies, no such unifying driving force existed in the independent telephone industry. Telephone companies negotiated interconnection with neighboring businesses and built localized toll networks that addressed

3212-516: The local communications system can be compromised. Open wire Open wire was an early transmission technology in telecommunication , first used in telegraphy . It consisted of pairs of electric wire strung on a pole line between communities, towns, and cities. The wire of the transmission line was attached to the cross-arms of each pole with glass insulators. It was originally manufactured from iron or steel, but developments in annealing of copper made it possible to use this metal by

3285-428: The long-distance transmission networks, over the next several decades. With the development of stored program control and MOS integrated circuits for electronic switching systems , and new transmission technologies such as pulse-code modulation (PCM), telephony gradually evolved towards digital telephony , which improved the capacity, quality, and cost of the network. Integrated Services Digital Network (ISDN)

3358-433: The mid-20th century for transmission between mobile stations on ships and in automobiles. Hand-held mobile phones were introduced for personal service starting in 1973. In later decades, the analog cellular system evolved into digital networks with greater capability and lower cost. Convergence in communication services has provided a broad spectrum of capabilities in cell phones, including mobile computing, giving rise to

3431-435: The middle of the century. Rural and other telephones that were not on a common battery exchange had a magneto 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. Some local farming communities that were not connected to the main networks set up barbed wire telephone lines that exploited the existing system of field fences to transmit

3504-418: The nation that had trunks for connecting to other communities. The systems were designated as toll centers to which all local calls were routed that had to be connected to another toll center closer to the destination of each long distance call. The technological improvements since the transcontinental transmission line of 1914 required a new methodology and plan of managing the traffic. The purpose of this plan

3577-495: The operators in the signaling towers would shout to each other by means of what he called "speaking tubes", but would now be called giant megaphones . A communication device for sailing vessels, called telephone , was invented by Captain John Taylor in 1844. This instrument used four air horns to communicate with vessels in foggy weather. Johann Philipp Reis used the term in reference to his invention, commonly known as

3650-409: The receiver was included in the local loop. The coupling transformer and the ringer were mounted in a separate enclosure, called the subscriber set. The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line one to ten times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while

3723-460: The regional needs of their customers. The interconnection agreements with the Bell System provided access beyond these networks. Long-distance toll lines for transmission of telephone calls were almost entirely open-wire pair installations early in the 20th century. By 1911, the Long Lines network had reached from New York as far west as Denver, using loading coil circuits, but this distance

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3796-527: The results of this research outlined a new fundamental layout of the toll plant ( circuit ) and the routing of toll calls. This first continental toll switching system became known as the General Toll Switching Plan . During the growth of telephone service since the first installations of telephone exchanges and the development of advanced manual and automatic switching systems, approximately 2,500 switching systems had been established in

3869-399: The same physical cable medium. By 1925, the extent and quality of transmission lines in the nation was good enough, so that telephone subscribers could place telephone calls to almost anywhere in the continental United States. However, set-up times for calls were typically still long, and callers often had to hang up after ordering a call with an operator, who called them back when the circuit

3942-467: The second time, having left the company previously in 1887. Immediately, he steered the company into a new direction. He refined a vision of service, shaped new goals for supporting technological progress, and reorganized the company to facilitate his ideas. He envisioned universal telephone service as a public utility, and the future of the American telephone industry as a unified system of companies under

4015-403: The signal. 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

4088-406: The signals into audible sound in the receiver or sometimes a loudspeaker . Telephones permit transmission in both directions simultaneously. Most telephones also contain an alerting feature, such as a ringer or a visual indicator, to announce an incoming telephone call. Telephone calls are initiated most commonly with a keypad or dial, affixed to the telephone, to enter a telephone number , which

4161-510: The size of their keyboards. Typically, smartphones feature such tools as cameras, media players, web browsers, email clients, interactive maps, satellite navigation and a variety of sensors, such as a compass , accelerometers and GPS receivers . In addition to voice calls, smartphone users commonly communicate using a wide variety of messaging formats, including SMS, MMS, email, and various proprietary messaging services, such as iMessage and various social media platforms. In 2002, only 10% of

4234-517: The telephone switch, which allowed for the formation of telephone exchanges , and eventually networks. In the United Kingdom, the blower is used as a slang term for a telephone. The term came from navy slang for a speaking tube . In the U.S., a somewhat dated slang term refers to the telephone as "the horn," as in "I couldn't get him on the horn," or "I'll be off the horn in a moment." Early telephones were technically diverse. Some used

4307-408: The telephone to work a fluctuating current reproduced sounds the best. The fluctuating currents became the basis for the working telephone, creating Bell's patent. That first patent by Bell was the master patent of the telephone, from which other patents for electric telephone devices and features flowed. In 1876, shortly after Bell's patent application, Hungarian engineer Tivadar Puskás proposed

4380-544: The umbrella of the Bell System. This original purpose of the business would later be delegated to a division called Long Lines . By 1892, the company's long-distance network reached Chicago, but the New York–Chicago line did not become commercially successful until after 1900, and the invention of the loading coil . In 1907, Theodore Vail became president of the American Telephone and Telegraph Company for

4453-456: The world's population used mobile phones and by 2005 that percentage had risen to 46%. By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers. A satellite telephone, or satphone, is a type of mobile phone that connects to other phones or the telephone network by radio link through satellites orbiting

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4526-517: The years, many types of mobile phone, notably smartphones, require an operating system to run. Popular mobile phone operating systems in the past have included Symbian , Palm OS , BlackBerry OS and mobile phone versions of Windows . As of 2022, the most used operating systems are Google's Android and Apple's iOS . Before the era of smartphones, mobile phones were generally manufactured by companies specializing in telecommunications equipment, such as Nokia , Motorola , and Ericsson . Since

4599-481: Was $ 85.2 billion with a projection of $ 102.5 billion by 2026. IP telephony uses high-bandwidth Internet connections and specialized customer premises equipment to transmit telephone calls via the Internet, or any modern private data network. The customer equipment may be an analog telephone adapter (ATA) which translates the signals of a conventional analog telephone; an IP Phone , a dedicated standalone device; or

4672-404: Was able to effect several rate cuts in long-distance service in just a few years. However, the growth also caused major construction problems in the layout of the cable plant. By 1930, the long-haul business was handled by about 2,500 toll centers, out of 6,400 central offices in the United States and eastern Canada. The long-haul build-out in the United States was paralleled by the construction of

4745-570: 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 which was an impedance matching transformer to make it compatible with 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. Early telephones were locally powered, using either

4818-447: Was established. In 1925, the average time to establish connections was still over seven minutes, but this improved to about two and one half minutes by 1929. The extensions of the nationwide interconnections led to rapid increase in traffic. In 1915, less than a quarter billion toll messages had been carried in the Bell System. Over the next fifteen years, this more than quadrupled to over one trillion. A increasing fraction of this traffic

4891-411: Was for the long-haul routes in the network, between the largest cities in the nation and via the transcontinental routes. As a consequence, the build-out of long-haul plant was emphasized in investments, resulting in better quality circuits for long-haul transmissions. Due to the investments in the plant, the average speed of establishing connections was steadily decreasing throughout the 1920s, AT&T

4964-521: Was launched in the 1980's, providing businesses and consumers with access to digital telephony services such as data, voice, video , and fax services. The development of digital data communications methods made it possible to digitize voice and transmit it as real-time data across computer networks and the Internet , giving rise to the field of Internet Protocol (IP) telephony, also known as voice over Internet Protocol (VoIP). VoIP has proven to be

5037-406: 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 or " ringer box ". In phones connected to common battery exchanges, the ringer 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

5110-407: Was not slow in appreciating the potential. 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 in a ringer box , first operated over a second wire, and later over the same wire, but with a condenser ( capacitor ) in series with

5183-550: Was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. Before Bell's patent, the telephone transmitted sound in a way that was similar to the telegraph. This method used vibrations and circuits to send electrical pulses, but was missing key features. Bell found that this method produced a sound through intermittent currents, but in order for

5256-498: Was the limit for communication without amplification. The research efforts at Western Electric, committed to by Vail in c. 1909, into the principles of the electron tube recently invented by Lee de Forest , the Audion , and its efficient manufacture made it possible to build signal repeaters that extended the transmission distance of toll lines. In 1914, AT&T succeeded in the first transcontinental transmission line spanning between

5329-539: Was to provide systematically a basic layout of the plant compatible with the highest practicable standards of service achievable within given economic goals. The layout of cabling and major toll centers needed optimization in the number of switching steps required along a given route to connect any two telephones on the continent. The General Toll Switching Plan organized these local toll centers into geographical groups associated with region within which all toll centers forwarded calls to destinations outside their territory to

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