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  • Telephone

    telephone, colloquially referred to as a 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 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 is derived from Ancient Greek: τῆλε, romanizedtēlelit.‘far’ and φωνή (phōnēvoice), together meaning distant voice.[1]

    An old rotary dial telephone

    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.[2] This instrument was further developed by many others, and became rapidly indispensable in businessgovernment, and in households.

    The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice at a distant location.[3] 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 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 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 the mid-20th century for transmission between mobile stations on ships and in automobiles.

    AT&T push button telephone made by Western Electric, model 2500 DMG black, 1980

    Handheld 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 the smartphone, the dominant type of telephone in the world today.

    Modern telephones exist in various forms and are implemented through different systems, including fixed-linecellularsatellite, and Internet-based devices, all of which are integrated into the public switched telephone network (PSTN). This interconnected system allows any telephone, regardless of its underlying technology or geographic location, to reach another through a unique telephone number. While mobile and landline services are fully integrated into the global telecommunication network, some Internet-based services, such as VoIP, may not always be directly connected to the PSTN, though they still allow communication across different systems when a connection is made.

    Early history

    Main article: History of the telephone

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

    Alexander Graham Bell’s Telephone Patent Drawing
    Replica of the telettrofono at Museo Nazionale Scienza e Tecnologia Leonardo da Vinci of MilanItaly, invented by Antonio Meucci and credited by several sources as the first telephone.[4]
    Bell placing the first New York to Chicago telephone call in 1892

    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 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.[5] 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.[6][7]

    Johann Philipp Reis used the term in reference to his invention, commonly known as 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 radiotelevision, 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 BourseulAntonio MeucciJohann Philipp ReisAlexander Graham Bell, and Elisha Gray, amongst others, have all been credited with the invention of the telephone.[8][9]

    Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876.[10] 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 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.[11] That first patent by Bell was the master patent of the telephone, from which other patents for electric telephone devices and features flowed.[12]

    In 1876, shortly after Bell’s patent application, Hungarian engineer Tivadar Puskás proposed the telephone switch, which allowed for the formation of telephone exchanges, and eventually networks.[13]

    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.[14] 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.”[15]

    Timeline of early development

    For a chronological guide, see Timeline of the telephone.

    Reis’s telephone around 1861, first device called telephone[16]
    Bell’s first telephone transmitter, ca. 1876, reenacted 50 years later
    Acoustic telephone ad, The Consolidated Telephone Co., Jersey City, New Jersey, 1886
    1896 telephone from Sweden
    Wooden wall telephone with a hand-cranked magneto generator
    • 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”.
    • 26 August 1854: Charles Bourseul published an article in the magazine L’Illustration (Paris): “Transmission électrique de la parole” (electric transmission of speech), describing a “make-and-break” type telephone transmitter later created by Johann Reis.
    • 26 October 1861: Johann Philipp Reis (1834–1874) publicly demonstrated the Reis telephone before the Physical Society of Frankfurt.[9] It was the first device to transmit a voice via electronic signals and for that the first modern telephone.[17][18] Reis also coined the term.[19] He used his telephone to transmit the phrase “Das Pferd frisst keinen Gurkensalat” (“The horse does not eat cucumber salad”).
    • 22 August 1865, La Feuille d’Aoste reported “It is rumored that English technicians to whom Manzetti illustrated his method for transmitting spoken words on the telegraph wire intend to apply said invention in England on several private telegraph lines”.[citation needed] However, telephones would not be demonstrated there until 1876, with a set of telephones from Bell.
    • 28 December 1871: Antonio Meucci files patent caveat No. 3335 in the U.S. Patent Office, titled “Sound Telegraph”, describing communication of voice between two people by wire. A patent caveat was not an invention patent award, but only an unverified notice filed by an individual that he or she intends to file a patent application in the future.
    • 1874: Meucci, after having renewed the caveat for two years does not renew it again, and 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: Elisha Gray invents a liquid transmitter for use with the telephone but does not build one.
    • 14 February 1876: Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.
    • 14 February 1876: Alexander Graham Bell applies for the patent “Improvements in Telegraphy”, for electromagnetic telephones using what is now called amplitude modulation (oscillating current and voltage) but which he referred to as “undulating current”.
    • 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: Thomas Edison files a patent application for a carbon (graphite) transmitter. It was published as No. 474,230 on 3 May 1892, after a 15-year delay because of litigation. Edison was granted patent 222,390 for a carbon granules transmitter in 1879.

    Early commercial instruments

    Early telephones were technically diverse. Some used 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 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 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 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 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 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 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 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 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 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“.[20] 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 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 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.[21]

    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 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 the receiver was included in the local loop.[22] 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 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. The village of Bryant Pond, Maine is believed to be the last telephone exchange in the U.S. to convert from magneto to direct-dial service on October 11, 1983.[23] 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. A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by American Telephone & Telegraph Company (AT&T) in 1963.[24]

    Sound-powered telephones

    Modern emergency telephone powered by sound alone

    Main article: Sound-powered telephone

    A sound-powered telephone is a telephone which transmits voice communication by wire, powered by the energy of the sound waves of the operator speaking.

    Principle of operation

    A moving-coil microphone converts the sound waves into an electrical signal, which is then converted back into sound waves at the receiver’s end. Similar to early regular landline telephones, operators of sound-powered telephones generally alert the receiver of a call using a hand-cranked generator (magneto), which generates an electrical current which activates a buzzer at the receiver’s end, sometimes known as a howler or growler. Some telephone systems can use external electrical power to operate ringers or amplifiers, but will revert to sound-powered communications in the event of failure of the external power supply.[25] Stations are usually connected via twisted pair wires to reduce electrical interference, and can be positioned at considerable distances from each other in the order of several kilometers. Using 1mm core diameter twisted-pair wiring, some sound-powered telephone systems can operate a pair of handsets positioned up to 48km (30 miles) apart.[26]

    Applications

    U.S. Navy petty officer uses a sound-powered telephone during a general quarters drill.

    Because sound-powered telephones do not require external electrical power, they are used where reliable communications are vital even in event of loss of power. They are often used for communications in airports, railways and public utilities, mining, ski slopes, bridges, sporting arenas and shipyards. Because they operate at low voltages, they are suitable for use in situations where there is a risk of explosions or fire, such as chemical plants, oil and gas works, arsenals, mines and quarries.[27] They are frequently used aboard ships, especially naval vessels, and in land military communications.

    Aboard naval vessels, sound-powered telephones generally have auxiliary wiring circuits routed through the ship, to reduce the likelihood that all circuits will be rendered inoperable by battle damage.[28]

    Digital telephones and voice over IP

    Main articles: Digital telephony and Voice over IP

    An IP desktop telephone attached to a computer network
    Fixed telephone lines per 100 inhabitants 1997–2007

    The invention of the transistor in 1947 dramatically changed the technology used in telephone systems and in 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.[29]

    Integrated Services Digital Network (ISDN) was launched in the 1980’s, providing businesses and consumers with access to digital telephony services such as data, voice, video, and fax services.[30]

    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 a disruptive technology that is rapidly replacing traditional telephone network infrastructure.[31]

    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.”[32] 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 was $85.2 billion with a projection of $102.5 billion by 2026.[33]

    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 a computer softphone application, utilizing the microphone and headset devices of a personal computer or smartphone.[34]

    In recent years, VoIP technology has evolved to integrate with mobile networks, including Voice over LTE (VoLTE) and Voice over 5G (Vo5G), enabling seamless voice communication over mobile data networks. These advancements have made VoIP not only a primary method for Internet-based communication but also a central feature of modern mobile communication infrastructure.[35]

    While traditional analog telephones are typically powered from the central office through the telephone line, digital telephones require a local power supply.[36] Internet-based digital service also requires special provisions to provide the service location to the emergency services when an emergency telephone number is called.[37]

    Cordless telephones

    Main article: Cordless telephone

    A cordless telephone system consisting of a handset resting on a base station (left) and a second handset resting on a battery charger unit (right)

    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 a short distance from the base station.

    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 a display for caller ID. In addition, answering machine function may be built in.[38]

    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 a DC transformer which plugs into a wall AC power outlet.[38]

    Mobile phones

    Main article: Mobile phone

    Two decades of evolution of mobile phones, from a 1992 Motorola 8900X-2 to the 2014 iPhone 6 Plus
    A typical SIM card (mini-SIM with a cutout to convert the card to micro-SIM size)
    An SMS message written on a Motorola RAZR V3

    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 the global telecommunications network.[39] Analog cellular networks first appeared in 1979, followed by the introduction of digital cellular networks in the early 1990s, marking the beginning of the GSM standard. [40] Over time, these networks evolved, with each new generation (2G3G4G, and beyond) offering improved data transmission capabilities and more advanced features for mobile communication.

    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 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 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 SymbianPalm OSBlackBerry OS and mobile phone versions of Windows. As of 2022, the most used operating systems are Google’s Android and Apple’s iOS.[41][42]

    Before the era of smartphones, mobile phones were generally manufactured by companies specializing in telecommunications equipment, such as NokiaMotorola, and Ericsson. Since the advent of smartphones, mobile phone manufacturers have also included consumer electronics companies, such as AppleSamsung and Xiaomi.[42]

    Smartphones

    Main article: Smartphone

    A smartphone with a touchscreen user interface, held in landscape orientation

    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 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 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 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 compassaccelerometers 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.

    Mobile phone usage

    In 2002, only 10% of the world’s population used mobile phones and by 2005 that percentage had risen to 46%.[43] 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.[44]

    Satellite phones

    Main article: Satellite phone

    First generation late 1990s Iridium satellite phone

    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 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 callingtext messaging, and low-bandwidth Internet access are supported through most systems. The advantage of 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.[45] 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 the local communications system can be compromised.[46]

  • Mobile Phone

    mobile phone, or cell phone,[a] is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones (landline phones). This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as ‘cell phones’ in North America.

    Two decades of evolution of mobile phones, from a 1992 Motorola DynaTAC 8000X to the 2014 iPhone 6 Plus

    Beyond traditional voice communication, digital mobile phones have evolved to support a wide range of additional services. These include text messagingmultimedia messagingemail, and internet access (via LTE5G NR or Wi-Fi), as well as short-range wireless technologies like Bluetoothinfrared, and ultra-wideband (UWB).

    Mobile phones also support a variety of multimedia capabilities, such as digital photographyvideo recording, and gaming. In addition, they enable multimedia playback and streaming, including video content, as well as radio and television streaming. Furthermore, mobile phones offer satellite-based services, such as navigation and messaging, as well as business applications and payment solutions (via near-field communication (NFC)).

    Mobile phones offering only basic features are often referred to as feature phones (slang“dumbphones”), while those with advanced computing power are known as smartphones.[1]

    The first handheld mobile phone was demonstrated by Martin Cooper of Motorola in New York City on 3 April 1973, using a handset weighing c. 2 kilograms (4.4 lbs).[2] In 1979, Nippon Telegraph and Telephone (NTT) launched the world’s first cellular network in Japan.[3] In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to over seven billion; enough to provide one for every person on Earth.[4] In the first quarter of 2016, the top smartphone developers worldwide were SamsungApple and Huawei; smartphone sales represented 78 percent of total mobile phone sales.[5] For feature phones as of 2016, the top-selling brands were Samsung, Nokia and Alcatel.[6]

    History

    Main article: History of mobile phones

    Martin Cooper of Motorola, shown here in a 2007 reenactment, made the first publicized handheld mobile phone call on a prototype DynaTAC model on 3 April 1973.

    A handheld mobile radio telephone service was envisioned in the early stages of radio engineering. In 1917, Finnish inventor Eric Tigerstedt filed a patent for a “pocket-size folding telephone with a very thin carbon microphone”. Early predecessors of cellular phones included analog radio communications from ships and trains. The race to create truly portable telephone devices began after World War II, with developments taking place in many countries. The advances in mobile telephony have been traced in successive “generations”, starting with the early zeroth-generation (0G) services, such as Bell System‘s Mobile Telephone Service and its successor, the Improved Mobile Telephone Service. These 0G systems were not cellular, supported a few simultaneous calls, and were very expensive.

    The Motorola DynaTAC 8000X. In 1983, it became the first commercially available handheld cellular mobile phone.

    The first handheld cellular mobile phone was demonstrated by John F. Mitchell[11][12] and Martin Cooper of Motorola in 1973, using a handset weighing 2 kilograms (4.4 lb).[2] The first commercial automated cellular network (1Ganalog was launched in Japan by Nippon Telegraph and Telephone in 1979. This was followed in 1981 by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway, and Sweden.[13] Several other countries then followed in the early to mid-1980s. These first-generation (1G) systems could support far more simultaneous calls but still used analog cellular technology. In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone.

    In 1991, the second-generation (2G) digital cellular technology was launched in Finland by Radiolinja on the GSM standard. This sparked competition in the sector as the new operators challenged the incumbent 1G network operators. The GSM standard is a European initiative expressed at the CEPT (“Conférence Européenne des Postes et Telecommunications”, European Postal and Telecommunications conference). The Franco-German R&D cooperation demonstrated the technical feasibility, and in 1987, a Memorandum of Understanding was signed between 13 European countries that agreed to launch a commercial service by 1991. The first version of the GSM standard had 6,000 pages. The IEEE and RSE awarded Thomas Haug and Philippe Dupuis the 2018 James Clerk Maxwell medal for their contributions to the first digital mobile telephone standard.[14] In 2018, the GSM was used by over 5 billion people in over 220 countries. The GSM (2G) has evolved into 3G, 4G and 5G. The standardization body for GSM started at the CEPT Working Group GSM (Group Special Mobile) in 1982 under the umbrella of CEPT. In 1988, ETSI was established, and all CEPT standardization activities were transferred to ETSI. Working Group GSM became Technical Committee GSM. In 1991, it became Technical Committee SMG (Special Mobile Group) when ETSI tasked the committee with UMTS (3G). In addition to transmitting voice over digital signals, the 2G network introduced data services for mobile, starting with SMS text messages, then expanding to Multimedia Messaging Service (MMS), and mobile internet with a theoretical maximum transfer speed of 384 kbit/s (48 kB/s).

    Dupuis and Haug during a GSM meeting in Belgium, April 1992
    Personal Handy-phone System mobiles and modems, 1997–2003

    In 2001, the third-generation (3G) was launched in Japan by NTT DoCoMo on the WCDMA standard.[15] This was followed by 3.5G or 3G+ enhancements based on the high-speed packet access (HSPA) family, allowing UMTS networks to have higher data transfer speeds and capacity. 3G is able to provide mobile broadband access of several Mbit/s to smartphones and mobile modems in laptop computers. This ensures it can be applied to mobile Internet access, VoIP, video calls, and sending large e-mail messages, as well as watching videos, typically in standard-definition quality.

    By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications, such as streaming media.[16] Consequently, the industry began looking to data-optimized fourth-generation (4G) technologies, with the promise of speed improvements up to tenfold over existing 3G technologies. The first publicly available LTE service was launched in Scandinavia by TeliaSonera in 2009. In the 2010s, 4G technology has found diverse applications across various sectors, showcasing its versatility in delivering high-speed wireless communication, such as mobile broadband, the internet of things (IoT), fixed wireless access, and multimedia streaming (including music, video, radio, and television).

    Deployment of fifth-generation (5G) cellular networks commenced worldwide in 2019. The term “5G” was originally used in research papers and projects to denote the next major phase in mobile telecommunication standards beyond the 4G/IMT-Advanced standards. The 3GPP defines 5G as any system that adheres to the 5G NR (5G New Radio) standard. 5G can be implemented in low-band, mid-band or high-band millimeter-wave, with download speeds that can achieve gigabit-per-second (Gbit/s) range, aiming for a network latency of 1 ms. This near-real-time responsiveness and improved overall data performance are crucial for applications like online gamingaugmented and virtual realityautonomous vehicles, IoT, and critical communication services.

    Types

    Active mobile broadband subscriptions per 100 inhabitants[17]

    Smartphone

    Main article: Smartphone

    Smartphones are defined by their advanced computing capabilities, which include internet connectivity and access to a wide range of applications. The International Telecommunication Union measures those with Internet connection, which it calls Active Mobile-Broadband subscriptions (which includes tablets, etc.). In developed countries, smartphones have largely replaced earlier mobile technologies, while in developing regions, they account for around 50% of all mobile phone usage.

    Feature phone

    Main article: Feature phone

    Feature phone is a term typically used as a retronym to describe mobile phones which are limited in capabilities in contrast to a modern smartphone. Feature phones typically provide voice calling and text messaging functionality, in addition to basic multimedia and Internet capabilities, and other services offered by the user’s wireless service provider. A feature phone has additional functions over and above a basic mobile phone, which is only capable of voice calling and text messaging.[18][19] Feature phones and basic mobile phones tend to use a proprietary, custom-designed software and user interface. By contrast, smartphones generally use a mobile operating system that often shares common traits across devices.

    Infrastructure

    Main articles: Cellular network and Wi-Fi

    Cellular networks work by only reusing radio frequencies (in this example frequencies f1–f4) in non adjacent cells to avoid interference

    The critical advantage that modern cellular networks have over predecessor systems is the concept of frequency reuse allowing many simultaneous telephone conversations in a given service area. This allows efficient use of the limited radio spectrum allocated to mobile services, and lets thousands of subscribers converse at the same time within a given geographic area.

    Former systems would cover a service area with one or two powerful base stations with a range of up to tens of kilometers’ (miles), using only a few sets of radio channels (frequencies). Once these few channels were in use by customers, no further customers could be served until another user vacated a channel. It would be impractical to give every customer a unique channel since there would not be enough bandwidth allocated to the mobile service. As well, technical limitations such as antenna efficiency and receiver design limit the range of frequencies a customer unit could use.

    cellular network mobile phone system gets its name from dividing the service area into many small cells, each with a base station with (for example) a useful range on the order of a kilometer (mile). These systems have dozens or hundreds of possible channels allocated to them. When a subscriber is using a given channel for a telephone connection, that frequency is unavailable for other customers in the local cell and in the adjacent cells. However, cells further away can re-use that channel without interference as the subscriber’s handset is too far away to be detected. The transmitter power of each base station is coordinated to efficiently service its own cell, but not to interfere with the cells further away.

    Automation embedded in the customer’s handset and in the base stations control all phases of the call, from detecting the presence of a handset in a service area, temporary assignment of a channel to a handset making a call, interface with the land-line side of the network to connect to other subscribers, and collection of billing information for the service. The automation systems can control the “hand off” of a customer handset moving between one cell and another so that a call in progress continues without interruption, changing channels if required. In the earliest mobile phone systems by contrast, all control was done manually; the customer would search for an unoccupied channel and speak to a mobile operator to request connection of a call to a landline number or another mobile. At the termination of the call the mobile operator would manually record the billing information.

    In order to handle the high traffic, multiple towers can be set up in the same area (using different frequencies). This can be done permanently or temporarily such as at special events or in disasters. Cell phone companies will bring a truck with equipment to host the abnormally high traffic.

    Capacity was further increased when phone companies implemented digital networks. With digital, one frequency can host multiple simultaneous calls.

    Additionally, short-range Wi-Fi infrastructure is often used by smartphones as much as possible as it offloads traffic from cell networks on to local area networks.

    Hardware

    Main article: Mobile phone features

    The common components found on all mobile phones are:

    Low-end mobile phones are often referred to as feature phones and offer basic telephony. Handsets with more advanced computing ability through the use of native software applications are known as smartphones. The first GSM phones and many feature phones had NOR flash memory, from which processor instructions could be executed directly in an execute in place architecture and allowed for short boot times. With smartphones, NAND flash memory was adopted as it has larger storage capacities and lower costs, but causes longer boot times because instructions cannot be executed from it directly, and must be copied to RAM memory first before execution.[20]

    Central processing unit

    Mobile phones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments.

    Mobile CPU performance depends not only on the clock rate (generally given in multiples of hertz)[21] but also the memory hierarchy also greatly affects overall performance. Because of these problems, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications.

    Display

    Main article: Display device

    One of the main characteristics of phones is the screen. Depending on the device’s type and design, the screen fills most or nearly all of the space on a device’s front surface. Many smartphone displays have an aspect ratio of 16:9, but taller aspect ratios became more common in 2017.

    Screen sizes are often measured in diagonal inches or millimeters; feature phones generally have screen sizes below 90 millimetres (3.5 in). Phones with screens larger than 130 millimetres (5.2 in) are often called “phablets.” Smartphones with screens over 115 millimetres (4.5 in) in size are commonly difficult to use with only a single hand, since most thumbs cannot reach the entire screen surface; they may need to be shifted around in the hand, held in one hand and manipulated by the other, or used in place with both hands. Due to design advances, some modern smartphones with large screen sizes and “edge-to-edge” designs have compact builds that improve their ergonomics, while the shift to taller aspect ratios have resulted in phones that have larger screen sizes whilst maintaining the ergonomics associated with smaller 16:9 displays.[22][23][24]

    Liquid-crystal displays are the most common; others are IPSLEDOLED, and AMOLED displays. Some displays are integrated with pressure-sensitive digitizers, such as those developed by Wacom and Samsung,[25] and Apple’s “3D Touch” system.

    Sound

    In sound, smartphones and feature phones vary little. Some audio-quality enhancing features, such as Voice over LTE and HD Voice, have appeared and are often available on newer smartphones. Sound quality can remain a problem due to the design of the phone, the quality of the cellular network and compression algorithms used in long-distance calls.[26][27] Audio quality can be improved using a VoIP application over WiFi.[28] Cellphones have small speakers so that the user can use a speakerphone feature and talk to a person on the phone without holding it to their ear. The small speakers can also be used to listen to digital audio files of music or speech or watch videos with an audio component, without holding the phone close to the ear.

    Battery

    The typical lifespan of a mobile phone battery is approximately two to three years, although this varies based on usage patterns, environmental conditions, and overall care. Most modern mobile phones use lithium-ion (Li-ion) batteries, which are designed to endure between 500 and 2,500 charge cycles. The exact number of cycles depends on factors such as charging habits, operating temperature, and battery management systems.[29]

    Li-ion batteries gradually degrade over time due to chemical aging, leading to reduced capacity and performance, often noticeable after one or two years of regular use. Unlike older battery types, such as nickel-metal hydride (Ni-MH), Li-ion batteries do not need to be fully discharged to maintain their longevity. In fact, they perform best when kept between 30% and 80% of their full charge.[30] While practices such as avoiding excessive heat and minimizing overcharging can help preserve battery health, many modern devices include built-in safeguards.[31] These safeguards, typically managed by the phone’s internal battery management system (BMS), prevent overcharging by cutting off power once the battery reaches full capacity. Additionally, most contemporary chargers and devices are designed to regulate charging to minimize stress on the battery. Therefore, while good charging habits can positively impact battery longevity, most users benefit from these integrated protections, making battery maintenance less of a concern in day-to-day use.[32][33]

    Future mobile phone batteries are expected to utilize advanced technologies such as silicon-carbon (Si/C) batteries and solid-state batteries, which promise to offer higher energy densities, longer lifespans, and improved safety compared to current lithium-ion batteries.[34][35][36]

    SIM card

    Main articles: SIM card and Removable User Identity Module

    Typical mobile phone mini-SIM card

    Mobile phones require a small microchip called a Subscriber Identity Module or SIM card, in order to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores the service-subscriber key (IMSI) and the Ki used to identify and authenticate the user of the mobile phone. The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device, provided that this is not prevented by a SIM lock. The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient for the Finnish wireless network operator Radiolinja.[citation needed]

    A hybrid mobile phone can hold up to four SIM cards, with a phone having a different device identifier for each SIM Card. SIM and R-UIM cards may be mixed together to allow both GSM and CDMA networks to be accessed. From 2010 onwards, such phones became popular in emerging markets,[37] and this was attributed to the desire to obtain the lowest calling costs.

    When the removal of a SIM card is detected by the operating system, it may deny further operation until a reboot.[38]

    Software

    Software platforms

    Android smartphones

    Main article: Mobile operating system

    This section needs expansion. You can help by making an edit request(October 2018)

    Feature phones have basic software platforms. Smartphones have advanced software platforms. Android OS has been the best-selling OS worldwide on smartphones since 2011.

    Mobile app

    Main article: Mobile app

    A mobile app is a computer program designed to run on a mobile device, such as a smartphone. The term “app” is a shortening of the term “software application”.Messaging

    See also: SMS and MMS

    A text message (SMS)

    A common data application on mobile phones is Short Message Service (SMS) text messaging. The first SMS message was sent from a computer to a mobile phone in 1992 in the UK while the first person-to-person SMS from phone to phone was sent in Finland in 1993. The first mobile news service, delivered via SMS, was launched in Finland in 2000,[39] and subsequently many organizations provided “on-demand” and “instant” news services by SMS. Multimedia Messaging Service (MMS) was introduced in March 2002.[40]

    Application stores

    Main article: List of mobile app distribution platforms

    The introduction of Apple’s App Store for the iPhone and iPod Touch in July 2008 popularized manufacturer-hosted online distribution for third-party applications (software and computer programs) focused on a single platform. There are a huge variety of apps, including video games, music products and business tools. Up until that point, smartphone application distribution depended on third-party sources providing applications for multiple platforms, such as GetJarHandangoHandmark, and PocketGear. Following the success of the App Store, other smartphone manufacturers launched application stores, such as Google’s Android Market (later renamed to the Google Play Store), RIM’s BlackBerry App World, or Android-related app stores like AptoideCafe BazaarF-DroidGetJar, and Opera Mobile Store. In February 2014, 93% of mobile developers were targeting smartphones first for mobile app development.[41]

    Sales

    By manufacturer

    See also: List of best-selling mobile phones and List of mobile phone brands by country

    RankManufacturerStrategy
    Analytics
    report[42]
    1Samsung21%
    2Apple16%
    3Xiaomi13%
    4Oppo10%
    5Vivo9%
    Others31%
    Note: Vendor shipments are
    branded shipments and exclude
    OEM sales for all vendors.

    As of 2022, the top five manufacturers worldwide were Samsung (21%), Apple (16%), Xiaomi (13%), Oppo (10%), and Vivo (9%).[42]History

    From 1983 to 1998, Motorola was market leader in mobile phones. Nokia was the market leader in mobile phones from 1998 to 2012.[43] In Q1 2012, Samsung surpassed Nokia, selling 93.5 million units as against Nokia’s 82.7 million units. Samsung has retained its top position since then.

    Aside from Motorola, European brands such as Nokia, Siemens and Ericsson once held large sway over the global mobile phone market, and many new technologies were pioneered in Europe. By 2010, the influence of European companies had significantly decreased due to fierce competition from American and Asian companies, to where most technical innovation had shifted.[44][45] Apple and Google, both of the United States, also came to dominate mobile phone software.[44]

    By mobile phone operator

    Main article: Mobile phone operator

    The world’s largest individual mobile operator by number of subscribers is China Mobile, which has over 902 million mobile phone subscribers as of June 2018.[46] Over 50 mobile operators have over ten million subscribers each, and over 150 mobile operators had at least one million subscribers by the end of 2009.[47] In 2014, there were more than seven billion mobile phone subscribers worldwide, a number that is expected to keep growing.

    Use

    See also: Smartphone § Use

    Mobile phone subscribers per 100 inhabitants. 2014 figure is estimated.

    Mobile phones are used for a variety of purposes, such as keeping in touch with family members, for conducting business, and in order to have access to a telephone in the event of an emergency. Some people carry more than one mobile phone for different purposes, such as for business and personal use. Multiple SIM cards may be used to take advantage of the benefits of different calling plans. For example, a particular plan might provide for cheaper local calls, long-distance calls, international calls, or roaming.

    The mobile phone has been used in a variety of diverse contexts in society. For example:

    • A study by Motorola found that one in ten mobile phone subscribers have a second phone that is often kept secret from other family members. These phones may be used to engage in such activities as extramarital affairs or clandestine business dealings.[48]
    • Some organizations assist victims of domestic violence by providing mobile phones for use in emergencies. These are often refurbished phones.[49]
    • The advent of widespread text-messaging has resulted in the cell phone novel, the first literary genre to emerge from the cellular age, via text messaging to a website that collects the novels as a whole.[50]
    • Mobile telephony also facilitates activism and citizen journalism.
    • The United Nations reported that mobile phones have spread faster than any other form of technology and can improve the livelihood of the poorest people in developing countries, by providing access to information in places where landlines or the Internet are not available, especially in the least developed countries. Use of mobile phones also spawns a wealth of micro-enterprises, by providing such work as selling airtime on the streets and repairing or refurbishing handsets.[51]
    • In Mali and other African countries, people used to travel from village to village to let friends and relatives know about weddings, births, and other events. This can now be avoided in areas with mobile phone coverage, which are usually more extensive than areas with just land-line penetration.
    • The TV industry has recently started using mobile phones to drive live TV viewing through mobile apps, advertising, social TV, and mobile TV.[52] It is estimated that 86% of Americans use their mobile phone while watching TV.
    • In some parts of the world, mobile phone sharing is common. Cell phone sharing is prevalent in urban India, as families and groups of friends often share one or more mobile phones among their members. There are obvious economic benefits, but often familial customs and traditional gender roles play a part.[53] It is common for a village to have access to only one mobile phone, perhaps owned by a teacher or missionary, which is available to all members of the village for necessary calls.[54]
    • Smartphones also have the use for individuals who suffer from diabetes. There are apps for patients with diabetes to self monitor their blood sugar, and can sync with flash monitors. The apps have a feature to send automated feedback or possible warnings to other family members or healthcare providers in the case of an emergency.

    Content distribution

    In 1998, one of the first examples of distributing and selling media content through the mobile phone was the sale of ringtones by Radiolinja in Finland. Soon afterwards, other media content appeared, such as news, video games, jokes, horoscopes, TV content and advertising. Most early content for mobile phones tended to be copies of legacy media, such as banner advertisements or TV news highlight video clips. Recently, unique content for mobile phones has been emerging, from ringtones and ringback tones to mobisodes, video content that has been produced exclusively for mobile phones.[citation needed]

    Mobile banking and payment

    Mobile payment system

    Main articles: Mobile banking and Mobile payment

    See also: Branchless banking and Contactless payment

    In many countries, mobile phones are used to provide mobile banking services, which may include the ability to transfer cash payments by secure SMS text message. Kenya’s M-PESA mobile banking service, for example, allows customers of the mobile phone operator Safaricom to hold cash balances which are recorded on their SIM cards. Cash can be deposited or withdrawn from M-PESA accounts at Safaricom retail outlets located throughout the country and can be transferred electronically from person to person and used to pay bills to companies.

    Branchless banking has also been successful in South Africa and the Philippines. A pilot project in Bali was launched in 2011 by the International Finance Corporation and an Indonesian bank, Bank Mandiri.[55]

    Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually, the idea spread and in 1999, the Philippines launched the country’s first commercial mobile payments systems with mobile operators Globe and Smart.[citation needed]

    Some mobile phones can make mobile payments via direct mobile billing schemes, or through contactless payments if the phone and the point of sale support near field communication (NFC).[56] Enabling contactless payments through NFC-equipped mobile phones requires the co-operation of manufacturers, network operators, and retail merchants.[57][58]

    Mobile tracking

    See also: Cellphone surveillance and Mobile phone tracking

    Mobile phones are commonly used to collect location data. While the phone is turned on, the geographical location of a mobile phone can be determined easily (whether it is being used or not) using a technique known as multilateration to calculate the differences in time for a signal to travel from the mobile phone to each of several cell towers near the owner of the phone.[59][60]

    The movements of a mobile phone user can be tracked by their service provider and, if desired, by law enforcement agencies and their governments. Both the SIM card and the handset can be tracked.[59]

    China has proposed using this technology to track the commuting patterns of Beijing city residents.[61] In the UK and US, law enforcement and intelligence services use mobile phones to perform surveillance operations.[62]

    Hackers have been able to track a phone’s location, read messages, and record calls, through obtaining a subscribers phone number.[63]

    Electronic waste regulation

    Scrapped mobile phones

    See also: Mobile phone recycling

    Studies have shown that around 40–50% of the environmental impact of mobile phones occurs during the manufacture of their printed wiring boards and integrated circuits.[64]

    The average user replaces their mobile phone every 11 to 18 months,[65] and the discarded phones then contribute to electronic waste. Mobile phone manufacturers within Europe are subject to the WEEE directive, and Australia has introduced a mobile phone recycling scheme.[66]

    Apple Inc. had an advanced robotic disassembler and sorter called Liam specifically for recycling outdated or broken iPhones.[67]

    Theft

    According to the Federal Communications Commission, one out of three robberies involve the theft of a cellular phone.[citation needed] Police data in San Francisco show that half of all robberies in 2012 were thefts of cellular phones.[citation needed] An online petition on Change.org, called Secure our Smartphones, urged smartphone manufacturers to install kill switches in their devices to make them unusable if stolen. The petition is part of a joint effort by New York Attorney General Eric Schneiderman and San Francisco District Attorney George Gascón and was directed to the CEOs of the major smartphone manufacturers and telecommunication carriers.[68] On 10 June 2013, Apple announced that it would install a “kill switch” on its next iPhone operating system, due to debut in October 2013.[69]

    All mobile phones have a unique identifier called IMEI. Anyone can report their phone as lost or stolen with their Telecom Carrier, and the IMEI would be blacklisted with a central registry.[70] Telecom carriers, depending upon local regulation can or must implement blocking of blacklisted phones in their network. There are, however, a number of ways to circumvent a blacklist. One method is to send the phone to a country where the telecom carriers are not required to implement the blacklisting and sell it there,[71] another involves altering the phone’s IMEI number.[72] Even so, mobile phones typically have less value on the second-hand market if the phones original IMEI is blacklisted.

    Conflict minerals

    Main article: Conflict minerals

    Demand for metals used in mobile phones and other electronics fuelled the Second Congo War, which claimed almost 5.5 million lives.[73] In a 2012 news story, The Guardian reported: “In unsafe mines deep underground in eastern Congo, children are working to extract minerals essential for the electronics industry. The profits from the minerals finance the bloodiest conflict since the second world war; the war has lasted nearly 20 years and has recently flared up again. For the last 15 years, the Democratic Republic of the Congo has been a major source of natural resources for the mobile phone industry.”[74] The company Fairphone has worked to develop a mobile phone that does not contain conflict minerals.[citation needed]

    Kosher phones

    Due to concerns by the Orthodox Jewish rabbinate in Britain that texting by youths could waste time and lead to “immodest” communication, the rabbinate recommended that phones with text-messaging capability not be used by children; to address this, they gave their official approval to a brand of “Kosher” phones with no texting capabilities. Although these phones are intended to prevent immodesty, some vendors report good sales to adults who prefer the simplicity of the devices; other Orthodox Jews question the need for them.[75]

    In Israel, similar phones to kosher phones with restricted features exist to observe the sabbath; under Orthodox Judaism, the use of any electrical device is generally prohibited during this time, other than to save lives, or reduce the risk of death or similar needs. Such phones are approved for use by essential workers, such as health, security, and public service workers.[76]

    Restrictions

    Restrictions on the use of mobile phones are applied in a number of different contexts, often with the goal of health, safety, security or proper functioning of an establishment, or as a matter of etiquette. Such contexts include:

    While driving

    Main articles: Mobile phones and driving safety and Texting while driving

    A driver using two handheld mobile phones at once
    A sign in the US restricting cell phone use to certain times of day (no cell phone use between 7:30–9:00 am and 2:00–4:15 pm)

    Mobile phone use while driving, including talking on the phone, texting, or operating other phone features, is common but controversial. It is widely considered dangerous due to distracted driving. Being distracted while operating a motor vehicle has been shown to increase the risk of accidents. In September 2010, the US National Highway Traffic Safety Administration (NHTSA) reported that 995 people were killed by drivers distracted by cell phones. In March 2011, a US insurance company, State Farm Insurance, announced the results of a study which showed 19% of drivers surveyed accessed the Internet on a smartphone while driving.[77] Many jurisdictions prohibit the use of mobile phones while driving. In Egypt, Israel, Japan, Portugal, and Singapore, both handheld and hands-free use of a mobile phone (which uses a speakerphone) is banned. In other countries, including the UK and France and in many US states, only handheld phone use is banned while hands-free use is permitted.

    A 2011 study reported that over 90% of college students surveyed text (initiate, reply or read) while driving.[78] The scientific literature on the dangers of driving while sending a text message from a mobile phone, or texting while driving, is limited. A simulation study at the University of Utah found a sixfold increase in distraction-related accidents when texting.[79]

    Due to the increasing complexity of mobile phones, they are often more like mobile computers in their available uses. This has introduced additional difficulties for law enforcement officials when attempting to distinguish one usage from another in drivers using their devices. This is more apparent in countries which ban both handheld and hands-free usage, rather than those which ban handheld use only, as officials cannot easily tell which function of the mobile phone is being used simply by looking at the driver. This can lead to drivers being stopped for using their device illegally for a phone call when, in fact, they were using the device legally, for example, when using the phone’s incorporated controls for car stereo, GPS or satnav.

    A 2010 study reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.[80] In 2013, a national survey in the US reported the number of drivers who reported using their cellphones to access the Internet while driving had risen to nearly one of four.[81] A study conducted by the University of Vienna examined approaches for reducing inappropriate and problematic use of mobile phones, such as using mobile phones while driving.[82]

    Accidents involving a driver being distracted by talking on a mobile phone have begun to be prosecuted as negligence similar to speeding. In the United Kingdom, from 27 February 2007, motorists who are caught using a hand-held mobile phone while driving will have three penalty points added to their license in addition to the fine of £60.[83] This increase was introduced to try to stem the increase in drivers ignoring the law.[84] Japan prohibits all mobile phone use while driving, including use of hands-free devices. New Zealand has banned hand-held cell phone use since 1 November 2009. Many states in the United States have banned texting on cell phones while driving. Illinois became the 17th American state to enforce this law.[85] As of July 2010, 30 states had banned texting while driving, with Kentucky becoming the most recent addition on 15 July.[86]

    Public Health Law Research maintains a list of distracted driving laws in the United States. This database of laws provides a comprehensive view of the provisions of laws that restrict the use of mobile communication devices while driving for all 50 states and the District of Columbia between 1992 when first law was passed, through 1 December 2010. The dataset contains information on 22 dichotomous, continuous or categorical variables including, for example, activities regulated (e.g., texting versus talking, hands-free versus handheld), targeted populations, and exemptions.[87]

    On aircraft

    This section is an excerpt from Mobile phones on aircraft.[edit]

    In the U.S., Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight.[88] Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 permits airlines to determine if devices can be used in flight, allowing use of “any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used.”[89]

    In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight.[90] Many airlines still do not allow the use of mobile phones on aircraft.[91] Those that do often ban the use of mobile phones during take-off and landing.Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems.[92] Official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard.[93]

    See also: Airplane mode

    While walking

    Main article: Smartphones and pedestrian safety

    People using phones while walking

    In 2010, an estimated 1500 pedestrians were injured in the US while using a cellphone and some jurisdictions have attempted to ban pedestrians from using their cellphones.[94][95] Other countries, such as China and the Netherlands, have introduced special lanes for smartphone users to help direct and manage them.[96][97]

    In prisons

    This section is an excerpt from Mobile phones in prison.[edit]

    In most jurisdictions, prison inmates are forbidden from possessing mobile phones due to their ability to communicate with the outside world and other security issues. Mobile phones are one of the most smuggled items into prisons. They provide inmates the ability to make and receive unauthorized phone calls, send email and text messages, use social media, and follow news pertaining to their case, among other forbidden uses.[98][99]

    In hospitals

    As of 2007, some hospitals had banned mobile devices due to a common misconception that their use would create significant electromagnetic interference.[100][101]

    Health effects

    Main article: Mobile phone radiation and health

    See also: Nomophobia and Mobile phone overuse

    Screen time, the amount of time using a device with a screen, has become an issue for mobile phones since the adaptation of smartphones.[102] Research is being conducted to show the correlation between screen time and the mental and physical harm in child development. [103] To prevent harm, some parents and even governments have placed restrictions on its usage.[104][105]

    There have been rumors that mobile phone use can cause cancer, but this is a myth.[106][107]

    While there are rumors of mobile phones causing cancer, there was a study conducted by International Agency for Research on Cancer (IARC) that stated the there could be an increase risk of brain tumors with the use of smartphones, this is not confirmed. They also stated that with the lack of data for the research and the usage periods of 15 years will warrant further research for smartphones and the cause of brain tumors. [108]

    Educational impact

    See also: Mobile phone use in schools

    A study by the London School of Economics found that banning mobile phones in schools could increase pupils’ academic performance, providing benefits equal to one extra week of schooling per year.[109]

    Culture and popularity

    See also: SMS language and Xelibri

    Mobile phones are considered an important human invention as it has been one of the most widely used and sold pieces of consumer technology.[7][9] They have also become culturally symbolic. In Japanese mobile phone culture for example, mobile phones are often decorated with charms. They have also become fashion symbols at times.[110] The Motorola Razr V3 and LG Chocolate are two examples of devices that were popular for being fashionable while not necessarily focusing on the original purpose of mobile phones, i.e. a device to provide mobile telephony.[111]

    Some have also suggested that mobile phones or smartphones are a status symbol.[112] For example a research paper suggested that owning specifically an Apple iPhone was seen to be a status symbol.[113]

    Text messaging, which are performed on mobile phones, has also led to the creation of ‘SMS language‘. It also led to the growing popularity of emojis.[114]