A mobile phone (also known as a cell phone or cellular phone) is a telephone which can make and receive calls over a radio frequency carrier while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). A modern mobile telephone service uses a cellular network architecture. In addition to telephony, modern mobile phones support a variety of other services, such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming, and photography. Mobile phones which offer these and more general computing capabilities are referred to as smartphones.

The first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing around 4.4 lbs (2 kg). 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, penetrating 100% of the global population and reaching the bottom of the economic pyramid. In 2014, the top mobile phone manufacturers were Samsung, Nokia, Apple, and LG.

History

Main article: History of mobile phones

Martin Cooper of Motorola made the first publicized handheld mobile phone call on a prototype DynaTAC model on April 4, 1973. This is a reenactment in 2007.

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 "0G" (zeroth generation) services, such as Bell System's Mobile Telephone Service and its successor, the Improved Mobile Telephone Service. These "0G" systems were not cellular, supported few simultaneous calls, and were very expensive.

The Motorola DynaTAC 8000X. First commercially available handheld cellular mobile phone, 1984.

The first handheld mobile cell phone was demonstrated by Motorola in 1973. The first commercial automated cellular network 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. 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 technology.

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.

Ten years later, in 2001, the third generation (3G) was launched in Japan by NTT DoCoMo on the WCDMA standard. This was followed by 3.5G, 3G+ or turbo 3G enhancements based on the high-speed packet access (HSPA) family, allowing UMTS networks to have higher data transfer speeds and capacity.

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. Consequently, the industry began looking to data-optimized fourth-generation technologies, with the promise of speed improvements up to ten-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard, offered in North America by Sprint, and the LTE standard, first offered in Scandinavia by TeliaSonera.

Features

Main article: Mobile phone features

See also: Smartphone

All mobile phones have a number of features in common, but manufacturers seek product differentiation by adding functions to make them more attractive to consumers. This competition has led to great innovation in mobile phone development over the past 20 years.

The common components found on all phones are:

• A battery, providing the power source for the phone functions.
• An input mechanism to allow the user to interact with the phone. The most common input mechanism is a keypad, but touch screens are also found in most smartphones.
• A screen which echoes the user's typing, displays text messages, contacts and more.
• Basic mobile phone services to allow users to make calls and send text messages.
• All GSM phones use a SIM card to allow an account to be swapped among devices. Some CDMA devices also have a similar card called a R-UIM.
• Individual GSM, WCDMA, iDEN and some satellite phone devices are uniquely identified by an International Mobile Equipment Identity (IMEI) number.

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 became known as smartphones.

Several phone series have been introduced to address specific market segments, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs, the Sony-Ericsson 'Walkman' series of music/phones and 'Cyber-shot' series of camera/phones, the Nokia Nseries of multimedia phones, the Palm Pre, the HTC Dream and the Apple iPhone.

Sound quality

In sound quality, 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 with both, as this depends not so much on the phone itself, as on the quality of the network and, in long distance calls, the bottlenecks/choke points met along the way. As such, for long-distance calls even features such as Voice over LTE and HD Voice may not improve things. In some cases smartphones can improve audio quality even on long-distance calls, by using a VoIP phone service, with someone else's WiFi/internet connection.

Text messaging

Main article: SMS

The most commonly used data application on mobile phones is SMS (Short Message Service) text messaging. The first SMS text 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, and subsequently many organizations provided "on-demand" and "instant" news services by SMS.

Multimedia Messaging Service (MMS) was introduced in 2001.

SIM card

Main articles: Subscriber Identity Module and Removable User Identity Module

Typical mobile phone SIM card

GSM feature 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 K_i 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.

Multi-card hybrid phones

A hybrid mobile phone can hold up to four SIM cards. 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 India and Indonesia and other emerging markets, and this was attributed to the desire to obtain the lowest on-net calling rate. In Q3 2011, Nokia shipped 18 million of its low-cost dual SIM phone range in an attempt to make up for lost ground in the higher-end smartphone market.

Kosher phones

There are Jewish orthodox religious restrictions which, by some interpretations, standard mobile telephones overstep. To deal with this problem, some rabbinical organizations have recommended that phones with text-messaging capability not be used by children. Phones with restricted features are known as kosher phones and have rabbinical approval for use in Israel and elsewhere by observant Orthodox Jews. Although these phones are intended to prevent immodesty, some vendors report good sales to adults who prefer the simplicity of the devices. Some phones are approved for use by essential workers (such as health, security and public service workers) on the sabbath, even though the use of any electrical device is generally prohibited during this time.

Mobile phone operators

Growth in mobile phone subscribers per country from 1980 to 2009.

Main article: Mobile phone operator

The world's largest individual mobile operator by number of subscribers is China Mobile, which has over 500 million mobile phone subscribers. 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. In 2014, there were more than seven billion mobile phone subscribers worldwide, a number that is expected to keep growing.

Manufacturers

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

Prior to 2010, Nokia was the market leader. However, since then competition has emerged in the Asia Pacific region, from brands such as Micromax, Nexian and i-Mobile, which have chipped away at Nokia's market share. Android-powered smartphones have also gained momentum across the region at the expense of Nokia. In India, Nokia's market share dropped significantly to around 31% from 56% in the same period. Its share was displaced by Chinese and Indian vendors of low-end mobile phones.

In Q1 2012, according to Strategy Analytics, Samsung surpassed Nokia, selling 93.5 million units as against Nokia's 82.7 million units. In 2012 Standard & Poor's downgraded Nokia to "junk" status, at BB+/B, with negative outlook due to high loss and an expected further decline owing to insufficient growth in Lumia smartphone sales to offset a rapid decline in revenue from Symbian-based smartphones that was forecast for subsequent quarters.

In Q3 2014, the top ten manufacturers were Samsung (20.6%), Nokia (9.5%), Apple Inc. (8.4%), LG (4.2%), Huawei (3.6%), TCL Communication (3.5), Xiaomi (3.5%), Lenovo (3.3%), ZTE (3.0%) and Micromax (2.2%).

• Note: Vendor shipments are branded shipments and exclude OEM sales for all vendors

Other manufacturers outside the top five include TCL Communication, Lenovo, Sony Mobile Communications, Motorola. Smaller current and past players include Karbonn Mobile, Audiovox (now UTStarcom), BenQ-Siemens, BlackBerry, Casio, CECT, Coolpad, Fujitsu, HTC, Just5, Kyocera, Lumigon, Micromax Mobile, Mitsubishi Electric, Modu, NEC, Neonode, Openmoko, Panasonic, Palm, Pantech Wireless Inc., Philips, Qualcomm Inc., Sagem, Sanyo, Sharp, Sierra Wireless, SK Teletech, Soutec, Trium, Toshiba, and Vidalco.

Use of mobile phones

General

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.
• Some organizations assist victims of domestic violence by providing mobile phones for use in emergencies. These are often refurbished phones.
• 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.
• Mobile telephony also facilitates activism and public journalism being explored by Reuters and Yahoo! and small independent news companies such as Jasmine News in Sri Lanka.
  
• 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.
• 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. 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. It 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. 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.

Smartphones

Active mobile broadband subscriptions per 100 inhabitants.

Smartphones have a number of distinguishing features. The International Telecommunication Union measures those with Internet connection, which it calls Active Mobile-Broadband subscriptions (which includes tablets, etc). In the developed world, smartphones have now overtaken the usage of earlier mobile systems. However, in the developing world, they account for only 20% of mobile telephony.

For distributing content

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.

In 2006, the total value of mobile-phone-paid media content exceeded Internet-paid media content and was worth US$31 billion. The value of music on mobile phones was worth US$9.3 billion in 2007, and gaming was worth over US$5 billion in 2007.

While driving

Main article: Mobile phones and driving safety

A sign along Bellaire Boulevard in Southside Place, Texas (Greater Houston) indicating restrictions on mobile phone use while driving.

Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accidents; because of this, 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 is banned. In other countries including the UK and France and in many U.S. states, only handheld phone use is banned, while hands-free use is permitted.

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 or satnav.

A 2010 study reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.

Mobile banking and payments

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 may be deposited or withdrawn from M-PESA accounts at Safaricom retail outlets located throughout the country, and may be transferred electronically from person to person as well as 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.

Another application of mobile banking technology is Zidisha, a US-based nonprofit micro-lending platform that allows residents of developing countries to raise small business loans from Web users worldwide. Zidisha uses mobile banking for loan disbursements and repayments, transferring funds from lenders in the United States to the borrowers in rural Africa using the Internet and mobile phones.

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 on the mobile operators Globe and Smart.

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

Tracking and privacy

See also: Cellphone surveillance and Mobile phone tracking

Mobile phones are also 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.

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

China has proposed using this technology to track commuting patterns of Beijing city residents. In the UK and US, law enforcement and intelligence services use mobiles to perform surveillance. They possess technology to activate the microphones in mobile phones remotely in order to listen to conversations that take place near the phone.

Thefts

According to the Federal Communications Commission, one out of three robberies involved the theft of a cellular phone. Police data in San Francisco showed that one-half of all robberies in 2012 were thefts of cellular phones. An online petition on Change.org called Secure our Smartphones urged smartphone manufacturers to install kill switches in their devices to make them unusable in case of theft. 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.

On Monday, 10 June 2013, Apple announced it would install a kill switch on its next iPhone operating system, due to debut in October 2013.

Health effects

Main article: Mobile phone radiation and health

Further information: Mobile phones on aircraft

The effect mobile phone radiation has on human health is the subject of recent interest and study, as a result of the enormous increase in mobile phone usage throughout the world. Mobile phones use electromagnetic radiation in the microwave range, which some believe may be harmful to human health. A large body of research exists, both epidemiological and experimental, in non-human animals and in humans, of which the majority shows no definite causative relationship between exposure to mobile phones and harmful biological effects in humans. This is often paraphrased simply as the balance of evidence showing no harm to humans from mobile phones, although a significant number of individual studies do suggest such a relationship, or are inconclusive. Other digital wireless systems, such as data communication networks, produce similar radiation.

On 31 May 2011, the World Health Organization stated that mobile phone use may possibly represent a long-term health risk, classifying mobile phone radiation as "possibly carcinogenic to humans" after a team of scientists reviewed studies on mobile phone safety. Mobile phones are in category 2B, which ranks it alongside coffee and other possibly carcinogenic substances.

At least some recent studies have found an association between mobile phone use and certain kinds of brain and salivary gland tumors. Lennart Hardell and other authors of a 2009 meta-analysis of 11 studies from peer-reviewed journals concluded that cell phone usage for at least ten years "approximately doubles the risk of being diagnosed with a brain tumor on the same ('ipsilateral') side of the head as that preferred for cell phone use."

One study of past mobile phone use cited in the report showed a "40% increased risk for gliomas (brain cancer) in the highest category of heavy users (reported average: 30 minutes per day over a 10?year period)." This is a reversal from their prior position that cancer was unlikely to be caused by cellular phones or their base stations and that reviews had found no convincing evidence for other health effects. Certain countries, including France, have warned against the use of mobile phones especially by minors due to health risk uncertainties. However, a study published 24 March 2012 in the British Medical Journal questioned these estimates, because the increase in brain cancers has not paralleled the increase in mobile phone use.

Future evolution

Main article: 5G

5G is a technology and term used in research papers and projects to denote the next major phase in mobile telecommunication standards beyond the 4G/IMT-Advanced standards. The term 5G is not officially used in any specification or official document yet made public by telecommunication companies or standardization bodies such as 3GPP, WiMAX Forum or ITU-R. New standards beyond 4G are currently being developed by standardization bodies, but they are at this time seen as under the 4G umbrella, not for a new mobile generation.

Deloitte is predicting a collapse in wireless performance to come as soon as 2016, as more devices using more and more services compete for limited bandwidth for their operation.

Environmental impact

A mobile phone repair kiosk in Hong Kong

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.

The average user replaces their mobile phone every 11 to 18 months, 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.

Conflict minerals

See also: Conflict minerals

Demand for metals used in mobile phones and other electroncs fuelled the Second Congo War, which claimed almost 5.5 million lives. 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."

The company Fairphone has attempted to develop a mobile phone that does not contain conflict minerals. 

Source: Wikipedia