Mobile Phone

A mobile phone (also known as a cellular phone, cell phone and a hand phone) is a device that can make and receive telephone calls over a radio link while moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network. By contrast, a cordless telephone is used only within the short range of a single, private base station.
In addition to telephony, modern mobile phones also support a wide 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 that offer these and more general computing capabilities are referred to as smartphones.
The first hand-held mobile phone was demonstrated by John F. Mitchell and Dr Martin Cooper of Motorola in 1973, using a handset weighing around 2.2 pounds (1 kg). In 1983, theDynaTAC 8000x was the first to be commercially available. From 1990 to 2011, worldwide mobile phone subscriptions grew from 12.4 million to over 6 billion, penetrating about 87% of the global population and reaching the bottom of the economic pyramid

History of mobile phones
Inventor Charles E. Alden claimed, in the 29 April 1906 issue of the New York World, to have invented a device called the “vest pocket telephone" although Alden never had the chance to produce this device in large quantities.[9][10][11]
The first mobile telephone calls were made from cars in 1946. Bell System's Mobile Telephone Service was made on 17 June in St. Louis, Missouri, followed by Illinois Bell Telephone Company's car radiotelephone service in Chicago on 2 October. [12] The MTA phones were composed of vacuum tubes and relays, and weighed over 80 pounds (36 kg).[13][14] There were initially only 3 channels for all the users in the metropolitan area, increasing later to 32 channels across 3 bands. This service continued into the 1980s in large portions of North America. Due to the small number of radio frequencies available, the service quickly reached capacity. In 1956 the world’s first partly automatic car phone system, Mobile System A (MTA) was introduced inSweden.
John F. Mitchell, Motorola's chief of portable communication products in 1973, played a key role in advancing the development of handheld mobile telephone equipment. Mitchell successfully pushed Motorola to develop wireless communication products that would be small enough to use anywhere and participated in the design of the cellular phone.[15][16] Martin Cooper, a Motorolaresearcher and executive, was the key researcher on Mitchell's team that developed the first hand-held mobile telephone for use on a cellular network.[17] Using a somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on 3 April 1973 to his rival, Dr. Joel S. Engel of Bell Labs.[18][19]
As I walked down the street while talking on the phone, sophisticated New Yorkers gaped at the sight of someone actually moving around while making a phone call. Remember that in 1973, there weren't cordless telephones or cellular phones. I made numerous calls, including one where I crossed the street while talking to a New York radio reporter - probably one of the more dangerous things I have ever done in my life.
—Martin Cooper, [20]
The new invention sold for $3,995 and weighed two pounds, leading to a nickname "the brick".
The world's first commercial automated cellular network was launched in Japan by NTT in 1979, initially in the metropolitan area of Tokyo. In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden.[21] Several countries then followed in the early-to-mid 1980s including the UK, Mexico and Canada.
On 6 March 1983, the DynaTAc mobile phone launched on the first US 1G network by Ameritech. It cost $100m to develop, and took over a decade to hit the market.[22] The phone had a talk time of just half an hour and took ten hours to charge. Consumer demand was strong despite the battery life, weight, and low talk time, and waiting lists were in the thousands.[23][24]
In 1991, the second generation (2G) cellular technology was launched in Finland by Radiolinja on the GSM standard, which 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.[25] 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 like streaming media.[26] Consequently, the industry began looking to data-optimized 4th-generation technologies, with the promise of speed improvements up to 10-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard (offered in the U.S. by Sprint) and the LTE standard, first offered in Scandinavia by TeliaSonera.

Mobile phone features
All mobile phones have a number of features in common, but manufacturers also try to differentiate their own products by implementing additional functions to make them more attractive to consumers. This 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 some high-end smartphones.
• 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 a given market segment, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia Nseries of multimedia phones, the Palm Pre the HTC Dream and the Apple iPhone.
Text messaging
Main article: SMS
The most commonly used data application on mobile phones is SMS 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.
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, 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.
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 RUIM cards may be mixed together to allow both GSM and CDMA networks to be accessed.[27][28]
From 2010 onwards they became popular in India and Indonesia and other emerging markets,[29] 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 lost ground in the higher end smartphone market.[30]
Kosher phones
There are Jewish orthodox religious restrictions which standard mobile telephones do not meet. To fulfill this demand, phones without Internet access, text messaging or cameras are required.[31] These restricted phones are known as kosher phones and have rabbinical approval for use in Israel and elsewhere by observant Orthodox Jews. Some are even approved for use by essential workers (such as health, security and public services) on the sabbath, even though use of any electrical device is restricted.[32]
Although these phones are intended to prevent immodesty, some vendors report good sales to adults who prefer the simplicity of the devices.
Mobile phone operators

Global mobile phone subscribers per country from 1980-2009. The growth in users has been exponential since they were first made available.
The world's largest individual mobile operator by subscribers is China Mobile with over 500 million mobile phone subscribers.[33] Over 50 mobile operators have over 10 million subscribers each, and over 150 mobile operators had at least one million subscribers by the end of 2009.[34] In February 2010, there were 6 billion mobile phone subscribers, a number that is expected to grow.[5]

Use of mobile phones
In general

Mobile phone subscribers per 100 inhabitants 1997–2007

A cellphone repair kiosk in Mumbai, India
Mobile phones are used for a variety of purposes, including keeping in touch with family members, conducting business, and having access to a telephone in the event of an emergency. Some people carry more than one cell phone for different purposes, such as for business and personal use. Multiple SIM cards may also be used to take advantage of the benefits of different calling plans—a particular plan might provide cheaper local calls, long-distance calls, international calls, or roaming. The mobile phone has also been used in a variety of diverse contexts in society, for example:
• A study by Motorola found that one in ten cell phone subscribers have a second phone that often is kept secret from other family members. These phones may be used to engage in activities including extramarital affairs or clandestine business dealings.[39]
• Some organizations assist victims of domestic violence by providing mobile phones for use in emergencies. They are often refurbished phones.[40]
• 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.[41]
• Mobile telephony also facilitates activism and public journalism being explored by Reuters and Yahoo![42] 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 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 work, such as selling airtime on the streets and repairing or refurbishing handsets.[43]
• 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, which are now avoided within mobile phone coverage areas, which is usually greater than 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.[44] 86% of Americans use their mobile phone while watching TV.
• In 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 mobiles among their members. There are obvious economic benefits, but often familial customs and traditional gender roles play a part.[45] It is common for a village to have access to only one mobile phone, perhaps owned by a teacher or missionary, but available to all members of the village for necessary calls.[46]
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 tended to be copies of legacy media, such as the banner advertisement or the TV news highlight video clip. Recently, unique content for mobile has been emerging, from the ringing tones and ringback tones in music 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 31 billion dollars.[47] The value of music on phones was worth 9.3 billion dollars in 2007 and gaming was worth over 5 billion dollars in 2007.[48]
While driving
Main article: Mobile phones and driving safety

Texting in stop-and-go traffic in New York City
Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accident. Because of this, many jurisdictions prohibit the use of mobile phones while driving. Egypt, Israel, Japan, Portugal and Singapore ban both handheld and hands-free use of a mobile phone; others —including the UK, France, and many U.S. states—ban handheld phone use only, allowing hands-free use.
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 in distinguishing one usage from another as drivers use their devices. This is more apparent in those countries which ban both handheld and hands-free usage, rather than those who have banned 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 on a phone call when, in fact, they were using the device for a legal purpose such as the phone's incorporated controls for car stereo or satnav.
A recently published study has reviewed the incidence of mobile phone use while cycling and its effects on behaviour and safety.[49]
In schools
Some schools limit or restrict the use of mobile phones. Schools set restrictions on the use of mobile phones because of the use of cell phones for cheating on tests, harassment and bullying, causing threats to the schools security, distractions to the students, and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities, public restrooms and swimming pools due to the built-in cameras that most phones now feature.

Tracking and privacy
See also: 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 asmultilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phone.[56][57]
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.[58]
China has proposed using this technology to track commuting patterns of Beijing city residents.[59] In the UK and US, law enforcement and intelligence services use mobiles to perform surveillance. They possess technology to activate the microphones in cell phones remotely in order to listen to conversations that take place near to the person who holds the phone.[60][61]
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 themicrowave 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 confirmed that mobile phone use may represent a long-term health risk,[62][63] classifying mobile phone radiation as a "carcinogenic hazard" and "possibly carcinogenic to humans" after a team of scientists reviewed peer-review studies on cell phone safety.[64] One study of past cell 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)."[65] 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.[63][66] Certain countries, including France, have warned against the use of cell phones especially by minors due to health risk uncertainties.[67] 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.[68]
At least some recent studies have found an association between cell 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.”[69]
In addition, a mobile phone can spread infectious diseases by its frequent contact with hands. One study came to the result that pathogenic bacteria are present on approximately 40% of mobile phones belonging to patients in a hospital, and on approximately 20% of mobile phones belonging to hospital staff.[70]
A study on mice suggested that cell phone use during pregnancy may be likely to result in lasting mental health problems for offspring that resemble the effects of ADHD.[71]
Future evolution
Main article: 5G
5G is a technology used in research papers and projects to denote the next major phase of mobile telecommunication standards beyond the 4G/IMT-Advanced standards. 5G is not officially used for any specification or official document yet made public by telecommunication companies or standardization bodies such as 3GPP, WiMAX Forum, or ITU-R. New standard releases beyond 4G are in progress by standardization bodies, but are at this time not considered as new mobile generations but under the 4G umbrella.
Environmental impact
Studies have shown that around 40-50% of the environmental impact of a mobile phone occurs during the manufacturing of the printed wiring boards and integrated circuits.[72] After purchase, the average user then replaces their mobile phone every 11 to 18 months. The discarded phones then contribute to electronic waste.