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 whilst moving around a wide geographic area. It does so by connecting to acellular network provided by a mobile phone operator, allowing access to thepublic 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 world's largest individual mobile operator by subscribers is China Mobile with over 500 million mobile phone subscribers.[26] 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.[27] In February 2010, there were 5.6 billion mobile phone subscribers, a number that is expected to grow.[3]
The world's largest individual mobile operator by subscribers is China Mobile with over 500 million mobile phone subscribers.[26] 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.[27] In February 2010, there were 5.6 billion mobile phone subscribers, a number that is expected to grow.[3]
Prior to 2010,Nokia was the market leader. However, since then competition emerged in the Asia Pacific region with brands such as Micromax,Nexian, and i-Mobile and chipped away at Nokia's market share. Android powered smartphones also gained momentum across the region at the expense of Nokia. In India, their market share also dropped significantly to around 31 percent from 56 percent in the same period. Their share was displaced by Chinese and Indian vendors of low-end mobile phones.[28]
In Q1 2012, based on Strategy Analytics, Samsung surpassed Nokia sold by 93.5 million units and 82.7 million units, respectively.Standard & Poor's has also downgraded Nokia to 'junk' status at BB+/B with negative outlook due to high loss and still declined with growth of Lumia smartphones was not sufficient to offset a rapid decline in revenue from Symbian-based smartphones over the next few quarters.[29]
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 epidemiologicaland 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,[55][56] 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.[57] 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)."[58] 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.[56][59]Certain countries, including France, have warned against the use of cell phones especially by minors due to health risk uncertainties.[60] 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.[61]
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.”[62]
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.[63]
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.[64]
