AÂ mobile phoneÂ is aÂ telephoneÂ that can make and receiveÂ callsÂ over a radio frequency carrier while the user is moving within aÂ telephone service area. The radio frequency link establishes a connection to the switching systems of aÂ mobile phone operator,Â which provides access to theÂ public switched telephone networkÂ (PSTN). Most modern mobile telephone services use aÂ cellularÂ networkÂ architecture, and therefore mobile telephones are often also calledÂ cellular telephonesÂ orÂ cell phones. In additionÂ toÂ telephony, modern mobile phones support a variety of otherÂ services, such asÂ text messaging,Â MMS,Â email,Â Internet access,Â short-range wireless communications (infrared,Â Bluetooth), business applications, gaming, and photography.
Mobile phones whichÂ offer these and more general computing capabilities are referred to asÂ The first handheld mobile phone was demonstrated byÂ John F. Mitchell andÂ Martin CooperÂ ofÂ MotorolaÂ in 1973, using a handsetÂ weighing c. 4.4 lbs (2Â kg). In 1983, theÂ DynaTAC 8000x Â was the first commercially available handheld mobile phone. From 1983 toÂ 2014, worldwide mobile phone subscriptions grew to over seven billion, penetrating 100% of the global population and reachingtheÂ bottom of the economic pyramid. In 2014, the top mobile phone manufacturers were
Main article:Â History of mobile
Martin CooperÂ of Motorola made the first publicized handheld mobile phone call on a prototype DynaTAC model on April 4, 1973. This is a reenactmentÂ in 2007.Â A handheld mobile radio telephone service was envisioned in the early stages of radio engineering.
In 1917,Â FinnishÂ inventorÂ EricÂ TigerstedtÂ filed a patent for a “pocket-size folding telephone with a very thin carbon microphone”. Early predecessors of cellularÂ phones includedÂ analogÂ radio communications from ships and trains.
The race to create truly portable telephone devices beganÂ after World War II, with developments taking place in many countries. The advances inÂ mobile telephonyÂ have been traced insuccessive “generations”, starting with the early “0G” (zeroth generation) services, such asÂ Bell System’sÂ Mobile TelephoneÂ Serviceand its successor, theÂ Improved Mobile Telephone Service. These “0G” systems were notÂ cellular, supported fewÂ 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 byÂ MotorolaÂ in 1973. The first commercial automated cellular network was
launched in Japan byÂ Nippon Telegraph and TelephoneÂ in 1979. This was followed in 1981 by the simultaneous launch of theNordic
Mobile TelephoneÂ (NMT) system in Denmark, Finland, Norway and Sweden. Several other countries then followed in the early toÂ mid-1980s. These first-generation (1G) systems could support far more simultaneous calls, but still used analog technology.
In 1991, the second-generation (2G)Â digitalÂ cellular technology was launched in Finland byÂ RadiolinjaÂ on theÂ GSMÂ standard. ThisÂ 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 byÂ NTT DoCoMoÂ on theÂ WCDMAÂ standard. This wasÂ followed by 3.5G, 3G+ or turbo 3G enhancements based on theÂ high-speed packet accessÂ (HSPA) family, allowingÂ UMTSÂ networksÂ 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-intensiveÂ applications, such asÂ 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 availableÂ technologies billed asÂ 4GÂ were theÂ WiMAXÂ standard, offered in North America byÂ Sprint, and theÂ LTEÂ standard, first offered inÂ Scandinavia byÂ TeliaSonera.
Main article: Mobile phone radiation and healthÂ Further information: Mobile phones on aircraftÂ The effect of mobile phone radiation on human health is the subject of recent interest and study, as aÂ result of the enormous increase in mobile phone usage throughout the world. Mobile phones useÂ electromagnetic radiation in the microwave range, which some believe may be harmful to humanÂ health.
A large body of research exists, both epidemiological and experimental, in non-human animalsÂ and in humans. The majority of this research shows no definite causative relationship between exposureÂ to mobile phones and harmful biological effects in humans. This is often paraphrased simply as theÂ balance of evidence showing no harm to humans from mobile phones, although a significant number ofÂ individual studies do suggest such a relationship, or are inconclusive. Other digital wireless systems,Â such as data communication networks, produce similar radiation.
On 31 May 2011, the World Health Organization stated that mobile phone use may possibly represent aÂ long-term health risk, classifying mobile phone radiation as “possibly carcinogenic to humans”Â after a team of scientists reviewed studies on mobile phone safety. The mobile phone is in categoryÂ 2B, which ranks it alongside coffee and other possibly carcinogenic substances. Some recent studies have found an association between mobile phone use and certain kinds of brainÂ and salivary gland tumors. Lennart Hardell and other authors of a 2009 meta-analysis of 11 studies fromÂ peer-reviewed journals concluded that cell phone usage for at least ten years “approximately doublesÂ the risk of being diagnosed with a brain tumor on the same (‘ipsilateral’) side of the head as thatÂ preferred for cell phone use” .Â One study of past mobile phone use cited in the report showed a “40% increased risk for gliomas (brainÂ cancer) in the highest category of heavy users (reported average: 30 minutes per day over a 10âyearÂ period)”.
This is a reversal of the study’s 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 otherÂ health effects.Â Â However, a study published 24 March 2012 in the British Medical JournalÂ questioned these estimates, because the increase in brain cancers has not paralleled the increase inÂ mobile phone use. Certain countries, including France, have warned against the use of mobileÂ phones by minors in particular, due to health risk uncertainties. Mobile pollution by transmittingÂ electromagnetic waves can be decreased up to 90% by adopting the circuit as designed in mobile phoneÂ (MS) and mobile exchange (BTS, MSC etc.).