A mobile phone (also known as a cellularphone, cell phone and a hand phone) is adevice that can make andreceive telephone calls over a radiolink whilst moving around a widegeographic areaIt does so by connecting to a cellularnetwork provided by a mobile phoneoperator, allowing access to the publictelephone network. By contrast, a cordlesstelephone is used only within the shortrange of a single, private base station.
The first hand-held mobile phone wasdemonstrated by Dr MartinCooper of Motorola in 1973, using ahandset weighing around 1 kg. In 1983,the Dyna TAC 8000x was the first to becommercially available.In the twenty years from 1990 to 2011,worldwide mobile phone subscriptionsgrew from 12.4 million to over 5.6 billion,penetrating the developingeconomies and reaching the bottom ofthe economic pyramid.
HISTORY ABOUT MOBILEPHONE
The first hand-held mobile phone was demonstratedby Dr Martin Cooper of Motorola in 1973, using ahandset weighing around 1 kg. In 1983, the Dyna TAC8000x was the first to be commerciallyavailableRadiophones have a long and varied historygoing back to Reginald Fessendens invention andshore-to-ship demonstration of radio telephony,through the Second World War with military use ofradio telephony links and civil services in the 1950s.The first mobile telephone call made from a car occurredin St. Louis, Missouri, USA on June 17, 1946, usingthe Bell Systems Mobile Telephone ServiceIn 1956.
In 1991, the second generation (2G)cellular technology was launchedTen years later, in 2001, the thirdgeneration (3G) was launchedThis was followed by 3.5G, 3G+ or turbo3G enhancements based on the High-Speed Packet Access (HSPA) family.
The common components foundon all phones areA battery, providing the power source for thephone functions.An input mechanism to allow the user to interactwith the phone. The most common inputmechanism is a keypad, but touch screens are alsofound in some high-end smartphones.Basic mobile phone services to allow users to makecalls and send text messages.
All GSM phones use a SIM card toallow an account to be swappedamong devices. Some CDMA devicesalso have a similar card called a R-UIM.Individual GSM, WCDMA, iDEN andsome satellite phone devices areuniquely identified byan International Mobile EquipmentIdentity (IMEI) number.
Handsets with more advanced computing abilitythrough the use of native software applicationsbecame known as SMARTPHONES.The Nokia Nseries of multimedia phones, the PalmPre the HTC Dream and the Apple iPhone..The SonyEricsson Walkman series of musicphonesand Cybershot series of cameraphones.The RIM BlackBerry focusing onenterprise/corporate customer email needs.
GSM feature phones require a small microchip called aSubscriber Identity Module or SIM Card, to function,while smartphones can be used without it. The SIM card isapproximately the size of a small postage stamp and isusually placed underneath the battery in the rear of theunit. The SIM securely stores the service-subscriber key(IMSI) used to identify a subscriber on mobile telephonydevices (such as mobile phones and computers). The SIMcard allows users to change phones by simply removingthe SIM card from one mobile phone and inserting it intoanother mobile phone or broadband telephony device.The first SIM card was made in 1991 by Munich smart cardmaker Giesecke & Devrient for the Finnish wireless networkoperator Radiolinja. Giesecke & Devrient sold the first 300SIM cards to Elisa
The Multi-card hybrid phonesA hybrid mobile phone cantake more than one SIMcard, even of different types.The SIM and RUIM cards canbe mixed together, and somephones also support three orfour SIMs.
Manufacturer Gartner IDCNokia 23.4% 26.6%SAMSUNG 19.4% 22.8%Apple 7.4% 8.7%ZTE 4.0% 4.0%LG 3.6% 4.1%Others 30.2% 33.8%The top five manufacturers by market sharewere Nokia followed by Samsung, LGElectronics, ZTE and Apple.
Other manufacturers outside the top fiveare Research In Motion Ltd. (RIM), HTCCorporation, Motorola, Huawei, Sony Ericsson.Smaller playersinclude Audiovox (now UTStarcom), BenQ-Siemens, CECT, Fujitsu, Just5, Kyocera, MitsubishiElectric, NEC, Panasonic, Palm, Pantech WirelessInc., Philips, QualcommInc., Sagem, Sanyo, Sharp, Sierra Wireless, SKTeletech,Soutec, T&A Alcatel, Trium, Toshiba,and Vidalco.
A large body of research exists, both epidemiological andexperimental, in non-human animals and in humans, ofwhich the majority shows no definite causative relationshipbetween exposure to mobile phones and harmful biologicaleffects in humans.The effect mobile phone radiation has on human health isthe subject of recent interest and study, as a result of theenormous increase in mobile phone usage throughout theworld. Mobile phones use electromagnetic radiation inthe microwave range, which some believe may be harmful tohuman health..
This is often paraphrased simply asthe balance of evidence showing noharm to humans from mobilephones, although a significantnumber of individual studies dosuggest such a relationship, or areinconclusive. Other digital wirelesssystems, such as datacommunication networks, producesimilar radiation.
One study came to the resultthat pathogenic bacteria are present onapproximately 40% of mobile phonesbelonging to patients in a hospital, andon approximately 20% of mobile phonesbelonging to hospital staff.In addition, a mobile phone canspread infectious diseases by its frequentcontact with hands.