Celphone

lphoneA mobile phone (also called mobile, cellular phone, cell phone or handphone)[1] is an electronic device used for full duplex two-way radio telecommunications over a cellular network of base stations known as cell sites. Mobile phones differ from cordless telephones, which only offer telephone service within limited range through a single base station attached to a fixed land line, forexample within a home or an office. Low-end mobile phones are often referred to as feature phones, whereas high-end mobile phones that offer more advanced computing ability are referred to as smartphones.
A mobile phone allows its user to make and receive telephone calls to and from the public telephone network which includes other mobiles and fixed line phones across the world. It does this byconnecting to a cellular network owned by a mobile network operator. A key feature of the cellular network is that it enables seamless telephone calls even when the user is moving around wide areas via a process known as handoff or handover.
In addition to being a telephone, modern mobile phones also support many additional services, and accessories, such as SMS (or text) messages, email, Internetaccess, gaming, Bluetooth, infrared, camera, MMS messaging, MP3 player, radio and GPS.
The first hand held phone was demonstrated by Martin Cooper of Motorola in 1973, using a handset weighing in at two kilos.[2] In the year 1990, 12.4 million people worldwide had cellular subscriptions.[3] By the end of 2009, only 20 years later, the number of mobile cellular subscriptions worldwide reachedapproximately 4.6 billion, 300 times the 1990 number, penetrating the developing economies and reaching the bottom of the economic pyramid.[4]
Contents * 1 History * 2 Handset Features * 2.1 Software and applications * 2.2 Power supply * 2.3 SIM card * 3 Mobile phones in society * 3.1 Market share * 3.2 Media * 4 Uses * 5 Privacy * 6 Restriction on usage *6.1 Use while driving * 6.2 Schools * 7 Future evolution: Broadband Fourth generation (4G) * 8 Comparison to similar systems * 9 See also * 10 References * 11 Further reading * 12 External links |
History

Mobile car phone, 1964

Several examples of non-flip mobile phones, from the early 2000s.

History of mobile phones
Radiophones have a long and varied history going backto Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held mobile radio devices have been available since 1973.
In 1960, the world’s first partly automatic car phone system, Mobile System A (MTA), was launched in Sweden. MTA phones were composed ofvacuum tubes and relays, and had a weight of 40 kg. In 1962, a more modern version called Mobile System B (MTB) was launched, which was a push-button telephone, and which used transistors in order to enhance the telephone’s calling capacity and improve its operational reliability. In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success.Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for hand-held use in a non-vehicle setting, after a long race against Bell Labs for the first portable mobile phone. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone on April 3, 1973 to his rival, Dr. Joel S. Engel ofBell Labs.[7]
The first commercially automated cellular network (the 1G generation) was launched in Japan by NTT in 1979, initially in the metropolitan area of Tokyo. Within five years, the NTT network had been expanded to cover the whole population of Japan and became the first nation-wide 1G network. In 1981, this was followed by the simultaneous launch of the Nordic Mobile Telephone (NMT)...