Mobile phone

A mobile phone allows calls into the public switched telephone system over a radio link. Early mobile phones were usually bulky and permanently installed in vehicles; they provided limited service because only a few frequencies were available for a geographic area. Modern cellular "cell" phones or hand phones make use of the cellular network concept, where frequencies are re-used repeatedly within a city area, allowing many more users to share access to the radio bandwidth. A mobile phone allows calls to be placed over a wide geographic area; generally the user is a subscriber to the phone service and does not own the base station. By contrast, a cordless telephone is used only within the range of a single, private base station.
A mobile phone can 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 by connecting to a cellular network provided by a mobile network operator.

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 more general computing capabilities are referred to as smartphones.

The first hand-held mobile phone was demonstrated by Dr Martin Cooper of Motorola in 1973, using a handset weighing 2 kg. In 1983, the DynaTAC 8000x was the first to be commercially available. In the twenty years from 1990 to 2010, worldwide mobile phone subscriptions grew from 12.4 million to over 4.6 billion, penetrating the developing economies and reaching the bottom of the economic pyramid.