Mobile telephony

Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Mobile phones connect to a terrestrial cellular network of base stations (cell sites), whereas satellite phones connect to orbiting satellites. Both networks are interconnected to the public switched telephone network (PSTN) to allow any phone in the world to be dialed.

In 2010 there were estimated to be five billion mobile cellular subscriptions in the world.

According to internal memos, American Telephone & Telegraph discussed developing a wireless phone in 1915, but were afraid that deployment of the technology could undermine its monopoly on wired service in the U.S.

Public mobile phone systems were first introduced in the years after the Second World War and made use of technology developed before and during the conflict. The first system opened in St Louis, Missouri, USA in 1946 whilst other countries followed in the succeeding decades. The UK introduced its 'System 1' manual radiotelephone service as the South Lancashire Radiophone Service in 1958. Calls were made via an operator using handsets identical to ordinary phone handsets. The phone itself was a large box located in the boot (trunk) of the vehicle containing valves and other early electronic components. Although an uprated manual service ('System 3') was extended to cover most of the UK, automation did not arrive until 1981 with 'System 4'. Although this non-cellular service, based on German B-Netz technology, was expanded rapidly throughout the UK between 1982 and 1985 and continued in operation for several years before finally closing in Scotland, it was overtaken by the introduction in January 1985 of two cellular systems - the British Telecom/Securicor 'Cellnet' service and the Racal/Millicom/Barclays 'Vodafone' (from voice + data + phone) service. These cellular systems were based on US Advanced Mobile Phone Service (AMPS) technology, the modified technology being named Total Access Communication System (TACS).

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