Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception are satellite phones). Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation). The first fully automatic cell phone system was the Nordic Mobile Telephone (NMT) system, introduced in 1981.
Prior mobile telephones (the so-called 0G generation), such as Mobile Telephone Service, date back to 1945. These were not categorized as cellular phones, since they did not support handover, i.e. automatic change of channel frequency in the middle of a call, when the user moved from one cell (base station coverage area) to another.
Until the mid to late 1980s, most mobile phones were sufficiently large that they were permanently installed in vehicles as car phones. With the advance of miniaturization, currently the vast majority of mobile phones are handheld. In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video.
Mobile phone manufacturers include Apple Inc., Audiovox, Benefon, BenQ-Siemens, High Tech Computer Corporation, Fujitsu, Kyocera, 3G, LG, Motorola, NEC, i-mate, Nokia, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Sagem, Samsung, Sanyo, Sharp, Siemens, SK Teletech, Sony Ericsson, T&A Alcatel, T-Mobile, and Toshiba.
There are also specialist communication systems related to, but distinct from mobile phones, such as Professional Mobile Radio. Mobile phones are also distinct from cordless telephones, which generally operate only within a limited range of a specific base station. Technically, the term mobile phone includes such devices as satellite phones and pre-cellular mobile phones such as those operating via MTS which do not have a cellular network, whereas the related term cell(ular) phone does not. In practice, the two terms are used nearly interchangeably, with the preferred term varying by location. There are many different networks on mobile phones. Some are pay as you go, where top-ups can be purchased and added to a phone unit, so there is no monthly bill. Many are "pay monthly", where a bill is issued every month for the amount of calls and text messages made.
The concept of using hexagonal cells for mobile phone base stations was invented in 1947 by Bell Labs engineers at AT&T (see History of mobile phones) and was further developed by Bell Labs during the 1960s. In 1970 Amos Joel of Bell Labs invented "call handoff" that allowed a mobile phone user to travel through several cells during the same conversation. Martin Cooper of Motorola is widely considered to be the inventor of the first practical cell phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a handheld cell phone on April 3, 1973. At the time he made his call, Cooper was working as Motorola's General Manager of its Communications Division.
Mock-up of the "portable phone of the future," from a mid-1960s Bell System advertisement, shows a device not too different from today's mobile telephones.
Radiophones have a long and varied history that stretches back to the 1950s, with hand-held cellular radio devices being available since 1983. Due to their low establishment costs and rapid deployment, mobile phone networks have since spread rapidly throughout the world, outstripping the growth of fixed telephony.
Luxembourg has the highest mobile phone penetration rate in the world, at 164% in December 2005. [1] In Hong Kong the penetration rate reached 117% of population in September 2004.[1] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.[2] Around 80% of world's population have mobile phone coverage as of 2006. This figure is expected to increase to 90% by the year 2010.[3]
At present, Africa has the largest growth rate of cellular subscribers in the world.[4] African markets are expanding nearly twice as fast as Asian markets.[5] The availability of Prepaid or pay as you go services, where the subscriber does not have to commit to a long term contract, has helped fuel this growth on a monumental scale, not only in Africa but on other continents as well.
All European nations and most Asian and African nations have adopted GSM. In other countries, such as the United States, Australia, Japan, and South Korea, legislation does not require any particular standard, and GSM coexists with other standards, such as CDMA and iDEN.
