The introduction of cells for mobile phone base stations, invented in 1947 by Bell Labs engineers at AT&T, was further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been 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.
In 1945, the zero generation (0G) of mobile telephones was introduced. 0G mobile telephones, such as Mobile Telephone Service, were not officially categorized as mobile phones, since they did not support the automatic change of channel frequency during calls, which allows the user to move from one cell (the base station coverage area) to another cell, a feature called "handover". In 1970, Bell Labs invented such a "call handoff" feature, which allowed mobile-phone users to travel through several cells during the same conversation. Motorola is widely considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, they made the first call on a handheld mobile phone in April, 1973.
The first commercial cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation) with the Nordic Mobile Telephone (NMT) system in 1981.
In less than twenty years, mobile phones have gone from being rare and expensive pieces of equipment used primarily by the business elite to a pervasive low-cost personal item. In many countries, mobile phones now outnumber land-line telephones, with most adults and many children using mobile phones. In the United States, 50% of children are using mobile phones.[9]
In many young adults' households the mobile phone has supplanted land-line telephones. In some areas in developing countries with scarce fixed-line infrastructure, the mobile phone has introduced telephony as such. It has given poor people in isolated communties access to services that are considered elementary human rights, such as medical and legal advice. However, the mobile phone is also banned in some countries like North Korea.[10]
With high levels of mobile telephone penetration , mobile culture has evolved where the phone is a key social tool with people relying on their mobile phone address book to keep in touch with friends, not least by SMS, and a whole culture of "texting" has developed from this. The commercial market in SMSs is growing. Many phones offer Instant Messenger services to increase the simplicity and ease of texting on phones. Mobile phones in Japan, offering Internet capabilities such as NTT DoCoMo's i-mode, offer text messaging via standard e-mail.