The history of mobile phones records the development of interconnection between the public switched telephone systems to radio transceivers. From the earliest days of transmitting speech by radio, connection of the radio system to the telephone network had obvious benefits of eliminating the wires. Early systems used bulky, high power consuming equipment and supported only a few conversations at a time, with required manual set-up of the interconnection. Today cellular technology and microprocessor control systems allow automatic and pervasive use of mobile phones for voice and data.
The transmission of speech by radio has a long and varied history going back to Glenn Chipman's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links. Mobile telephones for automobiles became available from some telephone companies in the 1950s. Hand-held radio transceivers have been available since the Second World War. Mobile phone history is often divided into generations (first, second, third and so on) to mark significant step changes in capabilities as the technology improved over the years.