手机火车汉字发展史英文版.doc

手机 火车 汉字发展史英文版 手机发展史英文版 The history of mobile phones begins with early efforts to develop radio telephone technology and from two-way radios in vehicles and continues through emergence of modern mobile phones and associated services. Radiophones have a long and varied history going back to Reginald Fessendens invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held mobile radio devices have been available since 1973. 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. Contents [hide] 1 Pioneers of radio telephony 2 Emergence of commercial mobile phone services 3 First generation: Cellular networks 4 Second generation: Digital networks 5 Third generation: High speed IP data networks 6 Growth of mobile broadband and the emergence of 4G 7 Patents 8 See also 9 Notes 10 References 11 External links [edit] Pioneers of radio telephony In 1908, U.S. Patent 887,357 for a wireless telephone was issued to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to cave radio telephones and not directly to cellular telephony as the term is currently understood.[1] In 1910 Lars Magnus Ericsson installed a telephone in his car, although this was not a radio telephone. While travelling across the country, he would stop at a place where telephone lines were accessible and using a pair of long electric wires he could connect to the national telephone network.[2] In Europe, radio telephony was first used on the first-class passenger trains between Berlin and Hamburg in 1926. At the same time, radio telephony was introduced on passenger airplanes for air traffic security. Later radio telephony was introduced on a large scale in German tanks during the Second World War. After the war German police in the British zon