01:04 AM
ramesh ahir
History of mobile phones
The history of mobile phones begins with early efforts to develop mobile telephony concepts using two-way radios and continues through emergence of modern mobile phones and associated services.
Radiophones have a long and varied history going back to Reginald Fessenden's 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.
However it was the 1940s onwards that saw the seeds of technological development which would eventually produce the mobile phone that we know today. Motorola developed a backpacked two-way radio, the Walkie-Talkie and a large hand-held two-way radio for the US military. This battery powered "Handie-Talkie" (HT) was about the size of a man's forearm. In 1946 in St. Louis, the Mobile Telephone Service was introduced. Only three radio channels were available, and call set-up required manual operation by a mobile operator. Also that year, Soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version of a radio mobile phone mounted inside a car. This device could connect to local telephone network with a range of up to 20 kilometers.[citation needed]
Top of cellular telephone towerDuring the 1950s the experiments of the pioneers started to appear as usable services across society, both commercially and culturally. In the 1954 movie Sabrina, the businessman Linus Larrabee (played by Humphrey Bogart) makes a call from the phone in the back of his limousine. In 1957 a young Soviet radio engineer Leonid Kupriyanovich from Moscow created a portable mobile phone, and named it the LK-1 after himself.[1] This mobile phone consisted of a relatively small handset equipped with an antenna and rotary dial, and communicated with a base station. The LK-1 weighed 3 kilograms and could operate in a range of up to 20 or 30 kilometers. The battery lasted 20 to 30 hours. The LK-1 was depicted in popular Soviet magazines as Nauka i zhizn. Kupriyanovich patented his mobile phone in the same year. The base station serving the LK-1 (called ATR, or Automated Telephone Radiostation) could connect to local telephone network and serve several customers. During 1958, Kupriyanovich produced a "pocket" version. The weight of improved lighter handset was about 500 grams.
In 1964 Improved Mobile Telephone Service was introduced with additional channels and more automatic handling of calls to the public switched telephone network. Even the addition of radio channels in three bands was insufficient to meet demand for vehicle-mounted mobile radio systems.
In 1969, a patent for a wireless phone using an acoustic coupler for incoming calls was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969, but did not include dialing a number for outgoing calls.
The history of mobile phones begins with early efforts to develop mobile telephony concepts using two-way radios and continues through emergence of modern mobile phones and associated services.
Radiophones have a long and varied history going back to Reginald Fessenden's 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.
Pioneers of radio telephony
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 zone of occupation first used surplus tank telephony equipment to run radio patrol cars.[citation needed] In all of these cases the service was confined to specialists that were trained to use the equipment. In the early 1950s ships on the Rhine were among the first to use radio telephony with an untrained end customer as a user.However it was the 1940s onwards that saw the seeds of technological development which would eventually produce the mobile phone that we know today. Motorola developed a backpacked two-way radio, the Walkie-Talkie and a large hand-held two-way radio for the US military. This battery powered "Handie-Talkie" (HT) was about the size of a man's forearm. In 1946 in St. Louis, the Mobile Telephone Service was introduced. Only three radio channels were available, and call set-up required manual operation by a mobile operator. Also that year, Soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version of a radio mobile phone mounted inside a car. This device could connect to local telephone network with a range of up to 20 kilometers.[citation needed]
In 1964 Improved Mobile Telephone Service was introduced with additional channels and more automatic handling of calls to the public switched telephone network. Even the addition of radio channels in three bands was insufficient to meet demand for vehicle-mounted mobile radio systems.
In 1969, a patent for a wireless phone using an acoustic coupler for incoming calls was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969, but did not include dialing a number for outgoing calls.
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