手机火车汉字发展史英文版

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 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.

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 \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 zone of occupation first used disused tank telephony equipment to run the first 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.

Two-way radios (known as mobile rigs) were used in vehicles such as taxicabs, police cruisers, and ambulances, but were not mobile phones because they were not normally connected to the telephone network. Users could not dial phone numbers from their vehicles. A large community of mobile radio users, known as the mobileers, popularized the technology that would eventually give way to the mobile phone. Originally, mobile two-way radios were permanently installed in vehicles, but later versions such as the so-called transportables or \could also be carried, and thus could be used as either mobile or as portable two-way radios. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie and later developed a large hand-held two-way radio for the US military. This battery powered \

In 1946 soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version of a radio mobile phone mounted inside a car. The device could connect to local telephone network with a range of up to 20 kilometers.

Top of cellular telephone towerIn December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in vehicles.[3] Philip T. Porter, also of Bell Labs,

proposed that the cell towers be at the corners of the hexagons rather than the centers and have directional antennas that would

transmit/receive in three directions (see picture at right) into three adjacent hexagon cells.[4] The technology did not exist then and the frequencies had not yet been allocated. Cellular technology was undeveloped until the 1960s, when Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the electronics.

During 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 1958, Kupriyanovich resized his \version. The weight of improved \

In 1967, each mobile phone had to stay within the cell area serviced by one base station throughout the phone call. This did not provide continuity of automatic telephone service to mobile phones moving through several cell areas.

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. Dialing a number for outgoing calls was not provided.

The concepts of frequency reuse and handoff, as well as a number of other concepts that formed the basis of modern cell phone technology, were described in the 1970s. In 1970 Amos E. Joel, Jr., another Bell Labs engineer,[6] invented an automatic \handoff\system to allow mobile phones to move through several cell areas during a single conversation without loss of conversation. Also Fluhr and Nussbaum,[7] Hachenburg et al.[8] , and U.S. Patent 4,152,647, issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.

汉字发展史英文版

In the last 50 or so years, inscriptions have been found on pottery in a variety of locations in China such as Bànpō near Xī'ān, as well as on bone and bone marrows at Hualouzi, Chang'an County near Xi'an. These simple, often geometric marks have been frequently compared to some of the earliest known Chinese characters, on the oracle bones, and some have taken them to mean that the history of Chinese writing extends back over six millennia.

However, because these marks occur singly, without any context to imply, and because they are generally extremely crude and simple, Qiú Xīguī (2000, p. 31) concluded that \do not have any basis for stating that these constituted writing, nor is there reason to conclude that they were ancestral to Shang dynasty Chinese characters.\graphs and pictures continue to be found periodically, frequently