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近年来,移动通信作为现代社会经济和技术高度发展的产物,正越来越受到世界各国的重视。随着现代大经济、大科技、大市场的渗透和发展,人们在社会中的交往的沟通日益频繁,对信息数量和质量的需求不断提高,它正以日新月异、一日千里的速度发展。当今,移动通信国内外市场和应用的前景十分广阔诱人。 一、国外移动通信发展迅猛 移动通信作为一种主要的通信方式,早在第一次世界大战期间,就被人们利用长中短波无线电波在车船等移动体上装用。四十年代末期开始建立以基地台为中心的甚高频多信道小容量移动通信网,以人工转接方式与公众市话网联接。六十年代中期又进一步改成自动拨号通话,信道数增多,用户数达到中容量,使用频率也扩展到
In recent years, mobile communication, as a product of the modern socio-economic and technological development, is receiving more and more attention from all over the world. With the penetration and development of the modern economy, big science and technology, and big market, people’s communication in the society has been increasingly frequent and the demand for information quantity and quality has been constantly increasing. Nowadays, it is developing at a rapid pace with ever-changing speed. Today, the prospects of mobile communications markets and applications are very attractive. First, the rapid development of foreign mobile communications Mobile communications as a major means of communication, as early as during the First World War, was used by people in the long-shortwave radio waves in vehicles and other mobile body loaded with. The end of the forties began to establish a base station as the center of the VHF multi-channel small-capacity mobile communications network, with artificial public transit network connection. The mid-1960s was further changed to automatic dial-up calls, the number of channels increased, the number of users reached capacity, the use of frequency also extended to