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在无线通信世界,GSM 标准已在世界各地取得广泛的支持,开始由欧洲首创的东西已成为事实上的世界标准。但是GSM 没有独占市场:全世界移动电话用户的总安装基数中一半以上连接的网络都以美国而不是欧洲提出的无线标准为基础。高级移动电话业务(AMPS)标准及其数字版 D-AMPS-共占了约8千万用户。目前他们中的大多数(约7千万)连接到模拟 AMPS 网。即使如此,在现有网络设施上能将 AMPS 网
In the world of wireless communications, the GSM standard has gained widespread support around the world and what started as the first in Europe has become the de facto world standard. But GSM does not have an exclusive market: more than half of the total installed base of mobile phone users worldwide is connected to a network based on wireless standards proposed by the United States instead of Europe. The Advanced Mobile Phone Service (AMPS) standard and its digital version of D-AMPS- collectively account for about 80 million users. Currently, most of them (about 70 million) are connected to the analog AMPS network. Even so, AMPS can be deployed on existing network infrastructure