Global System for Mobile Communication is a short form of the digital mobile communication net, which is the most developed and advanced digital mobile communication system. This technology owns the largest scale, fastest developing speed and most valuable use for merchant, and the terminal unit——GSM telephone is the most popular among the mobile communicational products. With the developing and popularization of the communicational network, the application of the data business becoming more and more popular. Although the mobile communicational technology brings people to communicate, it is far from enough to realize more dreams of people, handle business while motioning for example. And now, the technology of GPRS supplies faster and more efficient data communication quality for the widely applied public communicational system. Especially in recent years, the mobile communication industries are flouring day by day, to make use of their advantage spontaneously on the research, desigh, manufacture and circulation, to improve their abilities in the competition to survive in this field.In the field of telephone manufacture, the efficient use and proper protection of the frequency resource is necessary for the good of nation's security and public's safety of life and property, to maintain the order of normal electric wave in the air, guarantee all kinds of wireless communicational devices work in right order.
