ＧＳＭ─全球移动通信系统曹永秋当今社会已进入信息时代，电话、移动电话、无绳电话、寻呼机—……层出不穷的电信器材使人眼花级乱。它们已成为传递信息，改善人们物质文化生活的重要工具。电话的发展与其他电子产品一样，必须迅速向数字化、小型化、智能化及系统化发展... GSM ─ global mobile communication system Cao Yongqiu Today’s society has entered the information age, the telephone, mobile phones, cordless phones, pagers - ... ... an endless stream of telecommunications equipment dazzled. They have become an important tool for transmitting information and improving people’s material and cultural life. As with other electronic products, the development of the phone must rapidly move towards digitization, miniaturization, intelligence and systematization ...