无绳电话是一种新型移动通信方式。无绳电话技术经过20多年的发展,已从第一代进入到第二代,目前正在大力开发第三代产品。到1993年底,全世界无绳电话已达5000余万部,并且仍以25%的年增长率递增。第一代无绳电话是供室内使用的,亦称子母电话机,即一个母机带一个子机。母机与公用电话网相连,子机可在母机的无线电波覆盖范围内(一般是几百米)进行移动通话。由于采用模拟技术,通话质量不很理想,保密性也差。第二代无绳电话是80年代初开始研制的。由于采用数字技术,使无绳电话走出家庭,进入密度较高的 Cordless phones are a new type of mobile communication method. After more than 20 years of development, the cordless phone technology has entered the second generation from the first generation, and the third generation product is being vigorously developed. By the end of 1993, more than 50 million cordless phones had reached the world level, and their annual growth rate still increased by 25%. The first generation of cordless phones for indoor use, also known as the parent telephone, that is, a parent machine with a child machine. The main unit is connected to the public switched telephone network. The sub units can make mobile calls within the radio coverage of the main unit (typically a few hundred meters). As the use of analog technology, call quality is not very satisfactory, confidentiality is poor. The second generation of cordless phones was developed in the early 1980s. As a result of digital technology, so that cordless phones out of the home, into the higher density