在此世纪之交之年,当个人通信的概念逐渐被更多的人们所认识后,无论是第三代移动通信,还是无线用户本地环路(WLL)都是当前的热点。从外部特性来看可以归纳以下几个方面,即业务范围、覆盖区域和支持的终端种类。构成这个系统的网络应该是一个宽带综合业务网。系统支持的业务包括:语音、数据、图片、图象和其他新的业务。对于第三代移动通信系 In the turn of the century, when the concept of personal communication is gradually recognized by more and more people, both the third generation mobile communication and the wireless local loop (WLL) are the current hot spots. In terms of external characteristics, the following aspects can be summarized: service area, coverage area and supported terminal types. The network that makes up this system should be a broadband integrated services network. Services supported by the system include: voice, data, pictures, images and other new services. For the third generation of mobile communications