一、引言８０年代初，公安通信业务从单一的语音通信，逐步向图文及语言通信发展，广州公安开始逐步发展传真业务。随着科学技术的不断发展，公安传真业务发展迅速。十几年来，经历了三个发展阶段：１．初期，使用国产的滚筒式传真机（称为一类机），利用公安专网的线路传输； I. INTRODUCTION In the early 1980s, the public security communications business gradually developed from graphic communications and graphic communications to voice communications from a single voice communications. The public security in Guangzhou began to gradually develop its fax business. With the continuous development of science and technology, public security fax business has developed rapidly. More than a decade, has gone through three stages of development: 1. Early use of domestic drum fax machine (known as a class of machines), the use of public security network transmission line;