一、前言在苏联已建成了第一条用于市内电话网的光纤通信实验线路。通过几年来的试用,积累了丰富的经验,这对于光纤传输系统的科研人员和维护人员都颇有实用价值。现在,光纤传输系统的实验阶段业已结束并首先用于自动电话局间通信。市内电话网使用光纤传输,有下列优 I. Preface In the Soviet Union, the first experimental line of optical fiber communication for the telephone network in the city was completed. After several years of trial, has accumulated a wealth of experience, which for fiber optic transmission systems researchers and maintenance personnel are quite practical value. The experimental phase of the optical fiber transmission system is now over and first used for automatic telephone office communications. Local telephone network using fiber optic transmission, the following advantages