论文部分内容阅读
美国电报电话公司ATT宣布,为适应高度信息化社会的需要,到1990年该公司将建成以光缆传输为主体的全国高速数字通信网。这一巨大的工程号称“世界上最大的光纤通信网路”,包括建设21000英里光缆线路,和在1987年前建成9000英里数字微波网路,同时对ATT原有的4500英里模拟同轴电缆线路完成数字化改造。按此计划,ATT将以数字光缆线路连接全国主要城市,不在光缆线路沿线的城市地区用数字微波和经过数字化改造的同轴电缆线路连接,这样即可在全国范围内实现电话、数据和视频信号的高速数字传输。本工程的实施将使ATT长途通信网的数字化率由目前的4％提高到35—40％。
At ATT, AT & T announced that in order to meet the needs of a highly informatized society, by 1990 the company will build a national high-speed digital communications network with cable transmission as its mainstay. Known as “the world’s largest fiber-optic communications network,” this huge project includes the construction of 21,000 miles of fiber-optic cable lines, the construction of a 9,000-mile digital microwave network by 1987 and the addition of ATT’s original 4500-mile analog coax cable Complete digital transformation. According to the plan, ATT will connect the major cities in the country with digital optical cable lines, and will not connect with digitally modified coaxial cable lines in urban areas along the optical cable lines so that telephone, data and video signals can be realized nationwide High-speed digital transmission. The implementation of this project will increase the digitization rate of the ATT long distance communications network from the current 4% to 35-40%.