What is a communication line?
Distinguish by importance:If the importance of communication lines, communication lines can be divided into one level of line, two lines and three lines.1) level 1 line: refers to the capital to the provinces, municipalities and autonomous regions, the capital, the provincial capital and municipality directly under the central government, the autonomous region and the capital of the Ministry designated by the Ministry of long-distance lines and international routes.2) level two lines: refers to the provinces, municipalities directly under the central government, the capital of the autonomous region to the municipalities, counties, municipalities, counties, neighboring provinces, counties and telecommunications between the designated long-distance lines.3) level three line: refers to the communication line below the county. Also known as local lines. Such as city communication lines are divided into inter Bureau trunk lines and user lines of two categories. The inter office trunk lines include the central office trunk line and the long-distance and municipal trunk line. The subscriber line can be divided into two categories: feeder and wiring.If the application area is divided according to the communication line, the communication line can also be divided into long distance lines, city lines and rural lines, etc..
Differentiated by transmission medium:There are different classifications of communication lines. If divided by the transmission medium, they can be divided into the following four categories:1) overhead;2) communication cable;3) communication fiber optic cable;4) communication cable.
Communication line is the gateway to ensure the transmission of information. At present long-distance trunk line, the cable is mainly uses the big core number of fiber optic cable, moreover has the satellite, the microwave and so on wireless line. The long distance between provinces and provinces is mainly fiber optic cable, with microwave and satellite circuits. The definition, history, classification, technology and trends of communication lines are introduced below. It also includes the professional setting of communication line, communication line equipment and communication line regulations and so on.
