Classification of communication cables
Communication cables can be divided into the following three categories:1, long-distance cable: long transmission distance, generally multiplexing, mostly buried directly in the ground, in a few cases by overhead installation, or installed in the pipeline.2, the cable conductor: "in the cable, and the logarithmic in pairs.". Generally installed in the pipe, a small amount of city cables are attached to buildings or overhead installations.3, office cable: mainly refers to the use of the communication cable telecommunications bureau, usually installed in the frame, there are installed in cable chute; Office cable for telecommunication station transmission equipment and switching equipment, office equipment and other internal. In the telecommunication office, in order to prevent fire, it is sometimes necessary to add a flame retardant sheath to the office cable.
In accordance with the type of cable, the communication cables are classified as follows:1, single wire: refers to the most primitive communication cable, single wire loop, the earth as a regression line.2 symmetrical cables: the circuit consists of two wires which are identical in the ideal condition.3. Coaxial cable: the inner and outer conductors of the same axis form the circuit, the outer conductor surrounds the inner conductor, and the two are insulated. If the application situation
