Optical cable has been widely used in various networks due to its advantages such as light weight, small volume, long transmission distance, large capacity, small signal attenuation, and anti electromagnetic interference. With the coming of the 21st century, optical cable has become the main part of China's network data transmission, communication, cable radio and television and other special networks. When selecting twisted pair cable and coaxial cable, its performance can be generally judged through visual inspection and simple test. However, the selection of optical cable is not so simple. Compared with twisted pair cable and coaxial cable, it is not only complex in structure and various in materials, but also has many potential factors (materials, production process, equipment, etc.) in addition to existing technical parameters. If you are careless, let alone 20 or 30 years of service life, Even years of technical parameters may not meet the standard. Therefore, when we are building the network, it is necessary to have a deep understanding of the structure, materials, process, etc. of optical cables, so as to select and purchase high-quality optical cables of appropriate models.

1. Select optical cable according to the number of cores

According to the number of cores, different types of optical fiber cable can be divided into central bundle tube type, layer stranded type, skeleton type and ribbon type. Different application structures are different. Users can put forward corresponding requirements according to the line conditions. Generally, the central bundle pipe type is used for those with less than 12 cores. The central bundle pipe type process is simple and low cost, and it is competitive in overhead laying or branch and main line network with good pipeline protection; The layer twisted optical cable is reinforced by steel strand placed in the center or a single steel wire, and SZ continuous composite cable is used, with the number of cables up to 144 cores. Its greatest advantages are waterproof, anti strong pulling force and strong side pressure. It can be used for direct burial. At the same time, it is easy to bifurcate, that is, when some optical fibers of the optical cable need to be used separately, it is not necessary to disconnect the entire optical cable, just disconnect the optical fiber that needs to bifurcate, which is for the data communication network. It is advantageous to add optical nodes along the cable TV network; The number of cores of ribbon optical cable can reach thousands. It is to arrange 4~12 core optical fibers in a row to form a ribbon optical fiber unit, and then arrange several ribbon units into cables in a certain way. Our network level optical cables generally use two types: bundle tube type and layer by layer type.

2. Select optical fiber cable according to its use

Select and purchase the corresponding optical cables according to the different purposes. Optical cables can be divided into overhead optical cables, directly buried optical cables, pipeline optical cables, submarine optical cables and metal free optical cables. The overhead optical cable requires high strength and small temperature difference coefficient; Direct buried optical cables shall be resistant to burial, compression, moisture, humidity and chemical corrosion; Pipeline optical cable and submarine optical cable shall be resistant to water pressure, tension and water; The metal free optical cable can be erected together with the high-voltage line, and the insulation is good. Although there is no iron reinforcement core, it should also have a certain tensile capacity. Therefore, when selecting and purchasing optical cables, users should select according to the use of optical cables and put forward requirements to the manufacturer to ensure the stable and reliable use of optical cables.