According to the diameter of the coaxial cable, it can be divided into thin coaxial cable and thick coaxial cable. The impedance of the thin cable is 50Ω, the diameter is 0.26 cm, and the maximum transmission distance is 185 meters. When in use, it is connected to 50Ω terminating resistor, T-type connector, BNC connector and network card. The wire and cable cost of the cable is relatively cheap, and there is no need to purchase equipment such as a hub, which is very suitable for establishing a small Ethernet network using relatively concentrated terminal equipment. The total length of the thin coaxial cable must not exceed 185 meters, otherwise the signal will be severely attenuated. The impedance of the thick cable is 75Ω, the diameter is 1.27 cm, and the maximum transmission distance can reach 500 meters. Because of its large diameter, it has poor elasticity, so it is not suitable for installation in narrow indoor environments. Therefore, the main purpose of the thick cable is to play the role of the network. The backbone network is used to connect multiple networks composed of thin cables. Thick cables are suitable for relatively large LANs. Long standard distance and high reliability. Since there is no need to cut the cable during the installation process, the network access location of the computer can be flexibly adjusted as needed. But the thick cable network must install transceivers and transceiver cables, installation is difficult, so the overall cost is higher. In order to maintain the correct electrical characteristics of the coaxial cable, the cable shield must be grounded. At the same time, there must be terminators at both ends to reduce signal reflection. Shenzhen Mocolink Electronics usually uses thin coaxial cables, the most commonly used models are RG58, RG59, RG174 and RG316.