The coaxial cable is composed of a hollow outer cylindrical conductor and an inner conductor which is located in the central axis. Insulating material is separated from the inner conductor and the cylindrical conductor and the outside. According to the different transmission band, coaxial cable can be divided into two types: base band coaxial cable and broadband coaxial cable.
According to the different diameter of the coaxial cable, can be divided into two kinds of thin and thick cable. Cablet fast development in recent years, so the computer LAN in general if no special requirements are used in networking cablet. Cablet generally used for bus type wiring connection network. The T interface card is connected to the BNC interface card by using the BNC type interface connector. Thinnet cable joint network each section of route length maximum 185 meters, each section of route access up to 30 users. To broaden the scope of the network, requiring the use of repeaters, such as the use of four repeaters connected five segment, maximum network distance to 925 meters. Cablet easier installation, and low cost, but due to the limitation of network wiring structure, its daily maintenance is not very convenient, once a fault is a user will influence the normal operation of other users.
The thick cable is suitable for the main network of the large area network, the wiring distance is longer, and the reliability is better. The user usually uses an external transceiver to connect to the network trunk. Thickwire LAN each segment up to 500 meters in length, with 4 repeaters connecting the 5 segments after a maximum of up to 2500 meters. If the network is connected directly with the network card, the network card must have a AUI interface (15 pin D interface). Although the performance of the network is high, the cable connector installation process has a larger transmission distance, but the network installation, maintenance and other aspects of the more difficult, the cost is higher.