Differences in transmission media commonly used on the Internet

The network requires that each independent computer be connected. In this way, there must be a medium that connects the computer. This is the transmission medium, lan transmission media can be divided into wired and wireless media. Generally, wired media is used because of its high stability and reliable connection, wireless media is only used in special environments.

Common wired media mainly includes the following types.

(1) Coaxial Cable

The coaxial cable uses hard copper wires as the core to outsource a layer of insulation material. This layer of insulation material is surrounded by a woven mesh conductor, and a protective material is covered outside the mesh. There are many different types of coaxial cable, the most commonly used is fine coaxial cable and coarse coaxial cable.

The fine coaxial cable is mainly used for network connection in buildings, while the coarse coaxial cable is often used for connection between buildings. The difference between them is that the coarse coaxial cable has better shielding and can transmit farther distances. The coaxial cable consists of a shield layer consisting of a central conductor, an insulating material layer, a mesh fabric, and an external isolation material layer. Its structure 1 is shown below:

Figure 1 coaxial cable structure

(2) twisted pair wires

Twisted Pair wires are the most common transmission medium in integrated cabling. Twisted Pair wires are composed of two copper wires with an insulating protective layer.

The two insulated copper wires are twisted together at a certain density to reduce signal interference, the electric waves emitted by each wire during transmission are offset by the electric waves sent from the other wire. Compared with other transmission media, twisted Pair wires are limited in terms of transmission distance, channel width, and data transmission speed, but the price is relatively low.

Currently, twisted pair wires can be divided into unshielded twisted pair wires and shielded twisted pair wires. The structure of twisted pair 2 is shown as follows:

Figure 2 Category 4 unshielded twisted pair wires

(3) optical fiber

Optical fiber is a type of direct 50 ~ 100um is a soft medium that can transmit light waves. It is generally made of glass. Optical fibers include SingleModeFiber and MultiModeFiber ). The diameter of the core of a single-mode optical fiber is very small. It can only be transmitted in a single mode at a given working wavelength. The transmission bandwidth and capacity are large.

Multi-mode optical fiber is an optical fiber that can be transmitted simultaneously in multiple modes at a given working wavelength. Compared with single-mode optical fiber, multi-mode optical fiber has poor transmission performance. The basic structure of the optical fiber communication system is 3.

Figure 3 basic structure of the Optical Fiber Communication System