What is the network transmission medium?

There are four kinds of transmission media in computer networks.

1, twisted pair: shielded twisted pair (STP).

Unshielded twisted pair (UTP)

Features: It is easily interfered by external high-frequency electromagnetic waves and has high bit error rate, but it is still widely used because of its low price and convenient installation, which is suitable for both point-to-point connection and multipoint connection.

2. Coaxial cable: 50 W coaxial cable? 75 W coaxial cable

Features: high bandwidth (up to 300 ~ 400 Hz), low bit error rate and high cost performance, so it is used in LAN.

3. Optical cable?

Features: small diameter and light weight; Large transmission frequency bandwidth and communication capacity; Good lightning and electromagnetic interference resistance, no crosstalk interference, good confidentiality and low bit error rate. But the price of photoelectric interface is more expensive. Optical fiber is widely used to lay the trunk line of telecommunication system.

4. Wireless transmission: short wave communication/microwave/satellite communication.

Features: high frequency, wide frequency band and large communication channel capacity; The signal has little industrial interference, high transmission quality and relatively stable communication; Not affected by the geographical environment, the construction investment is small.

Extended data:

Transmission medium characteristics:

1, physical characteristics. Explain the characteristics of the media.

2. Transmission characteristics. Include signal form, modulation technology, transmission speed and frequency band width.

3. Connectivity. Point-to-point or multipoint connection.

4. Geographical scope. The maximum distance between two points on the internet.

5. Anti-interference. Ability to prevent noise and electromagnetic interference from affecting data transmission.

6. Relative price. Based on the price of components, installation and maintenance.

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