What are the common transmission media

Question 1: What are the common network transmission media The network transmission media is the entity in the network that transmits data and connects the various network sites. Network information can also be transmitted using radio systems, microwave radio systems and infrared technology. At present, the common network transmission medium are: twisted pair, coaxial cable, fiber optic and so on.

A twisted-pair cable (TP): more than one pair of twisted-pair wires encapsulated in an insulated jacket, in order to reduce the degree of signal interference, each pair of twisted-pair wires in the cable is generally twisted by two insulated copper wires twisted each other, and so it is also known as twisted-pair cable. Twisted pair cable is divided into unshielded twisted pair (UTP) and shielded twisted pair (STP).

Currently on the market for sale UTP is divided into Category 3, Category 4, Category 5 and ultra Category 5 four:

Category 3: transmission rate support 10Mbps, the outer layer of the protective rubber skin is thinner, the skin is noted on the "cat3"

Category 4: not commonly used in the network

Category 5 (Category 5) (ultra Category 5): transmission rate support 100Mbps. ): transmission rate support 100Mbps or 10Mbps, the outer layer of protective rubber is thicker, the skin is marked "cat5"

Super Category 5 twisted-pair cable in the transmission of signals than ordinary Category 5 twisted-pair attenuation is smaller, stronger anti-jamming ability, in the 100M network, the degree of interference is only ordinary Category 5 line of the 1 / 4.

The STP cable has been used for many years, and is now less used.

STP is divided into two types of Category 3 and Category 5, STP's internal and UTP the same, outsourcing aluminum foil, strong anti-jamming ability, high transmission rates but expensive.

Twisted-pair cable is generally used for star network cabling connections, installed at both ends with RJ-45 head (crystal head), connecting the network card and hub, the maximum cable length of 100 meters, if you want to increase the range of the network, between the two sections of twisted-pair cable can be installed repeaters, up to four repeaters, such as the installation of four repeaters even five network segments, the maximum transmission range of up to 500 meters.

Second, coaxial cable: by a hollow outer cylindrical conductor and an inner conductor is located in the center axis of the composition of the inner conductor and the cylindrical conductor and the outside world separated by insulating materials. According to the different diameters, can be divided into two kinds of thick cable and thin cable:

Coarse cable: long transmission distance, good performance but high cost, network installation, maintenance difficulties, generally used for large local area networks of the trunk line, connecting the two ends need to be terminated connector.

(1) The thick cable is connected to the external transceiver.

(2) AUI cable is used to connect the transceiver to the NIC.

(3) The NIC must have an AUI interface (15-pin D-type connector): 500 meters per segment, 100 users, up to 2500 meters for 4 repeaters, 2.5 meters minimum between transceivers, 50 meters maximum for transceiver cable.

Fine cable: connected to the BNC card, with 50 ohm termination resistors on both ends. Use T-head, minimum 0.5 meters between T-heads. Thin cable network per section of trunk length of up to 185 meters, each section of trunk access to a maximum of 30 users. If 4 repeaters are used to connect 5 segments, the maximum distance of the network can reach 925 meters.

Thin cable is easier to install and less expensive, but routine maintenance is not convenient, once a user failure, it will affect the normal work of other users.

According to the different transmission bands, can be divided into two types of baseband coaxial cable and broadband coaxial cable:

Baseband: digital signals, signals accounted for the entire channel, the same time can transmit a signal.

Wideband: can transmit signals of different frequencies.

Third, the optical fiber: is composed of a group of optical fibers used to propagate light beams, small and flexible transmission medium. The application of optical principles, by the light transmitter to produce light beams, electrical signals into optical signals, and then the optical signal into the optical fiber, at the other end of the optical receiver to receive optical signals coming from the optical fiber, and turn it into electrical signals, after decoding and then processed. Compared with other transmission media, optical fiber has good electromagnetic insulation, low signal attenuation, wide frequency band, fast transmission speed and large transmission distance. Mainly used for longer transmission distances, wiring conditions special backbone network connection.

Divided into single-mode fiber and multi-mode fiber:

Single-mode fiber: laser as a light source, there is only one light path, long transmission distance, more than 2 km.

Multimode fiber: light-emitting diode, low-speed short distance, within 2 km.

Question 2: What are the commonly used transmission media in computer networks? The transmission medium is the physical path between the sender and receiver in the communication network. Commonly used transmission media can be divided into wired (twisted pair, coaxial cable and fiber optics, etc.) and wireless (radio waves, microwaves and infrared, etc.) two categories.

1) wired transmission medium

Twisted pair can be used to transmit analog or digital signals, commonly used point-to-point connection, can also be used for multi-point connection.

Coaxial cable has two basic types: baseband coaxial cable and broadband coaxial cable. Among them, the baseband coaxial cable is used to transmit digital signals, and the broadband coaxial cable can transmit analog or digital signals. Coaxial cables can be used for point-to-point connections or multipoint connections.

Optical fiber transmits optical signals, which carry user data. Optical fiber has the advantages of low attenuation of optical signals, high bandwidth and strong anti-interference capability.

2) The commonly used wireless media are radio waves and microwaves. Wireless transmission does not require the laying of network transmission lines, and the network terminal is easy to move.

Question 3: What are the commonly used transmission media The network transmission medium is the entity that transmits data in the network and connects the various network sites. Network information can also be transmitted using radio systems, microwave radio systems and infrared technology. Currently common network transmission medium: twisted pair, coaxial cable, fiber optic

Question 4: What are the common transmission medium for computer networks Transmission medium: 1,, wired medium: twisted pair, coaxial cable, fiber optic

2, wireless: electromagnetic waves, light waves, infrared and other 。。。。

There are many interconnecting devices commonly used: routers, switches, hubs, repeaters, bridges and so on.

Question 5: What are the common network transmission media? Commonly used network transmission media are twisted pair, coaxial cable, fiber optic cable, wireless and satellite communication channels

Question 6: What are the common transmission media Previously used coaxial cable

Now commonly used twisted pair

And fiber optics, and wireless

Question 7: What are the common network transmission media Commonly used network transmission media are twisted pair, Coaxial cable, fiber optic cable, wireless and satellite communication channels

Question 8: What are the common network media Network transmission media refers to the carrier of the information transmitted in the network, the commonly used transmission media is divided into two categories: wired transmission media and wireless transmission media.

(1) wired transmission medium refers to the physical connection between the two communication devices to achieve the part, it can transmit the signal from one side to the other, wired transmission medium is mainly twisted pair, coaxial cable and optical fiber. Twisted-pair and coaxial cables transmit electrical signals, and optical fibers transmit optical signals.

(2) Wireless transmission medium refers to the free space around us. We can achieve a variety of wireless communications by utilizing the propagation of radio waves in free space. Electromagnetic waves transmitted in free space can be categorized into radio waves, microwaves, infrared, lasers, etc., based on their frequency spectrum, and the information is loaded on the electromagnetic waves for transmission.

Different transmission media have different characteristics. Their different characteristics have a greater impact on the quality of data communication and communication speed in the network!