Computer Network (Part-3)

COMMUNICATION CHANNELS

All networks are linked to each other through communication channels. These are the medium on which the data, instructions, or information can travel. When you send data from a computer or mobile device, the signal that carries the data may travel over various transmission media. Most commonly used media are physical and wireless.

PHYSICAL TRANSMISSION MEDIA

Physical transmission media use wire or cable to send communications signals. LANs often use physical transmission media. There are three main types of physical transmission media. They are twisted pair cable, coaxial cable and fiber optic cable.

TWISTED-PAIR-CABLE

Twisted-pair cable consists of one or more twisted-pair wires bundled together. Each twisted-pair wire consists of two separate insulated copper wires that are twisted together and is color-coded for identification. Landline phone networks and LANs often use twisted-pair cable.

COAXIAL CABLE

Coaxial cable consists of a single copper wire surrounded by at least three layers. The first one is an insulating material, the second is a wire mesh, and the third is a plastic outer coating. On coaxial cables, data travels through a copper wire. Cable TV network wiring uses

coaxial cable.

FIBER-OPTIC-CABLE

The core of a fiber-optic cable consists of hundreds of thin strands of glass or plastic that use light to transmit signals. Inside the fiber-optic cable, an insulating glass cladding and a protective coating surrounds each optical fiber. Many big companies use fiber-optic cables in high-traffic networks.

WIRELESS TRANSMISSION MEDIA

Wireless transmission media send communication signals through the air. Many people use this media because it is more convenient than installing cables. Types of wireless transmission media used in communications include infrared, broadcast radio, cellular radio, microwaves, and communication satellites.

INFRARED (IR)

Infrared (IR) is a wireless transmission medium that sends signals using infrared light waves.

Infrared systems use the same technology as household remote controls. It is also used with

computers and devices like cordless keyboards and mouses.

BROADCAST RADIO

Broadcast radio is a wireless transmission medium that distributes radio signals through the

air over long distances, such as between cities, regions, and countries, and short distances, such as within an office or home. Bluetooth and Wi-Fi communication technologies use broadcast radio signals.

CELLULAR RADIO

Cellular radio is a wireless transmission medium that is used for mobile communications. It is

a form of broadcast radio. Several categories of cellular radio transmissions exist, such as 1G

(first generation of cellular transmissions), 2G, 3G, 4G and 5G.

Wi-Fi

Wi-Fi is short for wireless fidelity, which is a popular wireless networking technology that uses radio waves to provide wireless high-speed network connections.

MICROWAVE

Microwaves provide a high-speed wireless signal transmission. It involves sending signals from one microwave station to another. A microwave station is an earth-based dish that contains the antenna and other equipment necessary for microwave communications. Microwave transmission is used in wide-open areas, such as deserts or lakes.

COMMUNICATION SATELLITE

A communication satellite is a space station that receives microwave signals from an earth-based station, amplifies (strengthens) the signals, and broadcasts the signals back over a wide area to any number of earth-based stations. Applications such as television and radio broadcasts, weather forecasting, videoconferencing, GPS, and Internet connections use communication satellites.

Please Read The Next Part Also.