Guided media and Unguided media with example (Explained-In-Details)

 Guided media and Unguided media with example (Explained-In-Details)

Wired or bounded media (Guided Media)

Bounded media is the type of transmission media in which data and signals are transferred in a closed conductor through the use of cables or wires. Two or more devices that are near to each other can be connected directly using cables. This is an easy, fast and secure way to transfer data and information from one computer to another. The three types of cables that are used in a computer network are:

1. Twisted pair Wire
2.  Co-axial Cable
3. Fiber Optic Cable

Twisted pair cable

Twisted pair cables are used only for lower bandwidth. It consists of two isolated strands of copper wire twisted around each other. It is also widely used in landline telephone. The RJ-45 connector is the most popular connector used in twisted pair cables. There are two types of twisted-pair cables. They are UTP (Unshielded Twisted Pair) and STP (Shielded Twisted Pair).

UTP (Unshielded Twisted Pair)

UTP cables do not have metal shields except plastic coating. It contains several twisted pairs of wires with a simple plastic casing. It is commonly used to transfer data and information in telephone and LAN connections. It is cheaper and easier to work with, but does not offer high bandwidth and good protection from interference. Its grade starts from cat1 to cat7. It can support data transmission rates from 10 to 100 Mbps.

STP (Shielded Twisted Pair)

STP cable is shielded with a metal sheath along with a plastic coating. It offers high bandwidth and good protection from interferences. Cabling is more difficult to install and more expensive than UTP. Its bandwidth is 10 to 500 Mbps (Megabits per second). RJ 45 connector is used in STP. It is cheaper than fiber optic cable. It provides better protection against EMI(Electromagnetic Interference) than UTP.

Co-axial cable

Co-axial cable is made up of copper or aluminum wire with an inner conductor surrounded by an insulating layer and again surrounded by conducting shield. So it consists of two conductors inner and outer conductors. It carries higher bandwidth and noise immunity. It does not bend readily. This cable consists of one or more small cables in a protective covering. It offers a very high data transfer rate and can be placed underground and laid on the floors of lakes and oceans. BNC and T connectors are the most popular connector used in co-axial cable. 

Fiber optic cable

Fiber optic cable is a thin filament of plastic or glass fiber wrapped in a protective jacket to transmit data. It consists of strands of glass-like thread, each about the diameter of a human hair. It offers a high-speed data transmission rate because data travel as high-speed pulses of light. So it is a widely used cable especially in ISP (Internet Service Provider). ST (Straight Tip) connector, SMA (Screw Mounted Adaptors), SC (Subscriber Connector), etc. are the common connectors used in fiber optic cable.

Wireless or unbounded media (Unguided Media)

Unbounded media is the type of transmission media in which data and signals are transferred through the help of air. It is used to transfer data within large geographical areas or globally without the use of interconnecting wires or cables. It uses other components such as radio signals, microwaves, or infrared to connect networks for receiving and transmitting electronic data. The types of wireless communication are:

1. Radio wave
2. Microwave System
3. Infrared
4. Satellite Communication

1. Radio Wave

The radio wave is an electronic magnetic wave. It is used in rural and hilly areas. The data and information can be changed into audio signals using high-frequency waves based on frequency, amplitude, and phase modulation. It is a wave or RADIO WAVES pattern received after the modulation of signals. The types of modulation signal are FM (Frequency Modulation): The waves are modulated due to their frequency change. AM (Amplitude Modulation): The waves are modulated due to their amplitude change. PM (Phase Modulation): The waves are modulated due to their phase change.

2. Microwave Systems

Microwave signals are similar to radio and television signals and are used to transmit data signals through the atmosphere. It provides high-speed data transmission. It is also known as the line of sight communication as signals cannot be bent and cannot pass through obstacles like hills and tall buildings. So, very high towers are used to mount the signals that should be in a clear line of sight. Chain of towers I required to transmit the microwave signals in a long distance. Repeaters are used to amplify the signal. The other important devices are the digital modem and antenna.

3. Infrared

Infrared light is an electromagnetic form of radiation. It comes from heat and thermal radiation, and it is not visible to the naked eyes. In infrared transmission, senders can be simple Light Emitting Diode (LED) or laser diodes. Photodiode act as receivers. Infrared is used in wireless technology devices or systems that convey data through infrared radiation. It is used for short-range communications and control. Infrared technology is used in instruction detectors; robot control systems, medium-range line of sight laser communication, cordless microphone, headsets, modems, etc.

4. Satellite communication

Both microwaves signals and telephone signals can be relayed to an earth station for transmission to a communication satellite. Satellite communication is used to transfer data wirelessly worldwide. The earth station consists of a satellite disk that functions as an antenna communication equipment to transmit and receive data from satellites passing overhead. It is not disturbed by hills and tall buildings and is visible from any point. So sender and receiver can easily communicate with each other using antenna by aiming the satellite. It is very expensive for placing satellites along the earth's orbit. It is an artificial satellite placed in outer space and most of the countries are using their own satellite to communicate.

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