UNIT NO.2
Data Communication and Computer Network
(Solved Exercise)
C. Answer the following short questions:
1. Describe the advantages and disadvantages of the twisted pair cable.
Advantages:
1. It is less expensive.
2. Perform best in short distance.
3. It is low in weigh.
Disadvantage:
1. It provides poor security.
2. They could break easily because they are thin.
3. Low durability.
2. What is coaxial cable?
Coaxial cable consists of a single copper wire surrounding by at least three layers.
• An insulating material
• A woven or braided meta
• A plastic outer coating
3. What are the basic elements of fiber optic cable?
1. Outer Jacket
2. Strengthening (Kevlar fibers)
3. Clating
4. Cladding
5. Core
4. What is the difference between Wi-Fi and Li-Fi?
Wi-Fi (Wireless Fidelity)
• Wi-Fi uses radio waves to transmit data wirelessly.
• Wi-Fi transmission speed can go up to 10 Gb per second or even higher.
Li-Fi (Light Fidelity)
• Li-Fi uses light waves, typically LED light, to transmit data wirelessly.
• Li-Fi transmission speed can go up to 100 Gb per second which is 14 times faster than the world’s fastest Wi-Fi.
5. Explain the terms data communication, message, encoder, and decoder.
Data Communication
The process of sending and receiving data electronically from one location to the other is called Data Communication.
Message
A message is the data to be sent. It may be text, image, audio, video, or a combination of these.
Encoder
Encoder are the device that convert digital signals into a form that can travel over wired or wireless media on the sender’s side.
Decoder
Decoder receive converted signals on the receiving side and covert them into digital form that can be stored and processed on computer or on other devices.
6. Differentiate between LAN and WAN.
LAN
1. LAN is restricted to a small geographical area. It links devices within a building or
group of buildings.
2. LAN operates at a faster speed, more than 2. WAN is slower than LAN in terms of WAN.
3. LAN is privately owned.
4. LANs are less expensive than WANs.
5. Data transfers more quickly through LAN.
WAN
1.WAN covers greater distances and operates worldwide.
2. WAN is slower than LAN in terms of speed.
3. WAN ownership might be either public or private.
4. WAN is more expensive than LAN.
5. WAN transmits data at a slower rate S than LAN.
7. What are the characteristics of a twisted pair cable?
1. It is relatively easy to implement and terminate.
2. It is less expensive.
3. Perform best in short distance.
4. It is low in weigh.
5. It is flexible to use.
6. It is easy to connect.
7. Suitable for data and voice infrastructure.
8. Why are computer networks necessary?
Computer networks are necessary for facilitating data communication, resource sharing, and collaboration among devices and users across various locations.
9. Do you believe the Internet of Things will become popular in the future?
Yes, the Internet of Things (IoT) is already gaining popularity and is likely to become even more popular in the future as more devices become interconnected for improved efficiency and convenience.
D. Answer the following long questions:
1. What is coaxial cable? Explain the advantages and disadvantages of the coaxial cable.
Coaxial cable consists of a single copper wire surrounding by at least three layers.
• An insulating material
• A woven or braided meta
• A plastic outer coating
It has a higher data transmission rate as compared to a twisted pair cable. Coaxial cable is frequently used in cable television (CATV) network cabling because it can be cabled over larger distance than twisted pair cable.
Advantages of coaxial cable:
• Data can be transferred at high speed.
• It has enhanced shielding as compare to twisted pair cable.
• It provides advanced bandwidth.
Disadvantages of coaxial cable:
• It is more expansive as compare to twisted pair cable.
• Any fault in the cable causes the failure of the entire network.
2. Write a detail note on wireless transmission media.
An Wireless transmission media transmits electromagnetic waves or signals without using any physical medium. It is also known as unguided transmission media. There are three main categories of wireless transmission media as follows:
Radio Waves Transmission
The electromagnetic waves that travel through open space in all directions are known as Radio Waves. These low-frequency electromagnetic waves range from ‘3 kHz to 1GHz’. As radio waves have a low frequency, they can pass through objects like walls, allowing you to receive signals even when you are within a structure.
Examples of radio waves include FM radio, cordless phones, and television.
Microwaves Transmission
Microwaves are electromagnetic waves that have frequencies between ‘1 and 300 GHz. Microwaves only travel in a straight line. The communication between two endpoints and lines of sight becomes much easier to establish once the transmission medium is facing each other.
Some examples of the areas where microwaves are used include radio navigation systems, point- to-point communication systems on the surface of the Earth, sensor systems, satellite communications, deep space radio
communications, and mobile phone communications.
Infrared Waves Transmission
A wireless method used for communication over short distances is infrared transmission. The infrared spectrum has frequencies between 300 GHz and 400 THz. Due to its high frequency, infrared transmission cannot pass through the walls.
Some examples of the areas where infrared waves are used include TV remote control usage, data transfer between two mobile phones, data transfer between a computer and cell phone, etc.
3. What is unguided media? write its three transmission categories in detail.
Unguided Media
An unguided transmission media transmits electromagnetic waves or signals without using any physical medium. It is also known as wireless transmission. There are three main categories of unguided media as follows:
Radio Waves Transmission
The electromagnetic waves that travel through open space in all directions are known as Radio Waves. These low-frequency electromagnetic waves range from ‘3 kHz to 1GHz’. As radio waves have a low frequency, they can pass through objects like walls, allowing you to receive signals even when you are within a structure.
Examples of radio waves include FM radio, cordless phones, and television.
Microwaves Transmission
Microwaves are electromagnetic waves that have frequencies between ‘1 and 300 GHz. Microwaves only travel in a straight line. The communication between two endpoints and lines of sight becomes much easier to establish once the transmission medium is facing each other.
Some examples of the areas where microwaves are used include radio navigation systems, point- to-point communication systems on the surface of the Earth, sensor systems, satellite communications, deep space radio
communications, and mobile phone communications.
Infrared Waves Transmission
A wireless method used for communication over short distances is infrared transmission. The infrared spectrum has frequencies between 300 GHz and 400 THz. Due to its high frequency, infrared transmission cannot pass through the walls.
Some examples of the areas where infrared waves are used include TV remote control usage, data transfer between two mobile phones, data transfer between a computer and cell phone, etc.