# Communication System and Network Topology

## Choose the correct option

#### Question 1

Which of the following is a wire-based transmission media?

1. Hi-Fi
2. Y-Fi
3. Wi-Fi
4. Coaxial cable

Coaxial cable

Reason — Coaxial cable is a wire-based transmission media used to connect the different communicating devices through a cable.

#### Question 2

Which of the following transmission signals is in square wave form?

1. Digital signal
2. Hybrid Signal
3. Analog signal
4. Clear signal

Digital signal

Reason — A digital signal works on discrete data which states only two conditions i.e., 'True' and 'False'. Hence, the pattern of this signal is referred to as the 'Square' wave.

#### Question 3

Which of the following is an appropriate statement for broadband transmission?

1. It uses electrical wire
2. It uses twisted pair cable
3. It uses an optical fiber cable
4. It uses coaxial cable

It uses an optical fiber cable

Reason — Earlier, the Broadband used co-axial cables or twisted pair cables for the data transmission. Nowadays, it uses optical fiber cable also.

#### Question 4

Which of the following is not an analog device?

1. Meter scale
2. Thermometer
3. Speedometer
4. Calculator

Calculator

Reason — A calculator works on discrete values and is a digital device.

#### Question 5

What does the letter A signify in the word ARPANET?

1. Army
2. Ariel
4. American

Reason — ARPANET stands for Advanced Research Project Agency Network.

#### Question 6

What is the other name given to multipoint topology?

1. Media
2. Group
3. Bus
4. Van

Bus

Reason — In multipoint topology, a single transmission medium is shared by all the terminals.

#### Question 7

Which of the following statements is true regarding star topology?

1. Computers are connected through a single communication line.
2. Computers are connected in the shape of a ring.
3. Computers are connected using different topological systems.
4. Computers are connected using a central host.

Computers are connected using a central host.

Reason — In this topology, there is a host computer storing all the data and information, which is connected to the local computers.

#### Question 8

Which is the full form of MAN?

1. Micro Access Network
2. Metropolitan Area Network
3. Medium Analytical Network
4. Monitored Area Network

Metropolitan Area Network

Reason — MAN stands for Metropolitan Area Network.

## Fill in the blanks

#### Question 1

A system of inter-connecting computers is known as a network.

#### Question 2

A co-axial/telephone cable sends a analog signal during the data transmission.

#### Question 3

In a star topology, the host computer is connected to the local computers.

#### Question 4

A combination of different types of topologies is known as the hybrid topology.

#### Question 5

The Wi-Fi system means wireless data transmission.

#### Question 6

In a Star topology, the local computers are connected to host computers.

#### Question 7

A digital signal works on discrete data which states only two conditions.

#### Question 8

The bluetooth is a wireless communication within a short range by using radio frequency bandwidth.

## State True or False

#### Question 1

Modulation is the process of converting analog signals to digital signals.
False

#### Question 2

There is no difference between an analog signal and a digital signal.
False

#### Question 3

A medium carries the transmitted messages to the destination.
True

#### Question 4

A modem converts only analog signals to digital signals.
False

#### Question 5

Bus topology is also known as Multipoint technology.
True

#### Question 6

The word Wi-Fi stands for Wireless Frequency.
False

#### Question 7

Broadband uses twisted pair cable for high speed data transmission.
False

#### Question 8

The network topological structure is the combination of physical as well as logical network.
True

## Name the following

#### Question 1

Three elements of communication system

1. Network Components
2. Transmission Media
3. Transmission Signals

#### Question 2

Three types of Network topologies

1. Star topology
2. Ring topology
3. Hybrid topology

#### Question 3

Three elements of network components

1. Sender
2. Medium

#### Question 4

Three types of computer networks

1. Personal Area Network (PAN)
2. Local Area Network (LAN)
3. Wide Area Network (WAN)

#### Question 5

Three types of cables used in the data transmission

1. Twisted Pair Cable
2. Coaxial Cable
3. Optical Fiber Cable

## Case-Study Based Question

#### Question 1

Network topology is the arrangement of computers or devices in a network. It defines how data flows from one node to other in a network. We can connect computers in different forms. In one system, the computers are connected through a host, whereas in other system, they are connected in circular fashion. To promote flawless communication, we can also use multiple topological systems together.

Based on the above case, answer the following questions:

(a) Name the topological system that uses a host node.

(b) Name the topological system that enables connection of computers in a circular fashion.

(c) Name the topological system that is a combination of multiple topologies.

(d) Name the topology that enables point-to-point connection.

(a) Star topology

(b) Ring topology

(c) Hybrid topology

(d) Complete topology

## Define the following

#### Question 1

Computer Network

A computer network is a system of interconnected computers or terminals. The network helps to share the resources of the series of interconnected computers, peripherals and terminals in the network. Apart from sharing resources, a computer network also facilitates the transmission of data from one location to another.

#### Question 2

Analog Signal

Any type of signal or wave which is continuously varying in nature is known as analog signal. It always gives output in the form of a pattern which is referred to as the 'Sine' wave.

#### Question 3

Communication Resources

Communication resources refer to the data communication between devices or other media. They may be a wired or wireless based transmission system to send or receive data. They mainly involve the following:

2. Wi-Fi System
3. Bluetooth

#### Question 4

An internet connection that offers more than 256 Kbps speed is considered to be a Broadband Internet. It is also referred to as High­ Speed internet. It offers much higher rates of data transmission as compared to other methods of internet access.

#### Question 5

Bluetooth

Bluetooth is a wireless technology that allows devices to communicate with each other over short distances (1 meter, 10 meters, 100 meters). It is commonly used in devices such as phones, laptops, speakers, printers, etc. to send and receive data. Bluetooth works by using radio waves to transmit data between devices, and it does not require a physical connection or cables.

#### Question 6

Hybrid Topology

It is defined as the combination of two or more topologies. The configuration of the network depends upon the needs of the organisational structure of the company. Hybrid topology is reliable and easy to detect the fault of the system. It includes both wired and wireless network. It is simple to extend the size of network with the addition of new elements without disturbing the existing architecture.

#### Question 7

Bus Topology

In this topology, a single transmission medium is shared by all the terminals. When a particular computer wants to send a message to another computer, the system checks whether the communication line is free or not. As soon as the communication line is free, the message is transmitted online.

#### Question 8

Local Area Network

A local area network (LAN) is a digital communication system which interconnects a large number of computers and other peripheral devices. This type of network is generally preferred within an office building or a lab building. The transmission channels use coaxial or fiber optic cables for high-speed transmission. For example, Ethernet.

## Give two differences between the following

#### Question 1

Local Area Network and Wide Area Network

Local Area NetworkWide Area Network
A local area network is restricted to a limited geographical area.A wide area network operates on a worldwide or nationwide basis.
In a local area network, the computers, the terminals and the peripheral devices are connected to each other through wires and co-axial cables.In a wide area network, there may not be physical connections between various computers.

#### Question 2

Analog Signal and Digital Signal

Analog SignalDigital Signal
It signifies a continuous signal which keeps on changing with a fixed time period.It signifies a discrete signal which carries binary data values (0 or 1).
Analog signals are continuous 'Sine' waves.Digital signals are 'Square' waves.

#### Question 3

Star Topology and Ring Topology

Star TopologyRing Topology
In star topology, the local computers are connected to the host computer which stores all the data and information.In ring topology, all local computers are connected to each other in a ring arrangement.
The transmission delays between the two terminals do not increase by adding a new terminal.The addition of a new terminal in the network delays the communication.

#### Question 1

What is meant by the term communication system? Name all the elements of a communication system.

A communication system is a collection of individual communication networks which interconnect and inter-operate to form an integrated communication environment. The purpose of a communication system is to facilitate effective communication between the source and the destination.

The elements of a communication system are as follows:

1. Network Components
2. Transmission Media
3. Transmission Signals
4. Communication Resources

#### Question 2

What is Network Component? Explain with reference to a communication system.

The components which are needed to facilitate an effective communication from the source to the destination are referred to as network components. These components help in transferring data from one point to another by using resources. This data may be analogous or digital in nature.

#### Question 3

Explain the term Network Topology. Name the other types of topologies.

The term Network Topology refers to the arrangement of various elements (links, nodes, etc.) of a computer network, physically and logically. Essentially, it is the topological structure of a network.

The different types of topologies are as follows:

1. Star topology
2. Ring topology
3. Complete topology
4. Hybrid topology
5. Multipoint (Bus) topology

#### Question 4

What are the advantages of a computer network?

The advantages of a computer network are as follows:

1. Information can be easily shared by people.
2. It helps us in staying updated with the events in and around the world.
3. It also helps in sharing resources. For example, a colour laser printer connected to a network can print several hard copies.
4. Interaction among people around the world becomes easy through chatting/video conferencing.
5. Email allows us to send or receive mails effortlessly.

#### Question 5

Explain the arrangements in different types of computer networks.

The arrangements in different types of computer networks are as follows:

1. Personal Area Network (PAN) — This network is used to establish communication among computer devices within the range of 20 to 30 feet. This network may be wired with computer buses or may be a wireless network through Bluetooth.
2. Local Area Network (LAN) — LAN is a digital communication system which interconnects a large number of computers and other peripheral devices. This type of network is generally preferred within a smaller area such as an office building or a lab building.
3. Campus Area Network (CAN) — This network connects two or more LANs that are limited to specific geographical areas viz. college campus, office building, etc. It is generally limited to an area between the local area network and the metropolitan area network.
4. Metropolitan Area Network (MAN) — This network connects two or more local area networks or campus area networks together. The MAN is bigger than the local area network but smaller than the wide area network. This network is located on a larger geographical area ranging from 5 to 50 kilometers but doesn't extend beyond the boundaries of the immediate town/city.
5. Wide Area Network (WAN) — A wide area network is a digital communication system which interconnects a large number of computers in a wide area. This type of communication network can operate worldwide. In a WAN, telephone lines, microwave, satellite links, etc. can be used as transmission mediums.

#### Question 6

What are the advantages of Digital Signal over Analog Signal? Explain.

The advantages of digital signal over analog signal are as follows:

1. Digital signals are more resistant to noise and interference.
2. Digital signals can be easily stored and transmitted over long distances without loss of quality.
3. Digital signals are more secure as they can be easily encrypted.
4. Digital signals are more precise and accurate than analog signals.

#### Question 7

(a) Complete Topology

(b) Hybrid Topology

(c) Multipoint Topology

(a) Complete Topology

1. It is the fastest way to transfer data between two computers.
2. If any computer breaks down, communication takes place via other modes.

It is comparatively expensive as the number of terminals/points connected to a computer are more.

(b) Hybrid Topology

1. It is reliable and easy to detect the fault of the system.
2. It includes both wired and wireless network.
3. It is simple to extend the size of network with the addition of new elements without disturbing the existing architecture.

1. Sometimes, it is difficult to understand the design and the architecture.
2. The cost of this topology is higher as compared to the other topologies.

(c) Multipoint Topology