A.

1. Server

2. Metropolitan Area Network

3. Hub

4. None of the above

5. Star

6. None of the above

7. Modem

 

B.

1. Bus topology

2. Ring topology

3. Star topology

 

C.

i.

 

ii.

 

iii.

 

4.

1. The process of transferring data or information between different computers is called data communication.

2. The process of electronic communication with people by the use of telephone, telegraph, teletype writing etc. is known as telecommunication.

3. The components of computer network are as follows:

a. Server = Server is a computer or computer program that manages access to a centralized resource or service in a network.

b. Workstation = Workstation refers to the computers that are attached to a network and use the resources of the network.

c. Network Interface Card = Network adaptor is the interface that is used for connecting computers in networks. It is commonly known as Network Interface Card (NIC).

d. Transmission Media = The communication channel provides the physical path through which data, information flow on a network.

 

5. Server = A computer that provides the facilities of sharing the data, software, and hardware resources on the network is known as server.

Client = A client is a piece of computer hardware or software that accesses a service made available by a server.

i. BIT = It stands for binary digits. It is a measuring unit that represents the smallest data in the computer system.

ii. Bandwidth = A term used to describe the data handling capacity of a communicating system is called bandwidth.

iii. Hertz = Hertz is a measuring unit used to measure the bandwidth of an analog device.

 

6. Modem (Modulation Demodulation) is the device that converts digital data to analog form and vice versa. It is a device used to transfer the data of one computer to another using telephone lines.

 

7. The importance of MODEM are as follows:

i. They allow higher speeds of transmission on a given analog line.

ii. They reduce the effects of noise and distortion.

 

8. Transmission Media refers to the transmission of data and information from one location to other location using one or more media. The commonly used transmission media are twisted pair cable, coaxial cable, fiber optic cable etc.

 

9. Cables are the most commonly use mediums as physical channels for transmitting from one computer to another network. There are three types of network cables. They are as follows:

a. Twisted pair cable

b. Coaxial Cable

c. Fiber Optic cable

 

10. Wireless communication refers to the communication in which transmission of data takes place without the use of interconnecting wires or cables. It uses wireless components such as radio signals, microwaves or infrared to connect a network.

 

11.

NIC = Each computer on any types of network needs a hardware component to control the flow of data. The device that performs this function is Network Interface Card (NIC), commonly called network card.

HUB = A hub is a device with multiple points or ports. It acts as a central point from where different computers and other devices are connected. It also amplifies the signals and sends them to all connected devices.

 

12. Network Operating System is required when a number of computers are connected together in a network. The operating system controls who logs on to network by means of user names and passwords, in order to protect the data and programs stored on the network.

 

13. Protocols are the sets of rules that the computer on the network must follow to communicate and to exchange the data with each other.

 

14. A computer network means two or more computers connected to each other to share data, hardware, software and other resources such as printers, CD Drive etc.

 

15. A LAN topology is the layout of the computers in the Local Area Network. It is the arrangement of connection pattern of computers or nodes and other devices of the network.

 

16. Two LAN topologies are as follows:

a. Bus Topology

A bus topology is a network (LAN) topology in which network nodes are arranged in a linear format, with each node connected directly in a linear format, with each node connected directly to the network cable with a T connecter or tap,

 

b. Ring Topology

A bus topology is a network topology or circuit arrangement in which each network node is attached along the same signal path to two other devices, forming a path in the shape of a ring.

 

17. Two advantages of Bus topology are as follows:

i. Easy to implement and extend.

ii. Easy identification of cable faults.

 

18. Peer to peer network is a network model in which resources sharing, processing and communications control are completely decentralized. It is a group of computers which function both as servers and workstations to share data, information and other resources of the network. In this networking architecture, there are no dedicated servers.

 

19. There are three types of network. There are as follows:

i. Local Area Network

A Local Area Network (LAN) is a network of computers that are relatively near to each other and are connected in a war that enables them to communicate by a cable and a small wireless device. A LAN consists of just two or three computers to exchange data or share resources or it can include hundreds of computers of different kinds.

ii. Metropolitan Area Network

Metropolitan Area Networks (MANs) are large computers networks spread over a city or neighboring cities. A MAN can have a group of many LANs. Especially, big companies, banks, offices etc. have their branches or sub offices in a city or in neighboring cities. They use MAN to connect with their branches or sub offices for communicating data and information. The communication media in MANs may be optical fiber or unbounded communication media like microwave system, infrared system, radiowave to link their branches and sub offices.

iii. Wide Area Network

Wide Area Network is a telecommunications network usually used for connecting computers that spans a wide geographical area. WANs can be used to connect cities, states or even computers. Typically, it will employ communication circuits such as long distance telephone wires, microwaves and satellites. WANs are often used by larger corporations or organizations to facilitate the exchange of data. The world's most popular WAN is the Internet.

 

20.

i. Local Area Network

A Local Area Network (LAN) is a network of computers that are relatively near to each other and are connected in a war that enables them to communicate by a cable and a small wireless device. A LAN consists of just two or three computers to exchange data or share resources or it can include hundreds of computers of different kinds.

 

ii. Metropolitan Area Network

Metropolitan Area Networks (MANs) are large computers networks spread over a city or neighboring cities. A MAN can have a group of many LANs. Especially, big companies, banks, offices etc. have their branches or sub offices in a city or in neighboring cities. They use MAN to connect with their branches or sub offices for communicating data and information. The communication media in MANs may be optical fiber or unbounded communication media like microwave system, infrared system, radiowave to link their branches and sub offices.

 

iii. Wide Area Network

Wide Area Network is a telecommunications network usually used for connecting computers that spans a wide geographical area. WANs can be used to connect cities, states or even computers. Typically, it will employ communication circuits such as long distance telephone wires, microwaves and satellites. WANs are often used by larger corporations or organizations to facilitate the exchange of data. The world's most popular WAN is the Internet.

 

iv. Network Interface Card (NIC) = Each computer on any types of network needs a hardware component to control the flow of data. The device that performs this function is Network Interface Card (NIC), commonly called network card.

 

v. Email = Electronic mail, most commonly abbreviated as an email or e-mail, is a method of exchanging messages across the Internet or other computer networks. Email system are based on a store and forward model in which email server computer systems accept, forward, deliver and store messages on behalf of users, who only need to connect the email infrastructure, typically in email server, with a network enabled device for the duration of message submission or retrieval.

 

vi. Network Operating System (NOS) = Network Operating System is required when a number of computers are connected together in a network. The operating system controls who logs on to network by means of user names and passwords, in order to protect the data and programs stored on the network.

 

21. The advantages of computer network are as follows:

i. Computers in a network can access the network connected hardware devices like printers. disk drives etc.

ii. Communication made by a computer network is very cheap.

iii. Computers in a network system share different software packages.

iv. Information can be exchanged rapidly in computer network. So, it makes communication very fast.

v. Data in a network environment can be updated from any computer. Updated data can be accessed by all computers of the network.

 

22. Since a network allows sharing of hardware and software, it saves a considerable amount of money which would otherwise be spent on buying separate hardware and software for each computer. Some special communication software installed on a network helps in faster and reliable exchange of messages between network users at a much cheaper cost.

 

23. The services the computer network provides are as follows:

i. Quick and Efficient transfer of data

ii. Resource Sharing

iii. Saving of Money

iv. Access to information on Remote Computer

v. Faster, Cheaper and Reliable Communication

vi. High Reliability

vii. Workgroup Sharing

 

24. Workstation refers to the computers that are attached to a network and use the resources of the network. It is a computer where the clients work. It request services, data and other resources available on the server.

 

25. A metropolitan area network is a network of computers which is spread over a metropolitan area such as within a city. It connects two or more LAN together.

 

26. Metropolitan Area Networks (MANs) are large computers networks spread over a city or neighboring cities. A MAN can have a group of many LANs. Especially, big companies, banks, offices etc. have their branches or sub offices in a city or in neighboring cities. They use MAN to connect with their branches or sub offices for communicating data and information. The communication media in MANs may be optical fiber or unbounded communication media like microwave system, infrared system, radiowave to link their branches and sub offices.

 

27.

Analog signal = An analog signal is a constantly changing electrical wave that changes into a rounded or a smooth pattern. They are the signals in which high voltage varies continuously from the lowest to highest value and vice versa. Most of the signals in the natural phenomenon are of analog nature.

Digital Signal = A digital signal uses a square waveform, which is reliably used to transmit electronic data. It uses combination 1 or 0, which is suitable for computer system.

 

28.

In Nepal, EDPC was established by National Computer Center in between 2031 and 2055 B.S. This EPDC was used for processing of census data, industry related data, agricultural data, SLC result processing etc. in Nepal. After 2055 B.S. this EPDC was demolished and its statistical data processing work is being carried out by the concerned department using microcomputers.

 

29. The means of wireless communications are as follows:

i. Microwave Systems

Microwave signals are similar to radio and television signals and are used to transmit data through the space without the use of cables. Microwaves signals provide very high speed transmission. These signals cannot bend or pass obstacles like hill, towers and should be in a line of sight.

ii. Radio waves

The high frequency waves are used to exchange data and information in the form of audio signals. Such waves are modulated on the basis of amplitude, frequency or phase. This action is called modulation. The waves or patterns received after the modulation of the signals are called radio waves.

iii. Communication Satellites

Both microwaves signals ad telephone signals can be relayed to an earth station for transmission to a communication satellite. The earth station consists of a satellite dish that functions as an antenna and communication equipment to transmit and receive data from the satellite passing overhead.

 

E.

2 The differences between LAN and WAN are as follows:

LAN	WAN
A LAN is restricted to a limited geographical coverage of a few kilometers.	WAN spans greater distance and may operate nationwide or even worldwide
Data transmission speed is much higher in LAN.	Data transmission speed is slower in WAN than in a LAN

 

3 Modulator and demodulator

Modulator	Demodulator
Modulation is the process of transferring by adding that information into a carrier signal.	Demodulation is the process of filtering out the actual transferred information from the received signal.
A modulator modulates the carrier frequency.	A demodulator detects the modulation on the carrier wave and recovers the original lower frequency wave form at a destination.

 

4 Microwave system and Satellite communication

Microwave system	Satellite communication
Microwave system requires a line of sight and uses towers to transmit information.	Satellite communication transmits signals that travel from a ground station on Earth to a satellite and back to another ground station of earth.
Microwave system have relatively smaller are coverage.	Satellite communication covers a wider area due to its location.

 

5. Repeater and Hub

Repeater	Hub
A repeater is a device that regenerates signals on the network and so that they can travel on additional segments.	A hub is a computer networking device that joins multiple computers or other network devices together to form a segment of computer network.
Repeater repeats electric signals that draw closer into one port.	Hub are similar to repeater and basically a multiport repeater.

 

6. NTC and Modem

NTC	Modem
NTC is a wireless modem that works with a GSM wireless network.	Modem is a device that modulates signals to encode digital information and demodulates signals to decode the transmitted information.
NTC sends and receives data through radio waves.	A modem sends and receives data through a fixed telephone line.

 

7. Telecommunication and Network

Telecommunication	Network
Telecommunication refers to the exchange of information by electronic and electrical means over a significant distance.	A network is the group of two or more computers linked and connected together.
Telecommunication involves the use of electronic transmitters such as television, radio or computer.	Network is any method of sharing information between two systems.

 

8.

Bus Topology	Star topology
A bus topology is a network topology in which nodes are connected in a daisy chain by a linear sequence of buses	Star topology is a network topology where each individual piece if network is attached to a central node.
It is an arrangement of computers on a local area network in which each computer is connected to a central cable through which data is channeled.	The attachment of these network pieces to the central component is visually represented in a dorm similar to a star.

 

F.

EDPC = Electronic Data Processing Center

CDPS = Communication Data Processing System

LAN = Local Area Network

NOS = Networking Operating System

E-mail = Electronic Mail

MBPS = Mega Byte per Second

WAN = Wide Area Network

FM = Frequency Modulation

UTP = Unshielded Twisted Pair