Whether you are going to prepare for an interview or you
need to appear in viva, the questions related to data communication that are
asked most frequently and extensively in every kind of examination are given
below:
Top 20 Data Communication FAQs and their Answers
1. What do you mean by data communication?
Ans: Such a process, in which data is transferred
electronically from one device to another, is what we call data communication.
Data is transferred using different communication media. Data which is to be
communicated from one place to another can be in the form of text, graphics,
videos etc.
2. What is the Difference between the terms "signal and
"signaling"?
Ans: Signal is basically an electromagnetic or light wave
that transmits the data from one place to another whereas the term signaling
refers to the propagation of these signals across the communication medium.
3. What are the necessary elements of data communication?
Ans: Some of the necessary data communication elements are
given below along with a short description:
Sender: the device that sends the message (also known as
source or transmitter)
Receiver: the device that receives the message from a
sending device (also known as sink)
Medium: the physical path connecting the sender and receiver
for data transmission.
Transmission medium: the path through which data is
transferred
Protocol: the set of rules governing the communication i.e. it’s
a sort of agreement between communication devices.
4. How can you differentiate simplex and half duplex mode of
data transmission?
Ans: In simplex data transmission mode, data transmission
can occur in only one direction i.e. the data transmission is unidirectional
whereas in case of half duplex mode, data transmission is bidirectional. Data
in half duplex data transmission mode can flow in both directions but not at the
same time.
5. What is analog and digital signal?
Ans: Analog signal is a variation in a smooth way over time;
for example: speech. In case of analog signals, we can have infinite number of
values in a range. On the other hand, digital signal maintains a constant level
and then changes to another constant level, e.g., binary 1's and 0's.
6. What do you know about parallel and serial data transmission?
Ans: parallel data transmission: such a unidirectional method
of data transmission in which groups of bits are sent at the same time over
multiple wires. Each bit is transmitted over separate line in parallel data
transmission.
Serial data transmission: a slow most type of data
transmission in which data is transferred one bit at a time. Each individual
bit in a serial data transmission travels along its own communication path.
7. How does asynchronous transmission take place?
Ans: Data is transmitted character by character in
asynchronous data transmission. This transmission method uses a special start
signal. This start bit has a value of 0. This value indicates that a character
is about to be transferred. Thus the receiver is got alert and gets ready to
receive the character. If the start bit has the value 1 then it indicates
that the line is idle.
8. Why is wireless connection slower than wired?
Ans: This is because
wireless signals are susceptible to interference from devices like microwave
ovens, cordless telephones and monitors. When interference affects a wireless
signal, data must be re transmitted that might take extra time.
9. What factors limit the range of a wireless network
signals?
Ans: Wireless network signal range can be limited by the type
of signal, the strength of transmitter as well as the physical environment. As
soon as the distance between the network devices increases, data signals start
fading. Moreover; signal range can also be limited by thick walls, floors or
ceilings. The speed also decreases with the decrease in signal strength.
10. What do you mean by communication channel?
Ans: Communication channel is the path through which data is
sent or received by the communication devices. It is also known as transmission
media.
11. How media is important in communication?
Ans: Without a medium; communication between devices is not
possible. Even communication network cannot exist without a medium. Basic
purpose of a medium is to connect source and receiver and provide path to send
messages.
12. Why fiber optic cable is a popular communication medium?
Ans: Because fiber optic cable is not at all affected by the
electromagnetic waves; thus it is among the fastest and popular communication
medium.
13. How does cellular communication work?
Ans: Cellular communication divides a physical region into
different sections known as cells. Each cell consists of a low-powered radio
transceiver which is known as base station. Cells are linked together to enable
a large number of cellular phones to communicate with each other.
14. For what purpose do we use satellite communication?
Ans: Generally, satellite communication is used for making
international phone calls, weather forecasting and television broadcasts.
15. What is the basic drawback of Microwave System?
Ans: One of the considerable drawbacks of microwave system
is that it is limited to line of sight transmission only. Thus microwave
signals must be transmitted in a straight line and there shouldn't be any
obstruction such as buildings or mountains between microwave stations.
16. What is attenuation?
Ans: Attenuation means "loss of energy". While
travelling; the signal loses some of its energy in overcoming the resistance of
the medium. That is the main reason why wires carrying electric signals get
warm after sometime.
17. What is OSI model?
Ans: OSI stands for Open System Interconnection. It is a
model that allows any two systems to communicate with each other even if their
architectures are different. All aspects of network communications are covered
by OSI model.
18. How do you differentiate the terms Unicasting, Multicasting
and Broadcasting?
Ans: Unicasting: When the required message is sent from a
source to a single destination node, it is called unicasting.
Multicasting: On the other hand if the message is sent to some
subset of other nodes, it is called multicasting.
Broadcasting: If the message is sent to all the network nodes,
then the process is called broadcasting.
19. Why we should prefer UDP over TCP?
Ans: Relying upon the data that is to be transmitted, we can
say that UDP is a better choice than TCP. This is because UDP does not require
sender and receiver to establish a connection for sending data. It saves user time
as well as efficiency.
20. How do you distinguish between frames and packets in
terms of data communication?
Ans: Generally; frames are the messages in single networks
whereas packets are the messages that are sent through Internet.
