The document discusses different modes of data transmission including simplex, half-duplex, and full-duplex. It also defines different types of data signals, computer networks, and networking devices such as hubs, switches, and routers. Key concepts covered include analog and digital signals, types of area networks, and different addressing schemes used in network communication.

1. Assignment
On
Class work
Course code : CSE-313
Course title : Data communication
Submitted to:
Pranab Bandhu Nath
Senior Lecturer
Dept. of CSE
City university
Submitted by:
Name : Rowshanara
ID : 1834902165
Batch : 49th
(B)
Dept. of CSE
City university
Submission date: 23/08/2021

2. Data transmission mode : Data Transmission mode defines the
direction of the flow of information between two communication devices. It is also
called Data Communication or Directional Mode. It specifies the direction of the
flow of information from one place to another in a computer network.
Figure : Types of transmission mode
Simplex mode: Simplex is the data transmission mode in which the
data can flow only in one direction, i.e., the communication is
unidirectional. In this mode, a sender can only send data but can not
receive it. Similarly, a receiver can only receive data but can not send it.
Half-duplex mode: Half-duplex devices can only transmit in one
direction at one time. With half-duplex mode, data can move in two

3. directions, but not at the same time. The term duplex, on its own, refers
to the capability to send and receive data. Duplex is often used when
talking about conversations over a telephone or computer.
Full-duplex : Full-Duplex is the data transmission mode in which
the data can flow in both directions at the same time.It is two-way
communication in which both the stations can transmit and receive the
data simultaneously. Full-Duplex mode has double bandwidth as
compared to the half-duplex.

4. Data signal : Data signal is a method of how information is
transferred; usually it's transferred in binary code in signals or pulses
and may be contained in a packet.
There are four possible combinations of data and signal types:
• Analog data, analog signal;
• Digital data, analog signal;
• Analog data, digital signal;
• Digital data, digital signal.
Aanalog signal : An analog signal signifies a continuous signal that
keeps changes with a time period. A digital signal signifies a discrete
signal that carries binary data and has discrete values. Digital signal is
square waves.
Digital signal :A digital signal is a signal that is being used to
represent data as a sequence of discrete values; at any given time
it can only take on, at most, one of a finite number of values.

5. Internet : The Internet is a vast network that connects
computers all over the world. Through the Internet, people can
share information and communicate from anywhere with an
Internet connection.
Intranet : An intranet is a computer network for sharing
information, collaboration tools, operational systems, and other
computing services within an organization, usually to the
exclusion of access by outsiders.
Computer network : computer network is a set of computers
sharing resources located on or provided by network nodes. The
computers use common communication protocols over digital

6. interconnections to communicate with each other.
LAN :A local area network is a computer network that
interconnects computers within a limited area such as a
residence, school, laboratory, university campus or office
building. By contrast, a wide area network not only covers a
larger geographic distance, but also generally involves leased
telecommunication circuits.
MAN : A metropolitan area network is a computer network that
interconnects users with computer resources in a geographic
region of the size of a metropolitan area.

7. WAN : A wide area network is a telecommunications network
that extends over a large geographic area for the primary
purpose of computer networking. Wide area networks are often
established with leased telecommunication circuits.
PAN : A personal area network is a computer network for
interconnecting electronic devices within an individual person's
workspace. A PAN provides data transmission among devices
such as computers, smartphones, tablets and personal digital
assistants.

8. Hub : An Ethernet hub, active hub, network hub, repeater hub,
multiport repeater, or simply hub is a network hardware device
for connecting multiple Ethernet devices together and making
them act as a single network segment
Swicth : A network switch is networking hardware that
connects devices on a computer network by using packet
switching to receive and forward data to the destination device.
A network switch is a multiport network bridge that uses MAC
addresses to forward data at the data link layer of the OSI
model.

9. Router :A router is a networking device that forwards data
packets between computer networks. Routers perform the traffic
directing functions on the Internet. Data sent through the
internet, such as a web page or email, is in the form of data
packets.
Network or data communication addressing :
1. Physical addressing : MAC
2. Logical addressing : IP address