Transmission Modes and Different Types of Computer Networks

1. Class Note
Course Title: Data Communication
Course Code: CSE– 313
Topic: Transmission Modes and Different Types of
Computer Networks
SUBMITTED TO:
Pranab Bandhu Nath
Senior Lecturer
Department of CSE
City University
Khagan, Savar, Dhaka
SUBMITTED BY:
Ridhy Chandro Modak
ID No: 181472063
Batch: 47th
(Eve)
Department of CSE
City University

2. Sender
Transmission Modes in a network
 Simplex
 Half Duplex
 Duplex
Simplex: In Simplex mode the data can flow only in one direction. This communication is
unidirectional. The sender can only send data and receiver can only receive data. Example:
keyboard, mouse.
Device 1 Device 2
Fig: Simplex Transmission Mode
Half Duplex: In Half-Duplex mode data can flow in both directions. It is also known as semi
duplex mode. In this mode each device can send and receive data but not at the same time. When
one device is sending data in this time the other device can only receive the data. Example:
Walkie-Talkie.
Device 1 Device 2
Fig: Half Duplex Transmission Mode
Duplex: In Duplex mode data can flow in both directions at the same time. It is also
known as bi-directional mode. In this mode each device can send and receive data at the same
time. Example: Mobile Phone.
Receiver
Sender/
Receiver
Sender/
Receiver

3. Device 1 Device 2
Fig: Duplex Transmission Mode
Signal: Signals are the electric or electromagnetic impulses used to carrying data from one
device or network to another.
Types of Signal
 Analog Signal
 Digital Signal
Analog Signal: An analog signal is any continuous signal for which the time-varying feature of
the signal is a representation of some other time-varying quantity.
Fig: Analog Signal
Digital Signal: A digital signal is a signal that represents data as a sequence of discrete values. A
digital signal can only take on one value from a finite set of possible values at a given time.
Fig: Digital Signal
Sender/
Receiver
Sender/
Receiver

4. Internet: Internet is a worldwide or global system of interconnected computer networks. Each
and Every computer or devices in a Internet is identified by a unique IP address.
Fig: Internet
Intranet: In Intranet system multiple PCs or devices are connected with each other. Devices in
intranet are not available outside the intranet. Normally each and every organization has its own
Intranet network.
Fig: Intranet

5. Different Types of Computer Networks:
Fig: Different types of computer network
Local Area Network (LAN): Full meaning of LAN is Local Area Network. It is a group of
computer and peripheral devices which are connected with each other in a limited area, for
example school, library, home, and office building.
Ethernet
Fig: Local Area Network
Network
LAN MAN WAN CAN
PC PC PC
PC
PC

6. Metropolitan Area Network (MAN): ): Full meaning of MAN is Metropolitan Area Network.
In (MAN) various Local area networks are connected with each other. It covers the larger area
than LAN such as small towns, cities, etc.
Fig: Metropolitan Area Network
Wide area network (WAN): Full meaning of WAN Wide area network. The size of the Wide
area network is larger than LAN and MAN. In (WAN) various MAN are connected with each
other. The WAN covers a large area than LAN as well as a MAN such as a country.
University
LAN
School
LAN
Shop LAN
College 2
LAN
College 1
LAN
Factory LAN
MAN

7. Fig: Wide area network
Campus Area Network (CAN): A CAN is a network of multiple interconnected local area
networks (LAN) in a limited geographical area.
Fig: Campus Area Network
WAN
LAN 1 MAN 2
LAN 2
MAN 1
LAN N
MAN N
CAN
Hostel
LAB
Library
Academic
Building

8. HUB: A hub is a common connecting device which is used for connection multiple devices in a
network. The hub has many connecting ports. Normally it is used to connect computers in a
LAN. The HUB works in physical layer. When a sender sent data the hub broadcast it to all devices of
the network.
Switches: Likes hub, switch is also a connecting device which is also used for connect multiple
devices in a network. Switch works in data link layer. When a data arrives at any port of a switch, it
examines the destination address and sends the frame to the exact destination.
Router: The router is a physical or virtual internetworking device which is designed to receive,
analyze, and forward data between computer networks. Router works in network layer. A router
examines a destination IP address of given data and it uses the headers and forwarding tables to
decide the best way to transfer the data packets.
Difference between Hub and Switch:
Hub Switch
The Hub operates on the physical layer. The switch operates on the data link layer.
Hub uses the half duplex transmission mode. Switch uses the full duplex transmission mode.
Hub doesn't provide packet filtering. Switch provides packet filtering.
Hub uses the broadcast type transmission. Switch uses the unicast, multicast and
broadcast type transmission.
In hub, there is only one collision domain. In switch, different ports have own collision
domain.
Hub cannot be used as a repeater. Switch can be used as a repeater.
Hub is not an intelligent device that sends
message to all ports hence it is comparatively
inexpensive.
Switch is an intelligent device that sends
message to selected destination so it is
expensive.
Physical Addressing (MAC)
Logical Addressing (IP)
Class of IP address:
Class of IP Range
Class A 0-126
Class B 128-191
Class C 192-223
Class D 224-239
Class E 240-255

9. References:
1. https://www.artofarticle.com/internet-and-intranet/
2. https://beginnersbook.com/2019/03/types-of-computer-network-lan-man-and-wan/
3. https://www.monolithicpower.com/en/analog-vs-digital-signal