2.1 a,b

SC015 SDS

Sesi 2020/2021

2.0 INTERNET TECHNOLOGY

2.1 Basic Concept of Network

LEARNING OUTCOME:

At the end of this lesson students will able to:

a) Explain the concept of network.
b) Explain types of communication devices and

transmission media used in a network.

DEFINITION OF NETWORK

A network is a collection of computers
and mobile devices connected

together via communications devices
and transmission media.

(Discovering Computers 2018)

PURPOSE OF CREATE NETWORK:

• To facilitate communications, share
hardware, shared data and
information, share software and
transfer fund.

DEFINITION OF
COMMUNICATIONS DEVICE

Hardware component that capable of
transferring items from computers and devices

to transmission media and vice versa.
(Discovering Computers 2018)

WHAT IS COMMUNICATIONS
DEVICE?

• Any type of hardware capable of transmitting
data, instruction, or information from the
sending device to transmission media.

• At the sending end, a communication device
send the data, instruction or information from
the sending device to transmission media.

• At the receiving end, a communication device
receive the signals from the transmission
media.

TYPES OF COMMUNICATIONS
DEVICE

Types of communications devices:

a) Digital Modems
b) Wireless Modems
c) Wireless access point
d) Routers
e) Network card
f) Hubs and switches

TYPES OF COMMUNICATIONS
DEVICE

a) Digital Modems

 also called Broadband Modem
 A communication device that sends and

receives data and information to and from a
digital line.
 Three types of digital modems:

i. cable modems
ii. DSL Modems
iii. ISDN modems

TYPES OF COMMUNICATIONS
DEVICE

i) Cable Modems

 A broadband modem that sends and receives
digital data over the CATV network.
 Usually is an external device, in which
one end of a cable connects to a
CATV wall outlet and the other end
plugs in a port on a computer.

TYPES OF COMMUNICATIONS
DEVICE

ii) DSL Modems

 A broadband modem that sends digital data
and information from a computer to a DSL line
and receives digital data and information from
DSL line.
 Usually is an external device, in which
one end connects to the phone line
and the other end connects to a port
on the computer.

TYPES OF COMMUNICATIONS
DEVICE

iii) ISDN (Integrated Services Digital Network)
Modems

 A broadband modem that sends digital data
and information from a computer to an ISDN
line and receives digital data and information
from an ISDN line.
 Usually is an external device, in which
one end connects to the phone line
and the other end connects to a port
on the computer.

TYPES OF COMMUNICATIONS
DEVICE

b)Wireless Modems

 A communication device that uses a mobile
service provider’s network to connect the Internet
wirelessly from a computer or mobile device.
 wireless modem, which have an
external or built-in antenna,
available as USB adapters and
other devices.

TYPES OF COMMUNICATION
DEVICE

c)Wireless Access Point (WAP)

A central communication device that allows
computers and devices to transfer data wirelessly
among themselves or to a wired network using
wireless technologies such as Wi-Fi.
 Have high-quality internal or external
antennas for optimal signals.
 A wireless access point either
connect to a routers via an Ethernet
or other cable or is part of a router.

TYPES OF COMMUNICATIONS
DEVICE

d)Routers

A communication device that connects multiples
computers or others routers together and transmits
data to its correct destination on a network

 Routers can be used on a network of any size.

TYPES OF COMMUNICATIONS
DEVICE

e) Network Cards

A communication device that enables a
computers or device that does not have built-in
networking capability to access a network.
 also known as network interface
card (NIC).
 A network card coordinates the
transmission and receipt of data,
instructions, and information to and
from the computer or device
containing the network card.

TYPES OF COMMUNICATIONS
DEVICE

f) Hubs or Switches

A device that provides a central point for cables in a
network.
 Larger networks typically use a hub, while smaller
networks use a switch.
 Some hubs and/or switches include
routers, thus the hub or switch
receives data from many directions
and the forward it to one or more
destinations.