AMUMARA: COMPUTER STUDIES LECTURE NOTE FOR SS3-002

1. HHCJ AMUMARA
COMPUTER STUDIES LECTURE NOTE –SS3
(NOTE 002)

2. PACKET-SWITCHED VS. CIRCUIT-SWITCHED
TELEPHONE SYSTEMS
• Circuit Switched Telephone Systems are used
by the Public Switched Telephone Network
(PSTN). They work with standard analogue
telephones where you have one line that
allows you to make or receive calls. A circuit
switched telephone system has a single,
dedicated connection between two end points
in a network.

3. example of a circuit-switched
network
• An example of a circuit-switched network is an
analog telephone network. The circuit switched
telephone system uses copper wires to transfer
voice data
• NOTE: packet-switched networks unlike circuit switched
network breaks the communication into packets and then send
those packets through the network independently of one
another. Packet switching is currently the most modern form of
telephone system. Instead of using one line and one
communication channel dedicated to a single call, packet
switching divides the call data up into small units, known as
packets.

4. Example of Circuit Switched Network

5. SATELLITE TELEPHONE SYSTEM
• What is a satellite Phone:
• A satellite phone is a telephone that has the
ability to connect to orbiting satellites.
• Satellite phones are mobile devices that do
not receive their signal via terrestrial (land
based) towers, but rather from satellites in
orbit.
• Satellite Phones work anywhere in the world

6. Example of Satellite Phone system

7. FIXED WIRELESS TELEPHONE SYSTEM
• Fixed wireless refers to wireless devices or
systems that are situated in fixed locations, such
as an office or home, as opposed to devices that
are mobile, such as smartphones and tablets.
• fixed wireless does not require satellite feeds or
local phone service. The advantages of fixed
wireless include the ability to connect with users
in remote areas without the need for laying new
cables

9. Data Network
• A network is a structure that has a
characteristic pattern. It is the interconnection
of computers and other devices that share
resources.
• Data is a term that indicates information, a
document in a raw form.
• Data networks are comprised of two or more
computers that are connected to share
information, hardware, programs and so forth

10. EXAMPLES OF DATA NETWORK
• There are so many types of Data Networks
which include but not limited to the following:
• Personal Area Network (PAN)
• The smallest and most basic type of network,
a PAN is made up of a wireless modem, a
computer or two, phones, printers, tablets,
etc., and revolves around one person in one
building.

11. • Local Area Network (LAN)
• LANs are the most frequently discussed
networks, one of the most common, one of
the most original and one of the simplest
types of networks. LANs connect groups of
computers and low-voltage devices together
across short distances to share information
and resources.
• Wireless Local Area Network (WLAN)
• hese types of networks don’t require that
devices rely on physical cables to connect to
the network.eg: Wi-fi.

12. • Metropolitan Area Network (MAN)
These types of networks are larger than LANs
but smaller than WANs – and incorporate
elements from both types of networks. MANs
span an entire geographic area like Cities.
• Wide Area Network (WAN)
Slightly more complex than a LAN, a WAN
connects computers together across longer
physical distances. This allows computers and
low-voltage devices to be remotely connected
to each other over one large network to
communicate even when they’re miles apart.

13. • Virtual Private Network (VPN)
• By extending a private network across the
Internet, a VPN lets its users send and receive
data as if their devices were connected to the
private network.
• Campus Area Network (CAN)
• They are larger than LANs, but smaller than
metropolitan area networks (MANs, explained
below), these types of networks are typically
seen in universities,

14. INFORMATION SYSTEM
• Information system is an example of
Integrated set of components for collecting,
storing, and processing data and for providing
information, knowlegde and digital products.
• Business firm and other organizations rely on
information systems to carry out and manage
their operations, interact with customers and
suppliers and compete in the market placce.

15. GLOBAL POSITIONING SYSTEM(GPS)
• This is a system of satellites, computers, and
receivers that are able to determine the
latitude and longitude of a receiver on Earth
by calculating the time difference for signals
from different satellites to reach the receiver.

16. STAY AT HOME, STAY SAFE , BE
POSITIVE.