2. HHCJ- COMPUTER STUDIES LECTURE NOTE
TOPIC: COMMUNICATIONS SYSTEMS
WHAT IS: Information and Communication
Technology
ICT is an acronym of Information and
Communication Technologies. The set of
technologies developed to manage information
and send it from one place to another.
3.
4. TYPES OF ICT
Broadcasting: is the distribution of audio or video
content to a wider audience via any electronic mass
communications medium.
Broadcasting: electronic transmission of radio and
television signals that are intended for general public.
Broadcasting: is the distribution of audio and/or video
signals (programs) to a number of recipients ("listeers"
or "viewers")
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6. • Telecommunication OR or Telecom: is the
exchange of signs, signals, messages, words,
writings, images and sounds or information of
any nature by wire, radio, optical or other
electromagnetic systems.
• Telecommunications:refer to the process of
exchanging information such as voice, data and
video transmissions via electronic technologies
like telephones (wired and wireless), microwave
communications, fiber optics, satellites, radio
and television broadcasting, and the internet.
7.
8.
9. • data network :A communication network that
is devoted to carrying computer information, as
opposed to voice, video, etc. It consists of a
number of nodes, or stations, connected by
various communication channels.
• Data networks: comprised of two or more
computers that are connected to share
information, hardware, programs and so forth.
A DATA NETWORK: is an electronic
communications process that allowsfor the
orderly transmission and receptive of data
10.
11. • Information system:A system is a group of
interacting or interrelated entities that form a
unified whole.
• Information: is data that have been converted
into a meaningful and useful context for
specific end users.. So you should view
information as processed data placed in a
context that gives it value for specific end
users.
• Information system:an integrated set of
components for collecting, storing, and
processing data and for providing information,
knowledge, and digital products.
12.
13. • Satellite communication: in
telecommunications, the use of artificial
satellites to provide communication links
between various points on Earth. Satellite
communications play a vital role in the global
telecommunications syste.
• A communications: system based on
geostationary satellitesm.
• Communications satellites are commonly used
for mobile phone signals, weather tracking, or
broadcasting television programs
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15.
16. • EXAMPLES OF BROACASTING
RADIO BROADCASTING: Radio broadcasting is transmission
of audioby radio waves intended to reach a wide audience.
Radio broadcasting refers to using radio waves to send signals to
large groups of listeners
Radio broadcasting is a one-way wireless transmission over radio
waves intended to reach a wide audience
17.
18. • Television broadcasting: form of broadcasting
in which a television signal is transmitted by
radio waves from a terrestrial (Earth based)
transmitter of a television station to TV
receivers having an antenna.
19.
20. • Satellite communications involves four steps:
• An uplink Earth station or other ground
equipment transmits the desired signal to the
satellite.
• The satellite amplifies the incoming signal and
changes the frequency.
• The satellite transmits the signal back to
Earth.
• The ground equipment receives the signal.
21.
22. • A Public Switched Telephone Network, or
PSTN for short, refers to a telecommunications
network which allows subscribers at different
sites to communicate by voice.
• A public switched telephone network: is a
combination of telephone networks used
worldwide, including telephone lines, fiber
optic cables, switching centers, cellular
networks, satellites and cable systems.
23.
24. • LANDLINE
• a phone that is connected to the phone system
by wires. a phone that is not a mobile phone
and that is connected to the phone system by
wires:
25. • The Mobile Telephone System
• Mobile telephone service (MTS) connects mobile radio
telephones with other networks like public switched
telephone networks (PSTN), other mobile telephones
and communication systems like Internet.
• Basic Mobile Communications System
• Mobile phones and other mobile devices, called mobile
stations are connected to base stations. Communication
between the mobile stations and the base stations are
done by wireless radio signals, which may be both data
signals and voice signals. Each base station has a
coverage area around it, such that mobile stations within
this area can connect provided they have access
permissions.
26. • Generations of Mobile Phone Systems
• 1G (First Generation) − They were standards for
analog voice mobile phone communications.
• 2G(Second Generation) − They were standards
for digital voice mobile phone communications.
• 3G(Third Generation) − These standards were for
communications in form of both digital voice as
well as digital data.
• 4G(Fourth Generation) − 4G standards provide
mobile broadband internet access in addition to
digital voice and data.
• 5G(Fifth Generation) − It is the next step of
mobile communication standards beyond 4G
which currently under development.
27. • What is a mobile Phone:
• A mobile phone is a wireless handheld device
that allows users to make and receive calls and
to send text messages. etc
