grade 10 student ict ppt

1. 2.2.2 Unguided (Wireless) Media
Wireless communication uses unguided media to
transport electromagnetic waves without a physical
conductor. Signals can travel through ground, sky, or
line-of-sight propagation. Ground propagation
involves low-frequency signals, sky propagation
radiates higher-frequency signals, and line-of-sight
propagation involves directional antennas.
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2. A. Radio Waves
 Radio waves, ranging from 3 kHz to 1 GHz, are
omnidirectional and can travel long distances, making them
suitable for long-distance broadcasting like AM radio, but are
susceptible to interference from other antennas.
Omnidirectional Antenna
 Radio waves use omnidirectional antennas for multicasting,
sending signals in all directions, making them useful for
AM/FM radio, television, maritime radio, cordless phones,
and paging.
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3. B. Microwaves
 Microwaves are unidirectional wireless communication
technologies that use high-frequency radio waves to send and
receive voice, video, and data without interference between
antennas.
Unidirectional Antenna
 Microwave communications use unidirectional antennas, such
as parabolic dish and horn. Parabolic dish uses a parabola's
geometry to direct waves to a common point, while horn
antennas use a scoop-like shape to collect and deflect received
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4. Applications of Microwave Technologies
Microwaves are utilized in cellular phones, satellite
networks, and wireless LANs for unicast
communication due to their unidirectional properties.
c. Infrared Waves
Infrared, or infrared light, is electromagnetic radiation
with longer wavelengths than visible lights, invisible to
the human eye. It's used to change channels on TVs and
remote controls.
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5. 2.3 Telecommunications Network
2.3.1 Telecommunications Concepts
Telecommunications refers to long-distance
communication using common carriers like
telephone, radio, and television, enabling the
exchange of information over networks. It plays a
crucial role in modern organizations.
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6. Telecommunications System
A telecommunications system is a network of hardware
and software used to transmit information from one
location to another. It consists of hardware, media,
networks, processors, software, data communications
providers, protocols, and applications. The system
performs functions like transmitting, establishing
interfaces, routing messages, processing information,
checking for errors, converting messages, controlling
information flow, and securing information.
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7. Electronic Signals
Telecommunications media can carry analog and digital
signals. Analog signals are continuous waves altering
amplitude and frequency, while digital signals are
discrete pulses conveying information in 1's and 0's.
Digital signals are less affected by interference and
require no conversion from digital to analog.
Communications processors, such as modems, convert
digital signals to analog before transmission over
standard telephone lines.
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8. 2.3.2 The Importance of Telecommunications
Advances in telecommunications technology enable
rapid communication, distance learning, and reduced
time for information transmission. Applications
include telephony, video conferencing, and more.
Ethio-telecom is implementing 4G LTE advanced
across regions.
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9. 2.4 Mobile Communications
 Mobile communication utilizes technology to facilitate
communication across locations without physical connections,
saving time and effort. Basic mobile communications
technologies are discussed in subsequent sections.
2.4.1 A Bluetooth Network
 Bluetooth technology replaces cables for short-range wireless
communications, enabling phone conversations via headsets.
It operates in the unlicensed ISM band at 2.4 gigahertz,
allowing devices to pair and communicate.
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10. 2.4.2 Wireless Local Area Network (WLAN)
The local computing market is transitioning towards
wireless LAN (WLAN) with high-speed data rates,
enabling mobility and connectivity. WLANs, based
on IEEE 802.11 standards, offer up to 11 Mbps of
data and can double distance between nodes.
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11. 2.5 Cellular Networks
A cellular network is a radio network distributed over
land areas, serving mobile stations and stationary units.
It allows service providers to locate and track callers,
assign channels, and transfer channels between cells,
controlled by a mobile switching center.
Generation of Cellular System
Cellular communication networks are categorized into
numeric generations like 1G, 2G, 3G, and 4G, with 5G
emerging as the fourth generation.
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12. A. Fourth Generation (4G)
 4G, also known as mobile broadband, is a complete wireless
communications evolution aiming for high network capacity, smooth
handoff, seamless connectivity, high service quality, and interoperability
with existing standards.
4G LTE
 4G LTE is a 4G technology that offers mobile broadband with data transfer
rates of 100 Mbps.
B. 5g
 5G is the 5th generation mobile network, offering faster downloads, flexible,
responsive connectivity, and improved efficiency, enabling new user
experiences and connecting various industries.
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13. 2.6 Satellite Networks
 Satellite networks consist of nodes, including satellites, earth stations,
uplink, downlink, and transponder, providing high-quality communication
from remote locations without significant ground-based infrastructure
investment.
2.6.1 Orbits of Satellite
 An artificial satellite must have an orbit, which can be equatorial, inclined,
or polar, to navigate around Earth.
2.6.2 Categories of Satellites
 Satellites are classified into three orbits: Geostationary Earth orbit (GEO),
low-Earth-orbit (LEO), and medium-Earth-orbit (MEO). Different orbits are
due to Van Allen belts.
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14. 2.6.3 Data Communications
 Data communication is a specialized telecommunications
subset that involves electronic data collection, processing, and
distribution between computer systems, with its effectiveness
based on delivery, accuracy, timeliness, and jitter.
2.6.4 Components of Data Communication
 A data communications system has five components sender,
transmission medium, message, receiver, and protocol.
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15. 2.6.5 Data Transmission Mode/Flow
 Data transmission mode refers to the direction of signal flow between two
devices, and can be simplex, half-duplex, or full-duplex.
Simplex
 Simplex mode is a unidirectional communication system where only one
device can transmit data, like keyboards or monitors, using the entire
channel capacity.
Half-Duplex
 Half-duplex mode allows stations to transmit and receive simultaneously,
reserving channel capacity for each direction, similar to a one-lane road,
when communication isn't needed simultaneously.
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16. Full-duplex
Full-duplex mode allows simultaneous transmission
and reception of signals in both directions, similar to
a two-way street. It shares link capacity through
separate transmission paths or channel capacity.
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17. 2.7 Internet Protocol
 The Internet Protocol (IP) is the primary communication protocol in
internetworking, and a comprehensive understanding of IP is essential
for modern networking.
2.7.1 IP Address
 IP addresses are unique identifiers for devices on the internet or local
network, governed by Internet Protocol. They enable communication
and location information exchange. IPv4 addresses are commonly used,
with a dotted quad format.
2.7.2 Classes of IP Address
 In the early 1980s, Internet addresses were standardized into five
classes: A, B, C, D, and E.
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18. Network Masks
The network mask identifies the network portion
and the node portion in an address.
Default Masks
Class A is 255.0.0.0
Class B is 255.255.0.0 and
Class C is 255.255.255.0.
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19. UNIT THREE
APPLICATION
SOFTWARE
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