Computers and devices use electromagnetic signals to transmit data through transmission media. Transmission media can be divided into guided and unguided categories. Unguided media, also called wireless communication, transports signals through the air without a physical conductor. Unguided signals can travel from source to destination in several ways, including ground propagation along the earth's surface, sky propagation reflecting signals off the ionosphere, and line-of-sight propagation transmitting signals directly between antennas.

2. Computers and other telecommunication devices use signals to represent data.
These signals are transmitted from one device to another in form of
electromagnetic energy wave, which is propagated through transmission
media/medium.
TRANSMISSION MEDIA:
UNGUIDED

3. For the purpose of telecommunication, transmission media can be divided into
two categories: Guided and Unguided.
Guided Media, which are those that provide a conduit from one device to
another, include twisted-pair cable, coaxial cable, and fiber-optic cable.
TRANSMISSION MEDIA:
(CONTI….)

4. TRANSMISSION MEDIA: TYPES

5. Unguided media transport electromagnetic waves without
using a physical conductor.
This type of communication is often referred to as a Wireless
Communication.
Signals are normally broadcast through air and thus are
available to anyone who has a device capable to receiving
them.
Unguided signals can travel from source to destination in
several ways.
UNGUIDED MEDIA: WIRELESS

6. Unguided signals can travel from source to destination in several ways. there are;
Ground propagation
Sky propagation
Line-of-sight propagation
In ground propagation, radio waves travel through the lowest portion of the
atmosphere, hugging the earth/data.
UNGUIDED MEDIA: TYPES

7. In sky propagation, higher-frequency radio waves radiate upward into the
ionosphere where they are reflected back to the earth.
In line-of-sight propagation, very high-frequency signals are transmitted in
straight lines directly from antenna to antenna.
TYPES ….

8. •Wireless transmission divided into three groups;
1: Radio waves
2: Micro waves
3: Infrared
WAVES TYPES

10. Radio waves are used for multicast communications, such as radio
and television.
They can penetrate through walls.
Highly regulated. Use Omni directional antennas
Frequencies between 3 kHz and 1Ghz
RADIO WAVES:

11. Microwaves are used for unicast communication such as cellular telephones,
satellite networks, and wireless LANs.
Higher frequency ranges cannot penetrate walls.
Use directional antennas - point to point line of sight communications.
1 and 300 GHz
MICROWAVES:

12. Infrared signals can be used for short- range communication is a closed area
using line-of-sight propagation.
300 GHz to 400 THz
INFRARED:

13. PROPAGATION METHOD