Unguided transmission media.

1. Presentation on Unguided
Transmission Media
Presented By: Mohammad Junayed
Khan Noor
ID:163002029

2. Unguided medium transport electromagnetic waves without
using a physical conductor. This type of communication is often
referred to as wireless communication. Signals are normally
broadcast through free space and thus are available to anyone
who has a device capable of receiving them.
TRANSMISSION MEDIA:
UNGUIDED

3. TRANSMISSION MEDIA: TYPES

4. How signals
broadcast
• 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.

5. 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

6. 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. 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 WAES:

9. MICRO WAVES:
• 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

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

11. PROPAGATION METHOD
Line of sight

12. Wireless Propagation
• Signal travels along three routes
• Ground wave
• Follows contour of earth
• Up to 2MHz
• AM radio
• Sky wave
• Amateur radio, BBC world service, Voice of America
• Signal reflected from ionosphere layer of upper atmosphere
• (Actually refracted)
• Line of sight
• Above 30Mhz
• May be further than optical line of sight due to refraction
• More later…

13. Ground Wave Propagation

14. Sky Wave Propagation

15. Line of Sight Propagation

16. Satellite Microwave
• Satellite is relay station
• Satellite receives on one frequency, amplifies or repeats
signal and transmits on another frequency
• Requires geo-stationary orbit
• Height of 35,784km
• Television
• Long distance telephone
• Private business networks

17. Satellite Point to Point Link