Transmission Media, guided media, Unguided media, and Microwave Communication, Ground Propagation, Sky Propagation, Line of Sight Propagation, Transmission and Reception of Signals.

1. TRANSMISSION MEDIA
Computer uses signals to represent data.
Functionality is to carry the information in the form
of bits through LAN.
Copper and Fiber based network
The signals are transmitted in the form of
electromagnetic energy.
This signals transfer through transmission media.
Transmission media can be classified into two
categories:
Guided Media
Unguided Media
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2. Transmission
Media
Guided
Media
Unguided
media
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Guided Media: Transmits signals by sending
electricity or light over a cable or wire.
Un-Guided Media: The data signals are not bounded
to cabling system.

3. UN-GUIDED MEDIA
• Also known as Un bounded media.
• It consist of signals but nothing to guide the signal
to a specific path.
• The signals aren’t bound to cabling system.
• It is wireless transmission.
• Signals are broadcast through air.
• It is available to anyone who has device to receive
them.
• Radio waves, infrared signals, satellite-based
microwave transmission
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5. FORMS OF TRAVELLING
• Can travel from source to destination in several ways:
• Sky propagation
• Ground propagation
• Line of sight propagation.
• Ground Propagation : Signals travel through lowest
portion of earth’s atmosphere.
• Sky Propagation : Higher frequency signals radiate
upward into the ionosphere and are reflected back to
earth.
• Line of Sight Propagation : Very high frequency signals
are transmitted in a straight line from antenna to antenna.
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6. TRANSMISSION OF SIGNALS
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7. HOW DOES IT WORK?
Transmission
• The signal is guided to antenna via guided media
• Antenna radiates electromagnetic energy in medium.
Reception
• Antenna picks up electromagnetic waves from the
surrounding medium.
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8. MICROWAVE
• A microwave signals are the electromagnetic wave of
short wavelength and very high frequency.
• Transmission of signal using radio wave in microwave
frequency.
• Development of Radar in World War II provided
technical exploitation of Microwave communication.
• Substitute for Coaxial cables in late 1940s.
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9. • Generally operates at 1 GHz- 50 GHz.
• Requires Line of Sight, free of obstruction.
• Line of sight (LoS) : type of propagation that can transmit
and receive data only where transmit and receive stations are
in view of each other without any sort of an obstacle between
them.
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10. A Microwave signal is generated by device called
Magnetron.
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12. APPLICATION AREAS
• Microwave oven is based on this principle
• Radar
• Navigation Application
• Bluetooth
• Telephone for long distance communication.
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13. PROS AND CONS
Pros
• Able to transmit large quantities of data.
• Relatively low cost.
Cons
• Not suitable for long distance transmission.
• Solid objects
• Subject to electromagnetic interference.
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14. Any Question?
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