wireless Transmission
What is wireless transmission?
Wireless Transmission — Uses atmosphere as a medium too carry electromagnetic waves between nodes. Examples include — point to point terrestrial microwave, satellites, wireless networks, bluetooth networks, infrared and mobile phones.
- Advantage — can transverse rugged terrain and allows nodes to move freely about within the coverage area.
- Disadvantage — susceptible to interference from other sources, which makes it largely unsuitable for critical high speed connections.
- Frequency range is 10KHz up to 30GHz — also known as Radio Frequency (RF) as currently all wireless signals transmit within the RF range.
- The RF range includes; AM and FM radio, analog and digital tv. — E.g. Radio stations such as 106.5FM transmits it signal by frequency modulating a 106.5MHz career signals.
Types of wireless transmission media
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MicrowaveOccupy frequencies between about 1GHz and 3000GHz. Short wavelengths microwaves behave like light. Naturally travel in straight lines and can easily be disturbed by solid objects in their path.
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sATELLITE
Satellite - uses microwaves to carry digital signals from and to both ground based stations and between satellites. Satellites contain transponders that receive microwaves on one frequency, amplify and then transmit microwaves on a different frequency.
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rADIORadio waves frequency can travel long distances, and can penetrate buildings easily. They are widely used for communication, both indoors and outdoors. They can travel in all directions from the source, so the transmitter and receiver do not have to be carefully aligned physically.
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iNFRAREDInfrared waves travel in straight lines as a direct line of sight is required between source and destination.Currently, can only travel short distances. E.g Remote controls used within many consumer products and for transferring data between a variety of portable devices and computers.
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