Difference between revisions of "Fade Mechanisms"

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Link Performance Definition
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The definition of link performance only considers multipath and rain fades.
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This implies the following assumptions:
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* the path has sufficient clearance / fade margin to obviate the possibility of an obstruction fade.
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* signal nulls due to a specular reflection are small com-pared to the fade margin or a space diversity configura-tion has been implemented.
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* the probability of ducting is unknown.

Revision as of 14:25, 21 February 2020

Microwave fades fall into the following categories:

  • Multipath fading
  • Obstruction fading
  • Fading due to a specular reflection
  • Ducting and propagation anomalies
  • Rain fading (above ~ 8 GHz)

With the exception of rain fading, microwave fading only depends on the change of the refractive index with height along the path


Availability Seconds Minutes Hours
99% 315360 5256 87.6
99.9% 31536 525 8.76
99.99% 3153 52.5 0.876
99.999% 315 5.3 0.088


Link Performance Definition The definition of link performance only considers multipath and rain fades. This implies the following assumptions:

  • the path has sufficient clearance / fade margin to obviate the possibility of an obstruction fade.
  • signal nulls due to a specular reflection are small com-pared to the fade margin or a space diversity configura-tion has been implemented.
  • the probability of ducting is unknown.