Does the weather affect satellite communications?
There is a perception that Ka-band satellite communications are more susceptible than C or Ku-band to extreme weather conditions.
To combat this perception Avanti has focussed on designing robust and resilient systems which continue operating in extreme atmospheric conditions, through:
- Spot Beams. These are focussed beams which ‘punch’ through rain, snow or ice flakes, and have been specifically designed for the climatic conditions of the areas they cover.
- Automatic Level Control (ALC). This allows adjustments to be made to the transmission power from the satellite. If the satellite detects falling power levels from the Ground Earth Station (GES) it is able to automatically adjust the amplification levels to compensate.
- Uplink Power Control (UPC). This monitors the power of received transmissions from both the GES and VSAT terminals, in real time. If the GES or VSAT terminals detect a reduction in power they instruct the transmitting device to increase its power level.
- Adaptive Coding and Modulation (ACM). This allows terminals to adjust to their link conditions. This means they can optimise their spectral efficiency under clear sky conditions, and also dynamically shift to lower spectral efficiency, but more robust link configuration during periods of extreme weather.
With these contingencies in place only a small number of Avanti’s end users have experienced service degradation, and those that do have had their service resumed promptly.
During December 2011, when Scotland experienced extreme winds, Avanti is proud to report that fewer than 2% of their end user customers in Scotland experienced any form of service degradation.
