Guest Post by Coleen Torres
Perhaps you have heard the term ‘rain fade’ in regard to satellites internet reception or television satellite reception. Rain fade refers to the fact that moisture in the air between the transmitting satellite and the end user of the signal, can interfere with the satellite signal.
Causes – What kind of moisture are we talking about when we use the term rain fade? It is referring to the presence of rain or snow in the air. Either type of moisture in the air can be a source of interference. The more the moisture, the worse the interference.
Unavoidable – There is no way to totally avoid this interference of moisture with satellite signals, but there are ways to minimize its effects and improve reception.
Best frequencies – There are certain frequencies that move through the moisture in the air better than others. Lower frequencies like ‘L’ and ‘C’ are the best for areas which have a lot of rain. Most tropical areas, which experience ‘rainy seasons’, use the ‘C’ frequency.
Worst frequencies – The higher frequencies, in contrast, experience the most deterioration in their signals due to rain fade. These would be frequencies such as ‘Ku’ and ‘Ka’.
Special techniques – For those using these higher band frequencies there are several special techniques that can be used to improve the reception. Increased rain margins, adaptive uplink power control and reduced bit rates are the three techniques that are usually used.
Rain margins – This refers to the extra communication links that are needed in order to minimize the loss of signal and interference of the satellite signal due to rain or snow in the air. The more additional links that can be established, the less affect will be realized from the precipitation.
Size of dish – One of the ways to increase the rain margin is to increase the size of the satellite dish. The bigger dish provides for the extra communication links needed to minimize the effects of rain fade.
Commercial dishes – A large commercial disk will not be affected by rain fade to the extent that a small consumer satellite disk will be. The interruption of service should be much shorter for a large commercial dish than it is for a homeowner with a small satellite dish.
Bit rates – Increased bit rates can also minimize the effects of rain fade and lower costs involved with satellite reception by decreasing the power draw on a satellite.
Costs – Rain fade interference with satellite signals do not simply affect the end users resulting performance, it also affects the cost. Rain fade can cause a greater power draw on a satellite, which creates a higher cost per bit of transmission.
If you’ve heard that weather is a factor with satellite transmission for internet or television, you have heard correctly. There are systems in place, however, to minimize the issue.