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Television signals received through direct satellite service are mostly interrupted by the climatic conditions. But other communication systems that uses satellites are not that much affected. Why is this so ? Or is it just because television signals are hard real time?

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  • \$\begingroup\$ I suspect it's because you only have one dish on your house with no alternative routing. Most important communications links have at least one backup path. \$\endgroup\$ – John U Mar 31 '14 at 7:30
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    \$\begingroup\$ Maybe you can give an example of a satellite system that isn't affected? \$\endgroup\$ – Andy aka Mar 31 '14 at 7:38
  • \$\begingroup\$ @john Direct broadcast service use geostationary satellites right? So how is it possible to have alternative routing? \$\endgroup\$ – tollin jose Mar 31 '14 at 7:42
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    \$\begingroup\$ Because the big boys have more than one satellite and more than one dish on more than one building. \$\endgroup\$ – John U Mar 31 '14 at 7:43
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The difference is probably because of the different Radio Frequency Bands used by the different Satellite Services. Normally the higher the frequency is, the more is affected by the rain. On RF links rain fade start to occur at some GHz and it becomes very important if you go above 10GHz. You can check the ITU-R model for the rain attenuation on this link: http://www.itu.int/rec/R-REC-P.838/en

Another thing that might make the difference is how fault tolerant the service is (they could have redundancy, diversity…).

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If one had two antennas located a mile apart pointing at the same satellite, it's likely that during adverse meteorological conditions both antennas would have a significant fraction of data packets disrupted by weather, but the sets of disrupted packets observed by the two antennas would be different and largely unrelated. Likewise if one had two adjacent antennas pointed at different satellites. A typical DBS receiver setup, however, will just have one antenna receiving a signal from one satellite.

Further, some forms of satellite communication can use after-the-fact error recovery: a receiver that can tell that a packet got corrupted can request a retransmission. The need for retransmission will increase latency, but can be made mostly transparent to the user. By contrast, if a receiver can't capture a broadcast video packet when it's transmitted, there's no mechanism for it to find out what it missed.

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Satellite reception degradation is determined by several factors. The lower the frequency the less affected by rain fading. C band less effected, Ku and Ka band more affected. The ground based receiver position in the satellites footprint. The further away from the maximum signal zone the greater the effect. The precision of the aiming of the antenna itself lessens the effects. Rain and snow absorption and refraction of the signal. The altitude of satellite above the horizon. Transmission mode and bandwidth would also be a consideration as well.

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