Satellite communications spectrum
The satellite transmission bands that are of interest to us are the C-, Ku- and Ka-bands.
C-band is the oldest allocation and operates in the frequency range around 6 GHz for transmission (uplink) and between 3.7 and 4.2 GHz for reception (downlink). Ku-band is the most common transmission format in Europe for satellite TV and uses around 14 GHz for uplink and between 10.9 and 12.75 GHz for downlink.
Ka-band uses around 30 GHz up- and between 18 and 20 GHz downlink frequency.
C-band and Ku-band are becoming congested by an increasing amount of users, so satellite service operators are more and more turning to the use of Ka-band.
The selection of the band is not something that individual service providers decide, but is rather chosen by large satellite operators based on different factors:
Availability: C-band is still the most widely available worldwide. Ku-band is becoming more available recently in regions which were less covered in the past (South America, Asia, Africa)
C-band is more prone to interference from other transmission services that share the same frequencies (adjacent satellites or terrestrial transmissions) than the higher bands
While the C-band technology is cheaper in itself, it requires larger dishes (1 to 3 m) than Ku- and Ka-band (0.6 to 1.8 m) and therefore imposes relatively higher (installation) costs on the end-user
Ku- and especially Ka-band make better use of satellite capacity
Higher frequency bands (Ku- and especially Ka-) suffer significantly more from signal deterioration...