Satellite Frequency Bands
There are a number of radio frequency ranges in use in satellite communications such as C, X, Ku, Ka and even EHG and V-band. To prevent interferance caused by multiple sites transmitting on the same frequencies, government agencies and standards organizations around the globe try to keep the usage organized and often such controls take the form of government regulations which carry the weight of law.
In the United States, the Federal Communications Commission periodically holds frequency auctions to sell available spectrum. Unauthorized use of regulated frequencies without authorization by the United States government or by its current lease-owner is punishable by fines or jail time.
Earth stations use unregulated frequencies within their facilities. Earth stations need to manipulate and transport the data in the signal without interfering with other radio communications in the area. The frequencies earthstations use are often in the same ranges as local radio and television broadcasts which can cause interferance for both parties even if they are not on the same frequency. Thus, radio shacks and/or the devices within them are heavilly sheilded to prevent such interferance.
Satellites use different, higher frequencies that are regulated. At the engineering level, there is what is known as sideband which is frequency spectrum that is set aside to create a separation between frequencies to prevent transmissions using adjacent frequencies from interfering with each other.
Satellites have power and regulatory restrictions governing which frequencies they may use. In addition, there are other requirements such as weather that may restrict use of certain frequencies. Below is a chart listing the approximate ranges of each frequency band.