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Description
Introduction to XM radio XM-Radio is a Satellite Based Radio Broadcast System that operates around 2.3 GHz from two 15,000 watts satellites; one named "ROCK," at 115 Degrees West, the other named "ROLL" at 85.0 Degrees West. Or another way of saying, the satellites are positioned over the East and West Coasts of US. The service covers only US. Due to the limitations of satellite transmission, the signal is not able to penetrate buildings, so it cannot effectively cover dense urban areas. The terrestrial repeater network extends SDARS coverage and allows providers to reach the greatest number of subscribers and provide quality coverage. The repeaters receive the XM signal directly from the satellites and then re-transmit it to XM radios anywhere. XM provides digitalized radio programs in terms of channels. Each channel is a program that the user can tune to. A category is a group of channels. Examples of categories are classical, news and sports. XM is a paid service. That means users have to make a subscription to XM before they can enjoy the programs. However, XM does give some free-to-air channels. The users can listen to one of them without making any subscription.