Many digital satellite providers now bundle DVR systems with their decoder box. With any Sirius-enabled radio, the user can see the artist and song information on display while listening to the stream. Sirius Radio has rights to a number of major college sports conferences, including the Big Ten and the Southeastern Conference as well as schools like Notre Dame. Unlike XM Radio, Sirius Radio does not use GEO satellites fro its satellite radio services. The Sirius Radio business model is to provide pay-for-service radio, music channels being free of commercials, analogous to the business model for premium cable television. On March 1, 2004, XM Radio launched Instant Traffic and Weather Channels for major metropolitan markets in the United States. XM Radio Online gives you unlimited access to over 75 channels of the same amazing programming you hear on XM Satellite Radio. Many customers prefer the additional channels available on satellite TV systems and the clarity of the digital signals. Audio channels on XM Radio are digitally compressed using the aacPlus codec from Coding Technologies for most channels, and the AMBE codec from Digital Voice Systems for some voice channels. XM Radio provides excellent coast-to-coast signal coverage to the densely populated regions of Canada through its satellites and a robust ground repeater network installed in major metropolitan areas. When you buy a plug-and-play satellite radio, you'll most likely pick up a car kit and a home kit, to take full advantage of the radio's capabilities. Satellite dishes must have a clear line of sight to the satellite itself for best reception. In the US market, there's two players: XM Satellite Radio and Sirius Satellite Radio. Some satellite radio models are designed to work with real-time traffic information services. Each satellite service offers close to 70 commercial-free music channels. The idea behind satellite radio is quite basic.