Satellite radio is a more refined alternative to the regular terrestrial-based services. The option of capturing radio frequencies via satellite intervention, enables access to a mobile service. Companies such as Sirius, XM, and Worldspace, the pioneers in the use of the technology, not only allow their dedicated listeners to span the continents, but also capture audio programming at any remote location. Satellite radio functions along the dictates of fixed-location receivers, dish antennas, and signal repeaters. These commercial investments are made by providers of the services, allowing the listeners to enjoy hands-free communication over vast geographical areas. It enables access to coverage around tall buildings and bridges, in any weather, without interruption. The dish antennas and signal repeaters are invested in and set-up by the providers of the technology, to make signals or frequencies available to listeners within a predetermined range. History The history of satellite radio dates back to 1992. Till around this time, radio services were provided by commercial ventures. They were largely subscription-based and subject to the clarity permitted by proprietary signals and specialized hardware. Sound reception was dictated by the extent of decoding and playback, demanded over a specific population density. Most earlier providers of radio frequencies did cover news, weather updates, reports from the world of sports, and music, as well as stock market readings. However, most of the time broadcasts were subject to weather conditions and proximity to structural obstructions, but all this changed with the advent of satellite radio. The use of orbiting satellites to refine sound quality and frequencies, slowly replaced the redundant Digital Audio Broadcasting and HD Radio. In 1992, XM and Sirius became the first companies to earn FCC licenses. This enabled them to commercially manufacture and facilitate the use of satellite radios. These two companies delivered SDARS or Satellite Digital Audio Radio Services across the United States of America. The venture took around a decade to be delivered, since its inception. Finally, in 2001, it was launched nationwide. XM is recognized as the first to deliver a national digital radio service, beginning with over 100 channels. Today, it caters to demands in music, current affairs, celebrity controversies, sports, science, and children's programs, through more than 170 channels. It is now encoded using the state-of-the-art CT-aacPlus technology. The highly digitized CD quality not only delivers robust and crisp signals, but also proves its superiority over analog signals, with little or no loss of signal quality. Satellite radio is facilitated from impressive recording studios and stations. These studios are empowered by flawless sound quality, delivered on account of broadcasters set in geo-stationary orbits. Higher elevations and inclination angles of around 60 degrees are consistently sought to enable access to a clearer 'line of sight' and fewer structural obstructions. The use of a number of omni-directional arrays and high quality land based repeaters located at various select locations, guarantee reception of optimum frequencies. Companies providing these services are now equipped with transportable and vehicle mounted antennas, to take receiver-configurations to the next level. Satellite radio, like AM, is an evolutionary stage in the life of the radio industry.