Science Fair Project Encyclopedia
Direct broadcast satellite
Direct broadcast satellite, or DBS, is a relatively recent development in the world of television distribution. "Direct broadcast satellite" can either refer to the communications satellites themselves that deliver DBS service or the actual satellite television service. DBS systems are commonly referred to as "minidish" systems.
The first commercial DBS service, Sky Television, was launched in 1989. Sky TV originated as a four-channel service on the Astra satellite. Sky TV is a Europe DBS service and is now owned by News Corporation.
Although PrimeStar transitioned to a digital system in 1994, it was ultimately unable to compete with DirecTV, which required a smaller satellite dish and could deliver more programming. DirecTV eventually purchased PrimeStar in 1999 and migrated all PrimeStar subscribers to DirecTV equipment.
In 1996, Echostar's DISH Network went online in the United States and went on to similar success as DirecTV's primary competitor. In 2003, Echostar attempted to purchase DirecTV, but the U.S. Department of Justice denied the purchase based upon monopoly concerns.
In addition there are dozens of satellite television stations that broadcast to specialized ethnic communities.
DBS uses special high-powered Ku-band satellites that send digitally-compressed television and audio signals to 18- to 24-inch (45 to 60 cm) fixed satellite dishes. DBS systems transmit signals to Earth in what is called the Broadcast Satellite Service (BSS) portion of the Ku band between 12.2 and 12.7 GHz. Thanks to digital compression technologies, DBS systems can deliver hundreds of cable TV-style programming channels, as well as local network television affiliates.
DBS services offer many advantages over traditional analog services such as cable TV. DBS services generally offer a better picture quality and more channels than analog cable. DBS services also offer additional features like an on-screen guide , DVR functionality, HDTV, Pay-Per-View, and 5.1 sound. Cable companies have responded by introducing digital cable, which offers more channels and many of the same features as DBS.
DirecTV and Echostar both offer DVR units. These units integrated the digital-recording of a DVR with the capabilities of a traditional receiver/decoder. DirecTV's unit is powered by technology licensed from TiVo Inc.
Hughes (the parent company of DirecTV) and Echostar also offer high-speed internet access, mostly to rural customers who cannot access broadband via ADSL or cable modem. Service is generally spotty and expensive, but it generally superior to dial-up service and is often the only option.
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