Information about Direct Broadcast Satellite

Direct broadcast satellite (DBS) is a term used to refer to satellite television broadcasts intended for home reception, also referred to as direct-to-home signals. The expression direct-to-home or DTH was, initially, meant to distinguish the transmissions directly intended for home viewers from cable television distribution services that sometimes carried on the same satellite. The term predates DBS satellites and is often used in reference to services carried by lower power satellites which required larger dishes (1.7M diameter or greater) for reception. In Europe, the expression was common prior to the launch of ASTRA-1 in 1988 as there were two markets: the DTH market which required the larger dishes and the DBS (ASTRA) market which required smaller (0.9M dishes). As higher powered satellites like ASTRA came into operation, the acronym DBS gradually supplanted it.

The term DBS now covers both analog and digital television and radio reception, and is often extended to other services provided by modern digital television systems, including video-on-demand and interactive features. A "DBS service" usually refers to either a commercial service, or a group of free channels available from one orbital position targeting one country.

Terminology confusion

In certain regions of the world, especially in North America, DBS is used to refer to providers of subscription satellite packages, and has become applied to the entire equipment chain involved. With modern satellite providers in the United States using high power Ku-band transmissions using circular polarization, which result in small dishes, and digital compression (hence bringing in an alternative term, Digital Satellite System, itself likely connected to the proprietary encoding system used by DirecTV, Digital Satellite Service), DBS is often misused to refer to these. DBS systems are often driven by pay television providers, which drives further confusion. Additionally, in some areas it is used to refer to specific segments of the Ku-band, normally 12.2 to 12.7 GHz, as this bandwidth is often referred to as DBS or one of its synonyms. In comparison, European "Ku band" DBS systems can drop as low as 10.7 GHz.

Adding to the naming complexity, the ITU's original frequency allocation plan for Europe, the Soviet Union and Northern Africa from 1977 introduced a concept of extremely high power spot-beam broadcasting (see Ekran satellite) which they termed DBS, although only a handful of the participating countries even went as far as to launch satellites under this plan, even fewer operated anything resembling a DBS service.

Commercial DBS services

The first commercial DBS service, Sky Television plc (now BSkyB), was launched in 1989. Sky TV started as a four-channel free-to-air analogue service on the Astra 1A satellite, serving the United Kingdom and Republic of Ireland. By 1991, Sky had changed to a conditional access pay model, and launched a digital service, Sky Digital, in 1998, with analogue transmission ceasing in 2001. Since the DBS nomenclature is rarely used in the UK or Ireland, the popularity of Sky's service has caused the terms "minidish" and "digibox" to be applied to products other than Sky's hardware. BSkyB is controlled by News Corporation.

PrimeStar began transmitting an analog service to North America in 1991, and was joined by DirecTV Group's DirecTV (then owned by GM Hughes Electronics), in 1994. At the time, DirecTV's introduction was the most successful consumer electronics debut in American history. 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 2003, News Corporation purchased a controlling interest in DirecTV's parent company, Hughes Electronics, and renamed the company DirecTV Group.

In 1996, EchoStar's Dish Network went online in the United States and, as DirecTV's primary competitor, achieved similar success. AlphaStar also launched but soon went under. Astro was launched, using its direct broadcast satellite system.

Dominion Video Satellite Inc.'s Sky Angel also went online in the United States in 1996 with its DBS service geared toward the faith and family market. It has since grown from six to 36 TV and radio channels of family entertainment, Christian-inspirational programming and 24-hour news. Dominion, under its former corporate name Video Satellite Systems Inc., was actually the second from among the first nine companies to apply to the FCC for a high-power DBS license in 1981 and is the sole surviving DBS pioneer from that first round of forward-thinking applicants. Sky Angel, although a separate and independent DBS service, uses the satellites, transmission facilities, & receiving equipment used for Dish Network through an agreement with Echostar. Because of this, Sky Angel subscribers also have the option of subscribing to Dish Network's channels as well.

In 2003, EchoStar attempted to purchase DirecTV, but the U.S. Department of Justice denied the purchase based on anti-competitive concerns.

Free DBS services

Germany is likely the leader in free-to-air DBS, with approximately 40 analogue and 100 digital channels broadcast from the SES Astra 1 position at 19.2E. These are not marketed as a DBS service, but are received in approximately 12 million homes, as well as in any home using the German commercial DBS system, Premiere.

The United Kingdom has approximately 90 free-to-air digital channels, for which a promotional and marketing plan is being devised by the BBC and ITV, to be sold as "Freesat". It is intended to provide a multi-channel service for areas which cannot receive Freeview, and eventually replace their network of UHF repeaters in these areas

India's national broadcaster, Doordarshan, promotes a free-to-air DBS package as "DD Direct Plus", which is provided as in-fill for the country's terrestrial transmission network.

While originally launched as backhaul for their digital terrestrial television service, a large number of French channels are free-to-air on 5W, and have recently been announced as being official in-fill for the DTT network.

In North America (USA, Canada and Mexico) there are over 80 FTA digital channels available on Intelsat Americas 5, the majority of them are ethnic or religious. Other popular FTA satellites include AMC-4, AMC-6, Galaxy 10R and SatMex 5. A company called GloryStar promotes FTA religious broadcasters on IA-5 and AMC-4.

•  • [ e] The Electromagnetic Spectrum
Visible (optical) spectrum	(Sorted by wavelength, short to long) Gamma ray • X-ray • Ultraviolet • Visible spectrum • Infrared • Terahertz radiation • Microwave • Radio waves
Microwave spectrum	W band • V band • K band: Ka band, Ku band • X band • C band • S band • L band
Radio spectrum	EHF • SHF • UHF • VHF • HF • MF • LF • VLF • ULF • SLF • ELF
Wavelength designations	Microwave • Shortwave • Mediumwave • Longwave

•  • [ e] Analog & Digital Audio broadcasting (DAB)
Terrestrial radio modulation	AM • FM • COFDM
Frequency allocations	LW • MW (MF) • SW (HF) • VHF • L-Band • (FSS/TVRO • DBS)
Hidden signals	AMSS • DirectBand • PAD • RDS/RBDS • SCA
Codecs	AAC • Musicam • PAC
Terrestrial DAB systems	DAB/DAB+ • DRM/DRM (+) • HD Radio • FMeXtra • CAM-D
L-Band DAB systems	Sirius • WorldSpace • XM
C-Band & Ku-Band DAB systems	SDR • DVB-SH • DAB-S • DMB-S
Related topics	Digital radio • Audio processing • History of radio • International broadcasting

See also

• List of Direct broadcast satellite providers
• Conditional access