Digital Satellite System is the initialism expansion of the DSS digital

satellite television Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...

transmission system used by

DirecTV DirecTV, LLC is an American Multichannel television in the United States, multichannel video programming distributor based in El Segundo, California. Originally launched on June 17, 1994, its primary service is a digital Satellite television, s ...

. Only when digital transmission was introduced did

direct broadcast satellite Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...

(DBS) television become popular in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, which has led to both DBS and DSS being used interchangeably to refer to all three commonplace digital transmission formats; DSS, DVB-S and

4DTV 4DTV is a proprietary broadcasting standard and technology for digital cable broadcasting and C-band/Ku-band satellite dishes from Motorola, using General Instrument's DigiCipher II for encryption. It can tune in both analog VideoCipher II and ...

. Analog DBS services, however, existed prior to DirecTV and were still operational in continental Europe until April 2012. At the time of DirecTV's launch in 1994, the

DVB-S Digital Video Broadcasting – Satellite (DVB-S) is the original DVB standard for satellite television and dates from 1995, in its first release, while development lasted from 1993 to 1997. The first commercial applications were by Canal+ in ...

digital satellite system in use in the majority of the world had not yet been standardised, the

Thomson Thomson may refer to: Names * Thomson (surname), a list of people with this name and a description of its origin * Thomson baronets, four baronetcies created for persons with the surname Thomson Businesses and organizations * SGS-Thomson M ...

developed DSS system was used instead. While functionally similar in DVB-S – MPEG 2 video,

MPEG-1 Layer II MP2 (formally MPEG-1 Audio Layer II or MPEG-2 Audio Layer II, sometimes incorrectly called Musicam) is a lossy data compression, lossy audio compression format. It is standardised as one of the three audio codecs of MPEG-1 alongside MPEG-1 Audio ...

or AC3 audio,

QPSK Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency carrier wave. The modulation is accomplished by varying the sine and cosine inputs at a precise time. It is ...

modulation, and identical error correction ( Reed–Solomon coding and Viterbi

forward error correction In computing, telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels. The centra ...

), the transport stream and information tables are entirely different from those of DVB. Also unlike DVB, all DSS receivers are proprietary DirecTV reception units. DirecTV is now using a modified version of

DVB-S2 Digital Video Broadcasting - Satellite - Second Generation (DVB-S2) is a digital television broadcast standard that has been designed as a successor for the popular DVB-S system. It was developed in 2003 by the Digital Video Broadcasting Proj ...

, the latest version of the DVB-S protocol, for

HDTV High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it ref ...

services off the SPACEWAY-1, SPACEWAY-2, DirecTV-10 and DirecTV-11{{Cite web , url=http://dtv.client.shareholder.com/releasedetail.cfm?ReleaseID=324646 , title=The DIRECTV Group, Inc. - DIRECTV Remains Clear HD Leader with 130 HD Channels on Tap for Mid-August , access-date=2008-08-03 , archive-url=https://web.archive.org/web/20080805052202/http://dtv.client.shareholder.com/releasedetail.cfm?ReleaseID=324646 , archive-date=2008-08-05 , url-status=dead satellites; however, huge numbers of DSS encoded channels still remain. The ACM modulation scheme used by DirecTV prevents regular DVB-S2 demodulators from receiving the signal although the data carried are regular MPEG-4 transport streams.

References

External links

DSS, the "Other Other" MPEG-2 system
Satellite television Digital television

See also

References

External links