Digital Satellite Service is the assumed initialism expansion of the DSS digital satellite television

Satellite television

Satellite television is television programming delivered by the means of communications satellite and received by an outdoor antenna, usually a parabolic mirror generally referred to as a satellite dish, and as far as household usage is concerned, a satellite receiver either in the form of an...

 transmission system used by DirecTV

DirecTV

DirecTV is an American direct broadcast satellite service provider and broadcaster based in El Segundo, California. Its satellite service, launched on June 17, 1994, transmits digital satellite television and audio to households in the United States, Latin America, and the Anglophone Caribbean. ...

. Only when digital transmission was introduced did direct broadcast satellite

Direct broadcast satellite

Direct broadcast satellite is a term used to refer to satellite television broadcasts intended for home reception.A designation broader than DBS would be direct-to-home signals, or DTH. This has initially distinguished the transmissions directly intended for home viewers from cable television...

 (DBS) television become popular in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, 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

4DTV is the name of a Television receive-only consumer satellite television tuner technology manufactured by Motorola for use with large-diameter parabolic satellite dish antennas on the C and Ku frequency bands on multiple satellites...

. Analogue DBS services however existed prior to DirecTV and are still operational in continental Europe .

At the time of DirecTV's launch in 1994, the DVB-S

DVB-S

DVB-S is an abbreviation for Digital Video Broadcasting — Satellite; it is the original Digital Video Broadcasting forward error coding and demodulation standard for satellite television and dates from 1994, in its first release, while development lasted from 1993 to 1997...

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

Thomson SA

Technicolor SA , formerly Thomson SA and Thomson Multimedia, is a French international provider of solutions for the creation, management, post-production, delivery and access of video, for the Communication, Media and Entertainment industries. Technicolor’s headquarters are located in Issy les...

 developed DSS system was used instead.

While functionally similar in DVB-S - MPEG 2 video, MPEG-1 Layer II or AC3 audio, QPSK modulation, and identical error correction (Reed-Solomon coding and Viterbi

Viterbi

Viterbi can mean:*Viterbi algorithm, an algorithm in signal processing.*Viterbi decoder, a device implementing the Viterbi algorithm.*Andrew Viterbi, the inventor of the Viterbi algorithm....

 forward error correction

Forward error correction

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

), 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

DVB-S2

Digital Video Broadcasting - Satellite - Second Generation 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 , an international industry consortium, and ratified by ETSI in March 2005...

, the latest version of the DVB-S protocol, for HDTV services off the SPACEWAY-1

SPACEWAY-1

Spaceway F1 is part of DirecTV’s constellation of direct broadcast satellites. The satellite was launched via a Zenit 3SL rocket from Sea Launch’s Odyssey equatorial platform on April 26, 2005. Its operational position is in geosynchronous orbit above the equator at 102.8 degrees west longitude....

, SPACEWAY-2

SPACEWAY-2

Spaceway F2 is part of DirecTV’s constellation of direct broadcast satellites. The satellite was launched via an Arianespace Ariane 5 ECA rocket from Kourou, French Guiana on November 16, 2005. Its operational position is in geosynchronous orbit above the equator at 99.2 degrees west longitude....

, DirecTV-10

DirecTV-10

DirecTV-10 is a Boeing model 702 direct broadcast satellite that provides high definition television to DirecTV subscribers in North America. It was launched by International Launch Services on July 7, 2007 from the Baikonur Cosmodrome in Kazakhstan aboard an Enhanced Proton Breeze-M rocket...

 and DirecTV-11

DirecTV-11

DirecTV-11, also known as D11, is a Boeing model 702 satellite built by the Boeing Satellite Development Center.- Technology :This satellite is functionally identical to DirecTV-10 and is co-located with SPACEWAY-2 at or very near 99.225°W.- Launch data :...

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 is regular MPEG-4 Transport Stream.