Editing DVB-S2 (section)

{{short description|Digital satellite television standard}}
{{More footnotes|date=January 2018}}
{{Table Digital video broadcast standards}}

[[Image:KNCone TV Station DVBS2 PLUS pci card front 0595 by HDTVTotalDOTcom.jpg|right|thumbnail|upright=0.8|DVB-S2 PCI tuner card]]
'''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]] Project, an international industry consortium, and ratified by [[ETSI]] (EN 302307) in March 2005. The standard is based on, and improves upon DVB-S and the [[electronic news-gathering]] (or Digital Satellite News Gathering) system, used by mobile units for sending sounds and images from remote locations worldwide back to their home television stations.

DVB-S2 is designed for broadcast services including [[Standard-definition television|standard]] and [[High-definition television|HDTV]], [[Return Channel Satellite|interactive]] services including Internet access, and (professional) data content distribution. The development of DVB-S2 coincided with the introduction of HDTV and [[H.264/MPEG-4 AVC|H.264]] (MPEG-4 AVC) [[video codec]]s.

Two new key features that were added compared to the DVB-S standard are:
* A powerful [[forward error correction|coding]] scheme based on a modern [[Low-density parity-check code|LDPC code]]. For low encoding complexity, the LDPC codes chosen have a special structure, also known as Irregular Repeat-Accumulate codes. 
* VCM (Variable Coding and Modulation) and ACM (Adaptive Coding and Modulation) modes, which allow optimizing bandwidth utilization by dynamically changing transmission parameters.

Other features include enhanced [[modulation]] schemes up to [[Amplitude and phase-shift keying|32APSK]], additional [[code rate]]s, and the introduction of a [[Generic Stream|generic transport mechanism]] for IP packet data including [[MPEG-4]] audio–video streams, while supporting backward compatibility with existing [[MPEG Transport Stream|MPEG-2 TS]] based transmission.

DVB-S2 achieves [[Spectral efficiency#Comparison table|significantly better performance]] than its predecessors – mainly allowing for an increase of available bitrate over the same satellite transponder bandwidth. The measured DVB-S2 performance gain over DVB-S is around 30% at the same satellite transponder bandwidth and emitted signal power. When the contribution of improvements in [[video compression]] is added, an ([[MPEG-4 AVC]]) [[HDTV]] service can now be delivered in the same bandwidth that supported an early DVB-S based MPEG-2 [[SDTV]] service only a decade before.

In March 2014, [[DVB-S2X]] specification has been published by DVB Project as an optional extension adding further improvements.<ref>{{cite news|title=DVB-S2X specification receives approval from DVB Steering board| url=http://www.dvb.org/resources/public/pressreleases/dvb_pr241_steering_board_approves_dvb-s2x.pdf| newspaper=DVB Project| archive-url=https://web.archive.org/web/20140407071914/http://www.dvb.org/resources/public/pressreleases/dvb_pr241_steering_board_approves_dvb-s2x.pdf| archive-date=7 April 2014| url-status=dead}}</ref>