DVB-S2

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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.

Contents

DVB-S2 is designed for broadcast services including standard and HDTV, 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) video codecs.

Two new key features that were added compared to the DVB-S standard are:

Other features include enhanced modulation schemes up to 32APSK, additional code rates, and the introduction of a generic transport mechanism for IP packet data including MPEG-4 audio–video streams, while supporting backward compatibility with existing MPEG-2 TS based transmission.

DVB-S2 achieves 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. [1]

Main features

Depending on code rate and modulation, the system can operate at a C/N between −2.4  dB (QPSK, 1/4) and 16 dB (32APSK, 9/10) with a quasi-error free goal of a 10−7 TS packet error rate. Distance to the Shannon limit ranges from 0.7 dB to 1.2 dB.

Modes and features of DVB-S2 in comparison to DVB-S:

DVB-SDVB-S2
Input interfaceSingle transport stream (TS)Multiple transport stream and generic stream encapsulation (GSE)
Modes Constant coding & modulation Variable coding & modulation and adaptive coding & modulation
FEC Reed–Solomon (RS) 1/2, 2/3, 3/4, 5/6, 7/8 LDPC + BCH 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 6/7, 8/9, 9/10
Modulation Single-carrier QPSK QPSK, 8PSK, 16APSK, 32APSK
Interleaving Bit-interleavingBit-interleaving
Pilots Pilot symbolsPilot symbols

Use cases

Envisaged scenarios for DVB-S2 by the standard document are:

Improvements over DVB-S

DVB-S2 is 30% more efficient than DVB-S. It allows a wider range of applications combining DVB-S features (for household tasks), and DVB-DSNG (for professional tasks). DVB-S2 can adapt codification to maximize satellites resources value. It is compatible with last generation.

The main disadvantage, there are many millions of devices deployed using DVB-S over the world which has to be upgraded.

The next table compares both standards.

Satellite EIRP (dBW)5153,7
SystemDVB-SDVB-S2DVB-SDVB-S2
Modulation and codificationQPSK 2/3QPSK 3/4QPSK 7/88PSK 2/3
Speed per token27,5 (a=0,35)30,9 (a=0,25)27,5 (a=0,35)29,7 (a=0,25)
C/N (27,5 MHz) (dB)5,15,17,87,8
Bitrate (Mbit/s)33,846 (+36 %)44,458,8 (+32 %)
N.º channels SDTV7 MPEG-2, 15 AVC10 MPEG-2, 21 AVC10 MPEG-2, 20 AVC13 MPEG-2, 27 AVC
N.º channels HDTV1-2 MPEG-2, 3-4 AVC2 MPEG-2, 5 AVC2 MPEG-2, 5 AVC3 MPEG-2, 6 AVC


The DVB-S to DVB-S2 upgrade process

The conversion process from DVB-S to DVB-S2 is being accelerated, due to the rapid increase of HDTV and introduction of 3D-HDTV. The main factor slowing down this process is the need to replace or upgrade set-top boxes, or acquire TVs with DVB-S2 integrated tuners, which makes the transition slower for established operators.

Current direct-to-home broadcasters using DVB-S2 are:

These broadcasters have used DVB-S2 in their internal broadcast distribution networks, but may not have instituted DVB-S2 transmissions for consumers.

Related Research Articles

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DVB-S2X is an extension of DVB-S2 satellite digital broadcasting standard.

References

  1. "DVB-S2X specification receives approval from DVB Steering board" (PDF). DVB Project.