Digital Video Broadcasting (DVB) is a set of international open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium, and are published by a Joint Technical Committee (JTC) of the European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU).
Transmission DVB systems distribute data using a variety of approaches, including: Satellite: DVB-S, DVB-DSNG, DVB-S2, DVB-S2X and DVB-SH DVB-SMATV for distribution via SMATV Cable: DVB-C, DVB-C2 Terrestrial television: DVB-T, DVB-T2 Digital terrestrial television for handhelds: DVB-H, DVB-SH Microwave: using DTT (DVB-MT), the MMDS (DVB-MC), and/or MVDS standards (DVB-MS)
These standards define the physical layer and data link layer of the distribution system. Devices interact with the physical layer via a synchronous parallel interface (SPI), synchronous serial interface (SSI) or asynchronous serial interface (ASI). All data is transmitted in MPEG transport streams with some additional constraints (DVB-MPEG). A standard for temporally-compressed distribution to mobile devices (DVB-H) was published in November 2004.
These distribution systems differ mainly in both the modulation schemes and error correcting codes used, due to the different technical constraints. DVB-S (SHF) uses QPSK, 8-PSK or 16-QAM. DVB-S2 uses QPSK, 8-PSK, 16-APSK or 32-APSK, at the broadcaster's decision. QPSK and 8-PSK are the only versions regularly used. DVB-C (VHF/UHF) uses QAM: 16-QAM, 32-QAM, 64-QAM, 128-QAM or 256-QAM. Lastly, DVB-T (VHF/UHF) uses 16-QAM or 64-QAM (or QPSK) in combination with (C)OFDM and can support hierarchical modulation.
The DVB-T2 specification was approved by the DVB Steering Board in June 2008 and sent to ETSI for adoption as a formal standard. ETSI adopted the standard on 9 September 2009. The DVB-T2 standard gives more robust TV reception and increases the possible bit rate by over 30% for single transmitters (as in the UK) and will increase the maximum bit rate by over 50% in large single-frequency networks (as in Germany and Sweden).
DVB has established a 3D TV group (CM-3DTV) to identify "what kind of 3D-TV solution does the market want and need, and how can DVB play an active part in the creation of that solution?" The CM-3DTV group held a DVB 3D-TV kick-off workshop in Geneva on 25 January 2010, followed by the first CM-3DTV meeting the next day. DVB now defines a new standard for 3D video broadcast: DVB 3D-TV.
Modes and features of the latest DVB-x2 system standards in comparison: DVB-S2DVB-T2DVB-C2Input interfaceMultiple transport stream and generic stream encapsulation (GSE)Multiple transport stream and generic stream encapsulation (GSE)Multiple transport stream and generic stream encapsulation (GSE)ModesVariable coding & modulation and adaptive coding & modulationVariable coding & modulationVariable coding & modulation and adaptive coding & modulationFECLDPC + BCH 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10LDPC + BCH 1/2, 3/5, 2/3, 3/4, 4/5, 5/6LDPC + BCH 1/2, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10ModulationSingle carrier, PSK or APSK, multiple streamsOFDMabsolute OFDMModulation schemesQPSK, 8-PSK, 16-APSK, 32-APSKQPSK, 16-QAM, 64-QAM, 256-QAM16- to 4096-QAMGuard intervalNot applicable1/4, 19/256, 1/8, 19/128, 1/16, 1/32, 1/1281/64 or 1/128Fourier transform sizeNot applicable1k, 2k, 4k, 8k, 16k, 32k DFT4k Inverse FFTInterleavingBit-InterleavingBit-, time-, and frequency-interleavingPilotsPilot symbols Scattered and continual pilots Scattered and continual pilots
Content
Digital video content is encoded using discrete cosine transform (DCT) based video coding standards, such as the H.26x and MPEG formats. Digital audio content is encoded using modified discrete cosine transform (MDCT) based audio coding standards, such as Advanced Audio Coding (AAC), Dolby Digital (AC-3) and MP3.
Besides digital audio and digital video transmission, DVB also defines data connections (DVB-DATA - EN 301 192) with return channels (DVB-RC) for several media (DECT, GSM, PSTN/ISDN, satellite etc.) and protocols (DVB-IPTV: Internet Protocol; DVB-NPI: network protocol independent).
Older technologies such as teletext (DVB-TXT) and vertical blanking interval data (DVB-VBI) are also supported by the standards to ease conversion. However, for many applications, more advanced alternatives like DVB-SUB for subtitling are available.
Encryption and metadata The conditional access system (DVB-CA) defines a Common Scrambling Algorithm (DVB-CSA) and a physical Common Interface (DVB-CI) for accessing scrambled content. DVB-CA providers develop their wholly proprietary conditional access systems with reference to these specifications. Multiple simultaneous CA systems can be assigned to a scrambled DVB program stream, providing operational and commercial flexibility for the service provider.
The DVB Project developed a Content Protection and Copy Management system for protecting content after it has been received (DVB-CPCM), which was intended to allow flexible use of recorded content on a home network or beyond, while preventing unconstrained sharing on the Internet. DVB-CPCM was the source of much controversy in the popular press and it was said that CPCM was the DVB Project's answer to the failed American Broadcast Flag. The DVB-CPCM specifications, which were standardized by ETSI as a multipart document (TS 102 825) between 2008 and 2013, were deprecated by the DVB Steering Board in February 2019.
DVB transports include metadata called Service Information (DVB-SI, ETSI EN 300 468, ETSI TR 101 211) that links the various elementary streams into coherent programs and provides human-readable descriptions for electronic program guides as well as for automatic searching and filtering. The dating system used with this metadata suffers from a year 2038 problem in which the limited 16 bits and modified Julian day offset used will cause an overflow issue similar to the year 2000 problem. By comparison, the DigiCipher 2–based ATSC system will not encounter this issue until 2048, in part due to the use of 32-bit fields.
DVB adopted a profile of the metadata defined by the TV-Anytime Forum (DVB-TVA, ETSI TS 102323). This is an XML Schema-based technology, and the DVB profile is tailored for enhanced Personal Digital Recorders.
In the early 2000s, DVB started an activity to develop specifications for IPTV (DVB-IPI, ETSI TR 102 033, ETSI TS 102 034, ETSI TS 102 814), which also included metadata definitions for a broadband content guide (DVB-BCG, ETSI TS 102 539).
DVB-I
In October 2017, the DVB Project established a working group to begin the definition of a specification for "standalone TV services over IP, referred to as DVB-I services". Work on the commercial requirements for DVB-I began in January 2018 and the terms of reference were agreed in March 2018.
The DVB-I specification, titled "Service Discovery and Programme Metadata for DVB-I", was approved by the DVB Project in November 2019 and first published as DVB BlueBook A177 in June 2020 and as an ETSI standard TS 103 770 in November 2020.
The DVB-I specification defines ways in which devices and displays connected to the internet can discover and access sets of audiovisual media services. These can include services delivered online through fixed and wireless Internet Protocol connections as well as broadcast radio and television channels received over radio frequency networks using traditional cable, satellite, or terrestrial transmissions.
Tests and pilots of DVB-I services have been undertaken in several countries, including Iran, Germany, Italy, Spain, and Ireland.
Software platform
The DVB Multimedia Home Platform (DVB-MHP) defines a Java-based platform for the development of consumer video system applications. In addition to providing abstractions for many DVB and MPEG-2 concepts, it provides interfaces for other features like network card control, application download, and layered graphics.
Return channel
DVB has standardized a number of return channels that work together with DVB(-S/T/C) to create bi-directional communication. RCS is short for Return Channel Satellite, and specifies return channels in C, Ku and Ka frequency bands with return bandwidth of up to 2 Mbit/s. DVB-RCT is short for Return Channel Terrestrial, specified by ETSI EN 301958.
Service discovery The DVB-I standard (ETSI TS 103 770) defines an internet-based request and response mechanism to discover and access audiovisual services delivered over traditional digital broadcast transmissions or Internet Protocol networks and present them in a unified way.
Adoption DVB-S and DVB-C were ratified in 1994. DVB-T was ratified in early 1997. The first commercial DVB-T broadcasts were performed by the United Kingdom's Digital TV Group in late 1998. In 2003, Germany was the first country to completely stop broadcasting analogue TV signals. Most European countries are fully covered by digital television and many have switched off PAL/SECAM services.
DVB standards are widely used across Europe and have also been adopted in countries including Australia, South Africa, and India. They are also used for cable and satellite broadcasting in most Asian, African, and many South American countries. Some have chosen ISDB-T instead of DVB-T, and a few (United States, Canada, Mexico, and South Korea) have chosen ATSC instead of DVB-T.
Africa Kenya DVB-T broadcasts were launched by the President of Kenya, Mwai Kibaki on 15 November 1998. Broadcasts are using H.264, with the University of Nairobi supplying the decoders. Kenya has also been broadcasting DVB-H since July 2006, available on selected Nokia and ZTE handsets on the Safaricom and other GSM networks.
Madagascar Since 1998, the pay TV operator Blueline launched a DVB-T service branded BluelineTV. It supplies both smart cards and set-top-boxes.
South Africa Since 1995, the pay TV operator DStv used the DVB-S standard to broadcast its services. In 1998, it started a DVB over IP service, and in 2006, it started DStv mobile using the DVB-H standard.
In late 1998, the South African cabinet endorsed a decision by a Southern African Development Community (SADC) task team to adopt the DVB-T2 standard.
Asia Hong Kong In Hong Kong, several cable TV operators such as TVB Pay Vision and Cable TV have already started using DVB-S or DVB-C. The government, however, has adopted the DMB-T/H standard, developed in mainland China, for its digital terrestrial broadcasting services which has started since 31 December 2007.
Iran DVB-H on 15 March 2006 and DVB-T on 15 November 1998 H.264/AAC broadcasting started in Tehran by the IRIB. DVB-T broadcasting is now widely available in other cities such as Isfahan, Mashhad, Shiraz, Qom, Tabriz, and Rasht as well.
Israel DVB-T broadcasts using H.264 commenced in Israel on 15 November 1998 with the broadcast trial, and the full broadcast began on 1 April 1999. Analog broadcasts were switched off on 17 October 2007.
During 2002, DVB-T broadcasts became widely available in most of Israel, and an EPG was added to the broadcasts.
Japan With the exception of SKY PerfecTV!, Japan uses different formats in all areas (ISDB), which are, however, quite similar to their DVB counterparts. SkyPerfect is a satellite provider using DVB on its 124 and 128 degrees east satellites. Its satellite at 110 degrees east does not use DVB, however.
Malaysia