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).
DVB systems distribute data using a variety of approaches, including:
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 the modulation schemes used 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 broadcasters 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 latest DVB-x2 system standards in comparison:
|Input interface||Multiple transport stream and generic stream encapsulation (GSE)||Multiple transport stream and generic stream encapsulation (GSE)||Multiple transport stream and generic stream encapsulation (GSE)|
|Modes||Variable coding & modulation and adaptive coding & modulation||Variable coding & modulation||Variable coding & modulation and adaptive coding & modulation|
|FEC||LDPC + BCH 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10||LDPC + BCH 1/2, 3/5, 2/3, 3/4, 4/5, 5/6||LDPC + BCH 1/2, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10|
|Modulation||Single carrier QPSK with multiple streams||OFDM||absolute OFDM|
|Modulation schemes||QPSK, 8-PSK, 16-APSK, 32-APSK||QPSK, 16-QAM, 64-QAM, 256-QAM||16- to 4096-QAM|
|Guard interval||Not applicable||1/4, 19/256, 1/8, 19/128, 1/16, 1/32, 1/128||1/64 or 1/128|
|Fourier transform size||Not applicable||1k, 2k, 4k, 8k, 16k, 32k DFT||4k Inverse FFT|
|Interleaving||Bit-Interleaving||Bit- time- and frequency-interleaving||Bit- time- and frequency-interleaving|
|Pilots||Pilot symbols||Scattered and continual pilots||Scattered and continual pilots|
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.
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.
DVB is also developing a Content Protection and Copy Management system for protecting content after it has been received (DVB-CPCM), which is intended to allow flexible use of recorded content on a home network or beyond, while preventing unconstrained sharing on the Internet. DVB-CPCM has been the source of much controversy in the popular press and it is said that CPCM is the DVB's answer to the failed American Broadcast Flag.
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 due to the limited 16 bits and modified Julian day offset used will cause an overflow issue similar to the year 2000 problem. By comparison, the rival DigiCipher 2 based ATSC system will not have this issue until 2048 due in part to 32 bits being used.
Recently, DVB has 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. DVB lately also started an activity to develop a service for IPTV (DVB-IPI, ETSI TR 102033, ETSI TS 102034, ETSI TS 102814) which also includes metadata definitions for a broadband content guide (DVB-BCG, ETSI TS 102 539).
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.
DVB has standardised 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.
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 Berlin, Germany was the first area to completely stop broadcasting analog TV signals. Most European countries are fully covered by digital television and many have switched off PAL/SECAM services.
In Europe, as well as in Australia, South Africa and India, DVB is used throughout. This also holds true for cable and satellite in most Asian, African and many South American countries. Many of these have not yet selected a format for digital terrestrial broadcasts (DTTV) and a few (Canada, El Salvador, Honduras, Mexico, South Korea and the United States) have chosen ATSC instead of DVB-T.
DVB-T broadcasts were launched by the President of Kenya, Mwai Kibaki on 9 December 2009. Broadcasts are using H.264, with the University of Nairobi supplying the decoders. Kenya has also been broadcasting DVB-H since July 2009, available on selected Nokia and ZTE handsets on the Safaricom and other GSM networks.
In Asia several Standards are under implementation
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.
DVB-T broadcasts using H.264 commenced in Israel on 1 June 2009 with the broadcast trial and the full broadcast began on 2 August 2009. Analog broadcasts were originally planned to end in 18 months after the launch, but analog broadcasts were switched off on 31 March 2011 instead.
During 2010, DVB-T broadcasts have become widely available in most of Israel and an EPG was added to the broadcasts.
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.
In Malaysia, a new pay television station MiTV began service in September 2005 using DVB-IPTV technology while lone satellite programming provider ASTRO has been transmitting in DVB-S since its inception in 1996. Free-to-air DVB-T trials began in late 2006 with a simulcast of both TV1 and TV2 plus a new channel called RTM3/RTMi. In April 2007, RTM announced that the outcome of the test was favourable and that it expected DVB-T to go public by the end of 2007. However, the system did not go public as planned. As of 2008, the trial digital line-up has expanded to include a music television channel called Muzik Aktif, and a sports channel called Arena, with a news channel called Berita Aktif planned for inclusion in the extended trials soon. Also, high definition trials were performed during the Beijing Olympics and the outcome was also favourable. It was announced that the system would go public in 2009.
In 2009, MiTV closed down, changed its name to U-Television and announced that it was changing to scrambled DVB-T upon relaunch instead of the DVB-IPTV system used prior to shutting down. However, RTM's digital network again did not go public, although around this time TVs that are first-generation DVB-T capable went on sale. The government has since announced that they will be deploying DVB-T2 instead in stages starting in mid-2015 and analog shutoff has been delayed to April 2019.
In the Philippines, DVB-S and DVB-S2 are the two broadcast standards currently used by satellite companies, while DVB-C is also used by some cable companies. The government adopted DVB-T in November 2006 for digital terrestrial broadcasting but a year later, it considered other standards to replace DVB-T. The country has chosen the ISDB-T system instead of DVB-T.
In Taiwan, some digital cable television systems use DVB-C, though most customers still use analog NTSC cable television. The government planned adopting ATSC or the Japanese ISDB-T standard as NTSC's replacement. However, the country has chosen the European DVB-T system instead. Public Television Service (PTS) and Formosan TV now provided high definition television. The former has a channel called HiHD; the latter uses its HD channel for broadcasting MLB baseball.
In Denmark, DVB-T replaced the analog transmission system for TV on 1 November 2009. Danish national digital TV transmission has been outsourced to the company Boxer TV A/S, acting as gatekeeper organization for terrestrial TV transmission in Denmark. However, there are still several free channels from DR.
DVB-T transmissions were launched on 21 August 2001. The analogue networks continued alongside the digital ones until 1 September 2007, when they were shut down nationwide. Before the analogue switchoff, the terrestrial network had three multiplexes: MUX A, MUX B and MUX C. MUX A contained the channels of the public broadcaster Yleisradio and MUX B was shared between the two commercial broadcasters: MTV3 and Nelonen. MUX C contained channels of various other broadcasters. After the analogue closedown, a fourth multiplex named MUX E was launched. All of the Yleisradio (YLE) channels are broadcast free-to-air, likewise a handful of commercial ones including MTV3, Nelonen, Subtv, Jim, Nelonen Sport, Liv, FOX, TV5 Finland, AVA and Kutonen. There are also several pay channels sold by PlusTV.
The switch-off from analogue terrestrial network to DVB-T started on 15 October 2008. Analogue broadcast was ended on 4 July 2012 after nearly four years of transition in phases.
In the Netherlands, DVB-S broadcasting started on 1 July 1996, satellite provider MultiChoice (now CanalDigitaal) switched off the analogue service shortly after on 18 August 1996. DVB-T broadcasting started April 2003, and terrestrial analog broadcasting was switched off December 2006. It was initially marketed by Digitenne but later by KPN. Multiplex 1 contains the NPO 1, NPO 2 and NPO 3 national TV channels, and a regional channel. Multiplexes 2~5 have the other encrypted commercial and international channels. Multiplex 1 also broadcasts the radio channels Radio 1, Radio 2, 3 FM, Radio 4, Radio 5, Radio 6, Concertzender, FunX and also a regional channel. As of June 2011, the Dutch DVB-T service had 29 TV channels and 20 radio channels (including free to air channels). DVB-T2 will be introduced during 2019/2020.
In Norway, DVB-T broadcasting is marketed under RiksTV (encrypted pay channels) and NRK (unencrypted public channels). DVB-T broadcasting via the terrestrial network began in November 2007, and has subsequently been rolled out one part of the country at a time. The Norwegian implementation of DVB-T is different from most others, as it uses H.264 with HE-AAC audio encoding, while most other countries have adapted the less recent MPEG-2 standard. Notably most DVB software for PC has problems with this, though in late 2007 compatible software was released, like DVBViewer using the libfaad2 library. Sony has released several HDTVs (Bravia W3000, X3000, X3500, E4000, V4500, W4000, W4500, X4500) that support Norway's DVB-T implementation without use of a separate set-top box, and Sagem ITD91 HD, Grundig DTR 8720 STBs are others.
Portugal follows the DVB-T implementation, using H.264 with AAC audio encoding. It has been live since 29 April 2009 and the switch-off date for all analog signals was on 26 April 2012.
Romania started digital terrestrial broadcasting in 2005 but it was virtually unknown by many people in Romania due to the lack of content, cable TV and satellite TV being far more popular, however it was the first platform to deliver HD content. Today, Romania is using DVB-T2 as terrestrial standard, but also DVB-S/S2, and DVB-C which is extremely popular. The only analogue broadcast remains on cable. Romania adopted the DVB-T2 standard in 2016 after a series of tests with mpeg2, mpeg4 on DVB-T, and has today fully implemented DVB-T2. DVB-C, which was introduced in late 2005, still remains with mpeg2 on SD content and mpeg4 on HD content. DVB-S (introduced in 2004 focus sat being the first such platform) is used in basic packages with standard definition content, while DVB-S2 set top boxes are provided for both SD and HD content.
Currently, Russia uses the DVB-T standard with MPEG-4 encoding for the limited experimental broadcasting and cable networks, majority of TV broadcasting still being done in the old analogue SECAM standard. The Ministry of Communication, however, pledged to switch to the DVB-T2 as the transmitting centers are gradually upgraded, and plans to abandon analogue broadcast by 2018. Several pilot broadcasting centers in some regions are already online and simulcasting in DVB-T2 SD and SECAM signal since February 2010, with more to go. Only one channel pack with eight to ten main national radio and TV channels (Channel One, Rossiya 1/2/K/24, NTV, Radio Mayak, Radio Rossii etc.) are available today, with more planned to be added as the digital TV network is expanded.
In the UK DVB-T has been adopted for broadcast of standard definition terrestrial programming, as well as a single DVB-T2 multiplex for high-definition programming. The UK terminated all analogue terrestrial broadcasts by the end of 2012. The vast majority of channels are available free-to-air through the Freeview service. DVB-T was also used for the now-defunct ONDigital/ITV Digital and Top Up TV service.
All satellite programming (some of which is available free-to-air via Freesat or free-to-view via Freesat from Sky; the remainder requires a subscription to Sky), is broadcast using either DVB-S or DVB-S2.
Subscription-based cable television from Virgin Media uses DVB-C, alongside a limited selection of analogue channels.
In North America, DVB-S is often used in encoding and video compression of digital satellite communications alongside Hughes DSS. Unlike Motorola's DigiCipher 2 standard, DVB has a wider adoption in terms of the number of manufacturers of receivers. Terrestrial digital television broadcasts in Canada, Mexico, El Salvador, Honduras, and the United States use ATSC encoding with 8VSB modulation instead of DVB-T with COFDM. Television newsgathering links from mobile vans to central receive points (often on mountaintops or tall buildings) use DVB-T with COFDM in the 2 GHz frequency band.
In Australia, DVB broadcasting is marketed under the Freeview brand name, and more recently 'Freeview Plus', denoting the integration of online HbbTV and EPG in certain DVB devices. Regular broadcasts began in January 2001 using MPEG 2 video and MPEG 1 audio in SD and HD.
Changes to broadcasting rules have enabled broadcasters to offer multi-channeling, prompting broadcasters to use H.264 video with MPEG 1 or AAC audio encoding for some secondary channels.
Specifications for HD channels now differ depending on the broadcaster. ABC, Nine and Ten use 1920x1080i MPEG 4 video with Dolby Digital audio. Seven and SBS use 1440x1080i MPEG 2 video with Dolby Digital and MPEG 1 audio respectively.
In New Zealand, DVB broadcasting is marketed under the Freeview brand name. SD MPEG-2 DVB-S broadcasts via satellite began on 2 May 2007 and DVB-T (terrestrial) broadcasts began April 2008 broadcasting in HD H.264 video with HE-AAC audio.
Since 2008, Colombia has adopted as a public policy the decision to migrate from the analog television implemented in 1954 to Digital Terrestrial Television (DVB-T2). This measure allows the viewers access to the open television (OTA) of public and private channels, with video quality in HD. As planned, analogue television broadcasts will end on December 31, 2019.
Companies that manufacture a product which is compliant to one or more DVB standards have the option of registering a declaration of conformity for that product. Wherever the DVB trademark is used in relation to a product – be it a broadcast, a service, an application or equipment – the product must be registered with the DVB project office.
DVB-C stands for "Digital Video Broadcasting - Cable" and it is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG-2 or MPEG-4 family digital audio/digital video stream, using a QAM modulation with channel coding. The standard was first published by the ETSI in 1994, and subsequently became the most widely used transmission system for digital cable television in Europe, Asia and South America. It is deployed worldwide in systems ranging from the larger cable television networks (CATV) down to smaller satellite master antenna TV (SMATV) systems.DVB-CPCM
DVB Content Protection & Copy Management often abbreviated to DVB-CPCM or CPCM is a digital rights management standard being developed by the DVB Project. Its main application is interoperable rights management of European digital television, though other countries may also adopt the standard.DVB-H
DVB-H (Digital Video Broadcasting - Handheld) is one of three prevalent mobile TV formats. It is a technical specification for bringing broadcast services to mobile handsets. DVB-H was formally adopted as ETSI standard EN 302 304 in November 2004. The DVB-H specification (EN 302 304) can be downloaded from the official DVB-H website. From March 2008, DVB-H is officially endorsed by the European Union as the "preferred technology for terrestrial mobile broadcasting". The major competitors of this technology are Qualcomm's MediaFLO system, the 3G cellular system based MBMS mobile-TV standard, and the ATSC-M/H format in the U.S. DVB-SH (Satellite to Handhelds) now and DVB-NGH (Next Generation Handheld) in the future are possible enhancements to DVB-H, providing improved spectral efficiency and better modulation flexibility. DVB-H has been a commercial failure, and the service is no longer on-air. Finland was the last country to switch-off its signals in March 2012.DVB-RCS
DVB-RCS is an acronym for Digital Video Broadcasting - Return Channel via Satellite or (Return channel over system). It is a specification for an interactive on-demand multimedia satellite communication system formulated in 1999 by the DVB consortium.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 application was by Galaxy in Australia, enabling digitally broadcast, satellite-delivered Television to the public.
It is used via satellites serving every continent of the world. DVB-S is used in both Multiple Channel Per Carrier (MCPC) and Single channel per carrier modes for Broadcast Network feeds as well as for direct-broadcast satellite services like Sky (UK & Ireland) via Astra in Europe, Dish Network and Globecast in the U.S. and Bell TV in Canada.
While the actual DVB-S standard only specifies physical link characteristics and framing, the overlaid transport stream delivered by DVB-S is mandated as MPEG-2, known as MPEG transport stream (MPEG-TS).
Some amateur television repeaters also use this mode in the 1.2 GHz amateur band.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 DVB 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 envisaged (contemplate) 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:
A powerful coding scheme based on a modern 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 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.DVB-SH
DVB-SH ("Digital Video Broadcasting - Satellite services to Handhelds") is a physical layer standard for delivering IP based media content and data to handheld terminals such as mobile phones or PDAs, based on a hybrid satellite/terrestrial downlink and for example a GPRS uplink. The DVB Project published the DVB-SH standard in February 2007.The DVB-SH system was designed for frequencies below 3 GHz, supporting UHF band, L Band or S-band. It complements and improves the existing DVB-H physical layer standard. Like its sister specification (DVB-H), it is based on DVB IP Datacast (IPDC) delivery, electronic service guides and service purchase and protection standards.
DVB-SH specifies two operational modes:
SH-A: specifies the use of COFDM modulation on both satellite and terrestrial links with the possibility of running both links in SFN mode.
SH-B: uses Time-Division Multiplexing (TDM) on the satellite link and COFDM on the terrestrial link.DVB-T
DVB-T is an abbreviation for "Digital Video Broadcasting — Terrestrial"; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998. This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. It is also the format widely used worldwide (including North America) for Electronic News Gathering for transmission of video and audio from a mobile newsgathering vehicle to a central receive point.DVB Dream
DVB Dream is a proprietary software for watching & recording of digital TV & radio with help of a digital TV tuner card (Internal PCI / PCI-Express cards or external USB devices). It supports the standards DVB-S (satellite), DVB-C (cable), DVB-T (terrestrial), ISDB-T, ISDB-S and ATSC.
It has STB-like features including PIP (Picture-in-picture), record, Timeshift, EPG, Scheduler, Unicable support, Positioner support(including GotoX.X / USALS), UHD(4K)/HD/HEVC/H264 support, child lock, remote control support.
There are also features that cannot be seen on STBs but provided with help of flexible Windows GUI environment. These are: Multi PIP(watching more than 1 channel at the same time)), Multi record (recording more than 1 channel at the same time), LAN Streaming, VLC or MPC Integration, Auto-zap, Unique channel list system by grouping/ordering/filtering by several flexible options, Render-less mode, Multi monitor support, Command line support, Plugins support.
Being a Windows application, user interface can be customized with help of themes and foldable GUI elements. It can be localized in most of the languages (29 languages are supported, as in 2015).IP over DVB
IP over DVB or IP over MPEG implies that Internet Protocol datagrams are transferred over the MPEG transport stream, and are distributed using some digital television system, for example DVB-H, DVB-T, DVB-S or DVB-C.Multimedia Home Platform
Multimedia Home Platform (DVB-MHP) is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java-based applications on a TV-set. Interactive TV applications can be delivered over the broadcast channel, together with audio and video streams. These applications can be for example information services, games, interactive voting, e-mail, SMS or shopping. MHP applications can use an additional return channel that has to support IP.