Digital Video Broadcasting (DVB) is being adopted as the standard for
digital television in many countries. The DVB project was an industry
led consortium of over 270 television broadcasting associated companies
world-wide. The DVB standard offers many advantages over the previous
analogue standards and has enabled television to make a major step
forwards in terms of its technology.
Digital Video Broadcasting, DVB is now one of the success stories of
modern broadcasting. The take up has been enormous and it is currently
deployed in over 80 countries worldwide, including most of Europe and
also within the USA. It offers advantages in terms of far greater
efficiency in terms of spectrum usage and power utilisation as well as
being able to affect considerably more facilities, the prospect of more
channels and the ability to work alongside existing analogue services.
History of DVB
From the very earliest days of television, right up until the 1990s,
all television broadcasts were made using analogue television and it had
not been thought feasible to introduce a digital system due to the
complexity of the processing required. However with the advance of
digital processing techniques and the advances made in integrated
circuit technology the possibility of using digital techniques for
television broadcasting became a real possibility.
As a result over the course of 1991various organisations discussed
how to move forwards with the idea and how to form a pan-European
platform that would enable considerable economies of scale to be
achieved.
The resulting organisation was named the Electronics Launching Group
(ELG), and it developed a memorandum of Understanding that was signed in
1993. At the same time it renamed itself the Digital Video Broadcasting
Project (DVB), and the development of the technologies and standards
started to move forwards with a swifter pace.
The first of the DVB standards to be agreed was the DVB-S standard
for satellite transmission which was agreed in 1994. With the standard
agreed, services were commenced in early 1995 and the first operator was
the pay TV operator Canalplus in France.
The DVB system used for terrestrial transmissions, DVB-T was agreed
later, in 1997. The first countries to deploy the system were Sweden,
launching their system in 1998, and the UK launching their system a year
later.
Agreement of DVB specifications
The way in which specifications are developed, agreed and released
may seem rather complicated, but it has proved to be a successful
system, enabling interested parties to have their say in the development
and maintenance of the DVB system and its technology. The member
organisations of the DVB project develop and agree specifications. Once
agreed they are then passed on to the EBU/CENELEC/ETSI Joint Technical
Committee, for approval. The specifications are then formally
standardised by either CENELEC or, in the majority of cases, ETSI.
The DVB project is managed by the DVB Project Office. This is staffed
by personnel who are employees of the European Broadcasting Union in
Geneva, Switzerland. While they are technically employees of the EBU,
they work exclusively in the interests of the members of the DVB
Project.
DVB Variants
Even a quick look at DVB will reveal the fact that there are many
flavours of the basic standard. In these days when there are many ways
in which television can be carried from the "transmitter" to the
"receiver" no one standard can be optimised for all applications. As a
result there are many different forms of the Digital Video Broadcasting,
DVB, standards, each designed for a given application.
The main forms of DVB are summarised below:
DVB Standard |
Meaning |
Description |
DVB-C |
Cable |
The standard for delivery of video service via cable networks. |
DVB-H |
Handheld |
DVB services to handheld devices, e.g. mobile phones, etc |
DVB-RSC |
Return satellite channel |
Satellite DVB services with a return channel for interactivity. |
DVB-S |
Satellite services |
DVB standard for delivery of television / video from a satellite. |
DVB-SH |
Satellite handheld |
Delivery of DVB services from a satellite to handheld devices |
DVB-S2 |
Satellite second generation |
The second generation of DVB satellite broadcasting. |
DVB-T |
Terrestrial |
The standard for Digital Terrestrial Television Broadcasting. |
With DVB being widely used in very many countries, it has now become
one of the defacto families of standards for broadcasting. Developments
have been made beyond the first DVB standards that were introduced, and
now new facilities and levels of performance are being achieved.
Source:
https://www.electronics-notes.com/articles/audio-video/broadcast-tv-television/what-is-dvb-digital-video-broadcasting-tutorial.php
https://dvb.org/specifications/