DVB

Atualizada em 03/04/2012

Digital Video Broadcasting. um padrão europeu para transmissão e recepção de informação digital que é largamente adotado no mundo. Existem sub protocolos DVB-S , para transmissões por satélite, DVB-T, para transmissões terrestres,  a nossa TV Digital, e DVB-C , para cabo.

A sigla DVB-RCS é formado pelas iniciais das palavras Digital Video Broadcasting - Return Channel via Satellite or Return Channel over System.
Tradução : Transmissão de Vídeo Digital - Canal de Retorno via Satélite.
É o sistema utilizado no acesso Korisko.

Texto reproduzido da WikiPedia

The DVB Group was started in the early 1990s to develop standards for digital TV for Europe. Every digital TV system in Europe - and in many other territories - uses DVB.

For further information about the DVB Group, manufacturers, standards and services please see their website

Here's a short intro to its use for high-speed internet via satellite.

DVB is a European Broadband Network - almost by accident!

Although DVB was developed by the TV industry for digital TV, some far-sighted people realised that a high-speed data pipe for TV could just as well be used as a high-speed data pipe for, well, data. Today, there's a Broadband Network available to every home in Europe - as long as it can install a small satellite dish. And it is available in the UK now from BeyonDSL.

DVB stands for Digital Video Broadcasting

DVB is the European standard for digital TV and, as such, provides a very high-speed, robust transmission chain capable of the many Megabits per second needed for each of several hundred MPEG-2 digital TV channels.

In the old days, a typical satellite transponder had about enough bandwidth for a single analogue PAL colour TV channel. So if your satellite had 22 transponders, you could transmit 22 TV channels.

Using DVB digital technology and standards means the same transponder can transmit around 40 Megabits per second. A typical PAL VHS standard TV channel can be compressed by DVB MPEG-2 to around 4 Megabits per second. Channels can be mixed - or “multiplexed” - in the same transponder giving a rule-of-thumb of 10 TV channels (each around 4Mb/s) in a typical (40Mb/s) transponder.

The core system is the same for digital satellite, cable and terrestrial TV with different modulation methods for each mode. In the UK, for some reason, Cable companies have chosen not to adopt the DVB standard.

DVB sets the Standards for the World

Many people are taken aback to find that Europe can lead the world in digital technology. Especially those brainwashed to think that the internet and the World Wide Web are purely an American invention. The DVB Group has made Europe's TV technology more advanced than elsewhere. The co-operation has led to European standards which have removed “format wars” so successfully that a Scandinavian DVB TV receiver built for the Italian market can receive French TV channels in the UK.

DVB for Satellite, Cable and Terrestrial TV

The basic "unit" of the DVB system is the DVB multiplex - a very high speed data stream containing data packets from a number of individual smaller data streams. The parameters can be chosen so that a DVB-S multiplex - that transmitted from a single satellite transponder - is the same effective bandwidth as a DVB-C multiplex - that transmitted down a single analogue cable TV channel.

This allows any service contained within a DVB multiplex to pass down any current TV infrastructure to be received on an appropriate DVB receiver - whether satellite or cable.

DVB for Internet & Interaction

DVB has been developed to include encapsulation techniques which allow the MPEG-2 data packets to carry TCP/IP traffic at the same multi-Megabits/sec speed as digital television. This allows both digital TV and internet traffic to co-exist on the same system and be received by either DVB PC cards or DVB set-top-boxes.

DVB is under development to include a number of capabilities of interest to the interactive community: standard return path protocols via satellite and cable, open platforms, MHEG and compatibility with HTTP, IPV6 and other internet protocols. DVB today has the ability to carry TCP/IP - and hence any other standard using TCP/IP - at a very high speed.

DVB is a new Mode for the Internet

Satellite has been considered a poor relation in the market which thinks it invented the internet - the US. Perhaps they have never forgiven the UK for Arthur C Clarke, Alan Turing, and Tim Berners-Lee!

Satellite is the cheapest and easiest way of breaking the geographical barriers of the internet. Thanks to services like Opensky from BeyonDSL, anyone can upgrade to broadband reception as long as they can install a small dish and have a phone connection of some sort. No-one has to dig up the road to lay cable.

More than that, open-minded internet organisations are starting to realise the astounding possibilities of satellite for distribution of content and multimedia experiences. There is no cheaper way of giving people access to the latest Service Pack, Virus Update or Madonna Concert.

DVB and BeyonDSL

The people in BeyonDSL are very proud of being involved in bringing satellite broadband internet to the UK since 1997. Whether project managing the very first independent DVB multiplex carrying TV and Internet (in Y Tower D of the BT Tower) or building and running the direct internet link from Telehouse to satellite homes across Europe, we have been at the forefront of this technology.

Our team has developed world-leading technology and systems - all using DVB. With a pedigree including Astra, Eutelsat, Merlin, SMS, Convergence1, Convergence2, BT, Energis and the BBC, we can now bring you the best in one-way, hybrid and two-way DVB satellite services.