EBU Technical Review : No. 266 (Winter 1995)
The DVB project
There is world-wide interest in digital television broadcasting and, in many countries, specialists have been involved in development and standardization programmes. In this issue of the Review, we focus on one of them – the European Digital Video Broadcasting (DVB) project. In spite of its name, the DVB project is endeavouring to develop digital television systems, including accompanying sound, for all potential television delivery systems. The project has been a great success, and it is a story well worth telling.
The first proposal for collaboration in the development of systems for digital television broadcasting in Europe arose inside the EBU. However, it was clear that a cross-industry forum was needed to cope with the many different dimensions encountered when new broadcast systems are developed and introduced. This is exactly what the DVB project is.
The project has grown in membership and in its activities since its inception in 1993, and it would be impossible to cover all the achievements of the project in a single issue of the Review. We have tried in this issue to give a flavour of some of the key goals and milestones, accepting that there are many things left for publication in future issues. We also include in this issue an article on the DAVIC project because of its importance.
It is particularly good to note the growing number of companies from outside Europe who have either joined the DVB project, or who are actually using the DVB systems in other parts of the world.
The project is continually reaching agreement on new systems or equipment configurations. This is a mark of its dynamism. This means that there is never a time which is just right for publishing a review of the project. There will always be the temptation to wait a little while longer for that next agreement to be reached. This has just happened in the case of digital terrestrial television; far-reaching discussions were being held as this issue of the Review was being prepared. As a result, only certain elements of the DVB digital terrestrial system are included in this issue. We intend to complement the article given here with another article on that topic in a future issue of the Review.
One of the critical elements in standardization is timing. Knowing when the technology is sufficiently mature to produce hardware which can be an attractive consumer product, and knowing when it is right to freeze a standard, is the information we would all like. There are no certain ways to predict these things. However, in planning and implementing its programme of work, the DVB project has tried firmly to learn from the lessons of the past.
Traditionally, engineers are over-optimistic people. They believe that standards development will take much less time than it actually does. They propose potential starting dates for new services which inevitably have to be revised. There is no reason to suppose that the introduction of digital television broadcasting will be an exception to the rule.
If we look across the Atlantic to the United States, we see that the development of a digital terrestrial television standard in the Advisory Committee on Advanced Television Service (ACATS) has taken much longer than originally predicted. There are often good reasons for extending the time needed to bring new systems to the marketplace.
In Europe, we have considerable pressure to create a digital terrestrial television standard that will allow receivers to be in the shops by 1997. This this is one of the reasons why a dual DVB-T system has recently been agreed.
The world of digital terrestrial television is more complex than the world of digital satellite television, whose launch in Europe is some months behind schedule. Thus, we should hardly be surprised if the terrestrial services start later than we think today.
This does not mean that we should be too relaxed in our endeavours to create and agree the standards. Human nature needs tight goals and tight time scales in order to be most productive. We need to get as close as we can to the magic formula that allows us to predict accurately the ideas, development, and marketing cycles for new systems.
This, alas, will always be an inexact science.
George T. Waters
Director
EBU Technical Department
European Broadcasting Union
