Digital Television

On the eve of the revolution – Digital television broadcasting in April 1994
D. Wood (54 KB)

In a relatively short time, the Digital Video Broadcasting Project has grown into one of Europe's fastest-moving and most ambitious projects in the media environment. Starting with a handful of specialists, DVB now involves over 130 companies and organizations in a joint effort aimed at establishing a coordinated set of standards for the digital transmission of television programmes by satellite, by cable and in terrestrial channels. A new page has been opened in the history of broadcasting, and the DVB Project is a key element in the process.

The conventional planning approach applied to digital terrestrial television
K.J. Hunt (94 KB)

This article continues and expands upon the discusion started in [3]. It is becoming ever more clear that the future of broadcasting, and that of television in particular, is digital. The transfer to digital is already taking place in the studio; many contribution circuits are already digital; the final stage in this process involves the transmission and reception part of the overall chain.

The potential benefits are considerable. The greater spectrum economy of digital signals will provide the capacity for more services, while also providing higher technical quality for the pictures displayed in viewers' homes.

The main difficulty lies in finding the spectrum in which to introduce the digital services, while maintaining the existing analogue services in operation for what could be an extended transition period.

Digital television and HDTV in America – A progress report
J.A. Flaherty (37 KB)

The development of advanced and high-definition television systems has been marked by more debate, more spectacular changes of direction and, no doubt, more heart-ache than any other aspect of television technology and programme-making in the past fifty years.

The European television industry has, with varying degrees of enthusiasm, encouraged a full spectrum of analogue, hybrid and digital systems for all quality targets from pocket TV to wide-screen HDTV. In contrast, the decision of the US Federal Communication Commission to set one clear goal – HDTV in 6-MHz terrestrial channels – might have seemed like a simple approach, guaranteed almost to lead rapidly to success.

This presentation of the path trodden by America's HDTV pioneers shows that, even if all the competitors had a rather clear vision of the goal before they started, success has nevertheless demanded compromise and commercial pragmatism as well as good technology.

Digital terrestrial HDTV for North America – The Grand Alliance HDTV system
R. Hopkins (97 KB)

The Grand Alliance HDTV system has been designed for the needs and requirements of North America. The system has a great deal of flexibility to facilitate inter-operability and is heavily based on international standards.

The Grand Alliance and the FCC Advisory Committee on Advanced Television Service have been working together to complete the design of the Grand Alliance HDTV system. When a technical decision is made, technical performance is the number one priority in making the decision.

The prototype is under construction and testing will begin late in 1994. The article describes the technical characteristics of the Grand Alliance HDTV system.

The inter-operability of digital HDTV satellite broadcasting (21.4-22GHz) with the existing and future media infrastructure – Status of the HD-SAT project
Ch. Dosch (224 KB)

The HD-SAT project began in 1992 with the objective of developing a digital satellite broadcasting system using the newly-allocated 21.4-22 GHz band and designed specifically to deliver studio-quality high-definition television programmes directly to viewers' homes.

This status report on the HD-SAT project shows how the project has evolved over the first three years, encouraging and embracing new technologies and adapting to the rapidly-changing scenarios under development for other television broadcasting services, notably the European Digital Video Broadcasting project.

Digital Audio

Transmission of coded sound signals in a future ATM network
U. Aßmus and M.S. Nunes (59 KB)

The article describes a method for the adaptation of high-quality digital sound signals to a future integrated-services broadband network. The digital signals, with a highly-reduced bit-rate, are transmitted in cells in the asynchronous transfer mode.

The method can be applied to the networking of signals for Digital Audio Broadcasting services between studio centres and the DAB transmission multiplexer.