With this the same movie is transmitted on four or six channels with starting times staggered by 20 minutes or so

With this, the same movie is transmitted on four or six channels with starting times staggered by 20 minutes or so. These can be used either for tightly themed, special-interest channels, such as the Golf Channel or the Sci-Fi Channel, or for near video on demand (NVOD). Digital television stores an image and sends only the differences in the next frame. Depending on the material being sent, it is possible to compress it by between five and 15 times.That means a digital broadcaster can offer hundreds of channels, rather than dozens. It will allow a few high-quality transmissions, or many lower- quality ones.

It is particularly effective at “compressing” a moving picture, which normally consists of thousands of separate images. Until recently, the emphasis was on quality: just as digital compact discs brought us better-quality sound, it was argued, so digital High Definition Television would bring us better pictures.The trouble was, the marketing people found it difficult to believe consumers would queue up to pay a fortune for a slightly sharper image. What they would pay for, they believed, was greater choice.Unlike analogue television, where a transmission has a set quality and takes up a fixed amount of broadcasting space, digital television allows a pay-off. Other satellites will be feeding digital TV into French and Scandinavian markets, giving a total capacity of well over a thousand channels by the end of 1997.Digital television has been pondered ever since the growing power of computers made it possible to convert sound and pictures into strings of digital codes. SES, the private Luxembourg-based owner of the Astra system, which BSkyB uses, plans to launch the all-digital Astra 1E in September, 1F next March and 1G in 1997. By the middle of 1997, digital TV will be a real star.”Next September, Eutelsat will launch Hot Bird 2, and Hot Bird 3 will follow in February 1997. Nobody expects take- up to be as rapid in Europe, especially in Britain, but Eutelsat believes it will make its mark within two years.

“1995 will be the year of the digital satellite TV pioneer in Europe,” says Giuliano Berretta, its commercial director. “Towards the end of the year, some other pioneers will go on to direct-to-home broadcasting. Nothing unusual about that – Eutelsat, owned by telecom companies, is one of the world’s biggest satellite operators. What is special about Hot Bird 1, though, is that it marks the introduction of digital satellite television to Europe. That in turn is a sign that satellite is determined to hang on to its position as a supplier of programmes direct to homes, rather than slipping to become no more than a subcontractor to the cable companies.
In the US, direct satellite digital TV has attracted almost a million subscribers since the launch of DirecTV last June.