ABSTRACT
The technical superiority of digital over analogue television broadcasting is widely recognised. Digital is much less susceptible to distortion and atmospheric interference. Digital broadcasters can transmit ‘enhanced’ programming, that is, additional content relating to a broadcast programme-for example, information concerning a player or choice of camera angles during a sports telecast. There is also far more scope with digital than analogue for on-screen display of programming information (electronic programme guide), and for ‘interactivity’ between viewers and broadcasters thus allowing the provision of a range of ‘interactive’ services (see chap. 5). In terms of the structure of the commercial television broadcasting industry, however, the most important feature of digital is that it facilitates the transmission of a much greater number of channels than analogue. This is largely due to the ability to ‘compress’ the digital signal, As well, for terrestrial transmissions, the spectrum currently used for ‘buffer’ channels between analogue signals and for ‘shadow infill’ in areas of hilly terrain is either not required or is greatly reduced. Ongoing developments in compression technologies are likely to increase further the number of channels that can be transmitted by each of the three main digital ‘platforms’—satellite, cable and terrestrial.
