Abstract :
The terms access control and conditional access may not be familiar to many telecommunications professionals unless they work within the broadcasting industry or, perhaps, they are domestic subscribers to satellite or cable television. Traditionally, conditional access has referred to the means of allowing viewers of subscription television to access only those services which are authorised to them. With the emergence of new digital technologies and the convergence of telecommunications and broadcasting, conditional access and, more generally, access control, will increase in importance as a means of controlling subscriber access to an increasingly wide range of services. This paper describes these technologies and shows the fundamental architectural features that sets access control apart from traditional telecoms networks