A COMMON CONDITIONAL ACCESS INTERFACE FOR DIGITAL VIDEO BROADCASTING DECODERS

A set of standards has been designed by the Digital Video Broadcasting (DVB) project in Europe for the broadcasting of digital television se rvices on satellite, cable, MMDS and terrestrial networks. These stand ards are based on the ISO MPEG2 specifications and include source codi ng, channel coding, modulation, service information and interfaces for consumer decoders. A conditional access system is used when there is a need to control the access to a broadcast service, mainly for commer cial reasons. It has been decided not to standardize the Conditional A ccess (CA) system, but only the mechanisms for interoperation of diffe rent CA systems on DVB decoders. Mechanisms had to be found in order t o allow the reception of DVB programmes using different CA systems wit h a single decoder. The DVB common interface described in this paper h as first been specified for that purpose. Decoder manufacturers will p rovide DVB decoders with the DVB common interface and CA system provid ers will provide detachable CA modules. This solution allows broadcast ers to use modules containing solutions from different suppliers in th e same broadcast system, thus increasing their choice and anti-piracy options. The DVB common interface that has first been specified for th e CA detachable application can be used for other DVB applications. Th is document summarizes the results of DVB in the area of conditional a ccess, it gives a functional description of a DVB decoder including CA functionalities, it recalls the commercial objectives that lead to th e specification of the DVB common interface and at last it give a tech nical presentation of this interface.