Full Title

Selective content distribution, e.g. interactive television or video on demand [VOD] (real-time bi-directional transmission of motion video data H04N7/14 ) > Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof > Structure of client; Structure of client peripherals > External card to be used in combination with the client device, e.g. for conditional access