System for processing user access control data at a decoder

摘要

A subscriber/user TV system operates in response to locally stored entitlements. A user gains access to a program only if the description of the program is consistent with entitled rights owned by the user. Each night at a given hour, decoders affiliated with the system tune to a predetermined video or audio channel, a so-called Barker channel. Decoders previously in a stand-by mode are activated in order to tune to the Barker channel. The program provider then sends the entitlement data on the Barker channel while every affiliated decoder is responsive to an incoming data stream.