| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a conditional access system in which contents broadcast from a broadcast center can be relayed in simple configuration without being descrambled at a relay station and further, the relay station can originally perform viewing control on a terminal device. <P>SOLUTION: When a broadcast signal from a broadcast center is relayed through a CATV station, viewing possibility information required for viewing is added to a part of signals, such as e.g., transmission control information. Further, if the viewing possibility information is not received for a specific time, a part of or all streams from a transmission line are disabled from being viewed. Thus, the CATV station can perform original viewing control, in simple configuration, regardless of performing modulation, conversion and retransmission without descrambling contents transmitted from the broadcast center. <P>COPYRIGHT: (C)2010,JPO&INPIT |
