Patent ID: 7873072

Claim:
A system for digital multimedia service including a relay center side that relays information to a terminal side, said system comprising: on the relay center side, a relay center incorporated in a relay network relaying the digital multimedia signals according to a predetermined relay center side packet identification description (PID) key, modifying a PID value of an audio and/or video data of a transport stream to obtain a modified PID value of the audio and/or video data of the transport stream, and generating a modified program specific information (PSI) by modifying an audio and/or video PID value and storing in a program map table (PMT) to obtain a modified audio and/or video PID value in the PMT; on the terminal side, a terminal receiving the digital multimedia service and demultiplexing the received digital multimedia service and for decoding in accordance with a preset terminal side PID key, said terminal recovering the modified PSI of the transport stream received from the relay center by utilizing the terminal side PID key, and decoding the transport stream (TS) including the audio and/or video data having the modified PID; and wherein, on the relay side, the modified audio and/or video PID value stored in the PMT does not match the modified PID of the audio and/or video data of the transport stream.