Process for transmitting digital television signals for multi-frequency terrestrial digital networks (DVB-T)

摘要

Digital television signals comprising a plurality of elementary binary streams, representing respective television programs, are multiplexed into a single, low-capacity transport stream, which also incorporates PSU/SU tables packets, PCR packets and null packets. The transport stream is then modulated and transmitted to a plurality of terrestrial stations, for broadcasting by terrestrial antennas. Before modulation, the packets transporting PSI/SI tables of type PAT, SDT, NIT e EIT are masked by replacing their respective PIDs with respective, predetermined, hiding PID values, chosen among values that are not reserved for satellite reception, and their "priority" bits are set. The resulting transport stream is then re-multiplexed to generate a high-capacity transport stream for transmission. At reception, the packets having unset "priority" bits are marked as null, and the original PIDs in the packets transporting the previously hidden PSI/SI tables (PAT, SDT, NIT e EIT) are restored.