The MPEG Data Stream - Digital Video and Audio Broadcasting Technology - page 73

In the NIT, the physical parameters of all transport streams of a network
are described via their TS_IDs. A TS_ID corresponds to the current trans-
port stream; precisely this TS_ID can be found in the header of the PAT at
the position of the Table ID extension.
The services (= programs) contained in this transport stream are listed in
the service descriptor table via the service IDs. The service IDs must cor-
respond to the prog_no in the PAT and in the PMTs.
This is continued in the EIT: there is an EIT for every service. In the
header of the EIT, the table_ID_extension corresponds to the service_ID of
the associated program. In the EIT, the events are associated with these by
way of event_IDs. If there are associated RSTs, then these are chained to
the respective RST via these event_IDs.

Table 3.3. Repetition rates of the PSI/SI tables according to MPEG/DVB

PSI/SI table Max. interval

(complete table)

Min. interval
(single sections)

PAT 0.5 s 25 ms

CAT 0.5 s 25 ms

PMT 0.5 s 25 ms

NIT 10 s 25 ms

SDT 2 s 25 ms

BAT 10 s 25 ms

EIT 2 s 25 ms

RST - 25 ms

TDT 30 s 25 ms

TOT 30 s 25 ms

The repetition rates of the PSI/SI tables are regulated through MPEG-2
Systems [ISO&IEC 13818/1] and DVB/SI [ETS 300468] (Table 3.3)

3.4 The PSIP according to the ATSC

In the US, a separate standard was specified for digital terrestrial and cable
TV. This is the ATSC standard, where ATSC stands for Advanced Televi-
sion System Committee. During the work on the ATSC standard, the deci-
sion was made to use the MPEG-2 transport stream with MPEG-2 video
and AC-3 Dolby Digital audio as the baseband signal. The type of modula-
tion used is 8 or 16VSB. In addition, it was recognized that other tables
going beyond PSI are needed. Like the SI tables in DVB, ATSC, therefore,