Deviser S7200 User Manual page 72

Part II: Settings and Measurements
6-12.8 PSI/PSIP Table Analysis
Like the SI tables, DVB & ATSC also provide PSIP tables.
PSIP stands for "program and system information protocol" and lists info similar to that given on DVB SI.
In ATSC, the following tables are used: the Master Guide Table (MGT), the Event Information Table (EIT), the
Extended Text Table (ETT), the System Time Table (STT), the Rating Region Table (RRT), and the Cable Virtual
Channel Table (CVCT) or the Terrestrial Virtual Channel Table (TVCT).
According to ATSC, the PSI tables defined in MPEG-2 and provided in the MPEG Standard are used for
accessing the video and audio streams, i.e. the transport stream carries one PAT and several PMTs. The
conditional access information is also referenced via a CAT.
The actual ATSC tables are implemented as "private tables". The MGT contains the PIDs for some of these
ATSC tables; it can be recognized by the packet ID = 0x1FFB and the table ID = 0xC7. The transport stream
must contain at least four EITs (EIT-0, EIT-1, EIT-2, EIT-3) and the PIDs for these EITs are found in the MGT. Up to
128 further EITs are possible, but are optional. An EIT contains a 3-hour section of an electronic program
guide (EPG). Together with the 4 mandatory EITs, it is possible to cover a period of 12 hours. Furthermore,
ETTs may optionally be accessed through the MGT. Each existing ETT is allocated to one EIT. Thus, e.g. ETT-0
contains extended text information for EIT- 0. It is possible to have up to a total of 128 ETTs.
In the Virtual Channel Table – which may exist either as Terrestrial (TVCT) or Cable (CVCT) depending on the
transmission path – identification for the virtual channels (programs) contained in a multiplexed transport
stream are transmitted. The VCT lists program names and other data. The VCT is thus comparable to the SDT
table in DVB.
In the System Time Table (STT), all the necessary time information is transmitted. The STT can be recognized
by the packet ID = 0x1FFB and the table ID = 0xCD. In the STT, the GPS time and time difference between
GPS and UTC (Universal Time Coordinated (= GMT)) is transmitted. The Rating Region Table (RRT) can be
used for restricting the size of the audience in terms of age or region. It includes info about the broadcast
region (e.g. a Federal State in the US), as well as info about the minimum age set for the program currently
being shown. Using the RRT, a type of parental lock can be implemented in the set-top box. The RRT is
recognized by the packet ID = 0x 1FFB and the table ID = 0xCA.
The PIDs and Table IDs of the PSIP tables are listed in Table: PSIP Table ID Ranges and Values (above).
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PSIP Table ID Ranges & Values
Table PID
PAT 0x0
PMT Per PAT
CAT 0x1
MGT 0x1FFB
TVCT 0x1FFB
CVCT 0x1FFB
RRT 0x1FFB
EIT per MGT
ETT per MGT
STT 0x1FFB
Table ID Value (hex)
0x0
0x2
0x1
0xC7
0xC8
0xC9
0xCA
0xCB
0xCC
0xCD