Tektronix MTD200, Руководство пользователя

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Measurement Functions
2–16
MTD200 MPEG Test Decoder User Manual
CAT_error (2nd priority)
If encrypted data are contained in a packet of the transport stream, this must be
indicated in the packet header (2nd byte) within the field that is two bits wide
and is labeled transport_scrambling_control. The individual values indicate the
following:
Value (binary) Description
00 No encrypted data contained in the
packet
01, 10, 11 Defined by user
If encrypted data are to be transmitted, the MPEG-2 standard recommends the
additional transmission of the tables containing the encryption data (Conditional
Access Table, CAT) in separate packets with (0x0001) as PID and 0x01 as table
index.
The MPEG-2 standard prescribes that packet header including the optional
adaptation fields must not be transmitted in encrypted form. According to DVB
specifications (ETS 300 468), the same applies to tables containing service
information (SI tables PAT, PMT, NIT, EIT, BAT, TDT, TOT and SDT). The
only exception to this rule is the EIT (Event Information Table) when program
overviews are transmitted.
In the DVB Measurement Guidelines (ETR 290) the preconditions for a
CAT_Error message are set as follows (abbreviated designations in parentheses
are the text displayed in the monitoring report):
CAT ERROR is signaled if
a packet contains encrypted data, but no CAT is found (MISSING) or
a packet with CAT-PID (0x0001) is found, but table index does not equal
0x01 (TABLE ID)
An error of this type is indicated in a cumulative message indicating several
single errors by the LED labeled OTHER lighting (line of LEDs at front panel).
Additional information on the type of error as listed in the above table can be
obtained from the monitoring report.