ETSI EN 300 468 V1.3.1 (1998-02)

SLOVENSKI STANDARD
01-november-2005
Digitalna videoradiodifuzija (DVB) – Specifikacija za servisne informacije (SI) v
sistemih DVB
Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB
systems
Ta slovenski standard je istoveten z: EN 300 468 Version 1.3.1
ICS:
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 300 468 V1.3.1 (1998-02)
European Standard (Telecommunications series)
Digital Video Broadcasting (DVB);
Specification for Service Information (SI) in DVB systems
European Broadcasting Union Union Européenne de Radio-Télévision
EBU
UER
European Telecommunications Standards Institute

2 EN 300 468 V1.3.1 (1998-02)
Reference
REN/JTC-DVB-43 (4c000j0o.PDF)
Keywords
DVB, broadcasting, digital, video, MPEG, TV
ETSI Secretariat
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Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1998.
© European Broadcasting Union 1998.
All rights reserved.
3 EN 300 468 V1.3.1 (1998-02)
Contents
Intellectual Property Rights.6
Foreword .6
1 Scope.7
2 References.7
3 Definitions and abbreviations .8
3.1 Definitions . 8
3.2 Abbreviations. 10
4 Service Information (SI) description.11
5 Service Information (SI) tables .14
5.1 SI table mechanism . 14
5.1.1 Explanation . 14
5.1.2 Mapping of sections into Transport Stream (TS) packets . 15
5.1.3 Coding of PID and table_id fields. 15
5.1.4 Repetition rates and random access. 16
5.1.5 Scrambling . 16
5.2 Table definitions . 16
5.2.1 Network Information Table (NIT) . 17
5.2.2 Bouquet Association Table (BAT). 18
5.2.3 Service Description Table (SDT). 20
5.2.4 Event Information Table (EIT) . 22
5.2.5 Time and Date Table (TDT) . 24
5.2.6 Time Offset Table (TOT). 24
5.2.7 Running Status Table (RST) . 25
5.2.8 Stuffing Table (ST) . 26
5.2.9 Discontinuity Information Table (DIT). 26
5.2.10 Selection Information Table (SIT) . 26
6 Descriptors .27
6.1 Descriptor identification and location. 27
6.2 Descriptor coding. 28
6.2.1 Bouquet name descriptor. 28
6.2.2 CA identifier descriptor. 28
6.2.3 Component descriptor . 29
6.2.4 Content descriptor . 31
6.2.5 Country availability descriptor. 34
6.2.6 Data broadcast descriptor. 35
6.2.7 Data broadcast id descriptor. 36
6.2.8 Delivery system descriptors . 36
6.2.8.1 Cable delivery system descriptor. 36
6.2.8.2 Satellite delivery system descriptor . 37
6.2.8.3 Terrestrial delivery system descriptor. 38
6.2.9 Extended event descriptor . 40
6.2.10 Frequency list descriptor . 41
6.2.11 Linkage descriptor. 42
6.2.12 Local time offset descriptor. 43
6.2.13 Mosaic descriptor. 44
6.2.14 Multilingual bouquet name descriptor. 47
6.2.15 Multilingual component descriptor . 47
6.2.16 Multilingual network name descriptor. 48
6.2.17 Multilingual service name descriptor . 49
6.2.18 Near Video On Demand (NVOD) reference descriptor . 49
6.2.19 Network name descriptor . 50
6.2.20 Parental rating descriptor . 50

4 EN 300 468 V1.3.1 (1998-02)
6.2.21 Partial Transport Stream (TS) descriptor . 50
6.2.22 Private data specifier descriptor . 50
6.2.23 Short smoothing buffer descriptor. 50
6.2.24 Service descriptor. 53
6.2.25 Service list descriptor. 54
6.2.26 Service move descriptor. 54
6.2.27 Short event descriptor . 55
6.2.28 Stream identifier descriptor. 55
6.2.29 Stuffing descriptor. 56
6.2.30 Subtitling descriptor . 56
6.2.31 Telephone descriptor. 57
6.2.32 Teletext descriptor. 58
6.2.33 Time shifted event descriptor. 59
6.2.34 Time shifted service descriptor . 59
7 Storage Media Interoperability (SMI) measures.60
7.1 SMI tables. 60
7.1.1 Discontinuity Information Table (DIT). 60
7.1.2 Selection Information Table (SIT) . 61
7.2 SMI descriptors. 62
7.2.1 Partial Transport Stream (TS) descriptor . 62
Annex A (normative): Coding of text characters.63
A.1 Control codes .63
A.2 Selection of character table.63
Annex B (normative): CRC decoder model.70
Annex C (informative): Conversion between time and date conventions.71
Annex D (informative): Bibliography.73
History.74

5 EN 300 468 V1.3.1 (1998-02)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETR 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of
ETSI standards", which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI
Web server (http://www.etsi.fr/ipr).
Pursuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI.
No guarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on
http://www.etsi.fr/ipr) which are, or may be, or may become, essential to the present document.
Foreword
This European Standard (Telecommunications series) has been produced under the authority of the Joint Technical
Committee (JTC) of the European Broadcasting Union (EBU), Comité Européen de Normalisation ELECtrotechnique
(CENELEC) and the European Telecommunications Standards Institute (ETSI).
NOTE: The EBU/ETSI JTC was established in 1990 to co-ordinate the drafting of standards in the specific field
of broadcasting and related fields. Since 1995 the JTC became a tripartite body by including in the
Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and
television receivers. The EBU is a professional association of broadcasting organizations whose work
includes co-ordination of its members' activities in the technical, legal, programme-making and
programme-exchange domains. The EBU has active members in about 60 countries in the European
broadcasting area; its headquarters is in Geneva *.
European Broadcasting Union
CH-1218 GRAND SACONNEX (Geneva)
Switzerland
Tel: +41 22 717 21 11
Fax: +41 22 717 24 81
Digital Video Broadcasting (DVB) Project
Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations in
the television industry. Its aim is to establish the framework for the introduction of MPEG-2 based digital television
services. Now comprising over 200 organizations from more than 25 countries around the world, DVB fosters
market-led systems, which meet the real needs, and economic circumstances, of the consumer electronics and the
broadcast industry.
National transposition dates
Date of adoption of this EN: 23 January 1998
Date of latest announcement of this EN (doa): 31 May 1998
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 November 1998
Date of withdrawal of any conflicting National Standard (dow): 30 November 1998

6 EN 300 468 V1.3.1 (1998-02)
1 Scope
The present document specifies the Service Information (SI) data which forms a part of DVB bitstreams, in order that
the user can be provided with information to assist in selection of services and/or events within the bitstream, and so that
the Integrated Receiver Decoder (IRD) can automatically configure itself for the selected service. SI data for automatic
configuration is mostly specified within ISO/IEC 13818-1 [1] as Program Specific Information (PSI).
The present document specifies additional data which complements the PSI by providing data to aid automatic tuning of
IRDs, and additional information intended for display to the user. The manner of presentation of the information is not
specified in the present document, and IRD manufacturers have freedom to choose appropriate presentation methods.
It is expected that Electronic Programme Guides (EPGs) will be a feature of Digital TV transmissions.
The definition of an EPG is outside the scope of the present document (i.e. the SI specification), but the data contained
within the SI specified in the present document may be used as the basis for an EPG.
Rules of operation for the implementation of the present document (i.e. EN 300 468) are specified in ETR 211 [7].
2 References
References may be made to:
a) specific versions of publications (identified by date of publication, edition number, version number, etc.), in
which case, subsequent revisions to the referenced document do not apply; or
b) all versions up to and including the identified version (identified by "up to and including" before the version
identity); or
c) all versions subsequent to and including the identified version (identified by "onwards" following the version
identity); or
d) publications without mention of a specific version, in which case the latest version applies.
A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same
number.
[1] ISO/IEC 13818-1: "Information Technology - Generic Coding of Moving Pictures and Associated
Audio Recommendation H.222.0 (systems)".
[2] ISO 3166: "Codes for the representation of names of countries".
[3] ISO 639.2: "Code for the representation of names of languages".
[4] EBU SPB 492 (1992): "Teletext specification (625 line Television Systems)".
[5] ISO 8859: "Information processing - 8-bit single-byte coded graphic character sets,
Latin alphabets".
[6] ETR 162: "Digital Video Broadcasting (DVB); Allocation of Service Information (SI) codes for
DVB systems".
[7] ETR 211: "Digital Video Broadcasting (DVB); Guidelines on implementation and usage of
Service Information (SI)".
[8] ISO/IEC 10646-1: "Information Technology - Universal Multiple-Octet Coded Character Set
(UCS) - Part 1: Architecture and Basic Multilingual Plane".
[9] ISO/IEC 6937: "Information Technology - Coded graphic character set for text communication -
Latin alphabet".
[10] ETR 289: "Digital Video Broadcasting (DVB); Support for use of scrambling and Conditional
Access (CA) within digital broadcasting systems".

7 EN 300 468 V1.3.1 (1998-02)
[11] IEC CD-100C/1883: Parts 1 and 4 "Digital Interface for Consumer Electronic Audio/Video
Equipment".
[12] ETR 154: "Digital Video Broadcasting (DVB); Implementation guidelines for the use of MPEG-2
Systems, Video and Audio in satellite, cable and terrestrial broadcasting applications".
[13] IEEE 1394: "High Performance Serial Bus".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following definitions apply:
bouquet: A collection of services marketed as a single entity.
broadcaster (SERVICE Provider): An organization which assembles a sequence of events or programmes to be
delivered to the viewer based upon a schedule.
component (ELEMENTARY Stream): One or more entities which together make up an event,
e.g. video, audio, teletext.
Conditional Access (CA) system: A system to control subscriber access to services, programmes and events e.g.
Videoguard, Eurocrypt.
delivery system: The physical medium by which one or more multiplexes are transmitted e.g. satellite system, wide-
band coaxial cable, fibre optics, terrestrial channel of one emitting point.
Entitlement Management Messages (EMM): Are private Conditional Access information which specify the
authorization levels or the services of specific decoders. They may be addressed to individual decoder or groups of
decoders.
event: A grouping of elementary broadcast data streams with a defined start and end time belonging to a common
service, e.g. first half of a football match, News Flash, first part of an entertainment show.
forbidden: The term "forbidden" when used in the clauses defining the coded bit stream, indicates that the value shall
never be used.
MPEG-2: Refers to the standard ISO/IEC 13818 [1]. Systems coding is defined in part 1. Video coding is defined in
part 2. Audio coding is defined in part 3.
multiplex: A stream of all the digital data carrying one or more services within a single physical channel.
network: A collection of MPEG-2 Transport Stream (TS) multiplexes transmitted on a single delivery system, e.g. all
digital channels on a specific cable system.
original_network_id: A unique identifier of a network.
programme: A concatenation of one or more events under the control of a broadcaster e.g. news show, entertainment
show.
reserved: The term "reserved" when used in the clause defining the coded bit stream, indicates that the value may be
used in the future for ISO defined extensions. Unless otherwise specified within the present document all "reserved" bits
shall be set to "1".
reserved_future_use: The term "reserved_future_use", when used in the clause defining the coded bit stream, indicates
that the value may be used in the future for ETSI defined extensions. Unless otherwise specified within the present
document all "reserved_future_use" bits shall be set to "1".
section: A section is a syntactic structure used for mapping all service information defined in the present document into
ISO/IEC 13818 [1] TS packets.
8 EN 300 468 V1.3.1 (1998-02)
service: A sequence of programmes under the control of a broadcaster which can be broadcast as part of a schedule.
service_id: A unique identifier of a service within a TS.
Service Information (SI): Digital data describing the delivery system, content and scheduling/timing of broadcast data
streams etc. It includes MPEG-2 PSI together with independently defined extensions.
sub_table: A sub_table is collection of sections with the same value of table_id and:
for a NIT: the same table_id_extension (network_id) and version_number;
for a BAT: the same table_id_extension (bouquet_id) and version_number;
for a SDT: the same table_id_extension (transport_stream_id), the same original_network_id and
version_number;
for a EIT: the same table_id_extension (service_id), the same transport_stream_id, the same original_network_id
and version_number.
The table_id_extension field is equivalent to the fourth and fifth byte of a section when the section_syntax_indicator is
set to a value of "1".
table: A table is comprised of a number of sub_tables with the same value of table_id.
Transport Stream (TS): A TS is a data structure defined in ISO/IEC 13818-1 [1]. It is the basis of the DVB standards.
transport_stream_id: A unique identifier of a TS within an original network.
The relationships of some of these definitions are illustrated in the service delivery model in figure 1.
Satellite
Cable Terrestrial
N etw orks
Transponder Transponder Transponder Transponder
Channel C hannel Channel C hannel C hannel C hannel
M ultiplexes
Bouquet
Service Service Service Service Service Service Service Service Service
Services Service
Components
V ideo A u dio 1 A udio 2 D ata
Figure 1: Digital broadcasting, service delivery model

9 EN 300 468 V1.3.1 (1998-02)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
BAT Bouquet Association Table
BCD Binary Coded Decimal
bslbf bit string, left bit first
CA Conditional Access
CAT Conditional Access Table
CLUT Colour Look-Up Table
CRC Cyclic Redundancy Check
DIT Discontinuity Information Table
DVB Digital Video Broadcasting
EBU European Broadcasting Union
EIT Event Information Table
EMM Entitlement Management Message
EPG Electronic Programme Guide
ETS European Telecommunication Standard
FEC Forward Error Correction
IEC International Electrotechnical Commission
IRD Integrated Receiver Decoder
ISO International Organization for Standardization
LSB Least Significant Bit
MJD Modified Julian Date
MPEG Moving Pictures Expert Group
NIT Network Information Table
NVOD Near Video On Demand
PAT Program Association Table
PID Packet IDentifier
PMT Program Map Table
PSI Program Specific Information
PSTN Public Switched Telephone Network
QAM Quadrature Amplitude Modulation
QPSK Quaternary Phase Shift Keying
rpchof remainder polynomial coefficients, highest order first
RS Reed - Solomon
RST Running Status Table
SDT Service Description Table
SI Service Information
SIT Selection Information Table
SMI Storage Media Interoperability
ST Stuffing Table
TDT Time and Date Table
TOT Time Offset Table
TS Transport Stream
uimsbf unsigned integer most significant bit first
UTC Universal Time, Co-ordinated

10 EN 300 468 V1.3.1 (1998-02)
4 Service Information (SI) description
ISO/IEC 13818 [1] specifies SI which is referred to as PSI. The PSI data provides information to enable automatic
configuration of the receiver to demultiplex and decode the various streams of programs within the multiplex.
The PSI data is structured as four types of table. The tables are transmitted in sections.
1) Program Association Table (PAT):
- for each service in the multiplex, the PAT indicates the location (the Packet Identifier (PID) values of the
Transport Stream (TS) packets) of the corresponding Program Map Table (PMT). It also gives the location of
the Network Information Table (NIT).
2) Conditional Access Table (CAT):
- the CAT provides information on the CA systems used in the multiplex; the information is private (not
defined within the present document) and dependent on the CA system, but includes the location of the EMM
stream, when applicable.
3) Program Map Table (PMT):
- the PMT identifies and indicates the locations of the streams that make up each service, and the location of
the Program Clock Reference fields for a service.
4) Network Information Table (NIT):
- the location of the NIT is defined in the present document in compliance with ISO/IEC 13818-1 [1]
specification, but the data format is outside the scope of ISO/IEC 13818-1 [1]. It is intended to provide
information about the physical network. The syntax and semantics of the NIT are defined in the present
document.
In addition to the PSI, data is needed to provide identification of services and events for the user. The coding of this data
is defined in the present document. In contrast with the PAT, CAT, and PMT of the PSI, which give information only
for the multiplex in which they are contained (the actual multiplex), the additional information defined within the present
document can also provide information on services and events carried by different multiplexes, and even on other
networks. This data is structured as nine tables:
1) Bouquet Association Table (BAT):
- the BAT provides information regarding bouquets. As well as giving the name of the bouquet, it provides a
list of services for each bouquet.
2) Service Description Table (SDT):
- the SDT contains data describing the services in the system e.g. names of services, the service provider, etc.
3) Event Information Table (EIT):
- the EIT contains data concerning events or programmes such as event name, start time, duration, etc.;
- the use of different descriptors allows the transmission of different kinds of event information e.g. for
different service types.
4) Running Status Table (RST):
- the RST gives the status of an event (running/not running). The RST updates this information and allows
timely automatic switching to events.
5) Time and Date Table (TDT):
- the TDT gives information relating to the present time and date. This information is given in a separate table
due to the frequent updating of this information.

11 EN 300 468 V1.3.1 (1998-02)
6) Time Offset Table (TOT):
- the TOT gives information relating to the present time and date and local time offset. This information is
given in a separate table due to the frequent updating of the time information.
7) Stuffing Table (ST):
- the ST is used to invalidate existing sections, for example at delivery system boundaries.
8) Selection Information Table (SIT)
- the SIT is used only in "partial" (i.e. recorded) bitstreams. It carries a summary of the SI information required
to describe the streams in the partial bitstream.
9) Discontinuity Information Table (DIT)
- the DIT is used only in "partial" (i.e. recorded) bitstreams. It is inserted where the SI information in the
partial bitstream may be discontinuous.
Where applicable the use of descriptors allows a flexible approach to the organization of the tables and allows for future
compatible extensions.
12 EN 300 468 V1.3.1 (1998-02)

MPEG -2 defined Defined in the present docum ent
NOTE: NIT table entitled "DVB (mandatory)" should read "Actual delivery system" instead of "Actual transport
stream".
NIT table entitled "DVB (optional)" should read "Other delivery system" instead of "Other transport
Stream".
Figure 2: General organization of the Service Information (SI)

13 EN 300 468 V1.3.1 (1998-02)
5 Service Information (SI) tables
5.1 SI table mechanism
The SI specified in the present document and MPEG-2 PSI tables shall be segmented into one or more sections before
being inserted into TS packets.
The tables listed in clause 4 are conceptual in that they need never be regenerated in a specified form within an IRD.
The tables, when transmitted shall not be scrambled, with the exception of the EIT, which may be scrambled if required
(see subclause 5.1.5).
A section is a syntactic structure that shall be used for mapping all MPEG-2 tables and SI tables specified in the present
document, into TS packets.
These SI syntactic structures conform to the private section syntax defined in ISO/IEC 13818-1 [1].
5.1.1 Explanation
Sections may be variable in length. The sections within each table are limited to 1 024 bytes in length, except for
sections within the EIT which are limited to 4 096 bytes. Each section is uniquely identified by the combination of the
following elements:
a) table_id:
- The table_id identifies to which table the section belongs.
- Some table_ids have been defined by ISO and others by ETSI. Other values of the table_id can be allocated
by the user for private purposes. The list of values of table_id is contained in table 2.
b) table_id_extension:
- The table_id_extension is used for identification of a sub_table.
- The interpretation of each sub_table is given in subclause 5.2.
c) section_number:
- The section_number field allows the sections of a particular sub_table to be reassembled in their original
order by the decoder. It is recommended, that sections are transmitted in numerical order, unless it is desired
to transmit some sections of the sub_table more frequently than others, e.g. due to random access
considerations.
- For the SI tables as specified in the present document, section numbering applies to sub_tables.
d) version_number:
- When the characteristics of the TS described in the SI given in the present document change (e.g. new events
start, different composition of elementary streams for a given service), then new SI data shall be sent
containing the updated information. A new version of the SI data is signalled by sending a sub_table with the
same identifiers as the previous sub_table containing the relevant data, but with the next value of
version_number.
- For the SI tables specified in the present document, the version_number applies to all sections of a sub_table.
e) Current_next_indicator:
- Each section shall be numbered as valid "now" (current), or as valid in the immediate future (next).
This allows the transmission of a future version of the SI in advance of the change, giving the decoder the
opportunity to prepare for the change. There is however, no requirement to transmit the next version of a
section in advance, but if it is transmitted, then it shall be the next correct version of that section.

14 EN 300 468 V1.3.1 (1998-02)
5.1.2 Mapping of sections into Transport Stream (TS) packets
Sections shall be mapped directly into TS packets. Sections may start at the beginning of the payload of a TS packet, but
this is not a requirement, because the start of the first section in the payload of a TS packet is pointed to by the
pointer_field. There is never more than one pointer_field in a TS packet, as the start of any other section can be
identified by counting the length of the first and any subsequent sections, since no gaps between sections within a TS
packet are allowed by the syntax.
Within TS packets of any single PID value, one section is finished before the next one is allowed to be started, or else it
is not possible to identify to which section header the data belongs. If a section finishes before the end of a TS packet,
but it is not convenient to open another section, a stuffing mechanism may be used to fill up the space.
Stuffing may be performed by filling each remaining byte of the TS packet with the value "0xFF". Consequently the
value "0xFF" shall not be used for the table_id. If the byte immediately following the last byte of a section takes the
value of "0xFF", then the rest of the TS packet shall be stuffed with "0xFF" bytes. These bytes may be discarded by a
decoder. Stuffing may also be performed using the adaptation_field mechanism.
For a more detailed description of the mechanism and functionality, specifically refer to section 2.4.4 and annex C of
ISO/IEC 13818-1 [1].
5.1.3 Coding of PID and table_id fields
Table 1 lists the PID values which shall be used for the TS packets which carry SI sections.
Table 1: PID allocation for SI
Table PID value
PAT 0x0000
CAT 0x0001
TSDT 0x0002
reserved 0x0003 to 0x000F
NIT, ST 0x0010
SDT, BAT, ST 0x0011
EIT, ST 0x0012
RST, ST 0x0013
TDT, TOT, ST 0x0014
network synchronization 0x0015
reserved for future use 0x0016 to 0x001D
DIT 0x001E
SIT 0x001F
Table 2 lists the values which shall be used for table_id for the service information, defined in the present document.

15 EN 300 468 V1.3.1 (1998-02)
Table 2: Allocation of table_id values
Value Description
0x00 program_association_section
0x01 conditional_access_section
0x02 program_map_section
0x03 transport_stream_description_section
0x04 to 0x3F reserved
0x40 network_information_section - actual_network
0x41 network_information_section - other_network
0x42 service_description_section - actual_transport_stream
0x43 to 0x45 reserved for future use
0x46 service_description_section - other_transport_stream
0x47 to 0x49 reserved for future use
0x4A bouquet_association_section
0x4B to 0x4D reserved for future use
0x4E event_information_section - actual_transport_stream, present/following
0x4F event_information_section - other_transport_stream, present/following
0x50 to 0x5F event_information_section - actual_transport_stream, schedule
0x60 to 0x6F event_information_section - other_transport_stream, schedule
0x70 time_date_section
0x71 running_status_section
0x72 stuffing_section
0x73 time_offset_section
0x74 to 0x7D reserved for future use
0x7E discontinuity_information_section
0x7F selection_information_section
0x80 to 0xFE user defined
0xFF reserved
5.1.4 Repetition rates and random access
In systems where random access is a consideration, it is recommended to re-transmit SI sections specified within the
present document several times, even when changes do not occur in the configuration.
For SI specified within the present document the minimum time interval between the arrival of the last byte of a section
to the first byte of the next transmitted section with the same PID, table_id and table_id_extension and with the same or
different section_number shall be 25 milliseconds. This limit applies for TSs with a total data rate of up to 100 Mbit/s.
5.1.5 Scrambling
With the exception of the EIT carrying schedule information, all tables specified in the present document shall not be
scrambled. One method for scrambling the EIT schedule table is given in annex D, bibliography. If a scrambling method
operating over TS packets is used, it may be necessary to use a stuffing mechanism to fill from the end of a section to
the end of a packet so that any transitions between scrambled and unscrambled data occur at packet boundaries.
In order to identify the CA streams which control the descrambling of the EIT data, a scrambled EIT schedule table shall
be identified in the PSI. Service_id value 0xFFFF is allocated to identifying a scrambled EIT, and the program map
section for this service shall describe the EIT as a private stream and shall include one or more CA_descriptors
(defined in ISO/IEC 13818-1 [1]) which give the PID values and optionally, other private data to identify the associated
CA streams. Service_id value 0xFFFF shall not be used for any other service.
5.2 Table definitions
The following subclauses describe the syntax and semantics of the different types of table.
NOTE: The symbols and abbreviations, and the method of describing syntax used in the present document are the
same as those defined in sections 2.2 and 2.3 of ISO/IEC 13818-1 [1].

16 EN 300 468 V1.3.1 (1998-02)
5.2.1 Network Information Table (NIT)
The NIT (see table 3) conveys information relating to the physical organization of the multiplexes/TSs carried via a
given network, and the characteristics of the network itself. The combination of original_network_id and
transport_stream_id allow each TS to be uniquely identified throughout the ETS application area. Networks are assigned
individual network_id values, which serve as unique identification codes for networks. The allocation of these codes
may be found in ETR 162 [6]. In the case that the NIT is transmitted on the network on which the TS was originated, the
network_id and the original_network_id shall take the same value.
Guidelines for the processing of SI at transitions between delivery media boundaries, e.g. from satellite to cable or
SMATV systems, can be found in ETR 211 [7].
IRDs may be able to store the NIT information in non-volatile memory in order to minimize the access time when
switching between channels ("channel hopping"). It is also possible to transmit a NIT for other networks in addition to
the actual network. Differentiation between the NIT for the actual network and the NIT for other networks is achieved
using different table_id values (see table 2).
The NIT shall be segmented into network_information_sections using the syntax of table 1. Any sections forming part of
an NIT shall be transmitted in TS packets with a PID value of 0x0010. Any sections of the NIT which describe the
actual network (that is, the network of which the TS containing the NIT is a part) shall have the table_id value 0x40 with
the network_id field taking the value assigned to the actual network in ETR 162 [6]. Any sections of an NIT which refer
to a network other than the actual network shall take a table_id value of 0x41 and the network_id shall take the value
allocated to the other network in ETR 162 [6].
Table 3: Network information section
Syntax No. of Identifier
bits
network_information_section(){
table_id 8  uimsbf
section_syntax_indicator 1  bslbf
reserved_future_use 1  bslbf
reserved 2  bslbf
section_length 12  uimsbf
network_id 16  uimsbf
reserved 2  bslbf
version_number 5  uimsbf
current_next_indicator 1  bslbf
section_number 8  uimsbf
last_section_number 8  uimsbf
reserved_future_use 4  bslbf
network_descriptors_length 12  uimsbf
for(i=0;i descriptor()
}
reserved_future_use 4  bslbf
transport_stream_loop_length 12  uimsbf
for(i=0;i transport_stream_id 16  uimsbf
original_network_id 16  uimsbf
reserved_future_use 4  bslbf
transport_descriptors_length 12  uimsbf
for(j=0;j descriptor()
}
}
CRC_32 32  rpchof
}
17 EN 300 468 V1.3.1 (1998-02)
Semantics for the network information section:
table_id: See table 2.
section_syntax_indicator: The section_syntax_indicator is a 1-bit field which shall be set to "1".
section_length: This is a 12-bit field, the first two bits of which shall be "00". It specifies the number of bytes of the
section, starting immediately following the section_length field and including the CRC. The section_length shall not
exceed 1 021 so that the entire section has a maximum length of 1 024 bytes.
network_id: This is a 16-bit field which serves as a label to identify the delivery system, about which the NIT informs,
from any other delivery system. Allocations of the value of this field are found in ETR 162 [6].
version_number: This 5-bit field is the version number of the sub_table. The version_number shall be incremented by
1 when a change in the information carried within the sub_table occurs. When it reaches value 31, it wraps around to 0.
When the current_next_indicator is set to "1", then the version_number shall be that of the currently applicable
sub_table defined by the table_id and network_id. When the current_next_indicator is set to "0", then the
version_number shall be that of the next applicable sub_table defined by the table_id and network_id.
current_next_indicator: This 1-bit indicator, when set to "1" indicates that the sub_table is the currently applicable
sub_table. When the bit is set to "0", it indicates that the sub_table sent is not yet applicable and shall be the next
sub_table to be valid.
section_number: This 8-bit field gives the number of the section. The section_number of the first section in the
sub_table shall be "0x00". The section_number shall be incremented by 1 with each additional section with the same
table_id and network_id.
last_section_number: This 8-bit field specifies the number of the last section (that is, the section with the highest
section_number) of the sub_table of which this section is part.
network_descriptors_length: This 12-bit field gives the total length in bytes of the following network descriptors.
transport_stream_loop_length: This is a 12-bit field specifying the total length in bytes of the TS loops that follow,
ending immediately before the first CRC-32 byte.
tran
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