SIST-TS TS 101 191 V1.3.1:2005

• Abstract:

  The document includes modifications to bring it into line with other DVB specifications destined for mobile networks. In addition, the changes required for operation in 6 MHz terrestrial channels are included.

• Status: Published
• Publication Date: 31-Oct-2005
• ICS: 33.170 - Television and radio broadcasting
• Technical Committee: RES - Radio equipment and systems
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Nov-2005
• Due Date: 01-Nov-2005
• Completion Date: 01-Nov-2005
• Ref Project: ETSI TS 101 191 V1.3.1 (2001-01) - Digital Video Broadcasting (DVB); DVB mega-frame for Single Frequency Network (SFN) synchronization

SIST-TS TS 101 191 V1.3.1:2005 is the Slovenian adoption of the DVB technical specification for DVB mega-frame for Single Frequency Network (SFN) synchronization, published by SIST. It specifies the mega-frame structure and the Mega-frame Initialization Packet (MIP) used to synchronize SFN transmitters and to carry optional control data for transmitter parameters. In practice, it is aimed at DVB-T network designers, transmitter operators, and equipment suppliers who need aligned output from multiple sites.

What does SIST-TS TS 101 191 V1.3.1:2005 specify?

SIST-TS TS 101 191 V1.3.1:2005 specifies a mega-frame format, including the MIP, for SFN synchronization and optional control of important SFN parameters. The scope also includes modifications aligned with other DVB specifications for mobile networks and the changes needed for operation in 6 MHz terrestrial channels.

The document is organized into a short set of clauses that move from basic terminology to the detailed packet structure and then to the optional control functions. It ends with three normative annexes that define CRC checking, the synchronization process, and modulator reconfiguration timing.

Clause or annex	What it covers
Clause 1	Scope
Clause 2	References
Clause 3	Definitions and abbreviations
Clause 4	General description and SFN system blocks
Clause 5	Mega-frame definition
Clause 6	MIP structure and functions
Annex A	CRC decoder model
Annex B	Functional description of SFN synchronization
Annex C	Reconfiguration of DVB-T modulator parameters by using the MIP

What are the key requirements of SIST-TS TS 101 191 V1.3.1:2005?

SIST-TS TS 101 191 V1.3.1:2005 defines how an SFN adapter builds a mega-frame, how the MIP is inserted, and how transmitters use the carried timing and control data. The practical aim is that all transmitters in the SFN emit identical transport streams at controlled, synchronized times.

Mega-frame structure and timing

Clause 5 defines the output of the SFN adapter as a valid MPEG-2 Transport Stream (TS) arranged in mega-frames. Each mega-frame contains exactly one MIP, and the pointer in that MIP identifies the start of the next mega-frame. The document also links the mega-frame start to the DVB-T super-frame start, so the timing relationship is fixed and not left to local interpretation.

The packet count per mega-frame depends on the DVB-T mode. In practice, this means the operator must match the SFN adapter settings to the emission mode and ensure the resulting stream remains compliant.

MIP format and mandatory fields

Clause 6 makes the MIP an MPEG-2 compliant TS packet with a fixed length of 188 bytes. The packet header uses PID 0x15, and the transport packet header fields are set for payload only and no scrambling. The MIP carries synchronization information such as the synchronization_id, the synchronization_time_stamp (STS), maximum_delay, tps_mip, and optional addressing data.

This matters because the receiving synchronization system depends on these fields to calculate when to transmit, how much delay to compensate, and which transmitter or cell to address.

Optional transmitter control functions

Clause 6.1 defines optional functions carried in the MIP:

• tx_time_offset_function - applies a deliberate time offset to transmitted mega-frames.
• tx_frequency_offset_function - applies a deliberate frequency offset to the RF carrier.
• tx_power_function - configures transmitter ERP.
• private_data_function - carries proprietary data.
• cell_id_function - sets the transmitter cell identifier.
• enable_function - triggers execution of earlier function commands.

In practice, these functions let the network operator adjust site timing, frequency, power, and identity through the same synchronization mechanism.

Reconfiguration timing and CRC checking

Annex C defines how tps_mip is used to reconfigure DVB-T modulator parameters without ambiguity. It describes the timing relationship between the MIP, the transported TPS data, and the application of the new modulator configuration. Annex A defines the CRC decoder model used to verify the MIP contents, which is important for detecting corrupted control packets before they affect synchronization.

What terms does SIST-TS TS 101 191 V1.3.1:2005 define?

• Single Frequency Network (SFN) - a broadcast network in which transmitters use the same frequency and must be tightly synchronized.
• Mega-frame - a group of TS packets used by the SFN adapter to organize synchronization timing.
• Mega-frame Initialization Packet (MIP) - the TS packet that carries synchronization data and optional transmitter control data.
• Synchronization Time Stamp (STS) - the time difference used to align the start of a mega-frame with the local time reference.
• DVB-T - the terrestrial Digital Video Broadcasting transmission system referenced by the document.
• Effective Radiated Power (ERP) - the transmitter power parameter that the MIP can configure.
• Transport Stream (TS) - the MPEG-2 stream format used as the transport basis for the mega-frame.

Who uses SIST-TS TS 101 191 V1.3.1:2005?

SIST-TS TS 101 191 V1.3.1:2005 is used by DVB-T network engineers, transmitter manufacturers, system integrators, and broadcast operators. It is relevant when designing SFN distribution networks, configuring modulator and transmitter timing, setting power and frequency offsets, and verifying that multiple sites emit a bit-identical TS. Quality and acceptance teams can also use it to check that the synchronization chain, CRC handling, and modulator reconfiguration follow the intended timing model.

Which standards are used with SIST-TS TS 101 191 V1.3.1:2005?

The document relies on three normative references:

• ISO/IEC 13818-1 - provides the MPEG-2 systems rules used for the transport packet header.
• ETSI EN 300 744 - defines DVB-T framing structure, channel coding, and modulation, including the frame and super-frame context used here.
• ETSI EN 300 468 - defines Service Information (SI) in DVB systems and supplies the cell definition referenced by this document.

What does the SIST-TS TS 101 191 V1.3.1:2005 document contain?

The document contains a system overview, the SFN block diagram, the mega-frame definition, the full MIP syntax, and the function tags used for optional transmitter control. It also includes the tables that map MIP fields to DVB-T parameters such as bandwidth and bitstream priority, plus the figure that shows how a MIP points to the next mega-frame.

Annex A provides the CRC decoder model and processing method. Annex B shows the timing relationship used in SFN synchronization. Annex C shows how tps_mip drives DVB-T modulator reconfiguration across mega-frames.

SLOVENSKI STANDARD
01-november-2005
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HQRIUHNYHQþQLKRPUHåLM6)1
Digital Video Broadcasting (DVB); DVB mega-frame for Single Frequency Network (SFN)
synchronization
Ta slovenski standard je istoveten z: TS 101 191 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.

Technical Specification
Digital Video Broadcasting (DVB);
DVB mega-frame for Single Frequency Network (SFN)
synchronization
European Broadcasting Union Union Européenne de Radio-Télévision
EBU·UER
2 ETSI TS 101 191 V1.3.1 (2001-01)
Reference
RTS/JTC-DVB-93
Keywords
Broadcasting, digital, video, DVB, TV
ETSI
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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 2001.
© European Broadcasting Union 2001.
All rights reserved.
ETSI
3 ETSI TS 101 191 V1.3.1 (2001-01)
Contents
Intellectual Property Rights .4
Foreword.4
1 Scope.5
2 References.5
3 Definition and abbreviations .5
3.1 Definitions . 5
3.2 Abbreviations. 5
4 General description.6
4.1 SFN system blocks . 7
5 Mega-frame definition .8
6 Mega-frame Initialization Packet (MIP) .9
6.1 Functions . 12
6.1.1 Transmitter time offset function . 12
6.1.2 Transmitter frequency offset function. 13
6.1.3 Transmitter power function . 13
6.1.4 Private data function . 13
6.1.5 Cell id function . 14
6.1.6 Enable function. 14
Annex A (normative): CRC decoder model.15
Annex B (normative): Functional description of SFN synchronization.16
Annex C (normative): Reconfiguration of DVB-T modulator parameters by using the MIP.17
History .18
ETSI
4 ETSI TS 101 191 V1.3.1 (2001-01)
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 ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://www.etsi.org/ipr).
Pursuant to the ETSI 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 ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by Joint Technical Committee (JTC) Broadcast of the European
Broadcasting Union (EBU), Comité Européen de Normalization ELECtrotechnique (CENELEC) and the European
Telecommunications Standards Institute (ETSI) (Broadcast).
NOTE: The EBU/ETSI JTC Broadcast was established in 1990 to co-ordinate the drafting of standards in the
specific field of broadcasting and related fields. Since 1995 the JTC Broadcast 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 the 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: [phone]
Fax: [phone]
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.
ETSI
5 ETSI TS 101 191 V1.3.1 (2001-01)
1 Scope
The present document specifies a mega-frame, including a mega-frame initialization packet (MIP), which may be used
for synchronization of the Single Frequency Networks (SFN) as well as for the optional control of other important
parameters in an SFN.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
[1] ISO/IEC 13818-1 (1994): "Information Technology - Generic coding of moving pictures and
associated audio information: Systems".
[2] ETSI EN 300 744: "Digital Video Broadcasting (DVB); Framing structure, channel coding and
modulation for digital terrestrial television".
[3] ETSI EN 300 468: "Digital Video Broadcasting (DVB); Specification for Service Information (SI)
in DVB systems".
3 Definition and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
cell: for the definition of a cell, see EN 300 468 [3], clause 3.1
frame: for the definition of a DVB-T frame, see EN 300 744 [2], clause 4.4
super-frame: for the definition of a DVB-T super-frame, see EN 300 744 [2], clause 4.4
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CRC Cyclic Redundancy Check
DVB Digital Video Broadcasting
DVB-T DVB-Terrestrial
ERP Effective Radiated Power
GPS Global Positioning System
HP High Priority
LP Low Priority
MFN Multi Frequency Network
MFP Mega-Frame Packet
MIP Mega-frame Initialization Packet
MPEG Moving Pictures Expert Group
PID Packet IDentifier
pps pulse per second
ETSI
6 ETSI TS 101 191 V1.3.1 (2001-01)
RF Radio Frequency
RS Reed-Solomon
SFN Single Frequency Network
SI Service Information
STS Synchronization Time Stamp
SYNC SYNChronization
TPH Transport Packet Header
TPS Transport Parameter Signalling
TS Transport Stream
TX/RX Transmitter/Receiver
4 General description
Figure 1 shows a block diagram of a complete SFN system.
MPEG-2
TS
RX
SYNC
DVB-T
MPEG-2
Network
system modulator
TS
adapter
10 MHz 1 pps
TX
MPEG-2 SFN
Distribution
Network GPS (note)
remultiplexer
adapter
Network
adapter
1 pps
10 MHz
RX
SYNC DVB-T
Network
system
GPS (note) modulator
adapter
10 MHz 1 pps
MPEG-2
TS
GPS (note)
NOTE: Could be any common available frequency reference.
Figure 1: DVB-T primary distribution with SFN adaptation
The SFN functionality is an extension to the DVB system. The blocks associated with SFN functionality are the grey
boxes in figure 1. These blocks could be implemented either as separate equipment or integrated in the multiplexer
and/or the DVB-T modulator.
ETSI
7 ETSI TS 101 191 V1.3.1 (2001-01)
4.1 SFN system blocks
MPEG-2 re-multiplexer
The MPEG-2 re-multiplexer re-multiplexes the programmes from various input channels, updates the SI and provides
an MPEG-2 TS which, after SFN adaptation, is transmitted via the DVB-T modulators in the SFN.
SFN adapter
The SFN adapter forms a mega-frame, consisting of n TS-packets corresponding to 8 DVB-T frames in the 8K mode or
32 frames in the 2K mode, and inserts a Mega-frame Initialization Packet (MIP) with a dedicated PID value. Inserted
anywhere within a mega-frame of index M, the MIP of that mega-frame, MIP , allows to uniquely identify the starting
M
point (i.e. the first packet) of the mega-frame M + 1. This is accomplished by using a pointer carried by the MIP itself
M
to indicate its position with regards to the start of the mega-frame M + 1.
The time difference between the latest pulse of the "one-pulse-per-second" reference, derived e.g. from GPS, that
precedes the start of the mega-frame M + 1 and the actual start (i.e. first bit of first packet) of this mega-frame M + 1 is
copied into the MIP . This parameter is called Synchronization Time Stamp (STS).
M
The time duration of a mega-frame is independent of the duration T constellation and code rate of the DVB-T signal.
,
u
Four different time durations exist, for each type of channel width, depending on the chosen guard interval proportion,
as shown table 1a:
Table 1a
Guard Interval Channel width
(ΔΔΔΔ/T ) 6 MHz 7 MHz 8MHz
u
1/4 0,812 373 0,696 320 0,609 280
1/8 0,731 136 0,626 688 0,548 352
1/16 0,690 517 0,591 872 0,517 888
1/32 0,670 208 0,574 464 0,502 656
The output of the SFN adapter shall be fully DVB/MPEG-2 TS compliant.
Transmitter/Receiver network adapter
The network adapters shall provide a transparent link for the MPEG-2 TS from the central to the local units. The
maximum network delay - caused by the different paths of the transmission network - the SYNC system can handle is
1 second.
SYNC system
The SYNC system will provide a propagation time compensation by comparing the inserted STS with the local time
reference and calculate the extra delay needed for SFN synchronization. See annex B for an example of the
synchronization process.
DVB-T modulator
The modulator should provide a fixed delay from the input to the air interface. The information inserted in the MIP
could be used for the direct control of the modulator modes or control of other transmitter parameters. The modulator
clocks at the different sites have to be synchronized. Since it is a requirement of an SFN that all transmitted signals be
identical, the MPEG-2 TS inputs to the various DVB-T modulators have to be bit identical.
Global Positioning System (GPS)
GPS is one among many possible time references but it is the only one available globally. GPS receivers are available
which provide both a 10 MHz frequency reference and a 1 pulse per second (1 pps) time reference. The 1 pps time
reference, used in SFN synchronization, is divided into 100 ns steps of the 10 MHz clock. The 10 MHz system clock is
assumed to be available at all nodes in the network.
The functional blocks "SFN adapter" and "SYNC system" are additional elements for SFN use, and not necessary in
MFN applications.
ETSI
8 ETSI TS 101 191 V1.3.1 (2001-01)
5 Mega-frame definition
The output of the SFN adapter shall be a valid MPEG-2 TS, where the individual packets are organized in groups,
which constitute a mega-frame. Each mega-frame consists of n packets, where n is an integer number which depends on
the number of RS-packets per super-frame in the DVB-T mode that will be used for DVB-T emission of the
MPEG-2 TS (see EN 300 744 [2], clause 4.7). In the 8K mode n is (the number of RS-packets per super-frame) × 2. In
the 2K mode n is (the number of RS-packets per super-frame) × 8.
Each mega-frame contains exactly one Mega-frame Initialization Packet (MIP). The actual position may vary in an
arbitrary way from mega-frame to mega-frame. The pointer value in the MIP is used to indicate the start of the
following mega-frame. In figure 2 the overall structure of the mega-frame, including the positioning of the MIP, is
given. The exact definition of the MIP format is given in clause 6.
Mega-frame
First Packet MIP Last Packet
MFP #0 MFP #1 …. MFP #p …. MFP #n-1 MFP #0
Pointer = (n-1) - p
The pointer indicates the location
of the first packet o
...