ETSI TS 102 550 V1.3.1 (2008-01)

Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR) Systems; Outer Physical Layer of the Radio Interface

RTS/SES-00300

General Information

• Status: Published
• Publication Date: 08-Jan-2008
• Technical Committee: SES SDR - SES Satellite Digital Radio
• Current Stage: 12 - Completion
• Due Date: 01-Jan-2008
• Completion Date: 09-Jan-2008

Standards Content (Sample)

ETSI TS 102 550 V1.3.1 (2008-01)
Technical Specification


Satellite Earth Stations and Systems (SES);
Satellite Digital Radio (SDR) Systems;
Outer Physical Layer of the Radio Interface

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2 ETSI TS 102 550 V1.3.1 (2008-01)



Reference
RTS/SES-00300
Keywords
digital, layer 1, radio, satellite
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3 ETSI TS 102 550 V1.3.1 (2008-01)
Contents
Intellectual Property Rights.5
Foreword.5
1 Scope.6
2 References.6
2.1 Informative references.6
3 Symbols and abbreviations.7
3.1 Symbols.7
3.2 Abbreviations.7
4 Outer physical layer.7
4.0 Number format definitions.7
4.0.1 Number format and transmission order .7
4.0.2 SI-Prefix Notation.8
4.0.3 Default Settings .8
4.1 Overview.8
4.2 Interfacing to Service Layer (SL).12
4.3 S-TS to OPL adaptation layer: S-TS encapsulation .12
4.3.1 PF infoword format for S-TS stream type 0 (dummy packet) .13
4.3.2 PF infoword format for S-TS stream type 1 (transparent) .14
4.3.3 PF infoword format for S-TS stream type 2 (MPEG-TS).14
4.3.4 PF infoword format for S-TS stream type 3 (IP stream).15
4.4 PL FEC: turbo code.17
4.4.1 Interface to OPL encapsulation.17
4.4.2 Turbo encoder.17
4.4.3 Turbo code termination.21
4.4.4 Turbo Interleavers.23
4.4.5 Output of turbo encoder.24
4.4.6 FEC Parameter signalling .24
4.4.7 Diversity combining.25
4.4.8 FEC Parameters for the signalling pipe .25
4.5 Mixer.25
4.6 Segmenter and Slot demultiplexer.26
4.7 Disperser.27
4.8 Collector.28
4.9 C-TS multiplexer.29
4.10 Configuration of the OPL.30
4.10.1 Signalling pipe.30
4.10.1.1 Encoding and interleaving of signalling pipe.30
4.10.1.2 SOF Preamble.30
4.10.1.3 Format of the signalling pipe infoword.30
4.10.2 Partitioning of the C-TS multiplex .36
4.10.3 S-TS schedule and slot allocation.37
4.10.4 S-TS re-scheduling and slot re-allocation.38
4.10.5 Birth/death of S-TS.38
4.10.6 S-TS ID.38
4.10.7 Calculation of the disperser profile.39
4.10.8 Configuration of the tail pipe.40
4.10.9 Unused pipes.40
4.10.10 Announcing reconfigurations and reschedulings.40
4.10.11 Pipe reconfiguration.41
4.11 Void.45
4.12 Network aspects.45
Annex A: Void .47
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4 ETSI TS 102 550 V1.3.1 (2008-01)
Annex B (normative): Calculation of the CRC word .48
Annex C (informative): Bibliography.49
History .50

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5 ETSI TS 102 550 V1.3.1 (2008-01)
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://webapp.etsi.org/IPR/home.asp).
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 ETSI Technical Committee Satellite Earth Stations and
Systems (SES).
TC SES is producing standards and other deliverables for Satellite Digital Radio (SDR) systems. An SDR system
enables broadcast to fixed and mobile receivers through satellites and complementary terrestrial transmitters.
Functionalities, architecture and technologies of such systems are described in TR 102 525 [1].
Several existing and planned ETSI standards specify parts of the SDR system, with the aim of interoperable
implementations. The physical layer of the radio interface (air interface) is divided up into the outer physical layer, the
inner physical layer with a single carrier transmission, and the inner physical layer with multiple carriers transmission.
These parts can be used all together in SDR compliant equipment, or in conjunction with other existing and future
specifications.
The present document specifies the outer physical layer. The inner physical layer with single carrier transmission is
specified in TS 102 551-1 [2], and with multiple carriers transmission in TS 102 551-2 [3].
The present document supersedes the previous version of the document and is recommended for new implementations.
All changes from the previous version are backward compatible.
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6 ETSI TS 102 550 V1.3.1 (2008-01)
1 Scope
The present document concerns the radio interface of SDR broadcast receivers. It specifies the functionality of the outer
physical layer. It allows implementing this part of the system in an interoperable way.
2 References
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.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Informative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] ETSI TR 102 525: "Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR)
service; Functionalities, architecture and technologies".
[2] ETSI TS 102 551-1: "Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR)
Systems; Inner Physical Layer of the Radio Interface; Part 1: Single carrier transmission".
[3] ETSI TS 102 551-2: "Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR)
Systems; Inner Physical Layer of the Radio Interface; Part 2: Multiple carrier transmission".
[4] ISO/IEC 13818-1: "Information Technology - Generic Coding of moving pictures and associated
audio - Part 1: Systems".
[5] ISO/IEC 11172-1: "Information technology - Coding of moving pictures and associated audio for
digital storage media at up to about 1,5 Mbit/s - Part 1: Systems".
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7 ETSI TS 102 550 V1.3.1 (2008-01)
3 Symbols and abbreviations
3.1 Symbols
For the purposes of the present document, the following symbols apply:
R Code rate
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AWGN Additive White Gaussian Noise
BCH Bose, Ray-Chaudhuri, Hocquenghem code
CRC Cyclic Redundancy Checksum
C-TS Channel-Transport Stream
CU Capacity Unit
FEC Forward Error Correction
ID IDentifier
IP Internet Protocol
IPL Inner Physical Layer
IU Interleaving Unit
LSB Least Significant Bit
MPEG-TS MPEG Transport Stream
MSB Most Significant Bit
MTU Maximum Transfer Unit
OPL Outer Physical Layer
PF Physical layer FEC
PFIW Physical layer FEC Info Word
PL Physical Layer
QoS Quality of Service
RFU Reserved for Future Use
SL Service Layer
SOF Start Of Frame
S-TS Service-Transport Stream
VBR Variable Bit Rate
WER Word Error Rate
4 Outer physical layer
4.0 Number format definitions
4.0.1 Number format and transmission order
Unless otherwise stated, all bit/symbol streams and values are transmitted with the following convention:
• In a stream, bits/symbols with a lower index are transmitted temporally earlier than those with a higher index.
• A prefix of a block of bits/symbols is transmitted temporally first, whereas a suffix is transmitted temporally
last.
• Signed integer and signed fixed-point values are stored in two's complement format.
• If a value is represented by N bits, the Most Significant Bit (MSB), i.e. bit N-1, is transmitted temporally first
followed by bits N-2 down to bit 0, the Least Significant Bit (LSB). This order is referred to as Big Endian.
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8 ETSI TS 102 550 V1.3.1 (2008-01)
• For Bytes, the MSB, bit 7, is transmitted temporally first and the LSB, bit 0, last.
• Symbols of a BCH, Reed-Solomon or CRC-code are transmitted temporally in the following order: the symbol
with highest degree in polynomial representation comes first and the symbol with degree 0 comes last.
• The format of integer and fix-point values are specified in the following way: the first letter is U for unsigned
and S for signed values, the following value following that letter states the number of integer bits. In the case
of fixed-point values, this value is followed by a dot"." and another value, which specifies the number of
fractional bits. Examples: U8, S3.2.
4.0.2 SI-Prefix Notation
The present document uses the prefix notation as defined by the "Système International d'Unités", i.e. M (mega)
represents 1 000 000 units, k (kilo) represents 1 000 units and m (milli) represents 0,001 units.
4.0.3 Default Settings
If not stated otherwise, the following default settings are used:
- RFU bits have value 0.
4.1 Overview
Figure 1 displays the position and the interfaces of the Outer Physical Layer (in the following denoted by OPL) inside a
complete broadcast transmission chain. The OPL connects to the Service Layer, where the interface is Service
Transport Streams (S-TS) on the one side, and on the other side to the Inner Physical Layer (IPL - described in
TS 102 551), where the interfaces are Channel Transport Streams (C-TS).
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9 ETSI TS 102 550 V1.3.1 (2008-01)

Figure 1: Position and interfaces of the OPL inside the transmission chain
The following table gives an overview about the terminology used for the data streaming through the system.
Description Comments
SC Service component E.g. source encoded audio or video or other data

SC-TS Service component transport stream
ES Elementary Stream ES: Elementary Stream, a generic term for one of the
coded video, coded audio or other coded data
bitstreams, cf. MPEG-1 standard
ISO/IEC 11172-1 [5].
Program A program is a collection of program Inline with the definition used for MPEG standard
elements. Program elements may be ISO/IEC 13818-1 [4].
elementary streams (ES, SC-TS).
Service Set of programs and related auxiliary
information
S-TS Service transport stream Generalized term for transport stream. MPEG-TS is
one example for a service transport stream.
MPEG-TS Transport stream compliant to MPEG
standard ISO/IEC 13818-1 [4]
C-TS Channel transport stream Data stream (bit stream) representing the input to the
modulator = data stream including all redundancy
added by the FEC encoder - possibly with
time-interleaving - and carrying configuration
signalling information for the receiver.
The content of the C-TS is referred to as a C-TS
multiplex (a multiplex of encoded and interleaved
S-TS plus signalling information).
A bouquet of programs is carried by one or more
C-TS multiplexes.
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Description Comments
Channel RF resource The meaning “RF resource” is aligned with the
terminology used for DVB.

The functionality of the Outer Physical Layer is to provide Forward Error Correction and time interleaving for
resistance against a variety of transmission channel conditions. Different transport channels are used in the OPL to offer
the requested performance for different types of services. These transport channels are called pipes in the scope of the
present document. The OPL is configurable in terms of error protection, outage mitigation in case of signal losses,
end-to-end delay, zapping time, payload throughput and receiver complexity.
Multiple pipes can be used as described above. Each of them contains FEC, Mixer and Disperser. One special pipe
exists whose functionality is to transmit all relevant parameters to decode the other pipes. The so-called signalling pipe
is always transmitted at the lowest coderate which is 1/5. The modulation of the signalling pipe is equal to the
modulation of the data pipes.
The general block diagram of the OPL functionality is given in figure 2.
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11 ETSI TS 102 550 V1.3.1 (2008-01)

Figure 2: General overview of the OPL functionality
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12 ETSI TS 102 550 V1.3.1 (2008-01)
The processing, multiplexing and demultiplexing of the data in the OPL is displayed in figure 3. An S-TS scheduler
multiplexes together all S-TS contained in the pipe. The scheduler is controlled by an S-TS schedule, which determines
the number of words taken from one S-TS before the multiplexer selects the next S-TS of the pipe. After an
encapsulation, FEC encoding and mixing, the codewords (segmented into interleaver units) are demultiplexed
codeword-wise to the slots of the considered pipe, each of the slots possessing its individual disperser. After
demultiplexing a codeword to a slot, i.e. to the input of its disperser, the slot demultiplexer selects the next
slot/disperser. At the outputs of the dispersers, the dispersed codewords are multiplexed together again by the collector
to form one pipe. The slot demultiplexer and the collector always select synchronously the same slot/disperser.
IUs of one slot Dispersed IUs of
Packets of an one slot
S-TS
Slots of IUs
OPL Slots or IUs of
Disperser
S-TS i one pipe of one
Encapsulation
Mixed
PF infowords PF codewords C-TS frame
codewords
OPL
S-TS i + 1
Encapsulation
C-TS
PL FEC Mixer Segmenter Disperser
mux
... Collector
Slot
Demux
OPL S-TS
S-TS j
Encapsulation scheduler
...
Number of S-TS
Disperser
in this pipe:
Num_STS
Number of
Dispersers in this
pipe:
Pipe_Width_Slots

Figure 3: Definition of the different blocks involved in the OPL processing
4.2 Interfacing to Service Layer (SL)
The interface to the service layer is the so-called Service-Transport Stream (S-TS). For the OPL, each S-TS source is
the smallest granularity which can be processed independently.
The interface may work synchronously or asynchronously. In the case of asynchronous interface, the PL must be able to
accept at least the average data rate that is provided by the SL. Any data buffering shall be done inside the SL, such that
no data from the S-TS is lost at this interface. When the PL requests new data for transmission, the SL can either
provide the requested data to the PL or it can signal that no data is currently available. If no data is available for
transmission, the PL instead transmits dummy data that is discarded in the receiver.
Inside an S-TS, multiplexing and de-multiplexing of information shall be carried out by the service layer.
Each pipe provides a different set of transmission parameters (e.g. FEC code rate and disperser profile), and achieves a
different QoS in terms of protection against transmission errors and end-to-end delay. One pipe of the OPL may carry
several S-TS, all with the same QoS parameters.
If PL time slicing is used, each time slice is associated with one S-TS. The scheduling of the S-TS, i.e. their start
instants and lengths, inside a pipe can be adapted frequently (once per schedule/time slicing period). This opens the
possibility of handling Variable Bit Rate (VBR) transmission.
The maximum allowed payload throughput per S-TS is 3,2 Mbit/s (this corresponds to approximately 8 to 10 video
services inside one S-TS). This is the throughput that the processing chain inside the receiver (e.g. the turbo decoder)
must be able to handle at least.
4.3 S-TS to OPL adaptation layer: S-TS encapsulation
The OPL is prepared to transport different types of S-TS, and a mixture of different S-TS types may be transported
simultaneously over one C-TS multiplex.
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13 ETSI TS 102 550 V1.3.1 (2008-01)
The following parameters have to be determined for each S-TS (for parameters, refer to signalling pipe in
clause 4.10.1):
• S-TS ID: identifier for the transported S-TS, that is unique for each network operator (i.e. for each
Operator_ID); observe that one S-TS may be transported over multiple instances of the PL and still have a
single unique S-TS ID; this helps, for example, for diversity combining of one S-TS transmitted over satellite
and simultaneously over terrestrial repeaters. Several rules apply for the S-TS:
- S-TS ID 0 plays a special role: this is the Service Layer configuration S-TS (the SL can signal its own
configuration via this S-TS).
- An S-TS may be fed to several C-TS multiplexes. The S-TS IDs in all of these C-TS multiplexes are
identical.
- An S-TS may not be fed to several pipes inside the same C-TS multiplex.
- S-TS IDs must be unique over the complete network of one operator except for S-TS ID 0 which is
allowed on every C-TS multiplex.
- S-TS with an identical Operator_ID and S-TS ID can always be diversity combined (except for
S-TS ID 0).
- The length of an S-TS can be configured in a granularity of one PL infoword per C-TS frame.
• Pipe number that this S-TS is transported over.
Moreover, for the ensemble of S-TS contained inside a complete C-TS multiplex, the following parameters have to be
fixed (for parameters, refer also to signalling pipe in clause 4.10.1):
• Operator_ ID: unique identifier for the network operator.
• Partitioning of the C-TS multiplex into pipes and scheduling of the S-TS inside the pipes, i.e. what is the data
rate of one S-TS and when are the bursts of one S-TS transported.
Each S-TS is partitioned into packets to match the length of the PL FEC information word (PF infoword). The packet
size is individual for each type of S-TS. The OPL encapsulation inside the S-TS to OPL adaptation layer adapts the
length of the S-TS packets to the PF infoword length by appending a suffix to the S-TS packet. Table 1 defines the S-TS
packet length and the suffix length for different S-TS types.
Table 1: Defined S-TS type IDs
S-TS Type S-TS Type ID S-TS payload packet Suffix length Comment
Size in bytes in bits
Dummy packet 0 0 26 used for asynchronous sl/pl interface.
is discarded in receiver.
Transparent
1 1 532 26 sl has to decide what to do with this
data.
MPEG-TS 2 1 504 250 payload packet is 8 mpeg packets of
188 bytes each; additionally, a bch
code of 196 bits is applied.
IP stream 3 1 504 250 mtu of ip = 4 095 bytes with 2 bytes
additional header per packet.
RFU
4 to 7  reserved for future s-ts types.

The detailed format for the different types of S-TS is given in the following clauses. The Cyclic Redundancy Check
8 5 3 2
(CRC) polynomial, which appears in the following clauses, is x + x + x + x + x + 1 for all S-TS stream types. The
calculation of the CRC is described in annex B.
4.3.1 PF infoword format for S-TS stream type 0 (dummy packet)
The format of the dummy packet is given in table 2. The insertion of a dummy packet is performed if no data was
available at the instant of processing the actual packet in the OPL.
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14 ETSI TS 102 550 V1.3.1 (2008-01)
Table 2: PF infoword format for S-TS stream type 0 (dummy packet)
Start bit Wordsize
Parameter Description Format Comment
index (bits)
1 532×U8
0 Dummy data To be filled with zeros 12 256
(1 532 bytes)
helps to bit-align the payload to
12 256 RFU 4 bits reserved for future use 4 U4
byte boundaries.
12 260 STS_ID S-TS ID 8 U8 can be chosen arbitrarily.
12 268 STS_Stream_Type_ID S-TS stream type identifier 3 U3 fixed to 0 for dummy packets.
Version number of the OPL
12 271 Encap_Ver 3 U3 fixed to 0.
encapsulation format
CRC over the 18 relevant the light grey marked bits are
12 274 HeaderCRC 8 U8
bits of the header included in the header.
 Total length of PFIW
12 282

4.3.2 PF infoword format for S-TS stream type 1 (transparent)
The format of the transparent mode is given in table 3. It provides a transparent transmission of whatever payload. The
throughput capability of the transparent strea
...