SIST EN 50478:2007

SLOVENSKI STANDARD
01-december-2007
Specifikacija funkcijskega sprejemnika satelitske digitalne interaktivne televizije s
povratnim kanalom z nizko podatkovno hitrostjo - Specifikacija modemske plasti
Functional receiver specification of satellite digital interactive television with a low data
rate return channel via satellite - Modem layer specification
Funktionale Empfängerspezifikation für digitales interaktives Satellitenfernsehen mit
Rückkanal niedriger Datenrate über Satellit - Festlegungen Modemschicht
Spécification pour le fonctionnement du récepteur pour la télévision interactive par
satellite avec une voie de retour a bas débit par satellite - Spécification du modem de la
couche
Ta slovenski standard je istoveten z: EN 50478:2007
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 50478
NORME EUROPÉENNE
February 2007
EUROPÄISCHE NORM
ICS 33.060.30; 33.170
English version
Functional receiver specification
of satellite digital interactive television
with a low data rate return channel via satellite -
Modem layer specification
Spécification pour le fonctionnement  Funktionale Empfängerspezifikation
du récepteur pour la télévision interactive für digitales interaktives
par satellite avec une voie de retour Satellitenfernsehen mit Rückkanal
à bas débit par satellite - niedriger Datenrate über Satellit -
Spécification du modem de la couche Festlegungen Modemschicht

This European Standard was approved by CENELEC on 2006-06-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in two official versions (English and German). A version in any other language
made by translation under the responsibility of a CENELEC member into its own language and notified to the
Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50478:2007 E
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 206, Consumer
equipment for entertainment and information and related sub-systems.
The text of the draft was submitted to the Unique Acceptance Procedure and was approved by
CENELEC as EN 50478 on 2006-06-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2007-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2009-06-01
__________
– 3 – EN 50478:2007
Contents
Introduction.7
1 Scope .9
2 Normative references .9
3 Definitions, symbols and abbreviations.9
3.1 Definitions.9
3.2 Symbols.10
3.3 Abbreviations.11
3.4 Reference Model for Satellite Interactive Networks.13
3.4.1 Protocol Stack Model.13
3.4.2 System Model.14
3.4.3 Reference System Architecture for SATMODE .15
4 Terminal forward link interface.18
4.1 Broadcast Interface .18
4.1.1 Frequency.18
4.1.2 Modulation/Coding.18
4.1.3 Symbol rate.18
4.1.4 Polarization.18
4.2 Forward Interaction Path .18
4.2.1 Forward Interactive Traffic Data.18
4.2.2 Forward Link signalling .19
5 Terminal return link interface .22
5.1 General.22
5.1.1 Access Method .22
5.1.2 Network.24
5.1.3 Beams.24
5.1.4 Carrier groups.24
5.1.5 Services.25
5.1.6 Classes of service and priority.25
5.1.7 Usage of return link physical resources .25
5.2 Physical Layer Interface .27
5.2.1 Return link synchronisation.27
5.2.2 Return Link Coding and Modulation.37
5.2.3 Frequency and time structuring .50
5.2.4 Power mask.55
5.2.5 Polarisation Return Link SATMODE terminal .56
5.2.6 Return Link Symbol rate .56
5.2.7 Power Spectral Control.56
5.2.8 Programmability, range and granularity of configurable parameters.57
5.3 Data Link Layer Interface .58
5.3.1 Return Data Link Layer and Protocols Stack .58
5.3.2 Description of the MAC protocol .67
6 Security, authentication, encryption.75
7 Software download .76
Annex A (normative) Description of tables syntax .77
Annex B (normative) Definition terminal processing delay D .95
proc_term
Annex C (informative) Typical implementation examples.96
Annex D (informative) SATMODE Project .112
Bibliography.114

Figures
Figure 1 – Layer structure for generic system reference model.13
Figure 2 – A generic system Reference Model for Interactive Systems .14
Figure 3 – Overall system description of SATMODE.16
Figure 4 – Interactive traffic data .17
Figure 5 – Tables of PAT, PMT descriptors.22
Figure 6 – Time and frequency Slotted Aloha.23
Figure 7 – Organisation of the network and spectral resources .26
Figure 8 – Description of delays between SATMODE terminal and HUB.28
Figure 9 – Forward link signalling parameters.29
Figure 10 – Frame start origin .30
Figure 11 – Terminal Operation.32
Figure 12 – Login Procedure .35
Figure 13 – TX pointing procedure .36
Figure 14 – Waveform generation .37
Figure 15 – Randomizer .38
Figure 16 – CRC calculation.38
Figure 17 – Flexible encoder architecture .39
Figure 18 – Equivalent scheme for mode 1 (PCCC).39
Figure 19 – Equivalent scheme for mode 2 (SCCC).40
Figure 20 – Equivalent scheme for mode 3 (CC).40
Figure 21 – Equivalent scheme for mode 4 (QRCC) .40
Figure 22 – Logical implementation of a programmable CC.41
Figure 23 – CC, ring quaternary mode .43
Figure 24 – Mapping of bits .45
Figure 25 – UW Sequence .49
Figure 26 – Organization of time slots.50
Figure 27 – State chart for content lost packets .52
Figure 28 – Power Mask.56
Figure 29 – SATMODE return channel protocol stack.59
Figure 30 – SATMODE datalink layer.60
Figure 31 – LLC header.61
Figure 32 – Segmentation and reassembly/adaptation to MAC packet format.63
Figure 33 – MAC packet format.64
Figure 34 – IEEE format MAC address .64
Figure 35 – SATMODE MAC protocol.67
Figure 36 – Sliding windows and priorities .68
Figure 37 – Reset sequence initiated by the Terminal.70
Figure 38 – Terminal State Diagram.71
Figure 39 – Reset sequence initiated by the HUB.71
Figure 40 – State diagram for the reset sequence initiated by the HUB.72
Figure C.1 – Scheme for mode 1.101
Figure C.2 – GMSK definition.105
Figure C.3 – Phase pulse shape .106
Figure C.4 – Overall Unique Word composition and length.108

– 5 – EN 50478:2007
Figure C.5 – Organisation of time and frequency slots for four CGs .109
Figure C.6 – Typical phase noise of the SATMODE terminal.110
Figure C.7 – Typical filter frequency response .110
Figure C.8 – SMATV Typical implementation.111

Tables
Table 1 – Repetition rates .19
Table 2 – Descriptor identification and location .20
Table 3 – (DVB-SI) service descriptor .20
Table 4 – SATMODE service descriptor.21
Table 5 – SATMODE content descriptor .21
Table 6 – Possible COS types.25
Table 7 – Definition of login and TX-pointing procedure states .33
Table 8 – Commands .33
Table 9 – Burst structure .36
Table 10 – Initial contents of the randomizer register.37
Table 11 – Flexible encoder modes map.39
Table 12 – Deserialising of data bits.42
Table 13 – SIPO definition.44
Table 14 – PISO definition.44
Table 15 – + mod 4 definition .44
Table 16 – x mod 4 definition.44
Table 17 – Definition of CPM ranges.47
Table 18 – Linear symbol mapping for binary CPM (M = 2) .47
Table 19 – Gray symbol mapping for quaternary CPM (M = 4) .48
Table 20 – Linear symbol mapping for quaternary CPM (M = 4).48
Table 21 – Normalisation sequence lookup table for GMSK (M = 2; k = 1; p = 2).50
Table 22 – Range and granularity of configurable parameters.58
Table 23 – End of message bit.64
Table 24 – Priority .65
Table 25 – Sequence number .65
Table A.1 – FCT Syntax .77
Table A.2 – modulation_type value .81
Table A.3 – encoder_type value.81
Table A.4 – CC1_trellis_termination type .82
Table A.5 – CC2_trellis_termination type .83
Table A.6 – FAT syntax.84
Table A.7 – cos_id types .86
Table A.8 – SMT syntax .87
Table A.9 – SATMODE_mac_address types.89
Table A.10 – message_type.89
Table A.11 – login_response.90
Table A.12 – reset_level.90
Table A.13 – Structure SMT table .90
Table A.14 – DMT syntax .91

Table A.15 – SUT syntax.93
Table C.1 – Typical SATMODE clear sky link budget.97
Table C.2 – Example of Ku/Ku link budget including provisions for rain fade.99
Table C.3 – Setting for muxes values.101
Table C.4 – PR polynomial.101
Table C.5 – PB polynomial .101
Table C.6 – PY polynomial .102
Table C.7 – PW polynomial .102
Table C.8 – CC1 puncturing periods .102
Table C.9 – CC1 puncturing patterns for code rate 1/2 .102
Table C.10 – CC2 puncturing periods .102
Table C.11 – CC2 puncturing patterns for code rate 1/2 .102
Table C.12 – Circular state look up table.103
Table C.13 – Interleaving function for PI1 .103
Table C.14 – Interleaver parameters PI1.104
Table C.15 – Interleaving function for PI2 .104
Table C.16 – Interleaving function for PI2 (randomized) .105
Table C.17 – q(k) codes for GMSK.107
Table C.18 – Implementation example of a Carrier group organisation.108

– 7 – EN 50478:2007
Introduction
This European Standard has been produced by CENELEC Committee TC 206 with the support of the
research and development activities carried out within the SATMODE Project. The SATMODE project
is part of the ARTES program of the European Space Agency (Contract No 16905/02/NL/US). More
information on SATMODE project is available in Annex D.
This document provides the specification containing the essential elements necessary to facilitate the
implementation of the interaction channel for interactive television networks using Geostationary
Satellites with fixed return channel satellite terminals via low data rate dedicated return link.
The system is called SATMODE and consists of many terminals installed at the user-customer
premises, one or several HUB stations, possibly co-located with the broadcaster or interactive service
provider uplink stations, and a satellite which is transparent for uplink and downlink signals. The main
application for SATMODE system is the implementation of suitable networks for interactive digital
television systems requiring a return channel of low data rate.
The document facilitates the use of SATMODE system for individual or collective installation (e.g.
SMATV) in a domestic environment applied to interactive digital television (iTV). It also supports the
connection of such terminals with in-house data networks. The document may be applied to all
frequency bands allocated to GEO satellite services. The solutions provided for interaction channel for
satellite interactive networks are a part of a wide set of alternatives to implement interactive services
associated to digital television systems following the DVB reference model for interactive services.
The modem layer specification included in this document (physical air interface layer and data link
layer components) describes the requirements needed to establish radio communication links
between the user earth stations (terminals) and the HUB earth station and between the HUB station
and the user terminals.
The Satmode System
The SATMODE design having led to the present specification was optimized for the iTV case.
The choice of constant envelope modulations was made to minimize the terminal cost. Thanks to this
property, very low cost ODUs operating at full saturation and in non-linear mode can be used.
The moderate bit rates of SATMODE allow to use very low power transmitters (typically 100 mW),
keeping the cost compatible with the mass-market.
The selected access scheme -slotted ALOHA- is efficient on iTV traffic and very easy to scale up to a
very high number of terminals only sending a few packets from time to time.
The SATMODE modem specification aims at fully specifying the behavior SATMODE modem function
used in a terminal.
To increase the applicability and the probability of commercial success of SATMODE, it was decided
to design SATMODE as a system usable with existing space segments and ready for future satellites
improved for point-to-point applications.
Considering this objective, it was considered as mandatory to have built-in flexibility in terminals
deployed today and ready for the future.

This flexibility allows SATMODE to be used in extreme scenarios by adjusting the modem parameters:
• very power limited scenarios (it’s the case for most VSAT Ku-band satellites);
• aggressive multi-beam space segment, targeting high spectral efficiency.
To reach that goal and nevertheless keep full interoperatibility of terminals, SATMODE uses a fully
specified waveform toolbox.
Each building block has a well-defined space of operation and can be used without limitation in this
space.
The building blocks of the SATMODE toolbox are
• symbol Rate: 2 kHz to 128 kHz,
• binary or quaternary CPM,
• programmable phase filter for CPM modulations (GMSK being a specific case),
• flexible Turbo or Turbo-like,
• programmable interleavers (3),
• programmable constituent codes with bypass possibilities (2),
• programmable Unique Word structure,
• tables extraction from a DVB TS (DVB-S or DVB-S2 broadcast).
All the parameters are sent by the HUB through tables, even allowing changes during operation:
• FCT: Sprectrum organisation in Carrier Groups;
• FAT: Spectrum Allocation to services.
Signalisation information sent to specific terminals is embedded in the SMT tables.
The terminal is fully defined: it must be able to play the complete waveform space.
The HUB usually only implements one scheme and send the tables to the terminals to instruct them to
play that scheme.
Modem Layer providers can thus compete on the modem performances, although using fully
interoperable terminals.
– 9 – EN 50478:2007
1 Scope
This standard applies for the interaction channel for interactive television networks using
Geostationary Satellites with fixed return channel satellite terminals via low data rate dedicated return
link. It specifies the essential elements for the implementation of the interaction channel.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ETSI EN 300 421, Digital Video Broadcasting (DVB); Framing structure, channel coding and
modulation for 11/12 GHz satellite services
ETSI EN 300 468, Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB
systems
ETSI EN 300 802, Digital Video Broadcasting (DVB); Network-independent protocols for DVB
interactive services
ETSI EN 301 192, Digital Video Broadcasting (DVB); DVB specification for data broadcasting
ETSI EN 301 459, Satellite Earth Stations and Systems (SES); Harmonized EN for Satellite Interactive
Terminals (SIT) and Satellite User Terminals (SUT) transmitting towards satellites in geostationary
orbit in the 29,5 GHz to 30,0 GHz frequency bands covering essential requirements under Article 32 of
the R&TTE Directive
ETSI EN 302 307, Digital Video Broadcasting (DVB); Second generation framing structure, channel
coding and modulation systems for Broadcasting, Interactive Services, News Gathering and other
broadband satellite applications
ETSI 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
EN ISO/IEC 13818-1, Information technology - Generic coding of moving pictures and associated
audio information; Part 1: Systems (ISO/IEC 13818-1)
ETSI TR 101 202, Digital Video Broadcasting (DVB); Implementation guidelines for Data Broadcasting
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of this document, the following terms and definitions apply:
3.1.1
forward link
satellite link carrying traffic towards the user terminals

3.1.2
return link
satellite link carrying traffic originating from the user terminals
3.1.3
interactive Digital Television
service based on the reception of digital television and interaction between the end user and the
broadcaster or interactive service provider through a return channel
3.1.4
network
collection of resources and services providing the SATMODE return channel, which is under the
control of a single organisation (the network operator)
3.1.5
beam
satellite network associated to a return link transponder with its associated bandwidth and
geographical coverage
3.1.6
carrier group
set of return link carriers sharing the same SATMODE physical link parameters (modulation type,
symbol rate, coding rate). Different carrier groups are provided in the SATMODE network in order to
cope with variable link conditions (fades)
3.1.7
class of service
set of return link carriers that is shared by return traffic requiring the same Quality of Service
3.2 Symbols
For the purpose of this document, the following symbols apply:
× multiplication;
≠ different than, unequal to;
≤ lower than or equal to;
≥ higher than or equal to;
∑ sum;
∏ interleaver.
– 11 – EN 50478:2007
3.3 Abbreviations
The following acronyms are used in this document:
ACRONYM MEANING
ACPR Adjacent Channel Power Ratio
ACK Acknowledgment
ARQ Automatic Repeat Request
B Byte
BAT Bouquet Association Table
bd baud
BER Bit Error Rate
BSS Broadcast Satellite Service
CC Convolutional Encoding
CENELEC European Committee for Electrotechnical Standardization
CG Carrier Group
COS Class of Service
CPM Continuous Phase Modulation
CRC Cyclic Redundancy Check
DL Downlink
DMT Download Messaging Table
DSM-CC Digital Storage Media - Command and Control
DTH Direct-To-Home
DVB Digital Video Broadcast
DVB-S Digital Video Broadcast by Satellite
EIRP Effective isotropic radiated power
EIT Event Information Table
EN European Norm
EOM End Of Message
ESA European Space Agency
ETS European Telecommunications Standard
ETSI European Telecommunications Standards Institute
FAT Frequency Allocation Table
FCT Frequency Composition Table
FSS Fixed Services by Satellite
GEO Geostationary Earth Orbit
GMSK Gaussian Minimum Shift Keying.
GT Guard Time
G/T Gain to Temperature
HUB SATMODE modem hub
IEC International Electrotechnical Commission
IF Intermediate Frequency
IIM Interactive Interface Module
iLNB Interactive LNB
IPR Intellectual Property Rights
iSTB Interactive set top box
ITT Invitation to Tender
ITU International Telecommunication Union
iTV Interactive Digital Television
LFSR Linear Feedback Shift Register
LLC Link Layer Control
LNB Low Noise Block Converter
LSB Less Significant Bit
MAC Medium Access Control
MF-TDMA Multiple Frequency-Time Division Multiple Access
MPEG Moving Pictures Expert Group
MSB Most Significant bit
MTU Maximum Transmissible Unit
NCR Network Clock Reference
NIM Network Interface Module
NIT Network Information Table
NIU Network Interface Unit
OSI Open Systems Interconnection
PAT Program Association Table
pc Per cent
PCCC Parallel Concatenated Convolutional Coding
PDU Protocol Data Unit
PID Packet IDentifier
PISO Parallel in serial out block
PMT Program Mapping Table
PRBS Pseudo Random Binary Sequence
PSI Program Specific Information
QPSK Quaternary Phase Shift Keying
QRCC Quaternary Ring Convolutional Coding
RTF Reply To Field
S-ALOHA Slotted-ALOHA
SAR Segmentation and Reassembly
SCCC Serial Concatenated Convolutional Coding
SDT Service Description Table
– 13 – EN 50478:2007
SI Service Information
SIT Satellite Interactive Terminal
SIPO Serial in parallel out block
SMATV Satellite Master Antenna Television
SMT Signalling message table
STB Set Top Box
SUT Satellite User Terminal
SUT Software Update Table
TDMA Time Division Multiplex Access
UL Uplink
UW Unique Word
3.4 Reference Model for Satellite Interactive Networks
3.4.1 Protocol Stack Model
For interactive services supporting broadcast to the end user with return channel, a simple
communications model consists of the following layers:
– physical layer: where all the physical (electrical) transmission parameters are defined;
– transport layer: defines all the relevant data structures and communication protocols like data
containers, etc.;
– application layer: is the interactive application software and runtime environment (e.g. home
shopping application, script interpreter, etc.).
A simplified model of the OSI layers was adopted to facilitate the production of specifications for these
layers. Figure 1 points out the lower layers of the simplified model and identifies some of the key
parameters for the lower two layers.

Figure 1 – Layer structure for generic system reference model

The present document addresses the satellite interactive network dependent aspects only, which are
addressed here as the modem layer specification made up by physical air interface layer and data link
layer.
3.4.2 System Model
Figure 2 shows the system model which is used by the DVB for the definition of interactive services.
The same generic model is valid for SATMODE system and it is thus adopted.
In the system model, two channels are established between the service provider and the user.
– Broadcast Channel: a unidirectional broadband Broadcast Channel including video, audio and
data is established from the broadcast and/or interactive service provider to the users. In the case
of the SATMODE system, it includes the Forward Interaction Path.
– Interaction Channel: a bi-directional Interaction Channel is established between the service
provider/user and the user for interaction purposes. It is formed by
• Return Interaction Path (Return Channel): from the user to the service provider. It is used to
make requests to the service provider/user, to answer questions or to transfer data,
• Forward Interaction Path: from the service provider to the user. It is used to provide
information from the service provider to the user(s) and any other required communication for
the interactive service provision. In the SATMODE system, the forward interaction path is
embedded into the Broadcast channel.
The SATMODE terminal is formed by the Network Interface Unit (consisting of the Broadcast Interface
Module and the Interactive Interface Module) and the Interactive media player. The SATMODE
modem layer provides interface for both Broadcast and Interaction Channels. The interface between
the SATMODE and the interaction network is via the Interactive Interface Module.

Figure 2 – A generic system Reference Model for Interactive Systems
The generic model represented in the Figure above does assume the Network Interface Unit or the
Interactive Interface Module is embedded into the Set-Top-Box. Externally implemented NIU/IIM can
also be used.
– 15 – EN 50478:2007
3.4.3 Reference System Architecture for SATMODE
SATMODE is an interactive satellite communication system, in which GEO satellites are used to carry
forward and return traffic between a central HUB station (or one of a relatively small number of remote
HUB stations) and a very large number of end-user terminals. Figure 3 shows the overall concept of
the SATMODE interactive service with a low data rate return channel over satellite.
The SATMODE terminal consists of
• antenna,
• interactive LNB, that is an integrated LNB and low power transmitter,
• interactive Set-Top-Box, consisting of
• STB function, equipped with any necessary software for interactive digital television (iTV)
applications, capable to receive the DVB-S signals (and optionally the DVB-S2 Broadcast
mode signals),
• SATMODE modem function, providing an interactive return channel over satellite. The
SATMODE modem can be external to the STB.
The SATMODE modem generates a modulated IF signal that is upconverted by the iLNB and sent
over the satellite to the HUB. Data are forwarded from the HUB to the Broadcaster and/or Interactive
service provider.
NOTE The SATMODE modem function is represented in the generic DVB reference model as the NIU (Network Interface Unit),
as Figure 2 shows.
The forward channel is provided by a DVB-S compatible broadcast link, usually based on the Ku band
frequency range 10,7 GHz to 12,75 GHz. It uses ETSI EN 300 421 (DVB-S). The system also allows
the optional use of the new DVB-S2 (ETSI EN 302 307) framing coding and modulation scheme for
the satellite broadcast DVB channels (DVB-S2 Broadcast mode). Forward link interactive data is
multiplexed on the interactive service providers’ streams in the regular DVB-S streams.
The SATMODE return channel can work in any typical fixed satellite service frequency band, although
the system has been conceived originally for the use of the Ka band frequency range 29,5 GHz to
30 GHz. The SATMODE system does not restrict implementations which can make use of other
broadcast bands in combination with other return channel FSS bands. The forward and return channel
may be on the same satellite station.
In addition there can be remote HUB stations providing a forward link capability and a capability to
receive return channels. Remote HUB stations can be used in cases where it is not convenient or
economic to use the main HUB station. Remote HUB stations will offer service providers the possibility
of receiving the return channel signals from SATMODE terminals directly as well as the possibility of
uplinking forward traffic data directly instead of via the main satellite operator’s HUB. Remote HUB
stations can either manage a range of system resources (bandwidth and power) allocated by the main
HUB independently or they can simply
...