1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58television with a low data rate return channel via satellite Modem layer specificationThe European
2、Standard EN 50478:2007 has the status of a British StandardICS 33.060.30; 33.170Functional receiver specification of satellite digital interactive BRITISH STANDARDBS EN 50478:2007BS EN 50478:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on
3、 30 March 2007 BSI 2007ISBN 978 0 580 50441 9Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by B
4、SI. It is the UK implementation of EN 50478:2007.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on EPL/100 can be obtained on request to its secretary.This publication does no
5、t purport to include all the necessary provisions of a EUROPEAN STANDARD EN 50478 NORME EUROPENNE EUROPISCHE NORM February 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Sec
6、retariat: 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 ICS 33.060.30; 33.170 English version Functional receiver specification of satellite digital interactive television
7、with a low data rate return channel via satellite - Modem layer specification Spcification pour le fonctionnement du rcepteur pour la tlvision interactive par satellite avec une voie de retour bas dbit par satellite - Spcification du modem de la couche Funktionale Empfngerspezifikation fr digitales
8、interaktives Satellitenfernsehen mit Rckkanal niedriger Datenrate ber Satellit - 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 Europe
9、an 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
10、 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,
11、 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. EN 50478:2007
12、2 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 fo
13、llowing 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 50478:200
14、7 Contents Introduction.7 1 Scope .9 2 Normative references .9 3 Definitions, symbols and abbreviations.9 3.1 Definitions9 3.2 Symbols.10 3.3 Abbreviations.11 3.4 Reference Model for Satellite Interactive Networks.13 3.4.1 Protocol Stack Model13 3.4.2 System Model.14 3.4.3 Reference System Architect
15、ure for SATMODE 15 4 Terminal forward link interface18 4.1 Broadcast Interface .18 4.1.1 Frequency.18 4.1.2 Modulation/Coding18 4.1.3 Symbol rate.18 4.1.4 Polarization.18 4.2 Forward Interaction Path .18 4.2.1 Forward Interactive Traffic Data18 4.2.2 Forward Link signalling .19 5 Terminal return lin
16、k interface 22 5.1 General22 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 Services25 5.1.6 Classes of service and priority25 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 Lin
17、k Coding and Modulation37 5.2.3 Frequency and time structuring 50 5.2.4 Power mask55 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 In
18、terface 58 5.3.1 Return Data Link Layer and Protocols Stack 58 5.3.2 Description of the MAC protocol .67 6 Security, authentication, encryption75 7 Software download .76 Annex A (normative) Description of tables syntax .77 Annex B (normative) Definition terminal processing delay Dproc_term95 Annex C
19、 (informative) Typical implementation examples96 Annex D (informative) SATMODE Project .112 Bibliography114 EN 50478:2007 4 Figures Figure 1 Layer structure for generic system reference model13 Figure 2 A generic system Reference Model for Interactive Systems .14 Figure 3 Overall system description
20、of SATMODE16 Figure 4 Interactive traffic data 17 Figure 5 Tables of PAT, PMT descriptors22 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
21、 parameters29 Figure 10 Frame start origin 30 Figure 11 Terminal Operation32 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
22、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
23、UW Sequence .49 Figure 26 Organization of time slots50 Figure 27 State chart for content lost packets .52 Figure 28 Power Mask.56 Figure 29 SATMODE return channel protocol stack59 Figure 30 SATMODE datalink layer.60 Figure 31 LLC header61 Figure 32 Segmentation and reassembly/adaptation to MAC packe
24、t format.63 Figure 33 MAC packet format64 Figure 34 IEEE format MAC address 64 Figure 35 SATMODE MAC protocol67 Figure 36 Sliding windows and priorities .68 Figure 37 Reset sequence initiated by the Terminal70 Figure 38 Terminal State Diagram.71 Figure 39 Reset sequence initiated by the HUB71 Figure
25、 40 State diagram for the reset sequence initiated by the HUB.72 Figure C.1 Scheme for mode 1101 Figure C.2 GMSK definition.105 Figure C.3 Phase pulse shape 106 Figure C.4 Overall Unique Word composition and length108 5 EN 50478:2007 Figure C.5 Organisation of time and frequency slots for four CGs 1
26、09 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 serv
27、ice descriptor.21 Table 5 SATMODE content descriptor 21 Table 6 Possible COS types25 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 map39 Table 12
28、Deserialising of data bits.42 Table 13 SIPO definition44 Table 14 PISO definition44 Table 15 + mod 4 definition .44 Table 16 x mod 4 definition44 Table 17 Definition of CPM ranges47 Table 18 Linear symbol mapping for binary CPM (M = 2) .47 Table 19 Gray symbol mapping for quaternary CPM (M = 4) 48 T
29、able 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 .
30、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 syntax84 Table A.7 cos_id types 86 Table A.8 SMT syntax .87 Table A.9 SATMODE_mac_address types89 Table A.10 message_type.89 Table
31、 A.11 login_response90 Table A.12 reset_level.90 Table A.13 Structure SMT table 90 Table A.14 DMT syntax .91 EN 50478:2007 6 Table A.15 SUT syntax93 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 m
32、uxes 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
33、code rate 1/2 102 Table C.12 Circular state look up table103 Table C.13 Interleaving function for PI1 103 Table C.14 Interleaver parameters PI1104 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 Impl
34、ementation example of a Carrier group organisation108 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
35、 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 network
36、s 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 intera
37、ctive 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 facili
38、tates 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 allocate
39、d 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 lay
40、er 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.
41、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 use
42、d. 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 p
43、ackets 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 segme
44、nts 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. EN 50478:2007 8 This flexibility allows SATMODE to be used in extreme scenarios
45、by adjusting the modem parameters: very power limited scenarios (its 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 wave
46、form 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)
47、, 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 d
48、uring 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 in
