1、ETSI EN 300 708 1.2.1 (2003-04) European Sfandard (Telecommunicafions series) Television systems; Data transmission within Teletext 2 ETSI EN 300 708 VI .2.1 (2003-04) The pre ent d Reference REN/JTC-TTEXT-DT-RI Keywords broadcasting, data, Teletext, TV ETSI 650 Route des Lucioles F-O6921 Sophia Ant
2、ipolis Cedex - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-prfecture de Grasse (06) No 7803/88 Important notice Individual copies of the present document can be downloaded from: http:lwmv.etsi .arq cumen
3、t may be made available in more than one electronic version or in print. In any ca e of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF
4、 version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at ha p:/pa rta I. etsi I a rgltbistat us
5、lstatus .as p If you find errors in the present document, send your comment to: Cori vriaht Notifica tion No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. O European Telecommunications Standards Ins
6、titute 2003. O European Broadcasting Union 2003. All rights reserved. DECTTM, PLUGTESTSTMand UMTSTMare Trade Marks of ETSI registered for the benefit of its Members. TIPHONTM and the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark
7、 of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI 3 ETSI EN 300 708 VI . 2.1 (2003-04) Contents Intellectual Property Rights 6 Foreword . 6 1 2 3 3.1 3.2 4 4.1 4.1.1 4.1.2 4.1.3 4.2 4.2.1 4.2.2 4.2.3 4.2.3.1 4.2.3.2 4.2.3.3 4.2.3.4 4.2.3.5 4.3 4.3.1 4.3
8、.1.1 4.3.1.2 4.3.1.3 4.3.1.4 4.3.2 4.3.2.1 4.3.2.2 4.3.2.3 4.3.2.4 4.3.2.5 4.3.2.6 4.3.2.7 4.3.3 4.3a 4.4 4.4.1 4.4.2 4.4.2.1 4.4.2.2 4.4.2.3 4.4.3 4.5 4.5.1 4.5.2 5 5.1 5.2 5.3 5.4 5.4.1 Scope 7 References 7 Definitions and abbreviations . 7 Definitions 7 Abbreviations . 8 Page Format - Clear 9 App
9、lication data blocks Structure Header . 10 Bundle Information structure 11 Format . 11 Structure Header . 11 Checksum 12 Number of Applications 12 Application Type . 12 Coding ofthe Teletext page . 12 Page header . 12 Page number 13 Subcode . 13 Control bits C4 to C14 14 Data Bytes . 14 Packets 1 to
10、 25 14 Valid packets . 14 Packet encoding 14 Block Separator . 15 Block Pointer . 15 Filler Byte . 15 Mapping 15 Byte coding . 16 Packet 28 . 16 Page Transmission 16 Coding of the packets . 17 Page header . 17 Packets 1 to 25 19 Transmission order 19 The Structure Header (SH) 20 Packing the data int
11、o the pages . 20 Packet 28 . 21 Providing a service according to Page Format - Clear . 21 General points on Page Format . Clear . 21 Encoding scheme for electronic data transmission . 22 Page Format . CA . 22 General points 22 Advantages . 22 Disadvantages . 22 Method of coding . 22 Teletext page da
12、ta . 23 ETSI 4 ETSI EN 300 708 VI . 2.1 (2003-04) 5.4.1.1 5.4.1.2 5.4.2 5.4.2.1 5.4.2.2 5.4.2.3 5.4.2.4 5.4.2.5 5.4.2.6 5.4.2.7 5.4.3 5.4.3.1 5.4.3.2 5.4.3.3 5.4.3.4 5.4.3.5 5.5 5.5.1 5.5.2 5.5.3 Scrambled Data Pages . 24 Pages containing Reformatted Data 24 The Page Key Packet 24 Service Mode bits
13、25 Service Identification 25 Continuity and Repeat Indicators 26 Packet Flags 26 Data Length . 26 Scrambling Method . 26 The Cyclic Redundancy Check (CRC) word 27 Terminal Equipment Addressing Pages 27 System Key Packet 27 Shared User Packet 28 Unique User Packets 28 29 29 29 Cipher feedback algorit
14、hm 30 One-way function 30 31 Security of Page Format - 6 Independent Data Lines (IDL) . 31 6.1 6.2 6.3 6.4 6.4.1 6.4.1.1 6.4.2 6.5 6.5.1 6.5.2 6.5.3 6.5.4 6.5.5 6.5.6 6.5.7 6.5.7.1 6.5.8 6.5.8.1 6.5.8.2 6.5.9 6.6 6.6.1 6.6.2 6.6.2.1 6.6.3 6.6.4 6.6.5 6.6.6 6.6.6.1 6.6.6.2 6.7 6.7.1 6.7.1.1 6.7.2 6.7
15、.2.1 6.7.2.2 6.7.2.3 6.7.3 6.7.3.1 6.7.3.2 General points 31 Advantages . 31 Disadvantages . 31 Methods of coding 32 Designation code 32 Transmission multiplexing 32 Data Channel addressing 32 IDL Format A . 33 Format Type (FT) . 33 Interpretation and Address Length (IAL) . 33 Service Packet Address
16、 (SPA) 34 Repeat Indicator (RI) 34 Continuity Indicator ( 34 34 35 35 35 35 Transmission sequence 36 Datavideo forma 36 36 Control Bytes (CB) . 36 Packet Continuity Indicator (CI) . 36 Masking indicator . 36 Packet type indicator . 37 User data group . 37 Cyclic Redundancy Check (CRC) word . 37 Chec
17、k word generation . 37 Check result . 37 Low bit-rate audio 37 Method of coding 38 Decoder action 38 Programme-related audio service . 38 Service Byte (SB) 38 Control Byte (CB) . 38 Audio data . 39 Programme independent audio service . 39 Control Byte (CB) . 39 Check word generation 35 . Service Byt
18、e (SB) 39 ETSI 5 ETSI EN 300 708 VI . 2.1 (2003-04) 6.7.3.3 6.8 6.8.1 6.8.1.1 6.8.1.2 6.8.1.3 6.8.1.4 6.8.1.5 6.8.2 6.8.2.1 6.8.2.2 6.8.2.3 6.8.2.4 6.8.2.5 6.8.2.6 6.8.3 Audio data . 39 IDL Format B . 39 Packet structure . 39 Format Type 40 Application Identifier 40 Continuity Index . 40 User Data 4
19、0 FEC . 40 Forward Error Correcting algorithm . 41 Introduction . 41 Encoding . 41 Calculating FEC suffix bytes 41 Decoding 42 Detecting and correcting single byte errors 42 Effective data rate 43 Correcting data blocks 43 7 IDL . CA (type A) 43 7.1 7.2 7.3 7.4 7.4.1 7.4.2 7.4.3 7.4.3.1 7.4.3.2 7.4.
20、3.3 7.4.3.4 7.4.3.5 7.4.3.6 7.4.3.7 7.4.3.8 General points 43 Advantages . 43 Disadvantages . 44 Methods of coding 44 Block Separator 44 Block Formats . 44 Block Format A 44 Block Types 44 Primary Block Key Messages . 45 Secondary Block Messages and Scrambled User Data . 45 System-Key Message Block
21、45 Shared-User Message Block . 45 Unique User Message Block . 46 Service Address Message Block . Independent Data Service . 46 Service Address Message Block . Link to Page Format . CA 46 Annex A (informative): Additional information for Page Format . Clear 47 A . 1 Use of Block Pointer. Block Separa
22、tor and Block Length information . 47 History 48 ETSI 6 ETSI EN 300 708 VI .2.1 (2003-04) 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
23、 ETSI members and non-members, and can be found in ETSI SR O00 3 14: “Intellectual Property Rights (7PRs); Essential, orpotentially Essential, IPRs notlJied to ETSI in respect ofETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (5). Al
24、l published ETSI deliverables shall include information which directs the reader to the above source of information. Foreword This European Standard (Telecommunications series) has been produced by Joint Technical Committee (JTC) Broadcast of the European Broadcasting Union (EBU), Comit Europen de N
25、ormalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). 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 tr
26、ipartite 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 techn
27、ical, 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-I218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21 11 Fax: +41 22 717 24 81 Nationa
28、l transposition dates Date of adoption of this EN: Date of latest announcement of this EN (doa): Date of latest publication of new National Standard or endorsement of this EN (dop/e): Date of withdrawal of any conflicting National Standard (dow): 11 April 2003 3 1 July 2003 3 1 January 2004 3 1 Janu
29、ary 2004 ETSI 7 ETSI EN 300 708 VI .2.1 (2003-04) 1 Scope The present document describes the various ways in which Teletext may be used to carry non-Teletext services. It should be used in conjunction with EN 300 706 i. An example is fully described in EN 300 707 2. The present document includes add
30、itional practical information on implementing a data service of this type. Hooks into existing Teletext services may be provided from within the application which is carried as a non-Teletext service. A data broadcast application may be pointed to from the Magazine Inventory Page (MIP) or it may be
31、allocated a specific page number. A Code of Practice (COP) shall ensure that services destined for the consumer may be found quickly by “low-end“ Teletext decoders but this is outside the scope of the present document. There are two methods available for carrying data services. The first method carr
32、ies the data within Teletext pages. The data in these pages is not suitable for direct display by a Teletext decoder and shall normally be allocated a special page number andor have the display inhibited. The second method carries the data within Independent Data Lines (IDL) and these are independen
33、t of the page service. With both Page and IDL formats there exist versions which offer Conditional Access (CA). There are other specific IDL data services which have been defiied but it is beyond the scope of the present document to cover all of these. 2 Re fe re nces The following documents contain
34、 provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date of publication andor edition number or version number) or non-specific. For a specific reference, subsequent revisions do not apply. For a non-specific
35、 reference, the latest version applies. Referenced documents which are not found to be publicly available in the expected location might be found at htlu:/docbox.etsi.or:eerence. il 21 ETSI EN 300 706: “Enhanced Teletext specification“. ETSI EN 300 707: “Electronic Programme Guide (EPG); Protocol fo
36、r a TV Guide using electronic data transmission“. 31 ETSI EN 300 23 1: “Television systems; Specification of the domestic video Programme Delivery Control system (PDC)“. ETSI TR 101 23 1 : “Television systems; Register of Country and Network Identification (CNI) and of Video Programming System (VPS)
37、 codes“. 41 3 3.1 Definitions and abbreviations De fi nit ions For the purposes of the present document, the following terms and defiiitions apply: 20 ms rule: insertion of a one field period delay (20 ms) between the transmission of the Teletext page header and the next packet for that page NOTE: T
38、he delay provides sufficient time for all existing decoders to implement a memory clear. ETSI 8 ETSI EN 300 708 VI .2.1 (2003-04) application data: raw data from the service provider prior to encoding in the format of the chosen transmission method bit numbering within bytes: in common with earlier
39、and existing Teletext specifications, the bits of a Teletext data byte are numbered 1 to 8 (LSB to MSB) data stream: sequence of bytes carried in a uniquely addressable data service encryption: process whereby a sequence of data is made secret NOTE: See clause 5.5 for further information. Hamming 8/
40、4: coding scheme which adds four protection bits to four message bits such that a receiver can correct a single bit error and detect a double bit error in the resulting 8-bit byte NOTE: Defined in full in EN 300 706 i. network operator: organization responsible for the compilation of the Teletext se
41、rvice for insertion into the available Vertical Blanking Interval (VBI) lines scrambling: process whereby a sequence of data is made unintelligible NOTE: See clause 5.5 for further information. service provider: organization responsible for the creation and supply of the data service application tra
42、nsmitted bit order: unless otherwise stated, the bits of a Teletext byte are transmitted least significant bit first 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: AUDETEL BL BP BS BT CA CI COP EPG FB IDL LSB MIP MSB RI SH VBI Audio DEscription of TELe
43、vision Block Length Block Pointer Block Separator Block Type Conditional Access Continuity Index Code of Practice Electronic Programme Guide Filler Bytes Independent Data Lines Least Significant Bit Magazine Inventory Page Most Significant Bit Repeat Indic ator Structure Header Vertical Blanking Int
44、erval ETSI 9 ETSI EN 300 708 VI .2.1 (2003-04) 4 Page Format - Clear 4.1 I n trod u ction 4.1.1 General points The application data is broadcast within uniquely addressable Teletext pages. Unlike the Page Format - CA method described in clause 5, any conditional access requirements must be included
45、in the data prior to encoding. It is possible to carry several independent applications within a page identified by a 3-digit page number. Up to 15 separate data streams can be accommodated within one such page, individual streams being uniquely addressable via part of the subcode component of the p
46、age header. Each data stream can carry multiple applications. Within each stream, blocks of application data are preceded by service identifier and length information. Pointers placed at the start of each packet indicate the location of block boundaries within the page. Data streams can be broadcast
47、 with or without adherence to the 20 ms rule. It is possible to provide a total service, which is constructed from more than one data stream, requiring the receiver to handle more than one data page. An example is an electronic programme guide service as defined in EN 300 707 2. One stream, carrying
48、 “now and next“ type information, is intended for reception by all receivers and is transmitted obeying the 20 ms rule. A second stream, providing details on future programmes, is aimed at more sophisticated receivers which do not require the 20 ms delay. The two streams can be interleaved implying
49、a suitable receiver may have to acquire and process two or more separate data pages simultaneously. 4.1.2 Advantages This method is appropriate for reception by all existing Teletext decoders. A default coding scheme is defiied in order that services may be offered using standard Teletext systems. To allow for future applications, the default method can be overridden by including an additional packet 28 per page to defiie the coding scheme in use. The network operator requires no knowledge of the application data he is transporting apart from knowing where each blo
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