1、-1 ERNATI ION UNION ,HANDBOOK ON THE TECHNICAL SPECIFICATIONS ITU-R TELE O ITU 1999 All rights reserved. No part of this publication may be reproduced or utilised in any form or by any means, electronic or mechanical, including photocopying and microfilm, without written permission from the ITU. - I
2、ZI 4855212 05Y2662 368 INTERNATIONAL TELECOMMUNICATION UNION HANDBOOK ON THE TECHNICAL SPECIFICATIONS OF ITU=R TELETEXT SYSTEMS I999 Radiocommunication Bureau ACKNOWLEDGEMENTS As the Special Rapporteur of the Handbook on the Technical Specification of ITU-R Teletext Systems“ I wish to acknowledge th
3、e contributions of the following people which made possible the completion of the Handbook: For System A: Mr. Jean Michel SANNER, Project Engineer, Data Broadcasting Service, TI- Diffusion de France (France), Ms. F. Elvan BORATAV, Engineer, Turkish Radio- TV Corporation (Turkey) and Mr. Philippe MEI
4、LLAN, Chief, Data Broadcasting Service, TlDiffusion de France (France) For System B: Ms. Meltem ERGN, Chief Engineer, Turkish Radio-Television Corporation (Turkey), Mr. Roger MILES, Senior Engineer and Mr. Edgar J. WILSON, Senior Engineer, Technical Department, European Broadcasting Union For System
5、 C: Mr. Robert FITZGERALD, Manager, NORPAK Corporation, Mr. Bernard CARON, Research Engineer, Communications Research Center and Mr. Bruce GRACIE, International Telecommunications Division, Industry Canada (Canada) For System D: Mr. Tadashi ISOBE, Senior Research Engineer, NHK - Japan Broadcasting C
6、orporation (Japan) I also acknowledge Ms. Meltem ERGUNS support extended to me throughout the drafting of the Handbook. F. Elvan BORATAV Special Rapporteur I .I 4855212 OCid2bbY 130 HANDBOOK ON THE TECHNICAL SPECIFICATION OF (Note of the Special Rapporteur) ITU-R TELETEXT SYSTEMS I. Introduction The
7、 work carried out for the preparation of the Handbook on the Technical Specification of ITU-R Teletext Systems (concerning conventional television systems) has been finalised and the specification is enclosed herewith. The task accomplished conforms to the requirements given below: i) to produce, as
8、 a first priority, a Booklet in English where the four ITU-R teletext systems will be specified regarding the ISO/OSI 7-layered reference model (IS0 7498: “Basic Reference Model for Open Systems Interconnection“) in accordance with the presentation of Recommendation ITU-R BT.653 (“ Teletext Systems“
9、); i) to base this version on accurate text provided by the appropriate administrations, in a form suitable for direct copying by the ITU-R. Accordingly, the Handbook is composed of four parts and each part gives the technical specifi- cation of one of the four ITU-R Teletext Systems, namely, A, B,
10、C and D, in the ISO/OSI 7-layered reference model. This Handbook is the product of a collaborative work. The people who took part in the different stages of the work are acknowledged at the beginning of this Handbook. 2. References The material used in the preparation of the Handbook are as follows:
11、 I11 I21 I41 131 151 61 71 Pl 91 ITU-R Provisional Descriptive Booklet: “Specification of Teletext Systems“ (1 989); Recommendation ITU-R BT.653: “Teletext Systems; ABU Technical Monograph: “Reference Manual on Teletext Systems“ (1 992); The document titled “World System Teletext and Data Broadcasti
12、ng System (CCIR Teletext System i3) - Technical Specification“ dated February 1990, prepared by Mr. Bernard J. Rogers; EBU Interim Technical Document SPB 492: “Teletext Specification (625-line television systems)“ (December 1992); The document “Chinese Character System Teletext Broadcasting Specific
13、ation - GW 74219-93“ on teletext system B application in China; The message, dated 29 December 1989, of Mr. Bruce Gracie (then Head of WARC/CCI Affairs, International Relations Branch, Department of Communications, Government of Canada) addressed to Mr. Richard C. Kirby (then Director of CCIR, ITU)
14、which states the official comments of Government of Canada on ITU-R Provisional Descriptive Booklet (specifically concerning the Part 3 on teletext system C); The message, dated 25 December 1989, of Mr. Seikichi Sakakibara (then Director of Engineering Division, Broadcasting Bureau, MPT-Ministry of
15、Posts and Telecommuni- cations of Japan) addressed t o Mr. Richard C. Kirby (then Director of CCIR, ITU), which states the official comments of MPT-Japan on ITU-R Provisional Descriptive Booklet (specificalty concerning the Part 4 on teletext system D); The Layer 7 of teletext system D specification
16、 (which was originally non-existent in the ITU-R Provisional Descriptive Booklet) communicated to the Special Rapporteur on 7 April 1995 by Mr. Tadashi Isobe as a document titled “Teletext Handbook Manuscript System D, Layer 7 I. II I 4855232 0542bb5 077 111 3. Points to be Noted - In the preparatio
17、n of the Handbook all the information available in the references listed above has been included in the specifications, except system B. In system 6, the following three sections of “World System Teletext and Data Broadcasting System (CCIR Teletext System B) - Technical Specification“ by Bernard J.
18、Rogers (Refer- ence 4 above) have been excluded. The section numbers given in parentheses refer to the sections of this reference: a) Musical Sound in the Teletext Service (Section 23) b) Transmission Coding - MACPacket Systems (Section 24) c) Transmission Coding - NICAM 728 System (Section 26) In I
19、TU-R teletext system B, the information concerning 525-line television systems is based mainly on “World System Teletext and Data Broadcasting System (CCIR Teletext System B) - Technical Specification“ by Bernard J. Rogers (Reference 4 above). In this document there exist some missing figures which
20、could not be acquired from other sources. The decision on this point has been taken as to leave the missing figures out of the Handbook and delete all related information and references given to them in the specification. Those existing figures which do not have their complementary parts have also b
21、een treated the same way. The figures that have not been included in this Handbook are listed below with the basis of exclusion explained in the last column (The figure numbers correspond to the figures numbers of Reference 4 above): Figure Name - Loa Primary Character Set - Devanagari Supplementary
22、 Character Set - Tamil Primary Character Set - Tamil Supplementary Character Set - Assamese and Bengali Supplementary - Gujerati Supplementary Character Set - Punjabi Supplementary Character Set - Telegu Supplementary Character Set - Malayalam Supplementary Character Set - Sinhalese Supplementary Ch
23、aracter Set - Japanese 2-Byte Character Set including - Hangul 2-Byte Code Table - Line Drawing Character Set - Oriya Primary Character Set - Oriya Supplementary Character Set - VPT Functions - Format of Magazine Inventory Page for Character Set the Hiragana and Katakana Sets 525-line Systems Figure
24、 No. 33 35 37 38 43 45 47 49 51 53 54,58,59 56 60 67 68 75 77 status Non-existent Non-existent Non-existent Missing complementary figure Non-existent Non-existent Non-existent Non-existent Non-existent Non-existent Non-existent figure/missing complementary figure Missing parts Non-existent Non-exist
25、ent Missing complementary figure Non-existent Non-existent III _ e 4855212 Ci542bbb TO3 Io HANDBOOK ON THE TECHNICAL SPECIFICATION OF ITU-R TELETEXT SYSTEMS TABLE OF CONTENTS Page TECHNICAL SPECIFICATION OF ITU-R TELETEXT SYSTEM A Layer 1 : Physical . 1 Layer 2: Link . 3 Layer 3: Network . 4 Layer 4
26、: Transport . 6 Layer 5: Session 7 Annex 1 Level 1 encoding conventions in broadcasting . 25 Annex 2 Repertoire of signs 28 Annex 3 Operating conditions . 32 Layer 6: Presentation . 37 Annex 1 Restrictions on the use of the reference language for services intended for terminals with 16 bits per char
27、acter position . 48 Annex 2 Visual description of typographic type videographic messages 60 Layer 7: Application . 65 TECHNICAL SPECIFICATION OF ITU-R TELETEXT SYSTEM B Introduction 101 1 Layer 1 : Physical . 102 2 Layer 2: Link . 103 3 4 5 6 7 Appendix 1 Appendix 2 Layer 3: Network . 104 Layer 4: T
28、ransport . 105 Layer 5: Session 106 Layer 6: Presentation . 124 Layer 7: Application 147 Recommended code of practice for use of page and sub-code addresses 162 Page header packet control bits C4 (erase page) and C8 (update indicator) 163 Appendix 3 Decoder memory . 164 Appendix 4 Appendix 5 Appendi
29、x 6 Code of practice for optional user friendly page access 165 Recommended order of transmission for packets with Y = 26, Y = 27 and Y = 28 . 175 Data services (datavideo format) . 176 IV 4055232 054ZbL7 94T Page TECHNICAL SPECIFICATION OF ITU-R TELETEXT SYSTEM C Introduction 255 1 Layer 1: Physica
30、l . 257 2 Layer 2: Link . 258 3 Layer 3: Network 259 4 5 6 7 Layer 4: Transport 261 Layer 5: Session 262 Layer 6: Presentation 270 Layer 7: Application 284 8 Appendix A Glossary 323 Fundamental service specification . 299 TECHNICAL SPECIFICATION OF ITU-R TELETEXT SYSTEM D Introduction 345 1 Layer 1
31、“Physical”: Physical transmission 347 2 3 4 5 6 Layer 2 “Link”: Digital frame synchronization and error control . 349 Layer 3 “Network“: Multiplexing of data packet . 350 Layer 4 “Transport”: Data transmission control . 351 Layer 5 “Session”: Identification and control of programme data 353 Layer 6
32、“Presentation”: Presentation coding . 362 7 Annex A Annex B Layer 7 “Application” 394 Display formats and character font composition for Japanese language teletext in 525-line system application . 399 Character sets for Japanese language application . 401 V TECHNICAL SPECIFICATION OF ITU-R TELETEXT
33、SYSTEM A 1 LAYER I: PHYSICAL 1.1 TIME SLOT USABLE FOR DATA In the 625-line 50-field television system (ITU-R System L), all time intervals corresponding to the active duration of the television signal line can be used for transmitting a data signal. 1.2 DATA POSITIONING The time interval between the
34、 half-amplitude point of the line synchronization leading edge and the half-amplitude point of the first transition from the low to the high data signal state is, in transmission, 10.5 ps * 320 ns (see Figure 1) (Data positioning may be altered to suit particular transmission requirements.). Within
35、these tolerances, the position of the data signal may vary from one line to the next. Throughout the duration of the back porch of the signal, the television signal is maintained at the blanking level. Only the line identification sub-carrier can, if necessary, be superimposed upon it. The receiving
36、 equipment uses only the line sync signal for demodulating the data. The other sync signals attached to the television signal may be missing in certain channel utilization configurations. However, in the case of data transmission confined to field blanking when a picture signal is present, the recei
37、ving equipment can use the field sync signal to limit the search for data to the interval not occupied by the picture. 1.3 DATA AMPLITUDE The nominal amplitude A (see Figure 2) of the waveform constituting the data signal is defined in relation to the nominal amplitude S of the waveform constituting
38、 the line sync signal. Amplitude A is measured between the levels corresponding to binary states O (low level) and 1 (high level). These levels are defined after an unbroken sequence of O states or 1 states, respectively. The nominal value of the ratio NS is 713 (+O%, -10%) for positive modulation a
39、nd 14/9 (-O%, +6%) for negative modulation. Note 1: This value may be halved in certain particular planning exercises (not applicable to class A services in the DIDON ANTIOPE system in France - see Section 7.1.1 of Layer 7). Note 2: In France, since 1993, the nominal amplitude of the waveform has be
40、en changed to 66% * 6% of the difference between the black level and the peak white level, as in Teletext System B. The amplitude of the difference D between the low level of the data signal and the television signal line blanking level is called the pedestal amplitude. -1- - Ss Y85521r2 0542bb9 712
41、 W The nominal amplitude D is also defined in relation to the nominal amplitude S. The nominal value of the ratio D/S is O (13%). 1.4 BIT RATE The bit transmission frequency (bit rate) is 6.203125 MHz (10.005%). 1.5 DATA SHAPING The transmitted data signal is obtained from the signal in the logic st
42、ate by modulating the luminance signal and filtering the shaping. The nominal shaping is sine-squared. Parameters for data shaping may be altered to suit particular transmission requirements. 1.6 DATA CODING The logic states are non-return to zero level (NRUL) encoded. 1.7 DATA LINE INCLUDING CLOCK
43、RUN-IN See Figure 3. A television line used for transmitting the data signal is called a data line. The data line in the L standard carries a string of 320 bits (40 bytes) (the long-prefix configuration). The header bytes are transmitted first. The low order bits in a byte are transmitted first. Eac
44、h header consists of a “synchronization and procedure“ part and a “prefix“ part (see Figure 4). “Synchronization and Procedure“ Part: Each data line is self-synchronizable at both the bit and the byte levels. Each self- synchronizing operation is carried out by the first three header bytes which con
45、sist of: - a synchronization burst R, the Clock Run-in, is made up of the first 16 bits in the packet and consists of alternating 1s and Os. This burst is used by the receiver for synchronization at the bit level. - a framing code B (see Section 2.1 of Layer 2). “Prefix“ Part: The bytes which consti
46、tute the “prefix“ part immediately follow those which make up the “synchronization and procedure“ part of the header. Every byte in the prefix is Hamming encoded as described in Figure 7. It therefore consists of four information bits and four redundancy bits. The low order information bits are tran
47、smitted first. (See Layer 3 for more detailed information on “prefix“.) -2- Y855212 O542670 431+ E 2 LAYER 2: LINK 2.1 DIGITAL FRAME SYNCHRONIZATION (FRAMING CODE) This is the framing code B (Figure 4) which consists of a byte immediately following the clock run-in (the bit synchronization burst R).
48、 This serves as a reference for reconstituting the following bytes in the packet. It is chosen in such a way as to minimize the risk of false synchronization and to be detected correctly even if an error is present. For interpretation purposes, each packet contains a procedure code which is defined
49、by the choice of the framing code B. To be able to receive data transmitted in a channel in which several packet procedures are used simultaneously, a receiving equipment must detect its byte synchronization by simultaneously searching for all the framing codes which characterize the procedures used (see Layer 3 for “packet procedure“). This is an arrangement for ensuring compatible extensions. 2.2 LENGTH OF DATA UNIT The length of data unit is 38 bytes (see Figure 3) (the long-prefix configuration). 2.3 FORMAT INDICATOR Format Indicator (F in Figure 4) is byte 8
