1、Rep . ITU-R BT.2025 REPORT ITU-R BT.2025 1 PROGRESS ON DEVELOPMENT AND IMPLEMENTATION OF INTERACTIVITY IN BROADCASTING SYSTEMS AND SERVICES (Question ITU-R 256/11) (2000) CONTENTS Page 1 Interactivity in broadcasting services 1.1 Introduction . 1.2 What is interactive viewing? . 1.3 Functions requir
2、ed for interactive broadcasting services 1.4 Modes of interactivity in broadcasting 1.5 Actual interactivity in broadcasting services . 1.6 Conclusion 2 Europe . Progress of interactive digital television services in Europe (1997) . Overview of interactive digital television services in Europe (1998
3、) . 2.2.1 Differences in national environments Planned services by country 2.3.1 The Digital TV Market in Germany 2.3.1.1 DF1 - Das Digitale Fernsehen 2.3.1.2 Other Competitors 2.3.1.2.1 MMBG . 2.3.1.2.2 Premiere 2.3.1.2.3 Free-to-air offers . 2.3.1.3 Market assessment (early 1997) . 2.3.1.4 Change
4、of strategy 2.3.1.5 Technical Equipment 2.3.1.6 Services . The situation in the Netherlands 2.3.2.1 Return channel for interactive services . 2.3.2.2 Eurobox 2.3.2.3 Introduction of DVB and interactive services by Casema The situation in Spain 2.3.3.1 Terrestrial 2.3.3.2 Satellite . 2.3.3.3 CATV . 2
5、.3.3.4 Interactive Services . 2.3.3.5 The future . 2.3.3.5.1 Terrestrial 2.3.3.5.2 Satellite . 2.3.3.5.3 CATV . 2.3.3.5.4 Interactive Services . 2.3.3.5.5 TV-Anywhere . 2.3.4 DAVIC Equipment Developments and Technical Trials 2.4.1 The UHF Return Channel: Field Trials carried out by the ACTS INTERACT
6、 Project (August 1998) 2.4.1.1 Introduction 2.1 2.2 2.3 2.3.2 2.3.3 2.4 5 5 5 6 6 7 9 9 9 9 9 10 10 10 11 11 11 11 11 11 13 13 13 14 14 14 15 15 15 16 16 16 17 17 17 18 18 18 18 18 18 2 Rep . ITU-R BT.2025 2.4.1.2 2.4.1.2.1 2.4.1.2.2 2.4.1.3 2.4.1.3.1 2.4.1.4 2.4.1.4.1 2.4.1.4.1.1 2.4.1.4.1.2 2.4.1.
7、4.1.3 2.4.1.4.1.4 2.4.1.4.2 2.4.1.4.2.1 2.4.1.4.2.2 2.4.1.4.2.2.1 2.4.1.4.2.2.2 2.4.1.4.2.2.3 2.4.1.4.2.2.4 2.4.1.4.3 2.4.1.4.4 2.4.1.4.4.1 2.4.1.4.4.2 2.4.1.4.4.3 2.4.1.4.4.4 2.4.1.4.4.5 2.4.1.5 Laboratory tests on system tolerances Test overview . Summary of tests on the system tolerances Over-air
8、 trials in Rennes (France) Over-air trials in Metz (France) Static field tests at CCETT . Experimental Set-up Experimentation purpose Return link transmitter Receiver Trial results . Analysis Data correlation Frequency allocation . Received levels and BER performances . Frequency allocation . Max RF
9、 Power (outdoor conditions) Max RF Power (indoor conditions) Conclusions from the trials in Metz Annexes to the Metz trial Receiver performance . Spectrum plots Test points location . Map showing locations of test points . Service Range . General Conclusions . 2.4.2 Digisat Demonstration . 3 North A
10、merica Development of Interactive Television Systems in Canada 3.1.1 Digital television in Canada 3.1.2 Interactive Television in Canada . 3.1.3 MDS, MCS and LMCS in Canada 3.1.3.1 Broadband wireless services . 3.1.3.2 Some technical considerations 3.1.3.3 MDS . 3.1.3.4 MCS . 3.1.3.5 LMCS . Interact
11、ive Mobile Datacasting using Digital System A (Digital Audio Broadcasting) 3.1.4.1 Potential data services carried by DAB 3.1.4.2 The system concept . 3.1.4.3 The experimental system 3.1.4.4 The transmission system . The mobile link 3.1.4.5 3.1.4.6 The return link 3.1.4.7 Demonstrations . 3.1.4.8 Th
12、e scientific program 3.1.4.9 Future activities 3.1.4.10 Conclusion Canadian perspective on the European INTERACT project UHF Return Channel 3.1.5.1 Canadian Interest 3.1.5.2 3.1.5.4 3.1 3.1.4 3.1.5 Brief description of the INTERACT UHF Return Channel 3.1.5.3 Adaptation for Canada Conclusion Page 19
13、19 20 21 21 22 22 22 23 24 25 26 26 27 27 27 27 28 28 29 29 29 31 32 33 34 35 36 36 36 36 37 38 38 38 39 39 39 40 41 41 42 43 43 43 43 43 44 44 44 44 44 44 Rep . ITU-R BT.2025 3.2 ATSC Activities Progress in standards for interactive services protocols in the United States of America . 3.2.2.1 Scope
14、 3.2.2.3 Requirements Context 3.2.2.4.1 Two communication paths 3.2.2.4.2 Name of Interaction Channel . 3.2.1 3.2.2 ATSC interactive services protocols definition and system design guidelines 3.2.2.2 Functional Requirements 3.2.2.4 Requirements 3.2.2.4.3 Channel Efficiency . 3.2.2.4.4 Protocol Name
15、. 3.2.2.4.5 Session Management 3.2.2.4.6 Session Control . 3.2.2.4.7 Presentation Interface . 3.2.2.4.8 User Control . System services offer common characteristics of interactive TV broadcasting to both commercial and emergency response markets 3.3.1 Background . 3.3.2 Desired Services 3.3.3 Constra
16、ints on Return Channel 3.3.4 Proposal . 4 Asia-Pacific Region Overview of interactive broadcasting services in ABU 4.1.1 Introduction . 4.1.2 ABU W-A topics relevant to Task Group 11/5 . 4.1.3 Conclusion: ABU Area Activities outside the ABU Area . 3.3 4.1 4.2 4.3 Planned services by country 4.3.1 Ja
17、pan 4.3.1.1 4.3.1.2 4.3.1.2.1 4.3.1.2.2 4.3.1.2.2.1 4.3.1.2.2.2 4.3.1.2.3 4.3.1.2.4 4.3.1.2.5 4.3.1.2.5.1 4.3.1.2.5.2 4.3.1.2.6 4.3.1.2.6.1 4.3.1.2.6.2 4.3.1.3 4.3.1.3.1 4.3.1.3.2 Introduction Market and Service Information . Progress of Interactive Television Services in Japan (1997) Terrestrial an
18、d Satellite Broadcasting . Terrestrial Broadcasting Digital Satellite Broadcasting . Cable Television . Activity on Interactive Television in Japan (1998) . Interactive Broadcasting Experiments for BS Digital Broadcasting . TV Anytime: Interactive Services based on Home Storage Examples of TV Anytim
19、e . Interactive Broadcasting Experiments Using Current Analogue Broad- casting System Ad-insertion Video Clip Using Interactive System Analogue TV Receiver with EPG . Functions of home storage devices for TV Anytime Technical Details Experimental Programme Production Using Facsimile as a Return Chan
20、nel . 3 Page 45 45 45 45 45 45 46 46 47 47 47 47 48 48 48 48 49 49 49 49 50 50 50 50 52 52 52 52 52 53 53 53 53 53 58 59 59 59 59 60 60 60 60 60 61 4 Rep . ITU-R BT.2025 4.3.1.3.3 4.3.1.3.4 4.3.1.3.4.1 4.3.1.3.4.2 4.3.1.3.4.3 4.3.1.3.4.4 4.3.1.3.4.5 4.3.1.3.4.5.1 4.3.1.3.4.5.2 4.3.1.3.4.5.3 4.3.1.3.
21、5 4.3.1.3.5.1 4.3.1.3.5.2 4.3.1.4 4.3.1.4.1 4.3.1.4.2 4.3.1.4.2.1 4.3.1.4.2.2 4.3.1.4.3 4.3.1.5 4.3.1.5.1 4.3.1.5.2 4.3.1.5.3 4.3.1.5.4 4.3.2 Australia 4.3.3 Hong Kong 4.3.3.1 Technical Situation . 4.3.3.1.1 The Set-Top Box 4.3.3.2 The Network . 5 Spectrum considerations . Spectrum planning for inte
22、raction paths . 5.1.1 Introduction . 5.1.2 UHF Return Channel Spectrum Requirements 5.1.3 Summary ofrecent proposal for return paths 5.2 Conclusions . References 5.1 Future Digital TV Receivers . Requirements for Interactive Services in CATV and SMATV Systems Introduction Interactive System Overview
23、 Interactive Channel . Protocol Stack . Higher Layer . Physical Channel Middle Layer Lower Layer . Interactive Services over CATV and SMATV Systems . General Open LAN Services High Speed LAN Services Japan proposal for two new classes of digital interactive television broadcasting services Introduct
24、ion and summary Medium Interaction Hardware Requirement for the current DIRD . Software requirement of Japanese DIRD . Interactive services without return channel Report of server service system for existing interactive TV system using VBI forward and PSTN interaction channel . System Overview of IT
25、-Vision . Some Techniques On How To Avoid Telephony Traffic Congestion Current Server System and Result of Experimental Broadcasting . Conclusion Page 61 63 63 63 65 66 67 67 67 67 67 68 68 70 70 70 71 71 72 72 72 74 75 75 75 76 76 76 76 77 77 77 77 77 77 79 Rep. ITU-R BT.2025 5 Foreword This Report
26、 is a compilation of contributions of members of Radiocommunication Task Group 11/5 from the inaugu- ration of that Task Group in 1997 to its merger with JTG 10-1 1 in February 2000 to form Joint Working Party 10-1 1M. It charts the progress of the development and implementation of Interactive Broad
27、cast systems and services throughout the last three years of the 20th century. Whilst some of the contributions are three years old at the time of compiling this Report, it does in fact provide a brief history of the start-up of Interactive Services. The Report is in five main parts: General Introdu
28、ction, Europe, North America, Asia-Pacific region and Spectrum Considerations. Since this Report provides an overview of interactive television services in various regions of the world, some repetition may result in order to present a thorough description of the situation in each country of interest
29、. 1 Interactivity in broadcasting services 1.1 Introduction Multimedia featuring various presentational possibilities and interactive viewing is rapidly growing in the fields of telecommunications and computing. In telecommunications, interactivity is effected by two-way transmission facilities. Com
30、puters and package media achieve interactivity using data stored in the memories of their terminal. Broadcasting services have so far been marked by real-time, one-way transmission and passive viewing only. Communications networks will be used for new broadcasting services that need an up-link from
31、the viewer to the broadcasting station. TV programmes will increase in number and be separated into those received passively and those that the consumer can receive interactively. A receiver will be provided with a HDTV display and a server so that the viewer can easily operate it through personal f
32、ilters and software agents. This Report discusses interactivity in the broadcasting system, mainly based on one-way transmissions, as well as its effectiveness in broadcasting services. First, usage, implementation and required functions for introducing interactivity to broadcasting services are dis
33、cussed. The practicality of interactive services in one-way broadcasting transmission is clarified. 1.2 What is interactive viewing? Interaction and two-way information transmission, as offered by a telephone conversation, almost offer “face-to-face” services across remote places beyond spatial limi
34、ts. In information offering services, a viewer enters their response while watching the information presented. Subsequent information is displayed according to the response entered. Such repeated presentations and responses enable viewers to obtain information as if they were conversing with the sen
35、der of the information. This process, generally called interactivity, is one of the important functions for achieving information services that are user f?iendly to the viewer and easy to operate with no particular training. Interactive viewing is defined as viewing broadcasting or information servi
36、ces in which information presented is interactively altered in response to viewers choices. Table 1.1 gives a comparison of interactivity among different media. Interactivity in this context includes a case with some time-lag and some inequality in the presentation method and content of information
37、between senders and viewers, which is not the case with telephony interactivity. That is, a viewers response is given as a choice among some of the items presented; the method and the presentation of the information content depend on the given transmission capacity and the coding used in the broadca
38、sting system. Interactivity which is similar to that in telecommunication media can be ensured with a system consisting of two-way Cable Television (CATV) and/or telephone transmission lines or other alternative media (satellite, terrestrial, microwaves, etc). On the other hand the one-way transmiss
39、ion system specific to the broadcasting field, when used alone, will adopt a different system configuration from those media mentioned above to achieve interactivity. 6 Rep. ITU-R BT.2025 Class of interaction Strong interaction (Two-way transmission) 1.3 Functions required for interactive broadcasti
40、ng services Features One-to-one communication Real-time response Call loss with traffic limitation The following functions are desirable for interactive broadcasting services: a) the display in use should have a resolution capable of displaying information with a sufficient visibility to obtain bett
41、er responses from the viewer; access and use of information is easy to understand for the viewer to give a response; subsequent information that is responsive to the viewers choice is specified with link data. Programme producers have control over a broad range of link destinations of linked data; i
42、nformation from the viewer can be sent through public switched telephone network (PSTN)/integrated services digital network (ISDN), CATV or other media (terrestrial, satellite, etc), depending on system requirement. b) c) d) Strong interaction (Asymmetrical two-way transmission: return request by vi
43、ewer) TABLE 1.1 Interactivity in each media One-to-many communication Real-time response Weak interaction (One-way transmission + off-line return channel) One-to-many communication I Medium Interaction I one-to-many communication Interaction w/o return channel (One-way transmission + Home server) No
44、n-real-time response (Asymmetrical two-way transmission: return request by broadcaster) One-to-many communication Real-time response Interaction w/o return channel (Large read only memory) Stand-alone system at user side Real-time response with receiver In item a), resolution requirements depend on
45、the service used. It would be practical to use a display device which has been or may be widely used as a home terminal unit such as a high definition television (HDTV) set to keep the terminal cost as low as possible. In terms of human interfaces in b), it is necessary to allow viewers to select ap
46、propriate ones when their preferences are diverse. Item c) is important to minimize restrictions when producing programmes of interactive multimedia information to achieve a greater variety of programmes. 1.4 Modes of interactivity in broadcasting In various broadcasting services including existing
47、media such as television and those which will be available in the future, there are many modes of interactive viewing. They can be divided into threemajor categories in terms of interactivity: channel selection, stepped viewing and participation: - Channel selection The viewer switches between exist
48、ing multiple broadcast channels using the TV receivers channel selector. Programmes are viewed which have been produced with no intention for interactivity. “Zapping” is an example of this mode of use. Rep. ITU-R BT.2025 7 - Stepped viewing (stepped development of information) A series of programmes
49、 designed to be presented step-by-step are received by viewers so that they can give a response at each step. This is the case with TV-related information services and multimedia information services such as TV newspapers. - Participation The programme information sent from a broadcasting station is changed in real-time by responding to the inputs from viewers. That is, the viewer participates in Programme production. This viewing mode includes the case of a request Programme accepting postcard and telephone requests when assuming a very long time-lag. If, however, a certain real- time fac
