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Experimental Programme Production Using Facsimile As a Return Channel
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- 4.3.1.3.3 Future Digital TV Receivers
4.3.1.3.2 Experimental Programme Production Using Facsimile As a Return ChannelNHK demonstrated an experimental system for interactive service at an open house exhibition of its laboratories in May 1998. A sample programme titled “Health care in the future” was assumed to have three scenarios and change its story depending on the viewer’s answers. In this system, three types of user interface were assumed: a TV with on-screen display for additional information and remote controller, a facsimile machine for hand-written answers and a PC with keyboard connected to TV receiver. Answer forms are distributed via data broadcasts in advance and viewers can either input answers on a TV screen with remote controller, or fill in the form by hand, or type answers directly on a PC. Before the answers are sent to the broadcasting station, they are automatically processed inside the receiver to reduce redundant data. Facsimile data are analysed with graphic recognition tool. The information of checked items are extracted and values are encoded before transmission. The hand-written parts are also extracted and transmitted as graphical data, which are collected and stored in the multimedia database of the broadcasting station. Thus, the station can quickly sum up opinions from viewers. 4.3.1.3.3 Future Digital TV ReceiversIn this section, future digital TV receivers are discussed briefly. Considering the recent situation of digital broadcasting and interactive services, it is beneficial to use the physical layer of the return channel in order to classify interactive services. This is the same position as adopted in TG 11/5. The number of subscribers is a very important parameter for interactive broadcasting services. Broadcasters will need to prepare receiving equipment capable of manipulating properly a large number of viewer’s responses. However, interactive television services are still in the very early stage. There is little information about the relationship between the number of subscribers and suitable interactive channel architecture. In Japan the “TV Anytime” style of system is the most likely system architecture for countrywide interactive broadcasting. A typical receiver is shown in Fig. 4.3. This is one example of the interactive service without return channel. 
FIGURE 4.3 [2025-043] The second case is the receiver with store-and-forward type protocol and near-real time protocol. In this case, two types of return channel protocol can be assumed. The first one is “stor- and-forward” type, however the second one has (near) real-time response capabilities. A typical example of the latter case is the sample programme titled “Health care in the future” described in the previous section. A typical receiver is shown in Fig. 4.4. 
FIGURE 4.4 [2025-044] The most advanced interactive receiver will be a combination of TV receiver, Personal Computer, and communication interfaces. A personal computer is suitable to manipulate the interaction channel and TCP/IP protocol. Connection between future digital TV receiver and PC will be IEEE 1394 most likely. Digital TV receivers will have relatively longer lifetime than PCs. This is the reason PC is written separately in Fig. 4.5. Cable modem will be a possible interaction channel while the PSTN will be most widely used in Japan. In this case, accessed media will be “Internet” most likely. 
FIGURE 4.5 [2025-045] Directory: dms pub -> itu-r -> opb -> rep rep -> Report itu-r m. 2243 (11/2011) rep -> Report itu-r bt. 2053-2 (11/2009) L rep -> Report itu-r m. 2038 Technology trends rep -> Report itu-r sa. 2312-0 (09/2014) rep -> Report itu-r rep -> Report itu-r sm. 2179 (09/2010) Short-range radiocommunication devices measurements rep -> Report itu-r rep -> Report itu-r rs. 2194 (10/2010) rep -> Report itu-r rs. 2165 (09/2009) Download 2.21 Mb. Share with your friends:
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