Отчет мсэ-r bt. 2140-1 (05/2009)



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8.8 Applications on ISDB-T


In this section some examples of applications on ISDB-T are shown.

HDTV program in 6 MHz



A HDTV program requires 6 MHz bandwidth.

FIGURE 54






Multi SDTV programs in 6 MHz

Three SDTV programs require 6 MHz bandwidth.


FIGURE 55


EPG (Electronic Program Guide)

An Electronic Program Guide which presents program guide information in table form enables a user to quickly and seamlessly go from a TV channel selection mode to a TV program selection mode.

FIGURE 56

FIGURE 57

Program related data

Anytime news

Top menu

Traffic information

Weather forecast

7


Data broadcasting

Data broadcasting provides a variety of information such as anytime news, weather forecast, traffic information and program related data.

Internet access

All ISDB-T receivers can access to the Internet.

FIGURE 58
1. Guide & reservation of sports facilities 

2. Guide & rental service of city library

7. Mini-game
3. Information of library

4. Information of foods market 5. Sightseeing guide

6. Questionnaire 7. Mini-game


HDTV Mobile reception

HDTV program broadcasted through the ISDB-T system can be received even in mobile reception. Several car receivers are on the market.

FIGURE 59

One-Seg service : TV service for handheld/portable receivers

One-Seg TV service for cellular phones or portable TV receivers was launched in April 2006 in Japan. Such a terminal with a communications link is able to receive network-linked data broadcasting.

FIGURE 60

Human-friendly broadcasting services

Digital broadcasting has a variety of forms, from textual data and diagrams to regular video and audio data. It is intended to exploit this diversity to provide human-friendly broadcasting services that would be accessible to everyone, including the elderly and people with physical impairments.

FIGURE 61



8.9 Outline of ISDB-T transmission scheme, and related ARIB standards, ITU-R Recommendations


TABLE 10

Item

Contents

ARIB standards

ITU-R Recommen-dations

Video coding

MPEG-2 Video (ISO/IEC 13818-2)

STD-B32


BT.1208

Audio coding

MPEG-2 AAC (ISO/IEC 13818-7)

STD-B32


BS.1115

Data broadcasting

BML (XHTML), ECMA Script

STD-B24


BT.1699

Multiplex

MPEG-2 Systems (ISO/IEC 13818-1)

STD-B10, STD-B32

BT.1300, BT.1209

Conditional access

Multi 2

STD-B25


Transmission

ISDB-T transmission

STD-B31

BT.1306


System C

Channel Bandwidth

6MHz, 7MHz, 8MHz

Modulation

Segmented OFDM (13 segment / ch)

Mode,


guard

Mode : 1, 2, 3

Guard Interval ratio : 1/4, 1/8, 1/16, 1/32

Carrier Modulation

QPSK,16QAM,64QAM, DQPSK

Error correction

Inner

Convolutional code



(Coding rate : 1/2, 2/3, 3/4, 5/6, 7/8)

Outer


(204,188) Reed-Solomon code

Interleave

Frequency and time interleave

Time interleave : 0 - 0.5 sec

Information bit rate

(depends on parameters)

6MHz : 3.7 – 23.2 Mbit/s

7MHz : 4.3 – 27.1 Mbit/s

8MHz : 4.9 – 31.0 Mbit/s

Receiver


ISDB-T receiver

STD-B21


Operational guideline

ISDB-T broadcasting operation

TR-B14

8.10 Emergency warning by broadcasting


Early warning against massive natural disasters such as earthquakes, tsunami, hurricanes and volcanic activity, is a very effective measure for those who may suffer from the effects. Emergency warning by broadcasting is very effective to inform many people of the event and its related information for defending their lives and properties from disaster. In this chapter some emergency warning systems using broadcasting are shown.

8.10.1 Automatic activation of handheld receivers by EWS (Emergency Warning System) signals (See Recommendation ITU-R BT/BO.1774)


The Emergency Warning System (EWS) described in Recommendation ITU-R BT/BO.1774 enables a public warning to be made in the case of emergency due to disasters etc. through analog radio and/or analog TV sound channels. As analog broadcasting is one of the most widespread broadcasting services, it is quite effective to make the public warning using this method.

Digital terrestrial broadcasting has an emergency warning mechanism similar to that of analog broadcasting. Broadcasting differs from communications in that it can send information to a large number of handheld receivers at the same time. The ability to activate handheld receivers to receive emergency information would lead to a reduction in the damages caused by a disaster. For this to be effective, a handheld receiver would have to be in constant stand-by mode for the EWS signals, but if the power consumption were too high, it would be difficult to maintain stand-by for a long time.

To solve this problem, a low-power-consumption EWS signals stand-by circuit that can maintain stand-by for the digital terrestrial broadcasting EWS signals has been studied.

Figure 61 shows handheld receiver activation using EWS signals of digital terrestrial broadcasting.

An EWS signal is indicated by bit 26 of the TMCC (transmission and multiplexing configuration control) signals comprising 204 bits in System C of Recommendation ITU-R BT.1306-3. In the case of Mode 3 (number of carriers: 5,617), the number of TMCC carriers is 52 in total for 13 segments, or four carriers per segment. The TMCC signals modulated by differential binary phase shift keying (DBPSK) are transmitted at an interval of approximately 0.2 s.

To achieve remote activation, the EWS signals in one or more TMCC carriers are to be continuously monitored by each receiver. Furthermore, continuous monitoring shall be achieved without substantially shortening the stand-by time of handheld receivers. To reduce the power consumption, a dedicated stand-by algorithm is introduced that:

a)  extracts only TMCC carriers, and

b)  monitors only the EWS signals by limiting time slots.

The function for EWS stand-by with very low power consumption has been verified.

The remote activation technique which uses the EWS signals in TMCC can also be applied to the fixed receivers in System C of Recommendation ITU-R BT.1306-3. Many existing TV receivers are able to receive the EWS signal. In the case of analog TV receivers, they turn on automatically when the TV receiver detects the EWS signal even if the switch is off, and the viewer can obtain the urgent information. However, digital TV receivers can receive this signal only when the switch of the TV receivers is turned on under the current situation. Fundamentally, the operation when the EWS signal is received is established by the product specification of each manufacturer.

FIGURE 62

Handheld receiver activation using EWS signals


of digital terrestrial broadcasting

ews


8.10.2 Earthquake and Tsunami information services via data broadcasting


In January 2007 Japan began offering earthquake and tsunami information via data broadcasts, using three delivery media—BS (broadcast satellite) digital broadcasts, terrestrial digital broadcasts, and terrestrial digital broadcasts for mobile receivers (One-Seg). The features of this new “earthquake and tsunami information” service are that it enables people to get information about earthquakes that have just occurred or past earthquakes, and to rapidly learn of any impending danger due to a tsunami following an earthquake.

The content of “earthquake and tsunami information” via data broadcast is based on the information obtained from the Japan Meteorological Agency (JMA). The data broadcast content production system (hereinafter “production system”) processes data received from outside the station and automatically produces content in BML format*. The content that is automatically generated by the production system is registered to the data broadcast transmission system and then broadcasted. Earthquake and tsunami information is also produced automatically.

In the case of “earthquake and tsunami information” content, data delivered to the broadcaster from the JMA is first received by the “earthquake tsunami database system” which is commonly used by broadcasters for managing earthquake and tsunami information. Then, data is transferred to the “earthquake tsunami gateway (GW)” which is a dedicated system developed for “earthquake and tsunami information” content. The GW converts the data to data broadcast-ready format and sends it to the production system. Thus, content is produced automatically. The system configuration for “earthquake and tsunami information” service is shown below.

FIGURE 63

System configuration for earthquake and tsunami information

The “earthquake and tsunami information” service consists essentially of six kinds of screens. These are “Earthquake occurrence notification,” “Latest earthquake information,” “Most recent earthquakes,” “Tsunami Warnings/Advisories,” “Tsunami- Related earthquake information,” and “Tsunami monitoring information.” At the bottom of each screen are buttons for moving to other screens, and viewers can use a remote controller to switch between any of these screens.

________________

* BML is an XML-based data content format as described in Recommendation ITU-R BT.1699, originally developed by the ARIB.

Within a month of the commencement of earthquake and tsunami information services in January 2007, there were five occurrences of earthquakes of intensity 3 or higher, and information on these earthquakes was delivered via data broadcasts. On each occasion, the automatic production function to enable data broadcasts immediately after they occur worked effectively to enable the earthquake information to be broadcast rapidly. Due to the large volume of information involved in reporting earthquake magnitudes for areas throughout Japan, on regular TV services viewers sometimes fail to see the information relevant to their areas of residence. The data broadcasts, in contrast, were found to be extremely useful, because they enabled people to display relevant information after the broadcast was made, using their remote controllers. So the service is very helpful for this reason, too.


8.10.3 Broadcasting earthquake early warning


The Japan Meteorological Agency has introduced an Earthquake Early Warning system, which can alert people to an approaching earthquake upon detecting its initial small-scale vibrations (Primary waves) and by getting an estimated fix on its epicentre and magnitude (scale). The system can predict such factors as the amount of time remaining until the arrival of the earthquake’s main and potentially destructive vibrations (Secondary waves), and the intensity (degree of jolting). The Agency will issue an Earthquake Early Warning in the event the earthquake is likely to have a minimum intensity of 5 on the Japanese scale of intensity which runs from 0 to 7, alerting people that they can expect severe jolting within the next several or fifty or so seconds’ time.

Japan Broadcasting Corporation (NHK) has developed a system for relaying the alerts issued by the Meteorological Agency. The system, which commenced operation on 1 October 2007, can relay alerts nationwide via all of NHK’s radio and television channels.

Any Earthquake Early Warning issued by the Meteorological Agency must be conveyed to the public promptly and in a readily intelligible format. The system adopted by NHK for relaying such alerts is characterised by the following features:

1 Alerts are broadcasted on all NHK radio and television channels

Any alert is simultaneously broadcasted on all twelve NHK radio and television channels.

2 The alerts are fully automated

Speed is essential, which means a fully automated system is in place for relaying an alert the moment it is received from the Meteorological Agency, without any decision or intervention from a member of NHK staff.

3 A special chime sounds in the event an alert is being issued

A distinctive chime sounds and a CG (computer Graphics) appears on the television screen when an alert is being issued. The CG provides a map and lists the names of the prefectures that can expect jolting.

The alert is superimposed on all nationwide and local NHK TV broadcasts.

On NHK radio stations, an alert issued from Tokyo will interrupt all nationwide and local broadcasts. The warning chime is followed by a synthesised voice announcing the prefectures that can expect seismic jolting.




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