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HANDBOOK ON
EMERGENCY WARNING
BROADCASTING SYSTEMS
Prepared by: Dr Kazuyoshi Shogen, NHK
ABU Project Manger: Emergency Warning Broadcasting Systems
1
HANDBOOK ON EWBS (Emergency Warning Broadcasting Systems)
Prepared By:
Project Manager: Dr Kazuyoshi Shogen, NHK
Contributors: Mr Cheong Chee Keong, RTB
Mr Daebok Kwon, KBS
Mr Abdul Jalani Mahmud, RTM
Dato‟ Aminah Din, RTM (now retired)
Mr Wan Ariffin Wan Husin, RTM
Mr Tran Nam Trung, VTV
Mr Kong Bin, ABP, SARFT
Mr Shafique Ansari, DDI
Mr John Bigeni, DVB
Mr Hotaek Hong, LG (Korea)
Project Topic: T/ EWBS (Emergency Warning Broadcasting Systems)
Tasks:
1. Implementation of EWBS in the ABU region
2. Techniques employed for EWBS
3. Media suitable for EWBS (SW, MW, FM, etc).
4. Connection of broadcasting stations to governmental or international
organizations which issue the disaster forecast.
5. Emergency warning codes (Country code, Area code, Time code, etc.).
6. Receivers for EWBS including digital broadcasting.
2
Foreword
The Emergency Warning Broadcasting Systems use broadcasting networks to alert
people about impending disasters and enable them to prepare for emergencies. The
EWBS uses special warning or alert signals embedded in broadcasting signals to
automatically switch on the receiver equipment (if so equipped) in the home, and issue
an emergency bulletin, alerting people to an impending disaster such as a tsunami or an
earthquake.
At the ABU General Assembly in November 2006 at Beijing, an ABU Declaration was
adopted; “Implementation of Emergency Warning Broadcasting Systems in the Asia-
Pacific Region”. In pursuance of this declaration, focus was provided on the available
technology and requirement of such systems and the steps that needed to be taken
towards implementation of these systems in the Asia-Pacific region.
This led to the formulation of the Project on EWBS (T/EWBS) within the Transmission
study Topic Area of the ABU Technical Committee. The project highlighted some of the
issues that had to be overcome in implementing the EWBS in the Asia-Pacific region.
This monograph is the report of this Project and looks into the implementation and
operation of such systems in both the analogue and digital broadcasting platforms in TV
and radio broadcasting services. The analogue EWBS system has been in operation in
Japan since 1985 and the digital system since the year 2000.
I would like to express my deep appreciation to the Project Manager Dr Kazuyoshi
Shogen and his team for their excellent work and sincerely thank them for this valuable
report.
Sharad Sadhu
Director Technical Department
Asia-Pacific Broadcasting Union
June 2009
3
TABLE OF CONTENTS
1.0 Handbook on EWBS
1.1 Introduction ............................................................................................. 4
1.2 Activities on EWBS in ABU ......................................................................... 4
1.3 Implementation of EWBS ........................................................................... 5
1.4 Proposal .................................................................................................. 5
2.0 Explanatory Note on EWBS
2.1 Introduction ............................................................................................. 6
2.2 System Overview ..................................................................................... 6
2.3 Operational procedure ............................................................................... 7
2.4 EWBS for Digital Broadcasting .................................................................... 8
3.0 Emergency Warning Codes
3.1 Specification and Configuration of EWBS signal in Rec. ITU-R BT/BO.1774 ....... 9
4.0 Implementation of Emergency Warning Broadcasting Systems (EWBS)
4.1 Introduction ........................................................................................... 12
4.2 Japan .................................................................................................... 12
4.3 Korea .................................................................................................... 22
4.4 Nepal .................................................................................................... 30
4.5 China .................................................................................................... 56
4.6 Singapore .............................................................................................. 63
4.7 Disaster Warning System Implementation Using DVB-T ............................... 64
4
HANDBOOK ON
EMERGENCY WARNING BROADCASTING SYSTEMS
(EWBS)
1.1 Introduction
An ABU Declaration was adopted in the ABU General Assembly in November 2006 at
Beijing; “Implementation of Emergency Warning Broadcasting Systems in the Asia-
Pacific Region”. In pursuance of this declaration, a note was developed (See Appendix 1)
explaining, in general terms, the system, availability of technology - both at the sending
end and at the receiving end, and the steps that need to be taken towards
implementation of the system.
1.2 Activities on EWBS in ABU
During and after the ABU General Assembly in November 2006, some broadcasters
showed an intensive interest in EWBS.
(1) ITU/ESCAP REGIONAL WORKSHOP ON “DISASTER COMMUNICATIONS” in
December 2006 at Bangkok presented EWBS.
(2) BES EXPO2007 held in February 2007 in India set up a session “Role of
Broadcasting in Warning and Disaster Management” containing 5
presentations.
(3) ABU DTV Symposium held in March 2007 at Kuala Lumpur exhibited EWBS
functions.
(4) ABU Digital Broadcasting Symposium in March 2008 at Kuala Lumpur exhibited
EWBS functions.
(5) Broadcast Asia 2008 in June 2008 at Singapore exhibited EWBS functions, and
Radio Asia 2008 in June 2008 at Singapore presented EWBS.
(6) In Nepal the work on assigning the EWBS codes to Nepal was carried out, in
Korea field test is going on, and in China EWBS standard for CMMB has been
specified.
The T/ EWBS (Project on Emergency Warning Broadcasting System in Transmission
Topic Group of ABU Technical Committee) found some issues to be overcome in the
implementation of EWBS in the ABU region. Those issues are as follows:
(1) The equipment for issuing the control signal installed in broadcasting stations.
(2) The EWBS receivers.
(3) The regulation put up by the government and the support for EWBS by the
government.
(4) The attribution of EWBS control signal and the security against the abuse of
EWBS.
(5) Connection of broadcasting stations to governmental or international
organizations which issue the disaster forecast.
(6) Funding of the EWBS.
5
The item (4) above has been carried out and they are described in Recommendation
ITU-R BT/BO.1774. Recently, EEW (Earthquake Early Warning) technologies have been
developed and the service has been initiated.
1.3 Implementation of EWBS
Appendix 2 presents a system overview and the current status of EWBS in some
countries
1.4 Proposal
The T/ EWBS urges ABU members to develop and implement the EWBS and/or EEW
systems in the ABU region.
Dr Kazuyoshi Shogen, NHK (Project Manager)
Mr Cheong Chee Keong, RTB
Mr Daebok Kwon, KBS
Mr Abdul Jalani Mahmud, RTM
Dato‟ Aminah Din, RTM (now retired)
Mr Wan Ariffin Wan Husin, RTM
Mr Tran Nam Trung, VTV
Mr Kong Bin, ABP, SARFT
Mr Shafique Ansari, DDI
Mr John Bigeni, DVB
Mr Hotaek Hong, LG (Korea)
6
EXPLANATORY NOTE ON EWBS
2.1 Introduction
The Emergency Warning Broadcasting Systems uses broadcasting facilities to alert
people and enable them to prepare for emergencies. EWBS signals embedded in
analogue TV and radio broadcasts will automatically switch on TV and radio sets in the
home, and issue an emergency bulletin, alerting people to an impending disaster, e.g. a
tsunami, earthquake, cyclone, flood, or volcanic eruption.
The analogue EWBS only requires a dual-frequency control signal generator. The signals
can be sent from existing radio and TV facilities, without any special modifications. The
system is adaptable. The EWBS signals include time and area codes, as well as special
fixed codes for initiating and terminating the system‟s operation. Although the time code
is optional, the area code is essential to ensure that TV and radio sets are activated only
in the localities where a warning is necessary. The easiest option is to use CD players.
The analogue EWBS has been in operation in Japan since 1985, and has sent out signals
on more than ten occasions.
The digital EWBS signals are multiplexed with the broadcast signals. The digital EWBS
has been in operation in Japan since 2000.
2.2 System Overview
The Emergency Warning Broadcasting System (EWBS) alerts people to a tsunami,
earthquake and other natural disasters. It was developed by NHK, and the analogue
EWBS has been in operation in Japan since September 1985. The system is provided on
all of NHK‟s TV channels (terrestrial and satellite) and AM/FM radio services, as well as
on the commercial TV channels.
Fig.1-1 Configuration of EWBS
SwitchTrans-
mitterProgram
signal
Control
signal
generator
Program
signal
reception
Control
signal
reception
Control
Broadcasting station Receiver with
warning function
Radio
TV
Alarming sound,
followed by
announcement
7
The analogue EWBS, shown in Figure 1-1, has specially designed audio signals, which
will automatically switch on TV and radio sets when transmitted from a broadcasting
station. It works via conventional analogue broadcasting systems. The sounds are FSK
(frequency shift-keying) modulated audible frequencies: the 1024Hz tone is code „1‟,
while the 640Hz tone is code „0‟. These tones are readily audible to the human ear when
transmitted via analogue systems. People readily associate the noise with an alarm.
The low information rate (64bps) ensures
stable signal reception, providing enough
capacity for time and area codes for
security purposes. The special codes,
excluding the time codes, can be recorded
in a CD-ROM or similar storage device,
which is shown as the „control-signal
generator‟ in Figure 1-1. The analogue
EWBS codes are specified in
Recommendation ITU-R BT/BO.1774 and
they are given in Annex 1 of this
document.
It is important to offer EBWS reception at
a low price. Figure 1-2 shows an
inexpensive configuration developed by
NHK. An inexpensive chip is added to a
cheaply priced radio receiver.
2.3 Operational procedure
An Emergency Warning Broadcast is made in the following instances:
When a warning has been issued for a major earthquake in Japan‟s Tokai
(Pacific coast) region.
A tsunami warning.
A request from a prefectural governor to air an evacuation order.
NHK has a system in place which
immediately processes any tsunami or
earthquake bulletin issued from the
Meteorological Agency, irrespective of the
time of day, in order to provide prompt
and accurate news reports. Once a
bulletin has been relayed from the Agency
to NHK via special-purpose lines, the
information is routed to servers and
computers, which will automatically
generate graphics and an alert for the
News Centre.
Fig. 1-2
Prototype of low cost analogue EWBS
receiver
Conventional
Receiver ($2)
EWBS Adaptor
IC* parts: ($1)
Speaker
Enough for
receiving EWBS
*TI MSP430
Fig. 1-3 Emergency News Console
8
NHK‟s Emergency News Console, shown in Figure 1-3, speeds up the process. Incoming
data of a tsunami or major earthquake will pre-set the console so that an emergency
news bulletin can go to air at the touch of a single button. The EWBS control signal
automatically precedes the bulletin. When the EWBS signal and emergency bulletin are
aired, they automatically activate TV and radio sets which are adapted for the system.
An alarm is sounded to alert people‟s attention, which is then followed by an emergency
bulletin on the disaster. The system is particularly useful in event of a tsunami. Injuries
and fatalities can be reduced if people can be warned before a tsunami strikes.
2.4 EWBS for Digital Broadcasting
In the case of digital broadcasts, the EWBS signals are multiplexed with the broadcast
signals. The digital terrestrial telecasts, which can be sent to mobile phones, PDA
(portable digital assistance) units, and other mobile devices, could play a useful role in
helping people respond to a disaster or emergency. Digital EWBS signals have been
transmitted in Japan in actual emergencies, but the devices that can receive them are
still under development. The issue is to reduce the amount of power these devices
consume while they are in stand-by mode. NHK is currently developing technology to
reduce such power consumption.
In Korea field test for the DMB AEAS (Automatic Emergency Alert Service) is going on,
and in China EWBS standard for CMMB has been specified.
9
Annex 1
EMERGENCY WARNING CODES
(Fixed code, Country code, Time code)
3.1 Specification and configuration of EWBS signal in Rec. ITU-R BT/BO.1774
Modulation method of the EWBS signal is the frequency shift keying (FSK) method with a
space frequency of 640 Hz and a mark frequency of 1024 Hz. The configurations of the
Category I Start Signal and Category II Start Signal are shown in Figure 1, and that of
the End Signal is shown in Figure 2.
Fig.1 Configurations of Category-I Start Signal and Category-II Start Signal
Fig. 2 Configurations of End Signal
Notes for Figure 1 and 2:
1 Fixed code: The Fixed code consists of a 16-bit code inherent in the EWBS signal. It
is used for extracting the EWBS signals from sound signals. Furthermore, it is used
for distinguishing between the Category I Start Signal and the Category II Start
Signal.
2 Country code: The country code is for operating a receiver in a country. The
purpose of this code is to avoid triggering receivers other than the relevant
receivers by anomalous propagation of broadcasts.
10
3 Arbitrary code: The arbitrary code is optional, and may be used for area codes in a
country, or for transmitting real-time information for preventing operation of
receivers by illegal radiowaves that are recorded and retransmitted after the EWBS
signals have been transmitted.
The detail configuration of code is shown Fig.3.
Fig. 3 Configuration of code
Note :
Case Content Category
(1) Large-scale earthquake warning statement Category I
(2) Broadcasting of evacuation order Category I
(3) Tsunami warning Category II
Category I activates all EWBS receivers in the service area. On the other hand,
Category II activates EWBS receivers only set activating by this signal in the
restricted area, which may suffer Tsunami.
In cases (1) and (2), broadcasters transmit the Category I Start Signal. In case
(3), as inland users do not need to evacuate, broadcasters transmit the
Category II Start Signal.
After the emergency warning message, broadcasters transmit the End Signal to
turn off EWBS receivers.
Code type Type of EWBS Configuration of signal
Preceding code
Category I Start Signal and
Category II Start Signal 1100
End Signal 0011
Fixed code
Category I Start Signal and
End Signal
0010001111100101
(23E5)
Category II Start Signal 1101110000011010
(DC1A)
Country code
Category I Start Signal and
Category II Start Signal 10 Country code shown in Figure.4 (12 bits) 00
End Signal 01 Country code shown in Figure.4 (12 bits) 11
Arbitrary code
(Note 1)
Start Signal 01 Arbitrary code (12 bits) 00
End Signal 10 Arbitrary code (12 bits) 11
Note 1: The arbitrary code is optional, and may be used for area codes in a country, or for
transmitting real-time information for preventing operation of receivers by illegal
radiowaves that are recorded and retransmitted after the EWBS signals have been transmitted
11
Country Country Code Country Country Code
1 0001 0110 1011 34 1000 1010 0111
2 0001 1001 1101 35 1000 1101 0101
3 0001 1010 1110 36 1001 0010 1101
4 0001 1011 0011 37 1001 0101 1001
5 0001 1100 0111 38 1001 0110 0110
6 0010 1011 0101 39 1001 1000 1011
7 0010 1011 1010 40 1001 1011 0100
8 0010 1101 1100 41 1001 1101 0010
9 0010 1110 0011 42 1010 0010 1011
10 0011 0001 1011 43 1010 0101 1010
11 0011 0010 0111 44 1010 0110 0101
12 0011 0100 1101 45 1010 1001 0011
13 0011 0111 0010 46 1010 1010 1100
14 0011 1001 0110 47 1010 1100 0110
15 0011 1010 1001 48 1010 1100 1001
16 0100 0110 0111 49 1011 0011 0001
17 0100 1010 1011 50 1011 0101 0100
18 0100 1100 1110 51 1011 1001 1000
19 0101 0011 0110 52 1100 0101 0110
20 0101 0011 1001 53 1100 0110 1001
21 0101 0101 0011 54 1100 1000 1101
22 0101 0110 1100 55 1100 1011 0010
23 0101 1001 1010 56 1100 1101 1000
24 0101 1010 0101 57 1100 1110 0100
25 0101 1101 0100 58 1101 0001 1100
26 0110 0010 1101 59 1101 0010 0011
27 0110 0100 1011 60 1101 0100 0101
28 0110 0111 0100 61 1101 0100 1010
29 0110 1001 1001 62 1110 0011 1000
30 0110 1010 0110 63 1110 0100 1100
31 0110 1101 0010 64 1110 0101 0001
32 0111 0010 1010 65 1110 0110 0010
33 0111 0101 1000 66 1110 1001 0100
Fig. 4 Country code
12
IMPLEMENTATION OF EMERGENCY WARNING
BROADCASTING SYSTEMS (EWBS)
4.1 Introduction
This Appendix presents a system overview and the current status of EWBS in some
countries.
4.2 JAPAN
This chapter provides some information on the disaster management system in Japan for
the public warning system on broadcasting.
4.2.1 Disaster management system
The disaster management system is specified in the disaster countermeasures basic act.
The prime minister designated Japan broadcasting corporation (NHK) as the designated
public corporation and the governor of each prefecture designated most commercial
broadcasters operating terrestrial broadcasting stations as designated local public
corporations.
On the national level, central disaster management council is organized with the
representatives of designated public corporations. The council formulates the basic
disaster management plan as the national master plan, and promotes execution of the
plan (Fig. 1):
Fig 1 The Structure of Disaster Management (National Level)
Central Disaster
Management Council
- Prime Minister
- Other all ministers
- Representatives of
designated public
corporations
Designated Administrative Organs
Designated Public Corporations
Ministries and agencies
- Related incorporated administrative agencies
(National Hospital Organization, etc.)
- Japan Post
- Bank of Japan
- Japan Red Cross Society
- Japan Broadcasting Corporation
(NHK)
- major telecommunication carriers (NTT, KDDI,
NTT DoCoMo, etc.)
- Electric power companies
- Railway companies of Japan
Railways Group
- Some other public corporations and companies
The Basic Disaster Management Plan
13
On the prefectural level, Prefectural disaster management council is organized with the
representatives of designated public corporations and designated local public
corporations.
The Council formulates the disaster management local plan, and promotes execution of
the Plan (Fig. 2).
The disaster management local plan consists of several volumes, such as “Earthquake
disaster countermeasures”, “Storm and flood countermeasures”, “Volcano disaster
countermeasures”. The Plan is also used for manual of disaster management. Therefore,
the copy of the agreement between the governor and the broadcasters on the
broadcasting for disaster countermeasure is attached the Plan. The procedure of
broadcast request by the Governor or the Mayors to the broadcasters is specified by the
agreement and would be reflected to the Plan.
Fig 2 The structure of disaster management (Prefectural level)
14
4.2.2 EWBS over analogue broadcasting
The analogue EWBS has been in operation in Japan since September 1985. The
modulation method of the EWS signal is the frequency shift keying (FSK) method with a
space frequency of 640Hz and a mark frequency of 1024Hz. The allowable frequency
deviation is plus or minus ten parts per million in each case. The transmission speed of
the EWBS signal is at 64-bits per second and this deviation is ten parts per million.
Signal distortion is below 5%. The configurations of the Category I start signal and
Category II (See Table 1) start signal are shown in Fig. 3, and that of the end signal is
shown in Fig. 4.
Fig 3 Configurations of Category I start signal and Category II start signal
Fig 4 Configuration of End Signal
Notes for Figs. 3 and 4:
1 Fixed code: The fixed code consists of a 16-bit code inherent in the EWBS
signal. It is used for extracting the EWBS signals from sound signals.
Furthermore, it is used for distinguishing between the Category I start
signal and the Category II start signal.
2 Area classification code: The area classification code is for operating a
receiver in restricted regional areas. The purpose of this code is to avoid
triggering receivers other than the relevant receivers by anomalous
propagation of broadcasts.
3 Year/month/day/time classification code: The year/month/day/time
classification code is used for transmitting real-time information for
preventing operation of receivers by illegal radiowaves that are recorded
and retransmitted after the EWBS signals have been transmitted.
15
Table 1: Category of EWBS
Start signal Area code
(1) Large-scale earthquake warning statement is
declared by Meteorological Agency
Category I Nationwide
(2) Including broadcasting of evacuation order is
requested by governor of prefecture
Category I Prefecture or
wide area
(3) Tsunami warning is declared by Meteorological
Agency
Category II Nationwide, prefecture
or wide area
The analogue EWBS receivers are shown in Fig. 5. Less expensive receiver for analogue
EWBS (FM radio, Panasonic RF-U350) has been newly issued by Panasonic since June
2007.
Fig 5 - Analogue EWBS receivers. The AM/FM receiver in late 1980’s (Left) and new FM
receiver since June 2007 (Right)
4.2.3 EWBS over digital broadcasting
The digital EWBS has been started in 2000 for satellite broadcasting and in 2003 for
terrestrial broadcasting in Japan. The EWBS signals are issued simultaneously in
analogue and digital broadcasting.
The emergency information descriptor may be used only for ISDB-TSB recommended in
Recommendation ITU-R BS.1114 (System F), ISDB-T recommended in Recommendation
ITU-R BT.1306 (System C), broadcasting-satellite service (sound) system using the
2.6 GHz band recommended in Recommendation ITU-R BO.1130 (System E), and ISDB-
S recommended in Recommendation ITU-R BO.1408. The emergency information
descriptor for EWBS is placed in the Descriptor 1 field of the program map table (PMT),
which is periodically placed in the transport stream (TS). The details of the emergency
information descriptor is shown in Fig. 6.
16
Fig 6 - Structures of TS, PMT and emergency information descriptor
17
Notes to Fig.6:
1 ES (elementary stream): ES is encoded video and audio, etc.
2 PES (packetized elementary stream): PES is packetized ES in each significant
unit.
3 TS (transport stream): TS is divided PES, and the size is 188 bytes including
32 bytes of the header.
4 PID (packet identifier): PID shows what the transmitted packet is.
5 CRC (cyclic redundancy check): CRC is a type of hash function used to
produce a checksum, which is a small number of bits, from a large block of
data, such as a packet of network traffic or a block of a computer file, in order
to detect errors in transmission or storage.
6 Descriptor tag: The value of the descriptor tag shall be 0xFC, representing the
emergency information descriptor.
7 Descriptor length: The descriptor length shall be a field that writes the
number of data bytes following this field.
8 Service id: The service id shall be used to identify the broadcast program
number.
9 Start/end flag: The value of the start/end flag shall be „1‟ and „0‟,
respectively, when transmission of emergency information signal starts (or is
currently in progress) or when transmission ends.
10 Signal types: The value of the signal type must be „0‟ and „1‟, respectively, for
Category I and II start signals.
11 Area code length: The area code length shall be a field that writes the number
of data bytes following this field.
12 Area code: The area code shall be a field transmitting the area code.
The digital broadcasting receivers issued by SONY (W5000, X1000, X5000, X5050,
X7000) are automatically switched on by receiving the EWBS signal. Furthermore, most
digital broadcasting receivers in Japan display subtitle that the emergency warning
broadcasting is started when they receive the EWBS signal. The digital broadcasting
tuner, Panasonic TU-DTV200, for automobile switches its channel to the one providing
the emergency warning broadcasting when it receives the EWBS signal.
Information on Earthquake intensity and Tsunami warning has been provided since 17
January 2007 to digital satellite, digital terrestrial and One-Seg data broadcasting. NHK
facilitated the equipment which automatically produces pictures for data broadcasting.
The content of the picture is as follows.
Digital satellite and digital terrestrial data broadcasting : Earthquake intensity which is
over 3 and the name of town, Earthquake intensity in the past, Tsunami warning,
estimated arrival time, observed information.
One-Seg data broadcasting: Earthquake intensity which is over 3, Tsunami warning. This
information is automatically appeared on the receiver screen in the data broadcasting
when a receiver is set up to allow such function.
18
Fig 7 - Tsunami and Earthquake information on One-Seg screen
Fig 8 - Tsunami information on One-Seg screen
Fig 9 - Earthquake information on One-Seg screen
The earthquake warning information, which is issued from the Meteorological Agency
using P wave detection, has been provided by NHK since 1 October 2007 in all over
Japan. An example of the earthquake warning information on the receiver is shown in Fig.
10. Note that this service is also provided in analogue broadcasting.
19
Fig 10 - Example of earthquake warning information
4.2.4 Automatic activation of handheld receivers by EWBS signals
In order to realize remote activation, emergency warning flags in one or more TMCC
carriers are to be continuously monitored. Furthermore, continuous monitoring shall be
realized without substantially shortening stand-by time of portable receivers.
It is easily achieved to monitor emergency warning flags by using the One-Seg receiving
module. At present, however, since consumption power of at least 100 mW is required,
the stand-by time lasts for merely one day. Thus, this method is not a practical idea.
Accordingly, in order to save power, NHK considered a dedicated stand-by algorithm that
i) extracts TMCC carriers,
ii) monitors only emergency warning flags of bit 26.
Fig. 11 shows the prototype circuit for EWS stand-by with very low power consumption
based upon the algorithm.
It is assumed that power consumption of the prototype circuit is approximately 1/10,
below 10 milliwatts, compared to the case where the One-Seg receiving module is
directly used for the monitoring of the emergency warning flags. Since the actual
operation of the circuit is greatly reliant upon boot-up characteristics and stability of an
analogue system at its front-end unit, and a reception environment including fluctuation
in reception power, NHK will continue verification experiments for putting the circuit into
practical use.
Figure 11 Prototype circuit ready for EWS with very low power consumption
20
FM receivers implemented the EWBS and BEEW signal detection device have been on
market since April 2008 in Japan (See Fig.12)
.
Fig 12 - FM receiver implemented the EWBS and Broadcasting Earthquake Early
Warning signal detection device
4.2.5 Automatic activation of handheld receivers by EEW signals
The broadcasting earthquake early warning (EEW) service has been put into service in
Japan since 1 October 2007 as shown in Fig. 13.
Fig 13 - Outline of broadcasting earthquake early warning service
21
The earthquake waves consist of body waves and surface waves that travel along the
ground surface. The body wave is divided into small vertical waves called Primary waves
(P waves), and larger, horizontal waves called Secondary waves (S waves). Each of the
three types of wave propagates at a different speed, in the order P-wave, S-wave and
surface wave, from fastest to slowest. Most of the damage caused to structures by
earthquakes is due to S-waves. P-waves are said to propagate at about 7 km/s, while S-
waves propagate at about 4 km/s. Earthquake early warnings use this difference in
propagation speed to create a system that can issue a warning before the larger S-
waves arrive. If a seismometer close to the epicentre detects a P-wave, the
Meteorological Agency of Japan immediately estimates issues the epicentre location and
scale as well as the magnitude and arrival time of any S-waves bringing large tremors.
NHK began operating its EEW service, in which the occurrence prediction of a large
earthquake from the Meteorological Agency of Japan is delivered through broadcasting,
in October, 2007. Some of current difficulties with EEW are the transmission signals,
transmission time for EEW and reducing the required C/N for EEW signal. NHK is now
studying to solve these difficulties. Fig. 14 shows a prototype alarm clock with automatic
activation function using EEW transmission system.
Fig. 14 prototype alarm clock with automatic activation function using EEW
transmission system
22
4.3 KOREA
Development of T-DMB Automatic Emergency Alert Service
Transmission and Monitoring System
Abstract
The advent of the digital age and the various broadcasting networks opens up a new
horizon in alert broadcasting standards for the new environment. T-DMB is an effective
candidate system for the delivery of the alert in whole or regional area. This paper
describes the development of AEAS (Automatic Emergency Alert Service) system which
consists of a transmission part and a monitoring part.
T-DMB AEAS Standard was recently published, which defines encoding methods, the
signalling and delivery method, and functional requirements of the transmitter and the
receiver. For signalling used to activate receivers, FIDC (Fast Information Data Channel)
FIG 5/2 is used for the delivery of the alert message and MSC (Main Service channel) is
additionally used for delivery of supplemental information.
In this paper, the AEAS transmission and monitoring system conformity with AEAS
Standard is introduced. Finally, a T-DMB AEAS trial service of Korea Jeju Special Self-
Governing Province for interoperability test with the existing DMB receivers is described.
This paper will contribute as a guideline to the development for emergency alert service
standards for other broadcasting media.
4.3.1 Introduction
For emergency alert to general public, broadcasting systems have been used as the main
infrastructure for the delivery, because of its efficiency and reliability. Now DTV and DMB
are being serviced in many countries. Therefore, developing emergency warning system
(EWS) for the new digital environment is emphasized to reduce the risks and to protect
the life and property of the people from a disaster. EWS needs a usage of characteristics
of each media (terrestrial, satellite, cable, internet, etc.), and stability in transmission
path. In this aspect, T-DMB which contains characteristics such as personalization,
portability and mobility could be the best suitable media for EWS.
The rest of this paper is organized as follows. Section 2 presents the AEAS requirements
and specifications of technical standard is explained in Section 3. In Section 4, the T-
DMB AEAS system developed by KBS is introduced. Finally, results of interoperability test
with existing T-DMB receivers are briefly presented.
4.3.2 AEAS Requirements
If an infrastructure was constructed for rapidly delivering emergency warning
information to people in case disaster being forecasted or occurred, the damage of
disaster could be effectively reduced. With this view “localized service” and “automatic
alert service” are needed. The localized service means that emergency warning
information is displayed on only receivers located in region which disaster is forecasted
or occurred, and the automatic alert service means that in standby mode receiver
automatically alerts user to disaster by detecting emergency warning signal. According
to final target of the service, we can classify the alert broadcasting services into “General
23
Service” and “Special Service”. The general service alerts the message to the general
public, while the special service only to those who are equipped with receivers which has
special purpose receivers. For the purpose of these services, the method of emergency
warning information delivered to people using data channel and displayed on receiver in
various types is very effective. In particular, using data channel has a merit of delivering
emergency warning information to people without interrupting main program.
Major AEAS requirements are as follows.
a. AEAS should be processed prior to other data service for transmitting and
receiving emergency warning information.
b. Regional code should be used for identifying emergency warning region.
c. Receiver should identify a current location with the regional code inputted, and
the regional code could be easily changed with moving.
d. Exclusive receiver for the special service should always keep watch for whether
EAES signal is or not, and immediately response in case of detecting EAES
message.
e. The loudness of volume should be automatically controlled in case of detecting
AEAS signal.
f. Alarm may be announced in case of special AEAS message.
4.3.3 Technical Standard
4.3.3.1 Transmission Channel
T-DMB transmission channel is consisted of FIC(Fast Information Channel) and
MCI(Multiplex Configuration Information) such as figure 1. AEAS service uses FIC for
saving battery and minimizing time interval of changing channel. AEAS message is
transmitted through FIG 5/2(EWS) of FIDC, and additional message is transmitted
through all the data channels of MSC.
24
AEAS :Automatic Emergency Alert Service
FIDC :Fast Information Data Channel
FIC :Fast Information Channel
Fig 1 - T-DMB Protocol Stack
4.3.3.2 Signalling and Format
D2 bit of FIG 5/2 is used to signal to receiver whether AEAS message is or not, as shown
in Fig. 2 and Fig. 3.
Fig. 2 Structure of FIG 5/2
Fig 3 - Type 5/2 Field Contents with D2 Value
If D2 is zero, data area is filled with padding data. If D2 is one, data area is filled with
AEAS message concerning with emergency warning. Therefore receiver decides whether
AEAS message is or not. AEAS messages are transmitted in order of Event Code,
25
Severity, d&t(data and time), etc. as shown in figure 4. In particular Desc&Link presents
short human readable text and external link associated with the AEAS message.
EventCode Severity d&t tGeocode nGeocode rfu Geocodes Desc&Link
3bytes 2bits 28bits 3bits 4bits 3bits variable variable
Fig 4 - AEAS Message Format
The following are the syntax and semantics of each field:
EventCode: this field shall contain the event code which is defined in the annex1 of
the standard. . The major portions of the EventCode are quoted from USA‟s FCC Rule
47 Part 11.
Severity: this 2-bit field shall indicate the severity of the event, as Table 1:
Table 1 Severity
Severity Semantics
00 “Unknown” - Severity unknown
01 “Moderate” - Possible threat to life or property
10 “Severe” - Significant threat to life or property
11 “Extreme” - Extraordinary threat to life or property
d&t (date and time): this 28-bit field shall indicate the date and time when the
emergency information is announced by an originator. The first 17 bits shall be the
modified Julian data and the next 11 bits shall be the UTC code (short form), which is
defined in ETS 300 401 v1.4.1 Section 8.1.3.1.
tGeocode (Geocode Type): this 3-bit field shall indicate the type of the geocode used
in the message.
Table 2 Geocode Type
Geocode Type Semantics
000 The whole territory of the Republic of Korea
001 Define by the ROK Government.
010 Korean Regional Code. The target is general public.
011-011 Rfa
An AEAS message shall include only one type of Geocode. When tGeocode is 000,
nGeocode shall be set to 0000 and no Geocode shall be included in the message.
nGeocode: This field shall include the number of geographic codes delineating the
affected area of the AEAS message.
Geocodes: This field shall include one or more geographic codes delineating the
affected area of the AEAS message. The type and the number of geocodes are defined
in tGeocode and nGeocode fields, respectively. The length of the geocode shall be
fixed and defined implicitly.
Desc&Link: This variable length field shall present short human readable text and
external link associated with the AEAS message. The text includes description of the
event and instruction for targeted recipients. The external link shall be surrounded by
double quotes (“). The external field may be used for any additional information for
26
the message, for example, uniform resource identifier (URI) for web or other DMB
services. The URI shall be full and absolute.
4.3.3.3 Segmentation
An AEAS message shall be delivered via FIDC (FIG 5/2). The AEAS message shall be
segmented into several FIGs. The data field of an FIG shall contain one and only one
segment of the AEAS message. For this purpose, 2-byte segment header shall be used,
as shown in Table 3.
Table 3 Segment Header Fields
Current nSegment AEASId
4 bits 4 bits 8 bits
Current (n): this 4-bit field shall be the (n+1)th sequence number of the current
segment.
nSegment (m): this 4-bit field shall be the total number of segments of the AEAS.
The total number is (m+1). Since an FIG can accommodate at most 26 bytes of
AEAS message, therefore, the maximum size of an AEAS message is 26 bytes/FIG x
16FIG = 416 bytes.
AEASId: This Id enables an AEAS receiver assemble an AEAS message from FIG
segments. In addition, the Id prevents the AEAS receiver from presenting duplicate
AEAS messages. Since, during an emergency, an AEAS message will be emitted
repeatedly, the AEAS receiver should always remember the AEASId that has been
presented. However, if the AEASId is managed by a local authority, a mobile
receiver can face with problematic situations: the same AEAS message has different
AEASId, or two different AEAS messages have the same AEASId. In order to avoid
these situations, the AEASId shall be nationally managed by a central authority, so
that identical emergency information should always have a same AEASId nationwide.
Table 4 AEASID Fields
OriginL(Originator Level) MsgId (Message Id)
3 bits 5 bits
OriginL (Originator Level): this 3-bit field shall indicate the originator group of the
AEAS message. It represents three levels of government, i.e., national, state, and
local governments.
Table 5 List of Originator Level
OriginL Description
000 National Government (NEMA, KMA, etc)
001 Large City, Province
010 Small City, County
100~111 Rfa
MsgId: this 5-bit, modulo-32 counter shall be incremented by one for each
successive AEAS message
27
4.3.4 T-DMB AEAS System
Figure 5 shows T-DMB AEAS system which is developed by KBS and is complying with
AEAS standard. It is composed of transmission system and monitoring system.
Fig 5 - Diagram of T-DMB AEAS System
4.3.4.1 Transmission System
AEAS transmission system is consisted of four program modules. Functions of each
program module are described as follows;
- Program module of receiving AEAS message receives AEAS message from NEMA or
KMA, and transmits it to program module of transmission.
- Program module of transmitting AEAS message encodes AEAS message into binary
format for on-air.
- Program module of authoring AEAS message authors AEAS message for testing
purpose as depicted in Fig. 6.
- Program module of supervising AEAS system keeps lookout for whether AEAS
message is true or not
28
Fig 6 - Screenshot of AEAS Message Composition to Transmit
4.3.4.2 Monitoring System
On-air monitoring system is developed for analyzing AEAS signal. It receives on-air
TDMB signal including AEAS message through USB type T-DMB receiver, and analyzes
FIDC channel. It analyzes FIG 5/2 and extracts AEAS signalling information, message,
etc. Parsed and interpreted information is displayed on PC monitor as shown in Fig. 7.
4.3.5 Conclusion
From results of trial AEAS service for analogue TV and FM, this paper presents AEAS
requirements for T-DMB. In addition, technical standard to satisfy T-DMB AEAS
requirements is described and a developed T-DMB AEAS system based on AEAS technical
standard is introduced. It was installed in Korea Jeju-do province at June this year, and
was being operated for testing interoperability of existing T-DMB receivers. By
conducting the test, it was found that some receivers were not able to re-tune the
channel while AEAS signal is transmitted. This problem, however, is solved by upgrading
firmware of receiver. Experiences of T-DMB AEAS system described in this paper will be
helpful for those who are trying to launch AEAS broadcasting based on other new media
(DTV, digital, satellite DMB, etc.).
29
Fig 7 - Screenshot of AEAS Monitoring System
REFERENCES
[1] TTAS.KO-07.0046/R1: “Interface Standard for T-DMB Automatic Emergency
Alert Service,” December 2007.
[2] ETSI EN 300 401 V1.4.1: “Digital Audio Broadcasting to mobile, portable and
fixed receivers”.
[3] “Receiver Conformance Test Standard for T-DMB AEAS,” December 2007.
[4] Recommendation ITU-R BT.1774, “Examples of Public Warning Systems on
Broadcasting,” August 2006.
30
4.4 NEPAL
This work is being carried out by Mr. Udaya Krishna Shrestha of Radio Nepal in NHK
Science and Technical Research Laboratories as a visiting researcher under NHK
Research Award 2006.
NHK STRL JAPAN 2007 EMERGENCY WARNING BROADCASTING SYSTEM FOR NEPAL
CONTENTS
Project Focus on: EWBS Control Signal for Nepal
o Introduction
o Past Major Disasters
Structure of whole System
About Emergency Warning Signal
EWBS Signal
o Modulation Method
Set up of EWBS signal for Nepal
The nation code, the region code and the district code
o Classification of district codes,
o Operational standards for EWBS broadcasts for Nepal
EWBS fixed code for Nepal
EWBS nation and region Code
EWBS district Code for whole Nepal
Country Facts,
o Country Profile
The network of EWBS signal broadcasting
The network of EWBS signal in the districts
FM future in EWBS:
o Some information about EWBS system
o Automatic activation of an EWBS receiver
EWBS receivers at NHK STRL
Our programme will focus on:
o Information of VSAT / Transmitting DATA
o Regulatory Mechanism
o Radio signal depends upon the geographical situation
o Features of low-power consumption EWS stand-by circuit
EWBS coverage in Nepal
o EWBS Coverage map of Radio Nepal
o The Coverage map of RNE by AM & FM transmitters:
o Area covered by EWBS signal whole Nepal
National Policy on Disaster Management
o Government of Nepal disaster management structure
EWBS Message on TV broadcasting
Conclusion
Appendix: Block diagram of V-SAT link
31
A Case Study on: Emergency Warning Broadcasting System [EWBS] control signal for Nepal
4.4.1 Project Focus on: EWBS Control Signal for Nepal
Tasks:
EWBS codes for Nepal including country code, Area code, Time code, etc.
Implementation of EWBS signal
Techniques employed for this system
Broadcasting stations must be linked to the governmental or any organizations
which is responsible to issue the disaster forecast
Suitable media [FM, MW and SW],National Broadcasting Media Radio Nepal
Conclusion
Proverb by
Japanese physics Scientist, Dr. Torahiko TERADA (1878-1935)
“Natural Disasters will hit us by the time people have forgotten about it.”
Introduction
Radio Nepal [RNE] is the only national broadcasting service in Nepal.
RNE plays vital role in the case of a disaster. So, for disaster relief in Nepal there is a
nationwide broadcast system in place for natural and manmade disasters or other large
scale disasters.
RNE is broadcasting not only daily broadcasting matter but also used for transmitting the
EWBS side by side. In this way information can be provided to national, different districts
& local people about awareness of an emergency.
Main EWBS message will flow from the Ministry of Home Affairs to the government
medias such as Radio Nepal, Nepal Television & National News agency. The Government
of Nepal‟s Home Affair Ministry is responsible for responding to national disasters and for
helping the local governments and individuals to get ready for emergencies.
In the case of a disaster, all broadcasting stations and currently other systems are
required to broadcast EWBS messages from the Ministry of Home Affairs.
Past Major Disasters
Main natural disasters in Nepal are given bellows:
1. Earthquake
2. Flood, Landslide and Debris Flow
3. Fire
4. Epidemic
5. Avalanche
6. Glacier Lake Outburst Flood (GLOF)
7. Windstorm, Thunderbolt and Hailstorm
8. Drought
9. Airport emergencies
32
“The goal of my research is to introduce and implement the Emergency Warning System
in Nepal in the near future, at least to reduce the loss of lives and damage of properties
from different kinds of disasters.”
4.4.2 Structure of whole System
In the emergency warning broadcasting systems, the core thing is to manage
transmission system.
For coverage of most part of Nepal we have to proceed in the following ways.
Broadcast swiftly and assuredly during emergencies
Prevent improper transmissions
Prevent non-transmission
For a developing country like Nepal the main EWBS station will be located in Kathmandu.
In case of a precaution announcement, alert for large scale earthquakes or some
emergency warning alert, all the wavelengths are utilized and the warning is transmitted
from central office of Radio Nepal.
As for broadcast requests from prefecture and local district officers and so on , they can
be provided by the relevant broadcasting stations on three wavelengths, such as
Radio Nepal‟s all channels (Main central MW – transmission station is
Kathmandu transmitting station)
Nepal Television„s [NTV] Main station and other relays stations.
FM radios who have a stand by transmitting facilities.
To accomplish these transmitting formats, 30 stations – RNE main station and local
broadcasting stations (excluding prefecture region stations, prefecture sub stations, and
some TV stations) are equipped with emergency warning broadcasting equipment. The
following transmitting stations will be used at different locations in Nepal for terrestrial
transmission of EWBS.
Medium Wave [MW] Transmitters in Radio Nepal
1. Kathmandu transmitting station [100kW with 10 kW standby]
2. Pokhara Transmission Station [100kW with 10 kW standby]
3. Bardibas Transmission Station [10 kW with 10 kW standby]
4. Dharan Transmission Station [100kW with 10 kW standby]
5. Surkhet Transmission Station [100kW with 10 KW standby]
6. Dipayel Transmission Station [10 kW with 10 kW standby]
Frequency Modulation [FM] Transmitters in Radio Nepal
1. FM Kathmandu relay station [1Kw with 300w standby]
2. Hetauda FM relay Station [100w]
3. Bharatpur FM relay station [1Kw]
4. Daunne FM relay station [1Kw]
5. JomSom FM relay Station [10w]
6. Ilam FM relay station [1Kw]
7. Dang FM relay Station [1Kw]
8. Budhitola FM relay Station [1Kw]
9. Jumla FM relay station [100w]
10. Hulla FM relay station [100w]
33
Short wave [SW] Transmitter in Radio Nepal
1. Khumaltar transmitting station SW [100Kw]
The above mentioned from numbers 1 to 6 are our Medium Wave [MW] Transmitting
stations and others are Frequency Modulation [FM] relay stations and Short Wave [SW]
stations of Radio Nepal. Thus we can use other stations in the case of the disasters.
These are the some stations names:
a. Nepal Television [NTV]
b. Nepal 1 TV
c. Image FM radio 97.9 MHz
d. kantipur FM 96.1 MHz
e. Other Small communities FM stations.
There are several countries that have been operating disaster warning systems. In Japan,
this type of broadcasting has been started since September 1st, 1985. By sending out an
emergency broadcast signal from a broadcasting station to trigger people receivers, this
system is very powerful method to pass on information in reliable way for helping to
alleviate the effects of disasters and to prevent casualties when natural disasters occur.
4.4.3 About Emergency Warning Signal
As a signal for communicating information in aid to broadcasts regarding natural
disasters, the “Emergency warning Signal” consists of beginning (start) signal I,
beginning (start) signal no. II, and a completion (end) signal. Beginning (start) signal
I is transmitted in order to trigger all kinds of receivers in standby state. And beginning
signal II is transmitted in order to trigger receivers in special standby states. The
completion (end) signal, depending on the beginning signals I and II are transmitted in
order to return the status of the receiver back to the operational status that existed
before those emergency signals were transmitted.
There are three emergency scenarios:
1. Alarm warnings for the large-scale earthquakes,
2. Requests from the district administrations based on the disaster measures basic
law, and
3. Flood and landslide precaution announcements.
The classification of emergency warning signals (initiation signals I and II) used for each
scenario are listed in table 6.2
Firstly, in case no. 1 , by utilizing all broadcast wavelengths ( Radio Nepal all channel,
NTV, NTV Metro and FM radio station Channels), a local common code from Kathmandu
is used and emergency warning broadcasts are delivered.
Secondly, in case no.2, a region code or a district code is used by the relevant
broadcasting stations and broadcasts are sent on RNE MW channels, TV and FM.
Thirdly, in case no. 3 ,by using all wave lengths as well as a nation code from
Kathmandu, a region code or a district code from the first relevant broadcasting station
is used and an emergency warning is broadcasted.
34
The area code covers fixing an area that receives an emergency warning signal, namely-
Nation code
Region code
District code
4.4.4 EWBS Signal
For the country like Nepal it is very tough to cover the whole country with EWBS signal.
Nepal probably contains many mountains and high land territories than any other
country in the world. So mainly due to the lots of natural obstacles, we have only few
options to carry signal in these mountainous area.
The signal generated by the emergency warning signal generator is set up with the help
of the Ministry of Information and communication and Nepal telecommunication
authority‟s regulations. The transmission speed at 64-bits per second, this deviation
must be ten parts per million. And, signal distortion below 5 % is better.
So most of the people can afford the small low cost radio and they are familiar with the
radio receiver. My Aim is to add Emergency Warning Broadcasting System (EWBS) circuit
in each receiver and introduce the EWBS systems in the disaster areas for the prevention
of their valuable life and properties.
In the Medium frequency the day time attenuation is high, but at night time, attenuation
is low because of ionosphere propagation. MW signals cover a lot of area at night time.
To cover with good EWBS signal we have to plan the target area and certain amount of
beaming of power is required to be done.
The best way to cover the whole mountainous region is by using satellite radio
broadcasting with low power consumption radio receiver. The direct reception from the
satellite is possible; the effects of signal blockage by buildings, mountains and so on are
reduced.
Modulation Method
The allowable frequency deviation in the frequency shift keying (FSK) method space
frequency of 640Hz and mark frequency of 1024Hz is plus or minus ten parts per million
in each case.
35
4.4.5 Set up of an EWBS signal for Nepal
The schematic block diagram of an EWBS signal and national network audio program are
shown in the figure above. With EWBS & other signals interfacing in the broadcast
console.
So, the signal which is received from broadcast console will be controlled by the limiter
and from limiter we will get a 0dB output signal.
From the limiter two audio outputs with equal gain signals are divided into the two ways
one for the studio to transmitter link[STL] and the other one is for Very small Aperture
terminal [V-SAT].
By using STL link and V-SAT link our EWBS signal and national network program will link
with RNE radio Stations in outside of the Kathmandu valley.
4.4.6 The nation code, the region code and the district code
The nation code makes it possible to receive an emergency warning signal within all the
areas covered by each broadcasting station.
36
In the contest of a disaster, there is only one possible and suitable media, RNE. From
RNE we can distribute the messages to the whole country by using FM, MW and SW
systems.
The region code makes it possible to receive the EWBS signal shown in the region as
listed in table below. The district code makes it possible to receive the emergency
warning signals within each district and within each prefecture.
Classification of Local codes
Table 6.1 Classification of local codes S.No. Local classification Target area
Area sharing National wide
1. Region area Kathmandu, Patan, Bhaktapur ( Valley)
Five regional areas
2. District Area Zone of each prefecture and district government
6.2 Operational standards for emergency warning broadcasts for Nepal
Table 6.2 Operational standards for emergency warning broadcasts for Nepal Classification Incoming
Signal Local Code
Delivery Media
Performance standard for broadcasting
1. Caution Directive for large–scale earthquakes
SIGNAL I
Nation
All Wavelengths
All Channels All-wavelength simultaneous broadcast
2. Broadcast request according to disaster laws
SIGNAL I
District
Three wavelengths NTV,RNE channel, FM
Single prefecture or broadcasting area
Three wavelengths simultaneous broadcast
3. Flood and landslide precaution announcement
SIGNAL II
Nation Region District
All wavelengths
All channels All-wavelength simultaneous broadcast
37
4.4.7 EWBS Fixed code for Radio Nepal
Table 7.1 EWBS Fixed code No. FIXED CODE HEX REMARKS
1. 0010 0011 1110 0101 0x23E5 INTERNATIONAL
2. 0000 1011 0011 1101 0x0B3D … … … … … …
3. 0000 1011 1100 1101 0x0BCD … … … … … …
4. 0000 1100 1011 1101 0x0CBD … … … … … …
5. 0000 1110 0110 1101 0x0E6D JAPAN
6. 0000 1110 1011 1001 0x0EB9 … … … … … …
7. 0000 1110 1110 1001 0x0EE9 … … … … … …
8. 0000 1111 0011 0101 0x0F35 … … … … … …
9. 0000 1111 0101 1001 0x0F59 NEPAL
10. 0000 1111 0110 0101 0x0F65 … … … … … …
11. 0001 0001 1110 1101 0x11ED … … … … … …
12. 0001 0011 1110 0101 0x13E5 … … … … … …
13. 0001 0100 1110 1101 0x14ED … … … … … …
14. 0001 0100 1111 1001 0x14F9 … … … … … …
15. 0001 0110 1110 0101 0x16E5 … … … … … …
16. 0001 1010 0111 1001 0x1A79 … … … … … …
17. 0001 1010 1110 1001 0x1AE9 … … … … … …
18. 0001 1011 1100 0101 0x1BC5 … … … … … …
19. 0001 1110 1100 0101 0x1EC5 … … … … … …
20. 0001 1110 1101 0001 0x1ED1 … … … … … …
21. 0001 1111 0010 0101 0x1F25 … … … … … …
22. 0001 1111 0010 1001 0x1F29 … … … … … …
23. 0010 0001 1101 1101 0x21DD … … … … … …
24. 0010 0011 0101 1101 0x235D … … … … … …
25. 0010 0110 0011 1101 0x263D … … … … … …
26. 0010 0111 1001 0101 0x2795 … … … … … …
27. 0010 0111 1100 0101 0x27C5 … … … … … …
28. 0011 0000 1011 1101 0x30BD … … … … … …
29. 0011 0000 1111 0101 0x30F5 TEST
30. 0011 0111 1000 0101 0x3785 … … … … … …
31. 0011 1011 0000 1101 0x3B0D … … … … … …
32. 0011 1011 0100 0101 0x3B45 … … … … … …
33. 0011 1100 1000 1101 0x3C8D … … … … … …
34. 0011 1100 1001 0101 0x3C95 … … … … … …
35. 0011 1100 1010 1001 0x3CA9 … … … … … …
36. 0011 1100 1011 0001 0x3CB1 … … … … … …
37. 0011 1110 0010 0101 0x3E25 … … … … … …
38. 0011 1110 0010 1001 0x3E29 … … … … … …
39. 0011 1110 0100 0101 0x3E45 … … … … … …
40. 0011 1110 0101 0001 0x3E51 … … … … … …
Note: Fixed code “0010 0011 1110 0101” is recommended as the common fixed code of
the EWS control signal for analogue broadcasting.
For Nepal our EWBS nation and region area codes are divided in the way mention in
table number 8.1
38
4.4.8 EWBS nation and region Code:
Table 8.1 Nation and region code S.No.
Code
Area
Area Code(12bits
HEX
Start Code(16bits) 10+Area Code+00
HEX
End Code(16bits) 01+Area Code+11
HEX
I.
Nation
Common
101010101100
0xAAC
1010101010110000
0xAAB0
0110101010110011
0x6AB3
II.
Region
Mt. West
011010011001
0x699
1001101001100100
0x9A64
0101101001100111
0x5A67
III.
Region
Mt. East
010110100101
0X5A5
1001011010010100
0x9694
0101011010010111
0x5697
IV.
Region
Far-Western Region
100011010101
0X8D5
1010001101010100
0XA354
0110001101010111
0X6357
V.
Region
Mid-Western Region
100101100110
0X966
1010010110011000
0XA598
0110010110011011
0X659B
VI.
Region
Western Region
101001011010
0XA5A
1010100101101000
0XA968
0110100101101011
0X696B
VII.
Region
Central Region
110010110010
0XCB2
1011001011001000
0XB2C8
0111001011001011
0X72CB
VIII
Region
Eastern Region
010101010011
0x553
1001010101001100
0x954C
0101010101001111
0x554F
39
4.4.9 EWBS district Code for whole Nepal
Table 9.1 EWBS nation/region/district code
40
4.4.10 Country Facts
Population: 25.88 million (25886736)
Literacy rates: 56% (of population age 15+), 70.5% (of net primary enrolment)
Country Profile
Nepal is a landlocked country surrounded by India and China. Geographically, it can be
divided into three distinct belts - the mountains in the north, the hills in the middle and
the plain terrain to the south. The predominance of rugged mountainous areas has made
the development of transport and communication extremely difficult.
Even today a large part of the country remains inaccessible by modern transport and
communications; essential goods and information cannot reach remote areas in a timely
manner. The most remote and poorest districts have an additional burden. They have to
depend on outside economies, paying two to three times more for essential goods..
Nepal is a land of diversity with marked multi-ethnic characteristics. Approximately 55%
of the population comprises indigenous Nepali speakers.
Administratively, Nepal is divided into:
5 development regions,
14 zones,
75 districts,
58 municipalities,
3912 Village Development Committees (VDC), and nearly 36,000 wards.
The role of Chief District Officer is to maintain law and order whereas the Local
Development Officer co-ordinates the development activities in the district through the
District Development Committee (DDC).
District Development Committees are responsible for the political and economic
development of their respective districts. The District Development Act of 1992, later
replaced by Local Self Governance Act 1999, empowers the DDC to function as an
integrated development institution in line with the national decentralization policy.
Furthermore, this act delegates development authority to the respective municipalities
and villages.
41
In the case of our country it will be better to divide our EWBS Local code on the basis of
the area of the territorial of the districts. So, when we are applying the local code for the
each district we can use same local codes for the 2 districts. For example I used the
same local code for the 2 districts like Bhojpur and Khotang and so on. For easy
reference I have given some colour codes to the same local codes.
4.4.11 The network of EWBS Signal broadcasting
Fig 11.1 - Network of EWBS signal broadcasting
This is the main EWBS network in the Nepal. The main EWBS control system will be in
the Central Head office of Radio Nepal, Kathmandu. From that station we will broadcast
EWBS signal to Kathmandu valley and other cities as well as the whole of our country.
For the capital and other cities we have to use the STL link and for other stations V-SAT
42
link. In the regional stations, first we will catch the EWBS signal in the ABR 202A Audio
satellite receiver, then the analogue signal will be link to the studio, radio and TV news
centres.
After that we will be ready to broadcast EWBS signal from the regional Stations as well
as from the Districts FM relay stations.
The network in the districts is shown in figure below.
Fig 11.2 - Network of EWBS signal broadcasting in the districts
4.4.12 FM future in EWBS
RNE started broadcasting in FM since 1995. Now Government of Nepal has already
issued more than 180 licenses for FM broadcasting in various parts of Nepal. Already
more than 70 FM stations are broadcasting their programs in Nepali, English as well as
other local languages. So we can also utilize private FM stations for the purpose of EWBS
Broadcasting in order to increase the area of coverage, in order for EWBS signal to reach
the whole country.
Some information about EWBS system
• Delivering emergency information as soon as possible to anyone, anywhere
• Automatically turn on service-compatible radios and TVs so that home viewers
can promptly receive information on disasters, such as earthquakes or tsunamis
and others when their receivers have been turned off.
• This system is incorporated in the digital broadcasting service, as well as its
analogue counterpart.
43
• Digital terrestrial broadcasting for mobile receivers is scheduled to start in the
spring of 2006, and NHK STRL is developing an emergency warning broadcasting
function for this new service.
Automatic activation of a handheld receiver with EWBS signal
For automatic activation to be possible, the receiver has to be in constant stand-by mode,
ready to receive the Emergency Warning System (EWS) signal transmitted from a
broadcasting station. The battery power consumption of a conventional mobile receiver
is too high in the EWS stand-by mode (only one day of stand-by operation possible).
4.4.13 EWBS receivers at NHK STRL
Fig 13.1 - Different types of the EWBS receivers in NHK STRL, Japan
44
4.4.14 Our programme focus
Our organization has started its program distribution via V-SAT (Very Small Aperture
Terminal) network from August 26th, 1999. The main hub station is at the central office,
Singha Durbar, Kathmandu..
The system has the facility to provide multi-channel capability for further use. From year
2000 RNE has leased THAICOM III 100 KHz bandwidth to distribute its program via
satellite. Nowadays we are using THAICOM V for our national network audio link.
Information of VSAT / Transmitting DATA
For the reference we are using the V-SAT system to link the national networks in remote
places, below are the parameters of our transponders:
By using V-SAT audio uplink system we can cover the whole of the mountainous part
with the help of FM , MW and SW fill in relay broadcasting stations.
The locations of the fill in relay stations depend upon the area of remote place,
population and the target points as well.
Orbit Location : 78.5 degree East
Satellite : THAICOM V Satellite
Beam : Standard C-band Regional Beam
Frequency Band : C-Band, QPSK Modulation
Transponder : 9
Bandwidth : 0.10 MHz
Uplink Polarization : Horizontal
Uplink Frequency Range : 6259.95 MHz
Downlink Polarization : Vertical
Downlink Frequency Range : 4034.950 M
Fig 14.1 - Radio Nepal V-SAT System
45
Regulatory Mechanism
Need of National Broadcasting Authority
Authority should be independent, autonomous and governed by special Act
Authority should be representative
The authority to policy formulation, license, regulation and monitor
Radio signal depends upon the geographical situation
Today's technology offers a good solution for almost every network application. Smaller
networks (fewer than 500 sites) choose SCPC (Single Channel Per Carrier) digital
technology with its low uplink earth station installation and operation costs and very low
recurring space time charges. Slightly higher receiver costs are more than offset by
savings on recurring satellite space time access charges, and the overall quality of the
network technology is known to be reliable and stable.
The fill in relay radio station is the one which is operated in the Himalayan and remote
community, for the community, about the community and by the community.
Consequently, the broadcasting can be managed, monitored & controlled by using new
device Davicom Monitoring, alarm and remote control (MAC) telemetry system. So we
can monitor our broadcast from anywhere.
The MAC is already in use in many countries throughout the world, for example Canada,
USA, UK , Australia, Taiwan, Thailand, Kenya, Germany, Malaysia and so on.
The main link is made available for mountainous region through the use of limited power
of FM, MW, SW transmitters and satellite radio. During radio broadcasting in the
mountainous region the noise has its greatest damaging effect when the signal is
weakest. That‟s why we have to plan the broadcasting in different frequencies as well as
in different modulation systems.
Receivers in broadcasting systems are of widely different varieties depending on the
system requirements such as modulation systems used, operation frequency, range of
the system, etc.
It is essential, however, that a perfect agreement should exist between transmitter and
receiver concerning the modulation methods, coding methods and also the timing or
synchronization in certain systems.
Thus, in our case study the higher the carrier frequency; the better is the selection of
signal in the receiver. From this consideration higher carrier frequencies are preferred.
In this way, we can cover the whole of mountainous region with EWBS signals mainly
with the help of satellite radio broadcasting and also by establishing fill in FM relay
stations, and adding high power of SW Station.
46
Features of low-power consumption EWS stand-by circuit
Lower power consumption is achieved by specifying only the frequency
component used by the EWS for stand-by operation. This enables approximately
two weeks of stand-by time.
The EWS circuit functions even under extremely poor signal reception conditions.
The technology can be applied to other devices, e.g., as a built-in function of a TV
remote control device or a home TV set.
In contrast with communications, which experiences extreme circuit congestion
during an emergency, broadcasting's capability of instant information delivery to
a large number of automatically activated handheld receivers is considered to
make it an extremely effective disaster prevention schema.
4.4.15 EWBS coverage in Nepal
In the case of the EWBS mapping for Nepal. We can see different colour markings,
because we will have to give EWBS signal service from different transmitters. Firstly we
will have to use YELLOW & LIGHT GREEN COLOUR markings for the MW service,
Secondly, SKY BLUE colour marking for the SW service and the lastly PINK colour
marking is FM service.
For most of the mountainous areas we have to depend on the SW broadcasting. During
night and early morning we can provide a good signal with the help of the MW service.
For the rest of the districts, marked in other colours, we have to plan the new fill in relay
stations.
47
EWBS coverage map of Radio Nepal
48
The Coverage map of the RNE by AM & FM transmitters
49
AREA COVERED BY EWBS SIGNAL WHOLE NEPAL
Table 15.1 Eastern Region
COLOUR CODES:
Table 15.2 Central Region
COLOUR CODES:
MW SIGNAL EWBS
SW SIGNAL EWBS
FM SIGNAL EWBS
MW SIGNAL EWBS
SW SIGNAL EWBS
FM SIGNAL EWBS
50
Table 15.3 Western Region
COLOUR CODES:
Table 15.4 Midwestern Region S. No
District Population –in 2001
Area (Sq Km)
District head Quarter
zone Radio/ TV stations
Covered by EWBS
Remarks
52. Dang Deokhuri
462380 2955 Ghorahi Rapti 1KW/FM 98MHz/FM
53. Pyuthan 212484 1309 Pyuthan Rapti
54. Rolpa 210004 1879 Livang Rapti
55. Rukum 188438 2877 Jumlikhalanga Rapti
56. Salyan 60643 1462 Salyan Rapti
57. Banke 385840 2337 Nepalganj Bheri
58. Bardiya 382649 2025 Gularia Bheri
59. Surkhet 269870 2451 Birendranagar Bheri 100KW/ 10KW MW
576KHz
60. Jajarkot 134868 2230 Jajarkot Bheri
61. Dailekh 225201 1502 Dailekh Bheri
62. Kalikot 11510 1741 Manma Karnali
63. Jumla 69226 2531 Jumla Karnali 100W/FM 103MHz
64. Dolpa 22071 7889 Dunai Karnali
65. Mugu 31465 3535 Gamgadhi Karnali
66. Humla 40595 5655 Simikot Karnali 10W/FM 100MHz
MW SIGNAL EWBS
SW SIGNAL EWBS
FM SIGNAL EWBS
51
Table 15.5 Far-western Region S. No
District Population –in 2001
Area(Sq. Km)
District head Quarter
zone Radio/ TV stations
Covered by EWBS
Remarks
67.
Bajhang 167026 3422 Chainpur Seti
68.
Bajura 100626 2188 Martadi Seti
69.
Achham 231285 1680 Mangalsen Seti
70.
Doti 207066 2025 Dipayel Seti 10KW/ 10KW MW
810KHz
71.
Kailali 616697 3235 Dhangadhi Seti 1KW/FM 100MHz
72.
Kanchanpur
377899 1610 Maherndranagar
Mahakali
73.
Dadeldhura
126162 1538 Dadeldhura Mahakali
74.
Baitadi 234418 1519 Baitadi Mahakali
75.
Darchula 121996 2322 Darchula Mahakali
COLOUR CODES:
4.4.16 National Policy on Disaster Management
Realizing the need, the Natural Calamity Relief Act was drafted in 1982 by His Majesty's
Government with a view to protect life and property and make arrangements for the
operation of relief work. This act, already amended twice in 1989 and 1992, is the
milestone of disaster management in Nepal.
Ninth Plan (1998 to 2002) underlines the need to strengthen the disaster management
capability by adopting various possible means such as making efforts towards prevention,
mitigation and reduction of natural disaster through more advanced geological,
hydrological and meteorological technology, hazard mapping, vulnerability assessment,
risk analysis and early warning system along with provision of well trained and efficient
manpower. The plan also stresses the need to strengthen the capability of fire brigade.
The plan emphasizes the importance and the need for national and/or international
assistance. The Tenth Five Year Plan outlines the objectives, strategies, programmes,
working policy and expected achievements related to disaster management.
National Action Plan on Disaster Management 2005 was presented at the World
Conference on Disaster Reduction held in Kobe, Japan from 18-22 January, 2005.
MW SIGNAL EWBS
SW SIGNAL EWBS
FM SIGNAL EWBS
52
The organization structure for Disaster Relief Committee in Nepal as follows.
Fig 16.1 - Organization Structure for Disaster Management in Nepal
53
The Government of Nepal disaster management structure as below
Fig 16.2 - Government of Nepal‟s Disaster Management
27
54
4.4.17 EWBS Message on TV broadcasting
For a country like Nepal it is very helpful if we manage the EWBS messages in TV
Broadcasting in different colour markings to denote the EWBS signal message.
Harsh risk
High risk
EWBS Yellow
Significant risk
EWBS Blue
General risk
EWBS Green
Low risk
Fig 17.1 - EWBS Message on TV broadcasting
In this way people can receive the information very fast so no need to listen the audio if
they know the colour marking categories when they are watching or even far from the
TV set.
We know that the information about local natural disasters are often broadcast via EWBS.
So, all EWBS signals should be accessible by audio and visual means or simple visual
means, including closed-captioning, one captioning, crawls or scrolls.
EWBS allows broadcast stations, satellite radio, cable systems, DBS systems, and other
services to send and receive emergency information quickly and automatically.
Yes, radio and TV stations are to help develop faster and more effective early warning
systems by
Increasing the rate and accuracy of information flows from meteorological and
disaster management organizations to broadcasting stations.
Ensuring a rapid flow of disaster and emergency information from stations to the
public.
Before disasters strike people can set up a new place with the help of EWBS signal.
Exceptional Case:
If radio and television tower or studio is damaged during a natural disaster like a big
earthquake in the whole parts of the country at the same time, we cannot receive the
EWBS signal.
For this situation we have to arrange a portable type of EWBS system in the main
disaster areas.
EWBS Red
EWBS Orange
55
4.4.18 Conclusion:
In this way we can provide the EWBS signal to the whole country of Nepal. In the first
phase we have to establish the EWBS system in the capital of Nepal, Kathmandu. Our
main EWBS signal is controlled from the central office, Singha Durbar, Kathmandu.
This EWBS offers a high capacity and high intensity method for the delivery of messages
for the specific purposes to specific locations or people throughout the whole country, in
real time, within a few seconds of receipt of the data.
(The author highly acknowledged the valuable help from Dr. Yasuhiro Ito and other staff
of NHK STRL).
Appendix:
56
4.5 CHINA
Emergency Broadcasting in China
China is mostly influenced by natural disaster in the world. The CPC and State
Department focused highly on disaster reducing and prevention. China has built up
national disaster management system and mechanism in recent years. Moreover, the
national emergency broadcasting system has developed very quickly.
4.5.1 The Act and regulation in China
May 14th，2005，State Council (China) officially promulgated <National Act of Natural
Disaster Relief and Emergency>. This act regulates the course, procedure and principle
of the emergency disposition. As the act stipulates, the natural disaster includes flood,
drought, weather disaster, earthquake, geological disaster, oceans disaster, forest and
grassland fire, etc.
National Disaster Reduction Committee (NDRC) is the national disaster relief and
emergency coordinative organization and is responsible for formulating guidelines, policy
and plan of Chinese national disaster relief. The office of NDRC is in Ministry of Civil
Affairs and its responsibility is to collect all kinds of disaster warning information and
report message to other relative organizations. The disaster information reports content
is included of time, location, background, loss of disaster and demand of disaster area.
The type of information reports is divided into preliminary, consequent and verified ones.
Jan 8th, 2006, State Council (China) officially promulgated <National Overall Act of
Outbreak Public Event Emergency>. As the act stipulates, State Council is the top
administration organization and the Prime minister is the general director.
Warning information is included in sorts of public affair type, warning level, time of
beginning and ending, influence range, warning item, action measure and publish
department.
Warning level is based on harm, emergency and development trends of natural disaster.
In general, the level is divided into first level (special serious), second level (serious),
third level (relatively serious) and fourth level (general), and demonstrated with red,
orange, yellow and blue.
4.5.2 Implication of China Emergency Broadcasting
In Oct, 2006, the State Administrator Radio, Television and Film (SARFT) promulgated
industrial standard of China Mobile Multimedia Broadcasting (CMMB) and confirmed that
STiMi technology is the mobile TV standard of CMMB.
CMMB obligates emergency channel according to <National Overall Act of Outbreak
Public Event Emergency>. When the natural disaster happens, CMMB is able to propel
emergency messages to all of CMMB terminals. The CMMB test terminal is illustrated in
Figure 1.
57
Fig 1 - CMMB Test Terminal Equipment
14th Nov, 2007, the State Administrator Radio, Television and Film (SARFT) promulgated
<Fourth Part of CMMB: Emergency Broadcasting>, and implied on 20th Nov, 2007.
This standard is based on the State Department <General Emergency Act of National
Break out Public Event> (GY/T 220.4-2007), associating with the CMMB technology
system.
According to the influence area of the event, the emergency broadcasting is included
with National Emergency Broadcasting and Regional Emergency Broadcasting. The
National Emergency Broadcasting faced to the whole country and the Regional
Emergency Broadcasting faced to the local area. The emergency information in
Emergency Broadcasting system complied with the correlative standard and criterion to
encapsulate and transmit.
The national emergency information broadcasts by the nation emergency broadcasting
head end. There are three modes to cover with the mobile terminal. The first, covering
with the mobile terminal directly by satellite transmission. The second, covering with the
mobile terminal by S-band terrestrial appending transmit network. The third, the local
broadcast head end received the national emergency information from satellite or
through band-wide transmission channels to receive national emergency broadcast
information and broadcasted by head end at local network to receive local program.
Local emergency broadcasting information is sent by local broadcasting head end and
covered with local network terminal. In order to send the information to the long-
range mobile terminal, local information can be sent by national emergency broadcasting.
The national emergency broadcasting message is confirmed by national broadcast
organization. The test emergence message of CMMB is illustrated in Figure 2.
58
Fig 2 - Emergency Broadcasting Test Message of CMMB
Emergency broadcasting is demonstrated by text and extends to support audio, picture
and figure format, also it can be realized into multi-code and multi-language. National
emergency broadcasting can cover the whole countryside throughout satellite and
terrestrial covering network. Local broadcasting network can transmit national message
at once. Local emergency message can cover with local network and apply to trigger
national head-end to transmit the message. Emergency broadcasting system processing
is illustrated in Figure 3.
Fig 3 - Emergency broadcasting system processing
59
4.5.3 Sending and Receiving the Emergency Broadcasting
The stated flow chart of Emergency Broadcasting in <Fourth Part of CMMB: Emergency
Broadcasting>is illustrated in Figure 4.
Fig 4 - Emergency Broadcasting Flow Chart
When the emergency broadcasting information is sent, the information data would be
split and segment would be encapsulated as emergency data segment. Then the
segment would be encapsulated to emergency broadcasting chart. Finally, it was re-used
and sent. At receiver, it would be unlocked the re-use, chart, segment based on inverse
flow. The data segment of emergency broadcasting is illustrated in Table 1, Figure 5 and
6.
Table 1. Chart of Emergency Broadcasting Grammar Digit Id
Emergency Broadcasting（）
{
Chart ID 8 uimsbf
Intercurrent message number 4 uimsbf
Reserved 2 bslbf
Emergency Broadcasting Serial No. 2 bslbf
Emergency Broadcasting Date Segment Length 16 uimsbf
for （i = 0; i < N; i++）
{
Emergency Broadcasting Date Segment 8 uimsbf
}
CRC_32 32 uimsbf
}
60
Fig 5 - The Data Segment of Emergency Broadcasting Data message of Emergency Broadcasting
Fig 6 - Emergency Broadcasting Message
61
4.5.4 Emergency Broadcasting Operation System
4.5.4.1 Basic System Structure
Based on the emergency broadcasting system design schema, the broadcasting frond-
end is divided into national and local ones. The telecommunication of these two frond-
end systems can be transmitted by out-band transmission channel. The frame of
Emergency Broadcasting Operation System is illustrated in Figure 7.
Fig 7 - Emergency Broadcasting Operation System
1- National Emergency Broadcasting Head End
National Emergency Broadcasting Head End system is consisted of emergency
broadcasting message editor, message auditor, data server, broadcasting server and
receiver transformer. The transformer is used to receive local emergency message
through out-band transmission channel.
2 - Local Emergency Broadcasting Head End
Local Emergency Broadcasting Head End is consisted of the same items with National
ones. The transformer receives national emergency message not only throughout out-
band transmission channel, but satellite.
62
3 - Out-band Transmission Channel
Out-band transmission channel is the two-way channel with national and local
emergency message. The channel is used to transmit national emergency message and
submit trigged information to national department. Out-band transmission
telecommunication can be achieved by E-mail or VPN route way.
4.5.4.2 Primary Equipment
1 - Emergency Broadcasting Message Editor
The editor can create emergency broadcasting message based on message publish
organization and upload the data server to backup, then turning to next auditing.
2 - Emergency Broadcasting Message Auditor
The auditor can audit and confirm the information resource, level and content, the result
will be uploaded to emergency broadcasting data server to revise and transmit.
3 - Emergency Broadcasting Data Server
Emergency Broadcasting Data Server can store and manage message and provide data
service. Data server can also inquire data according to history data.
4 - Emergency Broadcasting Server
The emergency broadcasting server read the on call message from data server and
encapsulated data according to GY/T 220.4-2007.
5 - Emergency Broadcasting Receiver Transformer
The emergency broadcasting receiver transformer is mainly used to receive local
message and automatic upload to national broadcasting emergency data server.
63
4.6 SINGAPORE
Implementation of EWBS in Singapore
The Singapore Civil Defence Force (SCDF) implemented the Emergency Broadcast
Message System in 2003 for the public broadcast of emergency messages. The system
was jointly developed by MediaCorp Pte Ltd, SCDF and a local technology partners and
making use of MediaCorp‟s DAB (Digital Audio Broadcast) transmission infrastructure. In
the event of a national disaster, SCDF personnel at their headquarters can remotely send
emergency text messages for broadcast to members of the public via MediaCorp‟s DAB
service. Based on the Eureka-147 DAB DLS (Dynamic Label Segment) format,
emergency messages will appear as scrolling text on the LCD screen of a DAB receiver.
Fig 1 - Overview of the SCDF System
Overview of the SCDF SystemMediaCorp’s Eureka-147 DAB Service
Multip
lexer
MUSICAM
Channel 1
MUSICAM
Channel 7
......
...
From
SCDF HQ
NPAD
Services
Dedicated
Data Services
COFDM
DAB Transmitter
DAB Transmitter
DAB Radios
MUSICAM
Channel 2
Digital Radio’s PAD
SCDF Server
NPAD Server
Audio
Audio
Audio Multip
lexer
Multip
lexer
MUSICAM
Channel 1
MUSICAM
Channel 1
MUSICAM
Channel 7
......
......
......
From
SCDF HQ
NPAD
Services
NPAD
Services
Dedicated
Data Services
COFDMCOFDM
DAB Transmitter
DAB TransmitterDAB Transmitter
DAB RadiosDAB Radios
MUSICAM
Channel 2
Digital Radio’s PAD
SCDF Server
NPAD Server
Audio
Audio
Audio
64
4.7 DISASTER WARNING SYSTEM IMPLEMENTATION USING DVB-T
4.7.1 Introduction
DVB-T is now by far the most adopted and implemented Digital terrestrial Standard in
the world today. Indeed this also applies to the Asia Pacific region where the ASEAN
community has adopted DVB-T as its standard.
Unlike the European region the Asia Pacific region is renowned for its natural disasters
which range from Earthquakes, Tsunamis, and Forest Fires etc. The provision of a
Disaster Warning system in some countries of the region becomes a needed requirement.
Therefore the support of a broadcasting system to the provision of EWS is very
important.
DVB-T has very much the capabilities inbuilt into the standard through the use of the
System information specification DVB-SI to provide such support. This requirement was
foreshadowed many years ago and is an inherent part of the DVB system.
There are 3 fundamental elements to an EWS . These are:
Information gathering processing & delivery infrastructure. This element is
independent from the Broadcasting Transmission standard.
The signal delivery mechanism can be provided by many means. This could include
AM, FM, SW & TV. DVB-T has excellent capabilities to deliver the alert signal to
receivers. This is available Through the use of DVB-SI which is inherent within the
DVB-T standard framework.
Consumer receivers to support alerts. These would depend on the medium used.
However in the case of DVB-T receivers the capability already exists to respond to
directions being provided through DVB-SI signalling.
4.7.2 DVB-T processes in relation to EWS.
In the DVB-T system there is 3 general processes which are employed to deliver the
Warning message to receivers viz. (1) RF & Modulation Aspects , (2) Announcement
Services – Embed video & Audio streams & (3) Triggering the announcement
4.7.2.1 RF & Modulation aspects
Every DVB-T receiver is automatically configurable during transmission. The modulation
parameters and the FEC (forward error correction) is set in the TPS (Transmission
Parameter Signalling). This enables therefore a switch during the delivery of the
emergency warnings to a more robust transmission scheme.. As an example if the
normal transmission modulation parameters are set to 64 QAM, FEC 2/3 then the system
will allow when the disaster strikes to switch to QPSK, FEC ½. This will insure that all
receivers in the coverage footprint (and beyond) will be automatically switched so they
are capable of receiving the disaster information. The QPSK mode is the most robust
mode requiring very low C/N flux density. . The switching to a more robust mode is an
option with DVB-T but is not mandatory.
65
4.7.2.2 Service Announcements
When the receivers have switched to robust modulation parameters, they must be
instructed to play and if necessary also display the emergency warning message.
Warning messages should desirably be combined of visual and audio indications.
The viewer might not be looking at the screen at the time of the message e.g. (blind
person or e.g. radio listener) or
The sound on the receiver might be muted or no speakers connected (deaf person
or e.g. shop display).
DVB provides for dynamic and automatic switching of the receiver to the announcement
from any service during any event. (Advert. or Prog. segment).
DVB supports spoken announcements of several types. They can dynamically occur
during any event. This descriptor gives information about which types of announcements.
The announcement types & relevant descriptor are shown below.
Announcement Services may be located anywhere and referenced from anywhere:
Announcement can be broadcast in the usual audio stream of the service.
Announcement can be broadcast in a separate audio stream that is part of
the service.
Announcement can be broadcast by means of a different service within the
same transport stream.
Announcement can be broadcast by means of a different service within a
different transport stream.
• Indicates the set of
announcement
types supported by
the services.
• For each type of
announcement,
indicates the exact
location of the
announcement
audio.
0 1 1 0 1 1 1 0
7 0
0x6E
15 8
x x x x x x x x
7 0
0xXX
x x x x x x x x 0xXX
descriptor_tag
descriptor_length
announcement_support_indicatorEmergency Alarm
Road Traffic Flash
Public Transport Flash
Warning Message
News Flash
Weather Flash
Event Announcement
Personal Call
Reserved for future use
for (i=0; i<N; i++) {
0xX announcement_typeEmergency Alarm
Road Traffic Flash
Public Transport Flash
Warning Message
News Flash
Weather Flash
Event Announcement
Personal Call
Reserved for future use
0000
0001
0010
0011
0100
0101
0110
0111
1000 - 1111
x x x 0xX
Announcement is broadcast in the usual audio
stream of the service
Announcement is broadcast in a separate audio
stream that is part of the service
Announcement is broadcast by means of a different
service within the same transport stream
Announcement is broadcast by means of a different
service within a different transport stream
Reserved for future use
000
001
010
011
100 - 111if (reference_type == …) {
x x x x x x x x
15 8
x x x x x x x x
7 0
0xXX
x x x x x x x x x x x x x x x x 0xXX
x x x x x x x x 0xXX
}
original_network_id
transport_stream_id
service_id
component_tag
x x x x x x x x x x x x x x x x 0xXX
}
03
reference_type
x x x x
7 4
66
Audio is the baseline profile, use of video (to display a textual warning) is optional.
The Service Description Table (SDT) carries the announcement support descriptor.
It indicates the location of the service carrying audio announcements.
4.7.2.3 Triggering Mechanisms - Switchover to the announcement
The dynamic flags which trigger the real time announcement switching are encoded in
the private data bytes of the adaptation field of the TS packets carrying the audio. The
syntax of the announcement switching data field is defined in EN 300 743. This data field
is present only in those streams that carry announcements.
Services that support announcements by means of giving a reference to announcement
streams will not provide this announcement switching data field in their streams. Thus,
the demultiplexer has to monitor the adaptation field of the announcement stream if the
support of announcements is realized by referencing an announcement stream.
If a reference is made to an announcement stream in a different TS, a copy of the
announcement switching data field has to be embedded in the actual TS, namely in the
audio stream of a service that uses the reference to an announcement stream in a
different TS. The service and the stream that carries this duplicated trigger information
is also indicated by the announcement support descriptor of the SDT.
Typical Examples
Case 1 - The announcement is carried in the main audio of a regular service and the
receiver is decoding it.
TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio
0 1 1 1 0
time
Announcement Active
Announcement
Flag
TS 1 TS 2
SDT 1 SDT 2
Service w / Announcement
Dedicated Announcement Service
Video (optional)
Main Audio
Announcement Audio
Video (optional)
Main Audio
Regular Service Regular Service
SDT – Service Description Table TS – Transport Stream
67
In this case the receiver does not need to take specific action other than monitoring the
announcement flag in the audio PID (Packet Identifier). The system will also allow an
increase in the volume to some higher value (e.g. 66%) so that the audio is heard even
if the sound control on the receiver is set at a low level.
An overlay on the video with a textual message by the broadcaster for the hard of
hearing is also another added option available by the system..
Case 2 - The announcement is carried in the audio of a regular service within the same
Multiplex, but the receiver is not currently decoding that particular service stream.
In this case the receiver will need to monitor the audio PID of the announcement service
stream in addition to the current service stream. When the announcement flag “comes
on”, it switches to the announcement audio PID.
Optionally, if the announcement service does have video, the receiver may also switch
the video PID to that of the announcement service.
Case 3 – This example demonstrates an instance of Cross-Transponder. Here the
announcement is not carried in the audio of a regular service stream in the same
multiplex but in a different Multiplex to which the receiver is currently tuned.
In this case the broadcaster is required to constantly copy the announcement flag to an
audio PID on the current Multiplex. The receiver again needs to monitor the audio PID of
the proxy service in addition to the current service. When the announcement flag “comes
on”, it tunes to the other Multiplex and switches to the announcement audio PID.
Current Service (current Multiplex)
Audio
Announcement Proxy Service (current Multiplex)
TS HDR
AF
Audio
TS HDR
AF
TS HDR
AF
TS HDR
AF
TS HDR
AF
Audio
time
Actual Announcement Service (other Multiplex)
TS HDR
AF
Audio
TS HDR
AF
Audio TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio
0 1 1 1 0
time
Audio Audio Audio
Audio Audio Audio
Copy Flag
Current Service
Audio
Announcement Service
TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio
TS HDR
AF
Audio TS HDR
AF
Audio
0 1 1 1 0
time
Video
Audio Audio Audio
68
4.7.3 Summary & Conclusions
DVB through the capabilities of DVB-SI can support the transmission and receiver
functionalities required to provide an Emergency Warning System via DVB broadcasting
systems such as DVB-T. In particular;
DVB-T allows you to make sure every receiver accesses the warning message and if
necessary will display it visually on the receiver screen.
Due to the flexible pointer mechanism in DVB-SI both, national and regionalised
Disaster Warning services can be realised.
The requirements on the receivers are minimal. At most one additional packet
identifier (PID) needs to be monitored.
At the minimum, audio announcements are supported. Thus interoperability with
radio sound services is maintained.
Additional visual indicators on the screen can optionally and flexibly be inserted at the
discretion and under the control of the broadcaster and the authorities.
________