ETSI TR 103 273 V1.1.1 (2016-12)

Emergency Communications (EMTEL); Recommendations for public warning making use of pre-defined libraries

DTR/EMTEL-00032

General Information

• Status: Published
• Publication Date: 22-Dec-2016
• Technical Committee: EMTEL - Emergency Communications
• Current Stage: 12 - Completion
• Due Date: 07-Dec-2016
• Completion Date: 23-Dec-2016

Standards Content (Sample)

TECHNICAL REPORT
Emergency Communications (EMTEL);
Recommendations for public warning making use
of pre-defined libraries
2 ETSI TR 103 273 V1.1.1 (2016-12)

Reference
DTR/EMTEL-00032
Keywords
broadcasting, design for all
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3 ETSI TR 103 273 V1.1.1 (2016-12)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 Public Warning Paradigm . 9
4.1 General . 9
4.2 Best Practices in Public Warning . 11
4.2.0 Overview . 11
4.2.1 Criteria in the Public Warning Decision Process . 12
4.2.2 The Alert Message . 13
4.2.2.0 Introduction . 13
4.2.2.1 Alert Message Style . 13
4.2.2.2 Alert Message Content . 13
4.2.2.3 Size and information quantity . 14
4.2.2.4 Use of templates for alert messages . 14
4.3 Warning Message Recommendation . 15
4.3.1 Conditions to Maximize Actionability Upon Alert Message Reception . 15
4.3.2 Alert Message Recommendations . 16
4.4 Alerting Library Concept . 17
4.4.0 Introduction. 17
4.4.1 Alert message content . 17
4.4.2 Using alerting libraries . 19
4.4.3 Updating alerting libraries . 19
5 Alerting Libraries Description . 19
5.1 Alerting Libraries Architecture . 19
5.2 Alerting Libraries Structure . 21
5.3 Alerting Libraries . 22
5.4 Support of Time Information. 23
5.5 Support of Location Information . 23
5.6 Support of Unique Authority Identification . 23
5.7 Common Alerting Protocol Compliance . 24
5.7.1 Alerting libraries fields correspondence with CAP fields . 24
5.7.2 Special cases . 24
6 Application of Alert Libraries . 25
6.1 Alert4All Project Approach . 25
6.2 Examples of message translation . 27
6.2.1 CMAS approach . 27
6.2.2 Munich shooting on 22.06.2016 . 29
7 Recommendations for Alert Message Assembly Rules . 31
7.1 Introduction . 31
7.2 Principles of Alert Message Assembly . 31
7.2.0 Overview . 31
7.2.1 Structure Rules . 32
7.2.2 Syntax rules . 32
7.2.3 Conversion rules . 32
7.3 Example Structure Rules for Text in English . 32
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4 ETSI TR 103 273 V1.1.1 (2016-12)
7.4 Example Syntax Rules for Text in English . 33
7.4.1 Syntax of First and Update Messages . 33
7.4.2 Syntax of Release Messages . 37
7.4.3 Syntax of Cancel Messages . 37
7.5 Example Conversion Rules for Text in English . 37
8 Change Management . 38
History . 40

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5 ETSI TR 103 273 V1.1.1 (2016-12)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Special Committee Emergency Communications (EMTEL).
Modal verbs terminology
In the present document "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be
interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
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6 ETSI TR 103 273 V1.1.1 (2016-12)
1 Scope
The present document describes the rules and procedures to implement public warning making use of pre-defined
libraries that enable simple and systematic multi-language and multi-mode presentation of warning messages in any
European country. This includes the definition of dictionaries for public warning, syntax rules and procedures to
formulate warning messages, as well as rules and procedures to extend dictionaries when required.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] UNISDR Terminology on Disaster Risk Reduction (2009).
NOTE: Available at www.unisdr.org/eng/terminology/terminology-2009-eng.html.
[i.2] D. S. Mileti and J. H. Sorensen: "Communication of emergency public warning, A social science
perspective and state-of-the-art assessment", August 1990.
[i.3] Centers for Disease Control and Prevention, Crisis and Emergency Risk Communications: Best
Practices, 2009.
[i.4] D. S. Mileti: "Warning messages and public response", Social science research findings &
applications for practice, August 2009.
[i.5] Partnership for Public Warning, Protecting Americas Communities, An introduction to public alert
& warning, 2004.
rd
[i.6] W.T. Coombs: "Ongoing Crisis Communication: Planning Managing and Responding", 3
edition, Thousand Oaks: SAGE, 2011.
[i.7] Australian Government, Emergency management Australia Evacuation planning, 2005.
[i.8] California Emergency Management Agency, Alert and Warning, Report to the California State
Legislature, 2008.
[i.9] D. S. Mileti: "Factors related to flood warning response", U.S. Italy Research Workshop on the
Hydrometeorology, Impacts, and Management of Extreme Floods, Italy, 1995.
[i.10] Working Group on Natural Disaster Information Systems, Subcommittee on Natural Disaster
Reduction, Effective Disaster Warnings, 2000.
[i.11] C. Fitzpatrick and D. S. Mileti: "Motivating public evacuation". International Journal of Mass
Emergencies and Disasters, August 1991.
[i.12] CAP V1.2: "Common Alerting Protocol Version 1.2".
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7 ETSI TR 103 273 V1.1.1 (2016-12)
[i.13] J-STD-101: "Joint ATIS/TIA CMAS Federal Alert Gateway to CMSP Gateway Interface
Specification".
[i.14] ISO 22322-2015: "Emergency Management - Guideline for Public Warning Systems".
[i.15] International Federation of Red Cross and Red Crescent Societies: "Community early warning
systems: guiding principles".
NOTE: Available at www.ifrc.org.
[i.16] ISO EN 22300-2014: "Teminology".
[i.17] Recommendation ITU-T X.680 / ISO/IEC 8824-1: "Information technology - Abstract Syntax
Notation One (ASN.1): Specification of basic notation".
[i.18] T. De Cola, J. M. Chaves, C. Parraga: "Designing an efficient communications protocol to deliver
alert messages to the population during crisis through GNSS" in Advanced Satellite Multimedia
Systems Conference (ASMS) and 12th Signal Processing for Space Communications Workshop
(SPSC), 2012 6th volume, no. pp.152-159, 5-7 September 2012, Baiona, Spain.
[i.19] Alert4All (A4A), EU-FP7 SEC-2010.4,3-1 funded project, 2011-2014.
NOTE: Available at http://alert4all.eu/.
[i.20] US National Weather Service.
NOTE: Available at http://www.weather.gov/.
[i.21] ETSI TR 103 335: "Emergency Communications (EMTEL); Guidelines for alert message content
accessibility".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
alert decision maker: authority entitled to decide whether to warn the population or not based on the warning
information gathered from the warning author
alert message: Equivalent to the term warning message in ISO 22322 [i.14].
alert message issuer: authority (or authorities) entitled to formulate alert messages, based on the information gathered
from the warning author, and to send the alert message(s) to the population at risk in a direct manner or by means of one
or several intermediaries
alert message recipient: citizen(s) at risk that should receive alert messages disseminated by the alert message issuer
NOTE: The citizen could either be present in a residential, business or recreation environment during the incident.
area of authority: area in which the alert message issuer is entitled to warn/alert the population
early warning system: set of capacities needed to generate and disseminate timely and meaningful warning
information to enable individuals, communities and organizations threatened by an incident to prepare and to act
appropriately and in sufficient time to reduce the possibility of harm or loss, as defined in ISO 22322 [i.14]
NOTE: This definition has been established by the United Nations International Strategy for Disaster Reduction
in [i.1].
incident: This term is defined in the ISO EN 22300-2014 "Terminology" [i.16].
intermediary: service provider or operator that distributes the alert message provided by the alert message issuer over
its communication infrastructure
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8 ETSI TR 103 273 V1.1.1 (2016-12)
warning author: agency that implements the hazard monitoring function and provides warning information to the alert
decision maker and the alert message issuer
NOTE: Examples of the warning author are agencies that monitor and provide information on meteorology,
hydrology, health information, etc., and evaluate the related risks.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Approval Committee
ASN Abstract Syntax Notation
AVW Avalanche Warning
BZW Blizzard Warning
CAE Amber Alert
CAP Common Alerting Protocol
CBRNE Chemical, Biological, Radiological, Nuclear, Explosive
CC Certification Committee
CDW Civil Danger Warning
CEM Civil EMergency
CEN Comité Européen de Normalization
CET Central European Time
CFW Coastal Flood Warning
CMAS Commercial Mobile Alert Service/System
DSW Dust Storm Warning
EAN President has issued an alert
EQW EarthQuake Warning
EVI EVacuate now
EWS Early Warning System
FFW Flash Flood Warning
FLW FLood Warning
FRW FiRe Warning
HMW HazMat Warning
HUW HUrricane Warning
HWW High Wind Warning
ISO International Standards Organization
LAE Local Area Emergency
LEW Police Warning
LME Library Management Entity
NUW Nuclear Power plant Warning
OEZ Olympia EinkaufsZentrum
PDT Pacific Daylight Time
PSAP Public Safety Answering Point
PWS Pubic Warning System
QCC Quality Control Committee
RHW Radiological Hazard Warning
SMW Special Marine Warning
SPW Take Shelter Now
SVR SeVeRe storm warning
TC Technical Committee
TOR TORnado warning
TRW TRopical storm Warning
TSW TSunami Warning
UNISDR United Nations International Strategy for Disaster Reduction
US United States
UTC Coordinated Universal Time (literally Universel Temps Coordonné)
VOW VOlcano Warning
WEA Wireless Emergency Alert
WSW Winter Storm Warning
XML eXtensible Markup Language
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4 Public Warning Paradigm
4.1 General
Public Warning is aiming to support the public audience with information about incidents/crisis and recommendation on
remediating measures during incidents/crisis situations, incidents which could disrupt the safety and security of lives
and/or assets.
Public warning is one important part of the entire emergency communication within the emergency and/or crisis
management process. The complementary part of the emergency communication during such incidents/crisis is the
information provision to the emergency management staff in the field enforcing the efficient implementation of
effective response actions, thus limiting harm/damages to lives and assets.
Enabler for the emergency communication is well established risk knowledge/risk management functions, a monitoring
function as well as response capabilities. These three functions outline/define content to the messages, which have to be
disseminated either to the public or the emergency management staff.
The emergency communication should be capable of supporting man made as well as natural disasters based
incidents/crisis situation. In this respect the most prominent global references UNISDR [i.1] and ISO technical
committee "Security and Resilience" [i.14] are supplying two well-funded frame works (see figure 1), which are both
covering the main area addressed in the present document, i.e. dissemination of public warning.
UNISDR EWS frame work ISO PWS frame work
Risk knowledge
Monitoring function, incl. risk
management
Monitoring service
Warning dissemination
Response capabilities
Figure 1: UNISDR and ISO frameworks: functions
According to the UNISDR mandate the EWS frame work is only targeting natural disasters (meteorological, geological,
biological, etc.) while the ISO PWS framework also addresses manmade disasters (incidents/crisis situations, e.g. 9/11,
Oslo bombing, etc.) and also aims to cover the information provision to emergency management staff (first responders,
volunteers, etc.) in the field (see figure 2).

Figure 2: UNISDR and ISO frameworks: scope
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10 ETSI TR 103 273 V1.1.1 (2016-12)
Referring to both frameworks, the functions are characterized as follows:
• Risk knowledge. This term refers to prior knowledge of risks being faced by communities, for example by
means of risk assessment, mapping of incidents and vulnerabilities, their patterns and trends.
• Monitoring and warning function. This term refers to the solid scientific basis for risk prediction and
detection of incidents, as well as to the consequent decision process to disseminate warning messages to
affected communities.
• Dissemination and communication. This term refers to the process of formulating and disseminating
messages to affected communities upon detection or prediction of a risk situation.
• Response capability. This term refers to communities understanding their risks and reacting upon reception of
warning messages.
This clause refers to best practices on the dissemination and communication process that yield best results inactionable
warning and information, i.e. providing timely messages that reach, are understood and are acted upon by the
population at risk [i.15].
In the dissemination and communication process, four main actors are involved, see figure 3:
• The warning author: agency that implements the hazard monitoring function and provides warning information
to the alert decision maker and the alert message issuer. Examples of the warning author are agencies that
monitor and provide information on meteorology, hydrology, health information, etc. and evaluate the related
risks.
• The alert decision maker: authority entitled to decide whether to warn the population or not based on the
information gathered from the warning author. Depending on the civil protection organization of a specific
region, this role is typically covered by the Mayor, authorized personnel at civil protection agencies, or similar.
• The alert message issuer: authority entitled to (i) formulate alert messages, based on the information gathered
from the warning author, and (ii) send these alert messages to the population at risk in a direct manner or by
means of one or several intermediaries. This role is typically covered by civil protection agencies (or entities
having similar functions) or specific responders, such as fire brigades. The actors model in [i.15] refers to the
"alert message issuer" as "mediator", as its major role is to shape the alert message to be understandable by the
community at risk, avoiding jargon and technical language, which can be expected from the warning author
(agencies involved in the monitoring function), who has typically a scientific background.
• The intermediary: a service provider that distributes the alert message over its communication infrastructure
for delivery to the alert message recipient. The intermediary may adapt the format of the alert message to make
it compatible with the technology that will be used for delivery. Examples of intermediaries are
telecommunication operators or radio or TV broadcasters.
• The alert message recipient: the citizen(s) at risk that should receive (read and understand) alert messages.
It is worth noting that this actors' model represents generic roles in the communication process for public warning that
can be mapped into agencies and authorities in different manners, depending on the civil protection organization of each
region or country. Several warning authors can provide warning information to a single or several alert decision makers
and alert message issuers. The alert decision maker and alert message issuer may make use of information systems to
aggregate the information from several warning authors to build a comprehensive risk situation awareness. Also PSAPs
can be understood as warning authors when a risk situation is identified by means of citizens calling the emergency
number. The roles of alert decision maker and alert message issuer may be fulfilled by the same authority, even by the
same physical person in a specific context.
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Figure 3: Communication process in public warning
The process depicted in figure 3 shows the actors and functions involved in the communication process in public
warning. It should be noted that the monitoring and evaluation functions are functions that the warning author fulfil,
but are considered previous to the communication process.
The purpose of this process is to create awareness about the occurring risk during an incident and to trigger a specific
reaction or action plan at the alert message recipient site.
In this process, the warning author monitors hazards and evaluates the related risks to create warning information. This
warning information is taken as input by the alert decision maker to decide whether to warn. The alert message issuer
acts upon the decision formulating the alert message based on the input warning information and sends the alert
message through the intermediary. The intermediary adapts the alert message to make it compatible with the
technology or technologies that will be used to deliver the alert message and finally delivers it to the alert message
recipient.
The alert message recipient will make a decision about his/her reaction/action plan as a result of an own risk evaluation
in consideration of the alert message received, the own perception of the situation/environment and the available
response capacity.
The perception of the situation by the alert message recipient is influenced by a number of factors; some of those factors
may be autogenic (including cognition and physical abilities), others may be caused by a social and environmental
context, others may be caused by the own perception of the situation by means of other information sources. Therefore,
the dissemination and communication process should be managed by the alert message issuer in a manner that
maximizes the probability that the alert message recipient understands and acts upon alert message reception in the
intended manner.
4.2 Best Practices in Public Warning
4.2.0 Overview
There is a number of variables that the alert message issuer can steer to foster that the alert message recipient receives,
understands and acts upon alert message reception in the intended manner:
• The alert message content and style.
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• The channels used to disseminate the alert message.
• The frequency with which the alert message is repeated and updated.
This clause compiles best practices in the terms of the three variables listed above. Such best practices are a collection
of standards and guidelines built from past experiences.
4.2.1 Criteria in the Public Warning Decision Process
The warning decision process encloses several decisions as listed below:
Whether to warn
The decision whether to warn is commonly supported by available emergency plans derived from past experiences or
risk analysis of expected incidents in/for the area of authority. The decision has to consider a number of factors, e.g.:
• certainty of the available information;
• expected warning impact;
• long term trust in warning messages;
• costs.
The impact of false alarms can be negative (especially in the long term). On the one hand, emergency communication
services can get overloaded (e.g. by significantly increased calls to PSAPs); on the other hand, several false alarms can
yield the alert message recipient to dismiss other warning messages. Nevertheless, there is evidence that if the reasons
that triggered false alarms are explained with a valid and rational explanation, the public is more tolerant to them.
Hence, most authors recommend to warn in case of doubt, see Communication of emergency public warning, A social
science perspective and state-of-the-art assessment [i.2]. Furthermore, the citizens at risk are exposed to additional
information sources that can spread rumours. It is preferable to warn and state the certainty of the information than
remaining silent and letting rumours spread, see Crisis and Emergency Risk Communications: Best Practices [i.3].
When to warn
The decision when to warn is related to the decision whether to warn. Once the risk is quantified and the warning need
is identified and the action requested from the affected citizens has been determined, the alert message should be issued
as soon as possible. However, low certainty of the available information may cause that the alert issuer waits for more
data to increase the certainty of the warning decision. Furthermore, if the warning is issued too early, the available
information may not be sufficient to provide accurate recommendations for protective actions. Further update messages
should be issued including more details as they become available, see Communication of emergency public warning, A
social science perspective and state-of-the-art assessment [i.2], and Warning messages and public response, Social
science research findings & applications for practice [i.4].
Where and who to warn
An alert message should be addressed to all people at risk with regard to an occurred or expected incident within the
area of authority. This means all people located at a geographical area that is or may be affected by the incident. The
definition of the risk area boundaries may depend on the type of incident, existing emergency plans and additional
information (e.g. weather forecast). Nevertheless, the public should not be understood as a whole group, but as a set of
groups and the alert messages should address all of them. One solution is to issue different messages addressing each
group. However, a more efficient solution is to shape the alert messages in a manner that they address all groups with a
single message, unless different actions are recommended to different groups.
Consideration should be given to the fact that the area where the alert message is going to be distributed is partly
determined by the technology that is used (e.g. radio propagation does not stop at boundaries).
Updating information
After having sent the first alert message, it is important to maintain the communication with the public, updating
information when it becomes available until there is sufficient evidence to consider the situation "all clear". As soon as
the risk situation is "all clear", a message should be disseminated stating the end of the risk situation to return to
normality [i.5] and [i.6]. The frequency to provide update messages should be adapted to the time dynamics of the
concrete incident [i.2].
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Repeating information
Repeating the alert message through different channels has proven to improve the response efficiency [i.3], [i.5], [i.7]
and [i.8]. This is mainly due to two aspects: on the one hand, the repetition through different media reinforces the
authenticity of the information; on the other hand, the probability that an individual receives and notices the alert
message increases. However, too frequent repetitions (in each channel) may relax the attention of the warning recipient
[i.9]. This is especially risky when updated information is disseminated.
4.2.2 The Alert Message
4.2.2.0 Introduction
The content and style of the alert message influence significantly the response capability [i.2]. Optimal alert message
style and content are recommended in the following.
4.2.2.1 Alert Message Style
The aspects listed below contribute to the best practice style of alert messages:
Specificity
The incident should be described in a precise, non-ambiguous manner and avoiding information omission [i.10].
Consistency
The alert message should be consistent in its own content and with other alert messages (e.g. with regard to updated
information) [i.2] and [i.11].
Accuracy
The alert message should be accurate in the spelling and description of information. The latter aspect refers to
formulating open statements with regard to the accuracy of available information [i.11].
Clarity
The alert message should be intelligible by the warning recipients [i.2]. This implies that clear and simple words as well
as standard terminology should be applied, whereas technical language, codes, acronyms or jargon should be avoided
[i.10].
Credibility
As stated in [i.11], upon warning message reception, the public belief can be strongly affected by the message style. For
instance, the credibility of warning messages distributed over radio or video can be differently perceived, depending on
the language, the voice tone, and the body language being used.
Therefore, the reliability of the alert message content is always requested by final recipients, so that they can trust the
warning information therein provided and take the actions described in the related instructions and assess the risk
involved when not taking the described action.
4.2.2.2 Alert Message Content
Each alert message should be tailored to the situation. However, there are general elements that should be part of the
information contained in the alert message. Furthermore, the alert message content should include important
information in the first place, starting with standardized headlines that summarize the content [i.10] followed by the full
message. The way headlines are encoded should be such to avoid overly long messages, so as to keep the overall
delivery latency under reasonable threshold and then allow prompt response from the final recipients. The following
general elements should be contained in the full alert message to maximize the response capability.
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Incident information
This includes a brief description of the incident event, its intensity level and likelihood of the incident event. In
particular, intensity refers to the severity of the described incident, in order to inform the recipient about the impact that
specific incident might have. Example of intensity scales are those used to classify earthquakes, hurricanes, tornados,
and other related severe weather events. As far as likelihood is concerned, it refers to the certainty level of a disaster
event occurrence, hence triggering the population to take the adequate measures, as advised by the public authorities.
For instance, the certainty of flooding for the population not in close proximity to rivers can be assessed as 'unlikely',
whereas it should be classified as 'very likely' for the citizens residing next to the river.
Target Location
The alert message should specify the location that is or could be at risk. This is essential for the warning recipients to
understand if they are in or out of the risk area. The target location should be described in terms of geographic areas,
recognizable landmarks (e.g. transportation routes, jurisdictional boundaries or recognizable geographical features).
Time information related to the incident
Expected incident impact time and time extent should be included in the alert message. Furthermore, a statement should
be included with regard to the relevant time to take protective actions.
Guidance and protective actions
The alert message should include protective actions information, recommendations and guidance to the alert message
recipients. The goal of the alert message is to maximize the response capability of the citizens at risk and therefore the
incident information alone is not sufficient.
Alert message source (the alert message issuer)
Mentioning the source of the alert message is essential for the credibility of the message and trust of the alert message
recipients. This has therefore a high impact on the alert message recipient actionability. The source of the alert message
should be a competent authority and it is recommendable that several authorities endorse the message.
Further information sources
Disseminating an alert message could yield an overload of the PSAPs, as the alert message recipients might try to
validate the alert message through contact with the authorities. To mitigate this undesired effect, it is recommendable to
include sources of further information in the alert message.
However, it is not advised that such information is accessible over the service provider's network, since a huge
concurrent access may cause congestion in the service provider's network or on the server where the information is
made available.
Sequence
A crisis situation after a hazard onset evolves with time. Several alert messages should be disseminated over time with
regard to the same incident. It is therefore important that means are provided to correctly reconstruct the sequence of
alert messages corresponding to the same incident to allow the alert message recipients sorting the information
appropriately.
4.2.2.3 Size and information quantity
In case of disasters alert messages might need to be distributed with very limited capabilities of the communication
lines. Therefore alert messages should be as short as possible, still containing the information elements listed in
clause 4.2.2.2 and obeying the style guidelines stated in clause 4.2.2.1.
4.2.2.4 Use of templates for alert messages
The use of templates helps preventing errors and issuing complete alert messages. They may also help in easing multi-

language aspects. However, templates should remain sufficiently flexible to accommodate any possible incident.
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15 ETSI TR 103 273 V1.1.1 (2016-12)
4.3 Warning Message Recommendation
4.3.1 Conditions to Maximize Actionability Upon Alert Message Reception
Along with the discussion in clause 4.2, the dissemination and communication process maximizes the actionability in
the alert message recipient under the condition that the targeted recipients:
• Receive the alert message.
• Notice that there is an alert message.
• Understand the alert message and
• Trust the alert message
Several factors involved in the dissemination and communication function can influence the fulfilment of the conditions
above as indicated in figure 4 and further developed below.
RECEIVE NOTICE UNDERSTAND TRUST
ALERT MESSAGE ALERT MESSAGE ALERT MESSAGE ALERT MESSAGE
TRANSMISSION / INFORMATION PUBLIC WARNING
PRESENTATION INFORMATION STYLE ISSUER IDENTITY
DELIVERY MEANS CONTENT DECISION PROCESS

Figure 4: Factors of public warning influencing the response capability
Receive Alert Message
The condition that the targeted recipients actually receive the alert message depends on the use and availability of
transmission and/or delivery means and the public warning decision process.
Once the decision whether to warn and when to warn has been made, authorities will make use of means to deliver alert
messages to the targeted recipients. These may include any kind of media, sirens, pagers, public screens, alarm systems,
communication or entertainment devices (for public and/or private use), etc. The means used may also differ in different
regions and countries or even in areas with specific risks, such as chemical, biological, radioactive, nuclear or explosive
processing and even earthquakes.
The objective is that the maximum people at risk is able to receive the warning information independently of their
context (at home, at work, outdoors, on the move, during day or night) and their habits in the use of communication and
entertainment devices. Hence, the use of multiple means to disseminate alert messages has been identified as the most
suitable solution to maximize the number of targeted recipients that will actually receive the alert message [i.18], what
has been called Multi-Channel Public Warning.
Notice Alert Message
The condition that the targeted recipients actually notice that there is an alert message they should pay attention to
depends on two main factors. Firstly, the alert message should have been actually received through transmission or
delivery means. Secondly, the used transmission or delivery means should be capable of calling the attention of the
recipient when an alert message has been received; indicating uniquely that the message is an alert message.
In this context, the multi-channel public warning approach provides additional benefits, since the capabilities of
different devices can be combined to increase the probability that the recipient will notice the alert message [i.18].
ETSI
16 ETSI TR 103 273 V1.1.1 (2016-12)
Understand Alert Message
The correct style and content of the alert message are paramount to achieve that the maximum number of recipients will
understand the message, as already mentioned in clause 4.2.2. However, the manner in which the alert message is
presented to various recipients is of high importance to address people with special needs. This includes different
demographic/socio-economic segments and cognitive capabilities and/or impairments. Hence, human factors should be
considered to avoid excluding part of the potentially affected population.
Furthermore, the recipients may receive alert messages through different channels (different, public and/or personal
devices). Inconsistencie
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