SIST EN 62297-1:2006

Triggering messages for broadcast applications -- Part 1: Format

This part of IEC 62297 specifies an application-triggering scheme for TV broadcasting information sent from a service provider as part of a data broadcasting transmission and intended to control an application in a receiver.

Triggernachrichten für Rundfunkanwendungen -- Teil 1: Format

Messages de déclenchement pour les applications de radiodiffusion -- Partie 1: Format

La CEI 62297-1:2005 spécifie un schéma de déclenchement d'une application pour une information de télédiffusion envoyée par un fournisseur de service dans une émission de diffusion de données et destinée à commander une application dans un récepteur. La présente version bilingue, correspond à la version anglaise monolingue publiée en 2005-05.

Prožilna sporočila za radiodifuzijo – 1. del: Format (IEC 62297-1:2005)

General Information

• Status: Published
• Publication Date: 31-Dec-2005
• ICS: 33.170 - Television and radio broadcasting
• Technical Committee: AVM - Audio, video and multimedia systems and equipment
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Jan-2006
• Due Date: 01-Jan-2006
• Completion Date: 01-Jan-2006
• Ref Project: EN 62297-1:2005 - Triggering messages for broadcast applications - Part 1: Format

Standards Content (Sample)

SLOVENSKI SIST EN 62297-1:2006

STANDARD
januar 2006
Prožilna sporočila za radiodifuzijo – 1. del: Format (IEC 62297-1:2005)
(istoveten EN 62297-1:2005)
Triggering messages for broadcast applications – Part 1: Format (IEC 62297-
1:2005)
ICS 33.170 Referenčna številka
SIST EN 62297-1:2006(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD EN 62297-1
NORME EUROPÉENNE
EUROPÄISCHE NORM June 2005

ICS 33.170


English version


Triggering messages for broadcast applications
Part 1: Format
(IEC 62297-1:2005)


Messages de déclenchement  Triggernachrichten
pour les applications de radiodiffusion für Rundfunkanwendungen
Partie 1: Format Teil 1: Format
(CEI 62297-1:2005) (IEC 62297-1:2005)






This European Standard was approved by CENELEC on 2005-05-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 62297-1:2005 E

---------------------- Page: 2 ----------------------

EN 62297-1:2005 - 2 -
Foreword
The text of document 100/910/FDIS, future edition 1 of IEC 62297-1, prepared by IEC TC 100, Audio,
video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and
was approved by CENELEC as EN 62297-1 on 2005-05-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2006-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-05-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62297-1:2005 was approved by CENELEC as a European
Standard without any modification.
__________

---------------------- Page: 3 ----------------------

- 3 - EN 62297-1:2005
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
1)
ISO 8859-1 - Information technology - 8-bit single-byte - -
coded graphic character sets
Part 1: Latin alphabet No. 1

1)
ETSI TS 101 231 - Television systems - Register of Country - -
and Network Identification (CNI), Video
Programming System (VPS) codes and
Application codes for Teletext based
systems

1)
ETSI EN 300 706 - Enhanced teletext specification - -





1)
Undated reference.

---------------------- Page: 4 ----------------------

INTERNATIONAL IEC


STANDARD 62297-1





First edition
2005-05


Triggering messages
for broadcast applications –
Part 1:
Format

 IEC 2005  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale S
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

---------------------- Page: 5 ----------------------

– 2 – 62297-1  IEC:2005(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5

1 Scope.6
2 Normative references .6
3 Terms, definitions and abbreviations .6
3.1 Definitions .6
3.2 Abbreviations .8
4 Trigger message .9
4.1 General .9
4.1.1 Viewer interaction.9
4.1.2 Priority ratings .9
4.1.3 Character coding .9
4.1.4 Future compatibility .9
4.2 Life cycles .9
4.2.1 Trigger message and event message life cycle.9
4.2.2 Event message preparation life cycle.10
4.2.3 Application life cycle.11
4.3 Syntax of trigger message.13
4.3.1 General .13
4.3.2 Trigger text length .13
4.3.3 Syntax of trigger text .13
4.3.4 Trigger repetition .17

Annex A (informative) Recommendations.18
Annex B (informative) Code of practice.19

Bibliography.22

Figure 1 – Trigger messages and event messages life cycle.10
Figure 2 – TriggerObject life cycle .11
Figure 3 – ApplicationObject life cycle .12
Figure B.1 – Icon bitmap tailored for a display with a resolution of 640 by 480.20

Table 1 – Syntax of trigger_message .13
Table 2 – Syntax of trigger_text .13

---------------------- Page: 6 ----------------------

62297-1  IEC:2005(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

TRIGGERING MESSAGES FOR BROADCAST APPLICATIONS –

Part 1: Format


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62297-1 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/910/FDIS 100/949/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

---------------------- Page: 7 ----------------------

– 4 – 62297-1  IEC:2005(E)
IEC 62297 consists of the following parts, under the general title Triggering messages for
broadcast applications:
Part 1: Format
Part 2: Transport methods

The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date.indicated on the IEC web site under http://webstore.iec.ch in the
data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

---------------------- Page: 8 ----------------------

62297-1  IEC:2005(E) – 5 –
INTRODUCTION
Emerging data broadcasting specifications allow a service provider to trigger an application
in a TV receiver. This International Standard specifies the format of a triggering message for
TV broadcasting as based on the requirements defined in Annex A. Examples of possible use
include displaying information to warn for severe weather conditions or to give rating advice
for extreme content in TV programmes. In an interactive system, a message or icon might be
displayed inviting on-line access to vote, to register an interest in an advertised product, or to
browse programme-related content.
This standard describes a trigger mechanism for teletext transmission methods. The trigger
mechanism can also be used for services broadcast via MPEG-2 DSM-CC sections. For the
purposes of this standard, a trigger is defined as information sent from a service provider as
part of a data broadcasting transmission and intended to control an application in a TV
receiver. Additional information can be supplied along with the basic trigger to allow filtering
or prioritization techniques to be applied at the receiver. The transmission aspects of trigger
messages are specified in IEC 62297-2.
This trigger mechanism is very similar to the one defined in IEC/PAS 62292. The difference
lies primarily in different state models, semantics and attribute names.

---------------------- Page: 9 ----------------------

– 6 – 62297-1  IEC:2005(E)
TRIGGERING MESSAGES FOR BROADCAST APPLICATIONS –

Part 1: Format



1 Scope
This part of IEC 62297 specifies an application-triggering scheme for TV broadcasting
information sent from a service provider as part of a data broadcasting transmission and
intended to control an application in a receiver.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
ISO 8859-1, Information technology – 8-bit single-byte coded graphic character sets − Part 1:
Latin alphabet No. 1
ETSI TS 101 231, Television systems; Register of Country and Network Identification (CNI),
Video Programming System (VPS) codes and Application codes for Teletext based systems
ETSI EN 300 706, Enhanced Teletext Specification
3 Terms, definitions and abbreviations
3.1 Definitions
For the purposes of this document, the following terms and definitions, in singular or plural
form, apply.
3.1.1
ActiveTimeValue
member of the ApplicationObject. The value decrements at video frame rate. It is updated
on every reception of an event message.
3.1.2
Application
software running on a receiver that is addressed by the URL of a trigger message and
providing the following modes of operation:
a) the display of information, the playback of sound, the download of data;
b) the initiation of any action.
Application examples include the display of a simple text message sent as part of the trigger
message, the display of a Teletext, Superteletext (TeleWeb [Tw]) or Internet page, information
from an Electronic Programme Guide (EPG), electronic voting, an emergency alert
3.1.3
ApplicationObject
object storing the information about an application started or modified by triggers referencing
the same URL

---------------------- Page: 10 ----------------------

62297-1  IEC:2005(E) – 7 –
3.1.4
Attribute
member of an ApplicationObject or TriggerObject storing the information transported via an
attribute element
3.1.5
attribute element
attribute name/value pair
3.1.6
attribute string
any sequence of characters with codes in the range 0× 20 to 0× 7E inclusive, excluding square
brackets (0× 5B and 0× 5D)
3.1.7
charset
abbreviation for character set
3.1.8
CountdownValue
member of a TriggerObject. The value decrements at video frame rate. It is updated on every
reception of a trigger mes
3.1.9
DateTime
date and time instance of UTC expressed in the form: yyyymmddThhmmss, where yyyy
represents a year, mm represents a month (range 1–12), dd represents the day of the month
(range 1–31), the capital letter ‘T’ separates the date component from the time component, hh
represents an hour (range 0–23), mm represents the minutes (range 0–59) and ss represents
the seconds (range 0–59)
3.1.10
Dummy URL
URL that does not reference any application or data and used in the mandatory URL field of a
trigger message when the intention is to display only the trigger icon (together with its text)
and not to control an application
3.1.11
event message
information extracted from a trigger message that is used to create an ApplicationObject
3.1.12
event start
event message with its 'script' attribute element set to 'start'
3.1.13
event stop
event message with its 'script' attribute element set to 'stop'
3.1.14
pending trigger
state where a trigger message has created a TriggerObject but the conditions to create an
ApplicationObject have not yet occurred
3.1.15
priority filtering
rejecting a trigger message on account of the value assigned to its 'priority' attribute
element

---------------------- Page: 11 ----------------------

– 8 – 62297-1  IEC:2005(E)
3.1.16
RelativeTime
time period measured in seconds and video frames
3.1.17
string
any sequence of characters with codes in the range 0× 20 to 0× 7E inclusive. Throughout this
document strings are not case-sensitive unless otherwise indicated
3.1.18
trigger
signal sent from a service provider as part of a data broadcasting transmission with the
intention to start or modify an application at a certain time
3.1.19
trigger character
character with a code in the range 0× 20 to 0× 7E inclusive
3.1.20
trigger del
trigger message with a 'delete' attribute element
3.1.21
trigger event
instant in time when a trigger fires and an event message is created
3.1.22
trigger mes
trigger message without a 'delete' attribute element
3.1.23
trigger message
information embedded in a trigger and intended to control an application in a receiver
3.1.24
TriggerObject
object storing the information from all the triggers referencing the same URL
3.1.25
trigger_text
descriptive part of a trigger message.
3.1.26
URL string
any sequence of characters with codes in the range 0× 20 to 0× 7E inclusive, excluding angular
brackets (0× 3C and 0× 3E)
3.2 Abbreviations
CNI Country and Network Identification
URL Uniform Resource Locator
UTC Coordinated Universal Time
VPS Video Programming System

---------------------- Page: 12 ----------------------

62297-1  IEC:2005(E) – 9 –
4 Trigger message
4.1 General
4.1.1 Viewer interaction
The mechanism through which the viewer enables or disables trigger handling or sets priority
threshold levels is at the receiver manufacturer's discretion.
The appearance of an icon and the viewer interaction when responding to it is also at the
receiver manufacturer's discretion.
4.1.2 Priority ratings
Triggers labelled with the ‘emergency’ priority rating should always be processed, even if the
viewer has disabled trigger handling. The ‘emergency’ priority shall only be used by service
providers for genuine emergency situations. The set maker is allowed to provide the user with
the ability to switch off this emergency priority.
4.1.3 Character coding
All characters used to code triggers are taken from the ISO 8859-1 character set and are in
the range 0× 20 to 0× 7E inclusive. A character outside this range shall be encoded using the
per cent character ('%') followed by the two-digit hexadecimal value of the character. The ‘%’
character itself is represented by the string ‘%25’. The character '[' is represented by %5B,
the character ']' by %5D. The default character coding for all string attribute values is
ISO 8859-1. The character coding for the name attribute can be changed with the charset
attribute.
4.1.4 Future compatibility
To ensure future compatibility, a receiver should ignore data it does not understand, such as
attribute elements not defined by this edition.
4.2 Life cycles
4.2.1 Trigger message and event message life cycle
Figure 1 describes the life-cycle trigger message and an event message referencing the
same resource (URL). An incoming trigger message is acquired through the transport layer.
The priority filtering process provides the opportunity to reject a trigger message on
account of its 'priority' attribute element. However, it is not recommended to reject a trigger
message with its 'priority' attribute element set to '0' (zero) as this value is reserved for
emergency trigger messages.
The Event message preparation processes the filtered trigger messages and provides
robustness to the trigger protocol when carried over a unidirectional transport layer where the
reception of the information is not always guaranteed. Each trigger message carries a
countdown value indicating the time delay before the trigger should fire. To aid robustness,
the trigger message can be transmitted at intervals before the trigger event, each time with
an updated countdown value. When the trigger fires, an event message is generated to the
application referenced by the URL.

---------------------- Page: 13 ----------------------

– 10 – 62297-1  IEC:2005(E)

Incoming
Event message
trigger messages
attributes
elements
URL
name
Filtered
icon
trigger messages
active
Priority
expires
filtering
script
priority
Event
Trigger message
Event messages
attributes
message
elements
preparation
URL
name
icon
Application
active
A
expires
script
priority
Application
countdown
B
delete
IEC  562/05

Figure 1 – Trigger messages and event messages life cycle
4.2.2 Event message preparation life cycle
Figure 2 describes the state transitions within the event message preparation process. The
initial state of a TriggerObject is ‘TriggerObject does not exist’. On first reception of a trigger
message without a 'delete' attribute element, a TriggerObject referencing the defined URL
is created and the state becomes ‘TriggerObject pending’. The attributes of the Trigger
Object are adapted on subsequent arrivals of trigger messages referencing the same URL.
If the CountdownValue equals zero, either explicitly or as a result of decrementing at frame
rate a value received previously, an event message is signalled to the application
referenced by the URL. The event message inherits the attribute elements of the original
trigger message, excluding the 'delete' and 'countdown' attribute elements. After signalling
the event message to the application, the TriggerObject is deleted.

---------------------- Page: 14 ----------------------

62297-1  IEC:2005(E) – 11 –

Trigger
message
TriggerObject does not exist
Trigger mes Trigger del CountdownValue=0
CREATE-EM
CREATE-TO DELETE-TO
DELETE-TO
TriggerObject pending
Event
message
Trigger mes
ADAPT-TO
IEC  563/05

 Key
CREATE-TO The creation of a TriggerObject referenced by the URL.
ADAPT-TO The adaptation of a TriggerObject referenced by the URL.
The deletion of a TriggerObject referenced by the URL.
DELETE-TO
CREATE-EM An event message is created and signalled to the application.
CountdownValue=0 The CountdownValue equals 0.
Figure 2 – TriggerObject life cycle
4.2.3 Application life cycle
Figure 3 describes the state transitions within the application process. The initial state of an
ApplicationObject is ‘ApplicationObject does not exist’. An ApplicationObject is created as
a result of an event start. An icon is displayed before the application is started if the 'name'
attribute element is defined.
On first reception of an event start, an ApplicationObject referencing the defined URL is
created and the state becomes ‘ApplicationObject active’. The attributes of the Application
Object are adapted on subsequent arrivals of event messages referencing the same URL.
An ApplicationObject is deleted on reception of an event stop, on reaching the (absolute)
'expires' time or when the (relative) 'active' time period has been completed.
If the viewer terminates the application, the state becomes ‘ApplicationObject terminated’.
Once in this state, the application cannot be restarted until the ApplicationObject has been
deleted. This adds robustness to the procedure and prevents the application restarting if the
same trigger is repeated at a later time.
NOTE This is needed if the broadcaster wants to address viewers who join the programme later.

---------------------- Page: 15 ----------------------

– 12 – 62297-1  IEC:2005(E)

Event
message
ApplicationObject does not exist
Event Expire Active
Event
Event
start condition condition stop
stop
CREATE-AO DELETE-AO DELETE-AO DELETE-AO
DELETE-AO
Expire
condition
ApplicationObject active
DELETE-AO
Active
Terminate
condition
Event
condition
message
DELETE-AO
TERMINATE-AO
ADAPT-AO
ApplicationObject terminated
IEC  564/05
  Key
Expire condition The DateTime value from the 'expires' attribute element is greater than, or equal to,
the current DateTime value. The two values should be compared at video frame
rate. The 'expires' attribute element may be updated on every instance of an event
message referencing the same URL.
Active condition The ActiveTimeValue equals 0.
Terminate condition The ApplicationObject is terminated due to viewer action or other reason.
CREATE-AO Create the ApplicationObject referenced by the URL.
ADAPT-AO Adapt the ApplicationObject referenced by the URL.
DELETE-AO Delete the ApplicationObject referenced by the URL.
Terminate the ApplicationObject referenced by the URL.
TERMINATE-AO
Figure 3 – ApplicationObject life cycle
On the reception of an event start with a 'name' attribute element defined, an Application
Object referencing the defined URL is created but the application itself is not run immediately.
Instead, an icon defined by the 'name' attribute element is displayed. After the confirmation
of the icon by the viewer, the ApplicationObject is fully started. The icon is removed if the
ApplicationObject is deleted before a positive response from the viewer.

---------------------- Page: 16 ----------------------

62297-1  IEC:2005(E) – 13 –
4.3 Syntax of trigger message
4.3.1 General
The syntax of a trigger message is shown in Table 1.
Table 1 – Syntax of trigger_message
Syntax Number of Bytes
trigger_message() {
trigger_text_length 2
trigger_text() trigger_text_length
}

4.3.2 Trigger text length
The trigger_text_length field defines the number of characters in the following trigger_text
field.
NOTE For practical reasons, the maximum length of the trigger message may be limited by the application or
transport protocol.
4.3.3 Syntax of trigger text
4.3.3.1 General
The syntax of the trigger_text field is shown in Table 2.
Table 2 – Syntax of trigger_text
Syntax Number of
bytes
trigger_text() {
for (i=0; i  trigger_character 1
}
}

The sequence of trigger characters starts with a URL string delimited by angular brackets.
This is followed by one or more attribute strings delimited by square brackets. Optionally,
the final element is a checksum delimited by square brackets:
[attr1: val1][attr2:val2].[attrn:valn][checksum]
4.3.3.2 URL element
The first element of the trigger_text must be a URL string enclosed in angular brackets. The
URL element is used twofold: a) it uniquely identifies the trigger, and b) it locates the
resource of the application. This implies that for each resource only one current trigger can
be defined.
Internet URL – An Internet URL shall be identified by the sequence http:// and shall be
defined according to [URI].
Example:
Local Identifier URL – A Local Identifier URL is identified by the sequence lid://. The Local
Identifier URL scheme is defined in [DDE].

---------------------- Page: 17 ----------------------

– 14 – 62297-1  IEC:2005(E)
Example:
TeleWeb URL – A string with the following syntax shall be used to specify a TeleWeb URL:
tw://service_name/filename.filetype#position
Where the sequence is not case-sensitive and
tw:// identifies the following sequence as a Tel
...