SIST EN 302 637-3 V1.3.1:2019

Intelligent Transport Systems (ITS) - Vehicular Communications - Basic Set of Applications - Part 3: Specifications of Decentralized Environmental Notification Basic Service

The present document provides specification of the DEN basic service, which is in support of the RHW application.
More specifically, the present document specifies the syntax and semantics of the "Decentralized Environmental
Notification Message" (DENM) and the DENM protocol handling.
The DEN basic service may be implemented in an vehicle ITS-S, a road side ITS-S, a personal ITS-S or a central
ITS-S.

Inteligentni transportni sistemi - Komunikacija med vozili - Osnovni nabor aplikacij - 3. del: Specifikacije osnovne storitve decentraliziranega okoljskega obveščanja

V tem dokumentu so navedene specifikacije osnovne storitve DEN, ki podpira uporabo RHW.
Natančneje, ta dokument določa skladnjo in semantiko »decentraliziranega okoljskega obveščanja« (DENM) in obdelavo protokola DENM.
Osnovna storitev DEN se lahko izvaja v sistemu ITS-S v vozilu, sistemu ITS-S ob cesti, zasebnem sistemu ITS-S ali centralnem sistemu ITS-S.

General Information

• Status: Published
• Public Enquiry End Date: 31-Oct-2018
• Publication Date: 14-Apr-2019
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 08-Apr-2019
• Due Date: 13-Jun-2019
• Completion Date: 15-Apr-2019
• Mandate: M/453
• Ref Project: ETSI EN 302 637-3 V1.3.1 (2019-04) - Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic Service

Overview

SIST EN 302 637-3 V1.3.1:2019 specifies the Decentralized Environmental Notification (DEN) basic service within Intelligent Transport Systems (ITS). It defines the syntax and semantics of the Decentralized Environmental Notification Message (DENM) and the protocol handling required to support road hazard and environmental notifications (notably in support of the RHW - Road Hazard Warning - application). The DEN basic service can be implemented in a vehicle ITS‑S, roadside ITS‑S, personal ITS‑S or central ITS‑S.

Key topics and technical requirements

• DENM format and structure
  • ITS PDU header and DENM-specific containers: management, situation, location, and à la carte containers.
  • Decoding and presentation rules guided by a common data dictionary.
• Dissemination concepts
  • Event identification: use of actionID, stationID and referenceTime to manage event lifecycle.
  • Message lifecycle operations: trigger, update, repetition, termination.
  • Definitions of relevance area, location referencing, and DENM destination area.
  • Forwarding strategies: packet-centric and keep-alive forwarding.
• Protocol operation
  • Roles and operation for originating, forwarding, and receiving ITS‑S nodes.
  • Protocol timers and validity parameters (e.g., T_O_Validity, T_RepetitionDuration, T_F_Validity, T_Forwarding, T_R_Validity) and rules for constructing/updating DENMs.
  • Exception handling and reconstruction rules for forwarded messages.
• Interfaces and system integration
  • Interfaces to ITS application layer (IF.DEN.1 / IF.DEN.2), networking & transport (GeoNetworking/BTP and IPv6 stacks), ITS management, and security entities.
• Operational constraints
  • Security: Service Specific Permissions (SSP) and message protection requirements.
  • Priority and confidence constraints to ensure appropriate handling of safety-critical notifications.

Practical applications

• Real-time road hazard warnings (accidents, debris, ice patches).
• Roadworks and lane closures dissemination to nearby vehicles and infrastructure.
• Alerts for vulnerable road users and dynamic traffic event notifications.
• Integration with traffic management centers, roadside units, and OEM telematics for cooperative safety and traffic efficiency services.

Who should use this standard

• Automotive OEMs and telematics suppliers designing ITS‑S implementations.
• Roadside unit (RSU) vendors and ITS infrastructure integrators.
• ITS application developers (RHW and other safety apps).
• Network and security architects implementing GeoNetworking, BTP and ITS security.
• Test labs and certification bodies validating DENM compliance.

Related standards (contextual)

• References to GeoNetworking, BTP and combined IPv6/GeoNetworking stacks are provided in the document; implementers should align DENM use with relevant ITS networking and security ETSI/ISO standards for interoperable vehicular communications.

Keywords: DENM, Decentralized Environmental Notification Message, ITS, vehicular communications, RHW, GeoNetworking, service-specific permissions, road hazard warning, ITS‑S.

Standards Content (Sample)

Draft ETSI EN 302 637-3 V1.3.0 (2018-08)

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
Vehicular Communications;
Basic Set of Applications;
Part 3: Specifications of Decentralized
Environmental Notification Basic Service

2 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)

Reference
REN/ITS-0010090
Keywords
application, ITS, safety, service, transport

ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

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ETSI
3 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
Contents
Intellectual Property Rights . 7
Foreword . 7
Modal verbs terminology . 8
Introduction . 8
1 Scope . 9
2 References . 9
2.1 Normative references . 9
2.2 Informative references . 9
3 Definitions, symbols and abbreviations . 11
3.1 Definitions . 11
3.2 Symbols . 12
3.3 Abbreviations . 12
4 DEN basic service introduction . 13
4.1 Background . 13
4.2 Services provided by the DEN basic service . 14
5 DEN basic service functional description . 15
5.1 Introduction . 15
5.2 DEN basic service in the ITS architecture . 16
5.3 DEN basic service functional architecture . 16
5.4 Interfaces of the DEN basic service . 18
5.4.1 Interfaces to the ITS application layer . 18
5.4.1.1 Introduction . 18
5.4.1.2 Data passed via interface IF.DEN.1 for the request type AppDENM_trigger . 19
5.4.1.3 Data passed via interface IF.DEN.1 for the request type AppDENM_update . 20
5.4.1.4 Data passed via interface IF.DEN.1 for the request type AppDENM_termination . 21
5.4.1.5 Data passed via interface IF.DEN.2 for received DENM . 21
5.4.1.6 Methods for data exchanges between DEN basic service and ITS application layer . 22
5.4.2 Interface to the ITS networking & transport layer . 22
5.4.2.1 General requirements . 22
5.4.2.2 Interface to the GeoNetworking/BTP stack . 23
5.4.2.3 Interface to the IPv6 stack and the combined IPv6/GeoNetworking stack . 23
5.4.3 Interface to the ITS management entity . 24
5.4.4 Interface to the ITS security entity . 24
6 DENM dissemination . 24
6.1 DENM dissemination concepts . 24
6.1.1 Event identification . 24
6.1.1.1 actionID . 24
6.1.1.2 stationID update and actionID management . 24
6.1.2 Trigger, update, repetition and termination of DENM. 25
6.1.2.1 DENM trigger . 25
6.1.2.2 DENM update . 25
6.1.2.3 DENM repetition . 25
6.1.2.4 DENM termination. 25
6.1.3 Relevance area, location referencing and destination area . 26
6.1.3.1 DENM relevance area . 26
6.1.3.2 Location referencing . 27
6.1.3.3 DENM destination area . 27
6.1.4 DENM forwarding . 27
6.1.4.1 Packet centric forwarding . 27
6.1.4.2 Keep-alive forwarding . 28
6.2 DENM dissemination constraints . 28
6.2.1 General confidence constraints . 28
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4 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
6.2.2 General security constraints . 28
6.2.2.1 Introduction . 28
6.2.2.2 Service Specific Permissions (SSP) . 29
6.2.3 General priority constraints. 31
7 DENM format specification . 31
7.1 DENM structure . 31
7.1.1 General structure of a DENM . 31
7.1.2 ITS PDU header . 31
7.1.3 DENM management container . 32
7.1.4 DENM situation container . 32
7.1.5 DENM location container . 36
7.1.6 DENM à la carte container . 37
7.2 DENM format and decoding rules. 37
7.2.1 Common data dictionary . 37
7.2.2 DENM data presentation . 37
8 Protocol operation of the DEN basic service . 38
8.1 Introduction . 38
8.2 Originating ITS-S operation . 38
8.2.1 Protocol data setting rules . 38
8.2.1.1 General requirements . 38
8.2.1.2 actionID . 38
8.2.1.3 referenceTime . 39
8.2.1.4 termination . 39
8.2.1.5 T_O_Validity, T_RepetitionDuration and T_Repetition . 39
8.2.1.6 Originating ITS-S message table . 40
8.2.2 General protocol operation . 40
8.2.3 Exception handling . 47
8.2.3.1 General requirements . 47
8.2.3.2 DENM construction exception . 47
8.2.3.3 actionID non-existence exception . 47
8.2.3.4 Time operation exception . 47
8.3 Forwarding ITS-S operation . 47
8.3.1 Introduction. 47
8.3.2 Protocol data setting rules . 47
8.3.2.1 General requirements . 47
8.3.2.2 actionID . 48
8.3.2.3 referenceTime . 48
8.3.2.4 termination . 48
8.3.2.5 T_F_Validity and T_Forwarding . 48
8.3.2.6 Forwarding ITS-S message table . 48
8.3.2.7 DENM reconstruction . 49
8.3.3 General protocol operation . 49
8.3.4 Exception handling . 51
8.3.4.1 General requirements . 51
8.3.4.2 DENM construction exception . 51
8.4 Receiving ITS-S operation . 52
8.4.1 Protocol data setting rules . 52
8.4.1.1 General requirements . 52
8.4.1.2 actionID . 52
8.4.1.3 referenceTime . 52
8.4.1.4 termination . 52
8.4.1.5 T_R_Validity . 52
8.4.1.6 Receiving ITS-S message table . 52
8.4.2 General protocol operation . 53
8.4.3 Exception handling . 55
8.4.3.1 General requirements . 55
8.4.3.2 DENM decoding exception . 55
Annex A (normative): ASN.1 specification of DENM . 56
Annex B (normative): Description for data elements and data frames. 58
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5 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
B.1 header . 58
B.2 denm . 58
B.3 management . 58
B.4 situation . 58
B.5 location . 59
B.6 alacarte . 59
B.7 actionID . 59
B.8 carryingDangerousGoods . 59
B.9 closedLanes . 60
B.10 defaultValidity . 60
B.11 detectionTime . 60
B.12 energyStorageType . 60
B.13 eventHistory . 61
B.14 eventPosition . 61
B.15 eventPositionHeading . 61
B.16 eventSpeed . 62
B.17 eventType . 62
B.18 externalTemperature . 62
B.19 heightLonCarrLeft . 62
B.20 heightLonCarrRight. 62
B.21 impactReduction . 63
B.22 incidentIndication . 63
B.23 informationQuality . 63
B.24 lanePosition . 63
B.25 lightBarSirenInUse . 64
B.26 linkedCause . 64
B.27 numberOfOccupants . 64
B.28 posCentMass . 64
B.29 posFrontAx . 65
B.30 positioningSolution . 65
B.31 positionOfOccupants . 65
B.32 positionOfPillars . 65
B.33 posLonCarrLeft . 66
B.34 posLonCarrRight . 66
B.35 recommendedPath . 66
B.36 referenceDenms . 66
B.37 referenceTime . 67
B.38 relevanceDistance . 67
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6 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
B.39 relevanceTrafficDirection . 67
B.40 requestResponseIndication . 67
B.41 restriction . 68
B.42 roadType . 68
B.43 roadWorks . 68
B.44 speedLimit . 68
B.45 startingPointSpeedLimit . 69
B.46 stationaryCause . 69
B.47 stationarySince . 69
B.48 stationaryVehicle . 69
B.49 stationType . 69
B.50 termination . 70
B.51 traces. 70
B.52 trafficFlowRule . 70
B.53 transmissionInterval . 71
B.54 turningRadius . 71
B.55 validityDuration . 71
B.56 vehicleIdentification . 72
B.57 vehicleMass . 72
B.58 wheelBaseVehicle . 72
Annex C (informative): Bibliography . 73
History . 74

ETSI
7 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables 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.
Trademarks
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ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
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Foreword
This draft European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport Systems
(ITS), and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN Approval
Procedure.
The present document is part 3 of a multi-part deliverable covering Vehicular Communications; Basic Set of
Applications, as identified below:
ETSI TS 102 637-1: "Functional Requirements";
ETSI EN 302 637-2: "Specification of Cooperative Awareness Basic Service";
ETSI EN 302 637-3: "Specifications of Decentralized Environmental Notification Basic Service".
The specification of the Decentralized Environmental Notification (DEN) basic service was initially developed in the
European Car-to-Car Communication Consortium (C2C-CC) Manifesto [i.2] and in C2C-CC Message description:
Decentralized Environmental Notification Message [i.3]. The service was evaluated by several initiatives, such as the
C2C-CC demonstration in 2008, by ETSI Plugtest events and European projects including PRE-DRIVE C2X, DRIVE
C2X, SafeSpot, CVIS, CoVeL, SCORE@F, simTD, etc. These evaluation efforts have provided feedback to ETSI TC
ITS.
The present document replaces ETSI TS 102 637-3 [i.16] in whole. It includes improvements and enhancements of the
DEN basic service specifications in ETSI TS 102 637-3 [i.16] according to the feedback provided by the various
initiatives.
Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

ETSI
8 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
Modal verbs terminology
In the present document "shall", "shall not", "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.
Introduction
ITS use cases are distributed over multiple instances of ITS stations (ITS-S). ITS-Ss interact in the ITS networks to
provide a large diversity of co-operating customer services that satisfy different types of functional and operational
requirements.
ETSI TC ITS has defined a "Basic Set of Applications" (BSA) in ETSI TR 102 638 [i.1] that can be deployed within a
three-year time frame after the completion of their standardization. In BSA, the Road Hazard Warning (RHW)
application is composed of multiple use cases with the objective to improve road safety and traffic efficiency using
vehicle-to-vehicle and vehicle-to-infrastructure communication technologies. ETSI TC ITS defines the decentralized
environmental notification (DEN) basic service that supports the RHW application.
The DEN basic service is an application support facility provided by the facilities layer. It constructs, manages and
processes the Decentralized Environmental Notification Message (DENM). The construction of a DENM is triggered
by an ITS-S application. A DENM contains information related to a road hazard or an abnormal traffic conditions, such
as its type and its position. The DEN basic service delivers the DENM as payload to the ITS networking & transport
layer for the message dissemination. Typically for an ITS application, a DENM is disseminated to ITS-Ss that are
located in a geographic area through communications among ITS stations. At the receiving side, the DEN basic service
of an receiving ITS-S processes the received DENM and provides the DENM content to an ITS-S application. This
ITS-S application may present the information to the driver if information of the road hazard or traffic condition is
assessed to be relevant to the driver. The driver is then able to take appropriate actions to react to the situation
accordingly.
ETSI
9 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
1 Scope
The present document provides specification of the DEN basic service, which is in support of the RHW application.
More specifically, the present document specifies the syntax and semantics of the "Decentralized Environmental
Notification Message" (DENM) and the DENM protocol handling.
The DEN basic service may be implemented in an vehicle ITS-S, a road side ITS-S, a personal ITS-S or a central
ITS-S.
2 References
2.1 Normative 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.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference.
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 necessary for the application of the present document.
[1] SAE J2735 (2009-11-19): "Dedicated Short Range Communications (DSRC) Message Set
Dictionary".
NOTE: Available at: http://standards.sae.org/j2735_200911/.
[2] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture".
[3] ETSI TS 102 636-3 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 3: Network Architecture".
[4] ETSI EN 302 931 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
Geographical Area Definition".
[5] ETSI TS 102 894-2 (V1.3.1): "Intelligent Transport Systems (ITS); Users and applications
requirements; Part 2: Applications and facilities layer common data dictionary".
[6] Recommendation ITU-T X.691/ISO/IEC 8825-2 (12-1997): "Information technology - ASN.1
encoding rules: Specification of Packed Encoding Rules (PER)".
[7] ETSI EN 302 637-2 (V1.4.0): "Intelligent Transport Systems (ITS); Vehicular Communications;
Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service".
[8] ETSI EN 302 636-2 (V1.2.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 2: Scenarios".
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.
ETSI
10 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
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] ETSI TR 102 638 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
Basic Set of Applications; Definitions".
[i.2] Car2Car Communication Consortium (2007-08): "Car2Car Communication Consortium
Manifesto", Version 1.1.
NOTE: Available at http://www.car-2-car.org.
[i.3] Car2Car Communication Consortium: "Message description: Decentralized Environmental
Notification Message", Version 1.0.
[i.4] ETSI TS 101 539-1: "Intelligent Transport Systems (ITS); V2X Applications; Part 1: Road Hazard
Signalling (RHS) application requirements specification".
[i.5] ETSI TS 101 539-2: "Intelligent Transport Systems (ITS); V2X Applications; Part 2: Intersection
Collision Risk Warning (ICRW) application requirements specification".
[i.6] ETSI TS 101 539-3: "Intelligent Transport Systems (ITS); V2X Applications; Part 3: Longitudinal
Collision Risk Warning (LCRW) application requirements specification".
[i.7] ETSI EN 302 895: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Local Dynamic Map (LDM)".
[i.8] ETSI EN 302 636-4-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
[i.9] ETSI EN 302 636-5-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol".
[i.10] TISA specification TAWG11071 (2011-11-07, drafted to potentially become ISO/TS 21219
Part 15): "Intelligent Transport Systems (ITS) - Traffic and Travel Information (TTI) via Transport
Protocol Experts Group, Generation 2 (TPEG2) - Part 15: Traffic Event Compact
(TPEG2-TEC-3.1/001)".
[i.11] ISO EN 17419: "Intelligent Transport Systems - Cooperative Systems - Classification and
management of ITS applications in a global context".
[i.12] ETSI TS 102 723-5: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 5: Interface
between management entity and facilities layer".
[i.13] ETSI TS 102 723-8: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 8: Interface
between security entity and network and transport layer".
[i.14] ETSI TS 102 723-11 (V1.1.1): "Intelligent Transport Systems (ITS); OSI cross-layer topics;
Part 11: Interface between networking and transport layer and facilities layer".
[i.15] ISO 3779 (2011-07): "Road vehicles - Vehicle identification number (VIN) Content and
structure".
[i.16] ETSI TS 102 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic
Service".
[i.17] ETSI TS 103 097 (V1.3.1): "Intelligent Transport Systems (ITS); Security; Security header and
certificate formats".
[i.18] ETSI TR 102 965 (V1.1.1): "Intelligent Transport Systems (ITS); Application object identifier
(ITS-AID); Registration list".
ETSI
11 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in SAE J2735 [1], ETSI EN 302 665 [2],
ETSI EN 302 895 [i.7] and the following apply:
actionID: identifier of an detected event
à la carte container: container of DENM that includes information of the detected event in addition to management
container, situation container and location container
NOTE: Due to coding constraints in programming language, the term "alacarte" is also used.
basic set of applications: group of applications, supported by the vehicular communication system
NOTE: The BSA is defined in ETSI TR 102 638 [i.1].
cancellation Decentralized Environmental Notification Message (DENM): DEN message type generated by the
ITS-S, which originated the new DENM, indicating the event termination
Decentralized Environmental Notification (DEN) basic service: facility at the facilities layer to support ITS-S
applications, DENM management and DENM dissemination
Decentralized Environmental Notification Message (DENM): ITS facilities layer PDU providing event information
Decentralized Environmental Notification Message (DENM) protocol: ITS facilities layer protocol that operates the
DENM transmission, forwarding and reception
destination area: geographical area for DENM dissemination
NOTE: The destination area is specified in ETSI EN 302 931 [4].
downstream traffic: direction from the event position towards the departing traffic on the same carriageway
event: road hazard, driving environment, or traffic condition
facility: functionality, service or data provided by the ITS facilities layer
forwarding Intelligent Transport System Station (ITS-S): ITS-S that forwards DENMs and implements the DENM
protocol
location container: container of DENM that includes location data of the detected event
management container: container of DENM that includes management data for DENM protocol
negation Decentralized Environmental Notification Message (DENM): DEN message type generated by an ITS-S
other than the ITS-S, which originated the new DENM, indicating the event termination
new Decentralized Environmental Notification Message (DENM): DEN message type indicating that the event is
detected for the first time
originating Intelligent Transport System Station (ITS-S): ITS-S that generates DENMs and implements the DENM
protocol
receiving Intelligent Transport System Station (ITS-S): ITS-S that receives DENMs from the ITS networking &
transport layer and implements the DENM protocol
relevance area: geographic area in which information concerning the event is identified as relevant for use or for
further distribution
situation container: container of DENM that includes data related to the detected event
update Decentralized Environmental Notification Message (DENM): DEN message type indicating the evolution of
the event
ETSI
12 Draft ETSI EN 302 637-3 V1.3.0 (2018-08)
upstream traffic: direction from the event position towards the approaching traffic on the same carriageway
3.2 Symbols
For the purposes of the present document, the following symbols apply:
actionID  Identifier of an event that is detected by an ITS-S
appDENM_trigger  Application re
...

EUROPEAN STANDARD
Intelligent Transport Systems (ITS);
Vehicular Communications;
Basic Set of Applications;
Part 3: Specifications of Decentralized
Environmental Notification Basic Service

2 ETSI EN 302 637-3 V1.3.1 (2019-04)

Reference
REN/ITS-0010090
Keywords
application, ITS, safety, service, transport

ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
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ETSI
3 ETSI EN 302 637-3 V1.3.1 (2019-04)
Contents
Intellectual Property Rights . 7
Foreword . 7
Modal verbs terminology . 8
Introduction . 8
1 Scope . 9
2 References . 9
2.1 Normative references . 9
2.2 Informative references . 9
3 Definitions, symbols and abbreviations . 11
3.1 Definitions . 11
3.2 Symbols . 12
3.3 Abbreviations . 12
4 DEN basic service introduction . 13
4.1 Background . 13
4.2 Services provided by the DEN basic service . 14
5 DEN basic service functional description . 15
5.1 Introduction . 15
5.2 DEN basic service in the ITS architecture . 16
5.3 DEN basic service functional architecture . 16
5.4 Interfaces of the DEN basic service . 18
5.4.1 Interfaces to the ITS application layer . 18
5.4.1.1 Introduction . 18
5.4.1.2 Data passed via interface IF.DEN.1 for the request type AppDENM_trigger . 19
5.4.1.3 Data passed via interface IF.DEN.1 for the request type AppDENM_update . 20
5.4.1.4 Data passed via interface IF.DEN.1 for the request type AppDENM_termination . 21
5.4.1.5 Data passed via interface IF.DEN.2 for received DENM . 21
5.4.1.6 Methods for data exchanges between DEN basic service and ITS application layer . 22
5.4.2 Interface to the ITS networking & transport layer . 22
5.4.2.1 General requirements . 22
5.4.2.2 Interface to the GeoNetworking/BTP stack . 23
5.4.2.3 Interface to the IPv6 stack and the combined IPv6/GeoNetworking stack . 23
5.4.3 Interface to the ITS management entity . 24
5.4.4 Interface to the ITS security entity . 24
6 DENM dissemination . 24
6.1 DENM dissemination concepts . 24
6.1.1 Event identification . 24
6.1.1.1 actionID . 24
6.1.1.2 stationID update and actionID management . 24
6.1.2 Trigger, update, repetition and termination of DENM. 25
6.1.2.1 DENM trigger . 25
6.1.2.2 DENM update . 25
6.1.2.3 DENM repetition . 25
6.1.2.4 DENM termination. 25
6.1.3 Relevance area, location referencing and destination area . 26
6.1.3.1 DENM relevance area . 26
6.1.3.2 Location referencing . 27
6.1.3.3 DENM destination area . 27
6.1.4 DENM forwarding . 27
6.1.4.1 Packet centric forwarding . 27
6.1.4.2 Keep-alive forwarding . 28
6.2 DENM dissemination constraints . 28
6.2.1 General confidence constraints . 28
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4 ETSI EN 302 637-3 V1.3.1 (2019-04)
6.2.2 General security constraints . 28
6.2.2.1 Introduction . 28
6.2.2.2 Service Specific Permissions (SSP) . 29
6.2.3 General priority constraints. 31
7 DENM format specification . 31
7.1 DENM structure . 31
7.1.1 General structure of a DENM . 31
7.1.2 ITS PDU header . 32
7.1.3 DENM management container . 32
7.1.4 DENM situation container . 32
7.1.5 DENM location container . 36
7.1.6 DENM à la carte container . 37
7.2 DENM format and decoding rules. 37
7.2.1 Common data dictionary . 37
7.2.2 DENM data presentation . 37
8 Protocol operation of the DEN basic service . 38
8.1 Introduction . 38
8.2 Originating ITS-S operation . 38
8.2.1 Protocol data setting rules . 38
8.2.1.1 General requirements . 38
8.2.1.2 actionID . 38
8.2.1.3 referenceTime . 39
8.2.1.4 termination . 39
8.2.1.5 T_O_Validity, T_RepetitionDuration and T_Repetition . 39
8.2.1.6 Originating ITS-S message table . 40
8.2.2 General protocol operation . 40
8.2.3 Exception handling . 47
8.2.3.1 General requirements . 47
8.2.3.2 DENM construction exception . 47
8.2.3.3 actionID non-existence exception . 47
8.2.3.4 Time operation exception . 47
8.3 Forwarding ITS-S operation . 47
8.3.1 Introduction. 47
8.3.2 Protocol data setting rules . 47
8.3.2.1 General requirements . 47
8.3.2.2 actionID . 48
8.3.2.3 referenceTime . 48
8.3.2.4 termination . 48
8.3.2.5 T_F_Validity and T_Forwarding . 48
8.3.2.6 Forwarding ITS-S message table . 48
8.3.2.7 DENM reconstruction . 49
8.3.3 General protocol operation . 49
8.3.4 Exception handling . 51
8.3.4.1 General requirements . 51
8.3.4.2 DENM construction exception . 51
8.4 Receiving ITS-S operation . 52
8.4.1 Protocol data setting rules . 52
8.4.1.1 General requirements . 52
8.4.1.2 actionID . 52
8.4.1.3 referenceTime . 52
8.4.1.4 termination . 52
8.4.1.5 T_R_Validity . 52
8.4.1.6 Receiving ITS-S message table . 52
8.4.2 General protocol operation . 53
8.4.3 Exception handling . 55
8.4.3.1 General requirements . 55
8.4.3.2 DENM decoding exception . 55
Annex A (normative): ASN.1 specification of DENM . 56
Annex B (normative): Description for data elements and data frames. 58
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5 ETSI EN 302 637-3 V1.3.1 (2019-04)
B.1 header . 58
B.2 denm . 58
B.3 management . 58
B.4 situation . 58
B.5 location . 59
B.6 alacarte . 59
B.7 actionID . 59
B.8 carryingDangerousGoods . 59
B.9 closedLanes . 60
B.10 defaultValidity . 60
B.11 detectionTime . 60
B.12 energyStorageType . 60
B.13 eventHistory . 61
B.14 eventPosition . 61
B.15 eventPositionHeading . 61
B.16 eventSpeed . 62
B.17 eventType . 62
B.18 externalTemperature . 62
B.19 heightLonCarrLeft . 62
B.20 heightLonCarrRight. 62
B.21 impactReduction . 63
B.22 incidentIndication . 63
B.23 informationQuality . 63
B.24 lanePosition . 63
B.25 lightBarSirenInUse . 64
B.26 linkedCause . 64
B.27 numberOfOccupants . 64
B.28 posCentMass . 64
B.29 posFrontAx . 65
B.30 positioningSolution . 65
B.31 positionOfOccupants . 65
B.32 positionOfPillars . 65
B.33 posLonCarrLeft . 66
B.34 posLonCarrRight . 66
B.35 recommendedPath . 66
B.36 referenceDenms . 66
B.37 referenceTime . 67
B.38 relevanceDistance . 67
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6 ETSI EN 302 637-3 V1.3.1 (2019-04)
B.39 relevanceTrafficDirection . 67
B.40 requestResponseIndication . 67
B.41 restriction . 68
B.42 roadType . 68
B.43 roadWorks . 68
B.44 speedLimit . 68
B.45 startingPointSpeedLimit . 69
B.46 stationaryCause . 69
B.47 stationarySince . 69
B.48 stationaryVehicle . 69
B.49 stationType . 69
B.50 termination . 70
B.51 traces. 70
B.52 trafficFlowRule . 70
B.53 transmissionInterval . 71
B.54 turningRadius . 71
B.55 validityDuration . 71
B.56 vehicleIdentification . 72
B.57 vehicleMass . 72
B.58 wheelBaseVehicle . 72
Annex C (informative): Bibliography . 73
History . 74

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7 ETSI EN 302 637-3 V1.3.1 (2019-04)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables 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.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport Systems (ITS).
The present document is part 3 of a multi-part deliverable covering Vehicular Communications; Basic Set of
Applications, as identified below:
ETSI TS 102 637-1: "Functional Requirements";
ETSI EN 302 637-2: "Specification of Cooperative Awareness Basic Service";
ETSI EN 302 637-3: "Specifications of Decentralized Environmental Notification Basic Service".
The specification of the Decentralized Environmental Notification (DEN) basic service was initially developed in the
European Car-to-Car Communication Consortium (C2C-CC) Manifesto [i.2] and in C2C-CC Message description:
Decentralized Environmental Notification Message [i.3]. The service was evaluated by several initiatives, such as the
C2C-CC demonstration in 2008, by ETSI Plugtest events and European projects including PRE-DRIVE C2X, DRIVE
C2X, SafeSpot, CVIS, CoVeL, SCORE@F, simTD, etc. These evaluation efforts have provided feedback to ETSI
TC ITS.
The present document replaces ETSI TS 102 637-3 [i.16] in whole. It includes improvements and enhancements of the
DEN basic service specifications in ETSI TS 102 637-3 [i.16] according to the feedback provided by the various
initiatives.
National transposition dates
Date of adoption of this EN: 7 November 2018
Date of latest announcement of this EN (doa): 31 July 2019
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 January 2020
Date of withdrawal of any conflicting National Standard (dow): 31 January 2020

ETSI
8 ETSI EN 302 637-3 V1.3.1 (2019-04)
Modal verbs terminology
In the present document "shall", "shall not", "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.
Introduction
ITS use cases are distributed over multiple instances of ITS stations (ITS-S). ITS-Ss interact in the ITS networks to
provide a large diversity of co-operating customer services that satisfy different types of functional and operational
requirements.
ETSI TC ITS has defined a "Basic Set of Applications" (BSA) in ETSI TR 102 638 [i.1] that can be deployed within a
three-year time frame after the completion of their standardization. In BSA, the Road Hazard Warning (RHW)
application is composed of multiple use cases with the objective to improve road safety and traffic efficiency using
vehicle-to-vehicle and vehicle-to-infrastructure communication technologies. ETSI TC ITS defines the decentralized
environmental notification (DEN) basic service that supports the RHW application.
The DEN basic service is an application support facility provided by the facilities layer. It constructs, manages and
processes the Decentralized Environmental Notification Message (DENM). The construction of a DENM is triggered
by an ITS-S application. A DENM contains information related to a road hazard or an abnormal traffic conditions, such
as its type and its position. The DEN basic service delivers the DENM as payload to the ITS networking & transport
layer for the message dissemination. Typically for an ITS application, a DENM is disseminated to ITS-Ss that are
located in a geographic area through communications among ITS stations. At the receiving side, the DEN basic service
of an receiving ITS-S processes the received DENM and provides the DENM content to an ITS-S application. This
ITS-S application may present the information to the driver if information of the road hazard or traffic condition is
assessed to be relevant to the driver. The driver is then able to take appropriate actions to react to the situation
accordingly.
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9 ETSI EN 302 637-3 V1.3.1 (2019-04)
1 Scope
The present document provides specification of the DEN basic service, which is in support of the RHW application.
More specifically, the present document specifies the syntax and semantics of the "Decentralized Environmental
Notification Message" (DENM) and the DENM protocol handling.
The DEN basic service may be implemented in an vehicle ITS-S, a road side ITS-S, a personal ITS-S or a central
ITS-S.
2 References
2.1 Normative 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.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference.
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 necessary for the application of the present document.
[1] SAE J2735 (2009-11-19): "Dedicated Short Range Communications (DSRC) Message Set
Dictionary".
NOTE: Available at: http://standards.sae.org/j2735_200911/.
[2] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture".
[3] ETSI TS 102 636-3 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 3: Network Architecture".
[4] ETSI EN 302 931 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
Geographical Area Definition".
[5] ETSI TS 102 894-2 (V1.3.1): "Intelligent Transport Systems (ITS); Users and applications
requirements; Part 2: Applications and facilities layer common data dictionary".
[6] Recommendation ITU-T X.691/ISO/IEC 8825-2 (12-1997): "Information technology - ASN.1
encoding rules: Specification of Packed Encoding Rules (PER)".
[7] ETSI EN 302 637-2 (V1.4.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service".
[8] ETSI EN 302 636-2 (V1.2.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 2: Scenarios".
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.
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10 ETSI EN 302 637-3 V1.3.1 (2019-04)
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] ETSI TR 102 638 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications;
Basic Set of Applications; Definitions".
[i.2] Car2Car Communication Consortium (2007-08): "Car2Car Communication Consortium
Manifesto", Version 1.1.
NOTE: Available at http://www.car-2-car.org.
[i.3] Car2Car Communication Consortium: "Message description: Decentralized Environmental
Notification Message", Version 1.0.
[i.4] ETSI TS 101 539-1: "Intelligent Transport Systems (ITS); V2X Applications; Part 1: Road Hazard
Signalling (RHS) application requirements specification".
[i.5] ETSI TS 101 539-2: "Intelligent Transport Systems (ITS); V2X Applications; Part 2: Intersection
Collision Risk Warning (ICRW) application requirements specification".
[i.6] ETSI TS 101 539-3: "Intelligent Transport Systems (ITS); V2X Applications; Part 3: Longitudinal
Collision Risk Warning (LCRW) application requirements specification".
[i.7] ETSI EN 302 895: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Local Dynamic Map (LDM)".
[i.8] ETSI EN 302 636-4-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
[i.9] ETSI EN 302 636-5-1: "Intelligent Transport Systems (ITS); Vehicular Communications;
GeoNetworking; Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol".
[i.10] TISA specification TAWG11071 (2011-11-07, drafted to potentially become ISO/TS 21219
Part 15): "Intelligent Transport Systems (ITS) - Traffic and Travel Information (TTI) via Transport
Protocol Experts Group, Generation 2 (TPEG2) - Part 15: Traffic Event Compact
(TPEG2-TEC-3.1/001)".
[i.11] ISO EN 17419: "Intelligent Transport Systems - Cooperative Systems - Classification and
management of ITS applications in a global context".
[i.12] ETSI TS 102 723-5: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 5: Interface
between management entity and facilities layer".
[i.13] ETSI TS 102 723-8: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 8: Interface
between security entity and network and transport layer".
[i.14] ETSI TS 102 723-11 (V1.1.1): "Intelligent Transport Systems (ITS); OSI cross-layer topics;
Part 11: Interface between networking and transport layer and facilities layer".
[i.15] ISO 3779 (2011-07): "Road vehicles - Vehicle identification number (VIN) Content and
structure".
[i.16] ETSI TS 102 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic
Service".
[i.17] ETSI TS 103 097 (V1.3.1): "Intelligent Transport Systems (ITS); Security; Security header and
certificate formats".
[i.18] ETSI TR 102 965 (V1.1.1): "Intelligent Transport Systems (ITS); Application object identifier
(ITS-AID); Registration list".
ETSI
11 ETSI EN 302 637-3 V1.3.1 (2019-04)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in SAE J2735 [1], ETSI EN 302 665 [2],
ETSI EN 302 895 [i.7] and the following apply:
actionID: identifier of an detected event
à la carte container: container of DENM that includes information of the detected event in addition to management
container, situation container and location container
NOTE: Due to coding constraints in programming language, the term "alacarte" is also used.
basic set of applications: group of applications, supported by the vehicular communication system
NOTE: The BSA is defined in ETSI TR 102 638 [i.1].
cancellation Decentralized Environmental Notification Message (DENM): DEN message type generated by the
ITS-S, which originated the new DENM, indicating the event termination
Decentralized Environmental Notification (DEN) basic service: facility at the facilities layer to support ITS-S
applications, DENM management and DENM dissemination
Decentralized Environmental Notification Message (DENM): ITS facilities layer PDU providing event information
Decentralized Environmental Notification Message (DENM) protocol: ITS facilities layer protocol that operates the
DENM transmission, forwarding and reception
destination area: geographical area for DENM dissemination
NOTE: The destination area is specified in ETSI EN 302 931 [4].
downstream traffic: direction from the event position towards the departing traffic on the same carriageway
event: road hazard, driving environment, or traffic condition
facility: functionality, service or data provided by the ITS facilities layer
forwarding Intelligent Transport System Station (ITS-S): ITS-S that forwards DENMs and implements the DENM
protocol
location container: container of DENM that includes location data of the detected event
management container: container of DENM that includes management data for DENM protocol
negation Decentralized Environmental Notification Message (DENM): DEN message type generated by an ITS-S
other than the ITS-S, which originated the new DENM, indicating the event termination
new Decentralized Environmental Notification Message (DENM): DEN message type indicating that the event is
detected for the first time
originating Intelligent Transport System Station (ITS-S): ITS-S that generates DENMs and implements the DENM
protocol
receiving Intelligent Transport System Station (ITS-S): ITS-S that receives DENMs from the ITS networking &
transport layer and implements the DENM protocol
relevance area: geographic area in which information concerning the event is identified as relevant for use or for
further distribution
situation container: container of DENM that includes data related to the detected event
update Decentralized Environmental Notification Message (DENM): DEN message type indicating the evolution of
the event
ETSI
12 ETSI EN 302 637-3 V1.3.1 (2019-04)
upstream traffic: direction from the event position towards the approaching traffic on the same carriageway
3.2 Symbols
For the purposes of the present document, the following symbols apply:
actionID  Identifier of an event that is detected by an ITS-S
appDENM_trigger  Application request type to generate a new DENM for a newly detected event
appDENM_update  Application request type to generate an update DENM for an update of the eve
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Intelligent Transport Systems (ITS) - Vehicular Communications -
Basic Set of Applications - Part 3: Specifications of Decentralized Environmental Notification Basic Service35.240.60Uporabniške rešitve IT v prometuIT applications in transportICS:Ta slovenski standard je istoveten z:ETSI EN 302 637-3 V1.3.1 (2019-04)SIST EN 302 637-3 V1.3.1:2019en01-junij-2019SIST EN 302 637-3 V1.3.1:2019SLOVENSKI
STANDARD
EUROPEAN STANDARD SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 2
Reference REN/ITS-0010090 Keywords application, ITS, safety, service, transport ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: [phone]
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Important notice The present document can be downloaded from: http://www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI deliverable is the one made publicly available in PDF format at www.etsi.org/deliver. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx If you find errors in the present document, please send your comment to one of the following services: https://portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2019. All rights reserved.
DECTTM, PLUGTESTSTM, UMTSTM and the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETM are trademarks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of the oneM2M Partners. GSM® and the GSM logo are trademarks registered and owned by the GSM Association. SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 3 Contents Intellectual Property Rights . 7 Foreword . 7 Modal verbs terminology . 8 Introduction . 8 1 Scope . 9 2 References . 9 2.1 Normative references . 9 2.2 Informative references . 9 3 Definitions, symbols and abbreviations . 11 3.1 Definitions . 11 3.2 Symbols . 12 3.3 Abbreviations . 12 4 DEN basic service introduction . 13 4.1 Background . 13 4.2 Services provided by the DEN basic service . 14 5 DEN basic service functional description . 15 5.1 Introduction . 15 5.2 DEN basic service in the ITS architecture . 16 5.3 DEN basic service functional architecture . 16 5.4 Interfaces of the DEN basic service . 18 5.4.1 Interfaces to the ITS application layer . 18 5.4.1.1 Introduction . 18 5.4.1.2 Data passed via interface IF.DEN.1 for the request type AppDENM_trigger . 19 5.4.1.3 Data passed via interface IF.DEN.1 for the request type AppDENM_update . 20 5.4.1.4 Data passed via interface IF.DEN.1 for the request type AppDENM_termination . 21 5.4.1.5 Data passed via interface IF.DEN.2 for received DENM . 21 5.4.1.6 Methods for data exchanges between DEN basic service and ITS application layer . 22 5.4.2 Interface to the ITS networking & transport layer . 22 5.4.2.1 General requirements . 22 5.4.2.2 Interface to the GeoNetworking/BTP stack . 23 5.4.2.3 Interface to the IPv6 stack and the combined IPv6/GeoNetworking stack . 23 5.4.3 Interface to the ITS management entity . 24 5.4.4 Interface to the ITS security entity . 24 6 DENM dissemination . 24 6.1 DENM dissemination concepts . 24 6.1.1 Event identification . 24 6.1.1.1 actionID . 24 6.1.1.2 stationID update and actionID management . 24 6.1.2 Trigger, update, repetition and termination of DENM. 25 6.1.2.1 DENM trigger . 25 6.1.2.2 DENM update . 25 6.1.2.3 DENM repetition . 25 6.1.2.4 DENM termination. 25 6.1.3 Relevance area, location referencing and destination area . 26 6.1.3.1 DENM relevance area . 26 6.1.3.2 Location referencing . 27 6.1.3.3 DENM destination area . 27 6.1.4 DENM forwarding . 27 6.1.4.1 Packet centric forwarding . 27 6.1.4.2 Keep-alive forwarding . 28 6.2 DENM dissemination constraints . 28 6.2.1 General confidence constraints . 28 SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 4 6.2.2 General security constraints . 28 6.2.2.1 Introduction . 28 6.2.2.2 Service Specific Permissions (SSP) . 29 6.2.3 General priority constraints. 31 7 DENM format specification . 31 7.1 DENM structure . 31 7.1.1 General structure of a DENM . 31 7.1.2 ITS PDU header . 32 7.1.3 DENM management container . 32 7.1.4 DENM situation container . 32 7.1.5 DENM location container . 36 7.1.6 DENM à la carte container . 37 7.2 DENM format and decoding rules. 37 7.2.1 Common data dictionary . 37 7.2.2 DENM data presentation . 37 8 Protocol operation of the DEN basic service . 38 8.1 Introduction . 38 8.2 Originating ITS-S operation . 38 8.2.1 Protocol data setting rules . 38 8.2.1.1 General requirements . 38 8.2.1.2 actionID . 38 8.2.1.3 referenceTime . 39 8.2.1.4 termination . 39 8.2.1.5 T_O_Validity, T_RepetitionDuration and T_Repetition . 39 8.2.1.6 Originating ITS-S message table . 40 8.2.2 General protocol operation . 40 8.2.3 Exception handling . 47 8.2.3.1 General requirements . 47 8.2.3.2 DENM construction exception . 47 8.2.3.3 actionID non-existence exception . 47 8.2.3.4 Time operation exception . 47 8.3 Forwarding ITS-S operation . 47 8.3.1 Introduction. 47 8.3.2 Protocol data setting rules . 47 8.3.2.1 General requirements . 47 8.3.2.2 actionID . 48 8.3.2.3 referenceTime . 48 8.3.2.4 termination . 48 8.3.2.5 T_F_Validity and T_Forwarding . 48 8.3.2.6 Forwarding ITS-S message table . 48 8.3.2.7 DENM reconstruction . 49 8.3.3 General protocol operation . 49 8.3.4 Exception handling . 51 8.3.4.1 General requirements . 51 8.3.4.2 DENM construction exception . 51 8.4 Receiving ITS-S operation . 52 8.4.1 Protocol data setting rules . 52 8.4.1.1 General requirements . 52 8.4.1.2 actionID . 52 8.4.1.3 referenceTime . 52 8.4.1.4 termination . 52 8.4.1.5 T_R_Validity . 52 8.4.1.6 Receiving ITS-S message table . 52 8.4.2 General protocol operation . 53 8.4.3 Exception handling . 55 8.4.3.1 General requirements . 55 8.4.3.2 DENM decoding exception . 55 Annex A (normative): ASN.1 specification of DENM . 56 Annex B (normative): Description for data elements and data frames. 58 SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 5 B.1 header . 58 B.2 denm . 58 B.3 management . 58 B.4 situation . 58 B.5 location . 59 B.6 alacarte . 59 B.7 actionID . 59 B.8 carryingDangerousGoods . 59 B.9 closedLanes . 60 B.10 defaultValidity . 60 B.11 detectionTime . 60 B.12 energyStorageType . 60 B.13 eventHistory . 61 B.14 eventPosition . 61 B.15 eventPositionHeading . 61 B.16 eventSpeed . 62 B.17 eventType . 62 B.18 externalTemperature . 62 B.19 heightLonCarrLeft . 62 B.20 heightLonCarrRight. 62 B.21 impactReduction . 63 B.22 incidentIndication . 63 B.23 informationQuality . 63 B.24 lanePosition . 63 B.25 lightBarSirenInUse . 64 B.26 linkedCause . 64 B.27 numberOfOccupants . 64 B.28 posCentMass . 64 B.29 posFrontAx . 65 B.30 positioningSolution . 65 B.31 positionOfOccupants . 65 B.32 positionOfPillars . 65 B.33 posLonCarrLeft . 66 B.34 posLonCarrRight . 66 B.35 recommendedPath . 66 B.36 referenceDenms . 66 B.37 referenceTime . 67 B.38 relevanceDistance . 67 SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 6 B.39 relevanceTrafficDirection . 67 B.40 requestResponseIndication . 67 B.41 restriction . 68 B.42 roadType . 68 B.43 roadWorks . 68 B.44 speedLimit . 68 B.45 startingPointSpeedLimit . 69 B.46 stationaryCause . 69 B.47 stationarySince . 69 B.48 stationaryVehicle . 69 B.49 stationType . 69 B.50 termination . 70 B.51 traces. 70 B.52 trafficFlowRule . 70 B.53 transmissionInterval . 71 B.54 turningRadius . 71 B.55 validityDuration . 71 B.56 vehicleIdentification . 72 B.57 vehicleMass . 72 B.58 wheelBaseVehicle . 72 Annex C (informative): Bibliography . 73 History . 74
ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 7 Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables 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. Trademarks The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners. ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This European Standard (EN) has been produced by ETSI Technical Committee Intelligent Transport Systems (ITS). The present document is part 3 of a multi-part deliverable covering Vehicular Communications; Basic Set of Applications, as identified below: ETSI TS 102 637-1:
"Functional Requirements"; ETSI EN 302 637-2:
"Specification of Cooperative Awareness Basic Service"; ETSI EN 302 637-3: "Specifications of Decentralized Environmental Notification Basic Service". The specification of the Decentralized Environmental Notification (DEN) basic service was initially developed in the European Car-to-Car Communication Consortium (C2C-CC) Manifesto [i.2] and in C2C-CC Message description: Decentralized Environmental Notification Message [i.3]. The service was evaluated by several initiatives, such as the C2C-CC demonstration in 2008, by ETSI Plugtest events and European projects including PRE-DRIVE C2X, DRIVE C2X, SafeSpot, CVIS, CoVeL, SCORE@F, simTD, etc. These evaluation efforts have provided feedback to ETSI TC ITS. The present document replaces ETSI TS 102 637-3 [i.16] in whole. It includes improvements and enhancements of the DEN basic service specifications in ETSI TS 102 637-3 [i.16] according to the feedback provided by the various initiatives.
National transposition dates Date of adoption of this EN: 7 November 2018 Date of latest announcement of this EN (doa): 31 July 2019 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
31 January 2020 Date of withdrawal of any conflicting National Standard (dow): 31 January 2020
ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 8 Modal verbs terminology In the present document "shall", "shall not", "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. Introduction ITS use cases are distributed over multiple instances of ITS stations (ITS-S). ITS-Ss interact in the ITS networks to provide a large diversity of co-operating customer services that satisfy different types of functional and operational requirements. ETSI TC ITS has defined a "Basic Set of Applications" (BSA) in ETSI TR 102 638 [i.1] that can be deployed within a three-year time frame after the completion of their standardization. In BSA, the Road Hazard Warning (RHW) application is composed of multiple use cases with the objective to improve road safety and traffic efficiency using vehicle-to-vehicle and vehicle-to-infrastructure communication technologies. ETSI TC ITS defines the decentralized environmental notification (DEN) basic service that supports the RHW application.
The DEN basic service is an application support facility provided by the facilities layer. It constructs, manages and processes the Decentralized Environmental Notification Message (DENM). The construction of a DENM is triggered by an ITS-S application. A DENM contains information related to a road hazard or an abnormal traffic conditions, such as its type and its position. The DEN basic service delivers the DENM as payload to the ITS networking & transport layer for the message dissemination. Typically for an ITS application, a DENM is disseminated to ITS-Ss that are located in a geographic area through communications among ITS stations. At the receiving side, the DEN basic service of an receiving ITS-S processes the received DENM and provides the DENM content to an ITS-S application. This ITS-S application may present the information to the driver if information of the road hazard or traffic condition is assessed to be relevant to the driver. The driver is then able to take appropriate actions to react to the situation accordingly. SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 9 1 Scope The present document provides specification of the DEN basic service, which is in support of the RHW application. More specifically, the present document specifies the syntax and semantics of the "Decentralized Environmental Notification Message" (DENM) and the DENM protocol handling. The DEN basic service may be implemented in an vehicle ITS-S, a road side ITS-S, a personal ITS-S or a central ITS-S. 2 References 2.1 Normative 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. Referenced documents which are not found to be publicly available in the expected location might be found at https://docbox.etsi.org/Reference. 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 necessary for the application of the present document. [1] SAE J2735 (2009-11-19): "Dedicated Short Range Communications (DSRC) Message Set Dictionary". NOTE: Available at: http://standards.sae.org/j2735_200911/. [2] ETSI EN 302 665 (V1.1.1): "Intelligent Transport Systems (ITS); Communications Architecture". [3] ETSI TS 102 636-3 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 3: Network Architecture". [4] ETSI EN 302 931 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications; Geographical Area Definition". [5] ETSI TS 102 894-2 (V1.3.1): "Intelligent Transport Systems (ITS); Users and applications requirements; Part 2: Applications and facilities layer common data dictionary". [6] Recommendation ITU-T X.691/ISO/IEC 8825-2 (12-1997): "Information technology - ASN.1 encoding rules: Specification of Packed Encoding Rules (PER)". [7] ETSI EN 302 637-2 (V1.4.1): "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service". [8] ETSI EN 302 636-2 (V1.2.1): "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 2: Scenarios". 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. SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 10 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] ETSI TR 102 638 (V1.1.1): "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Definitions". [i.2] Car2Car Communication Consortium (2007-08): "Car2Car Communication Consortium Manifesto", Version 1.1. NOTE: Available at http://www.car-2-car.org. [i.3] Car2Car Communication Consortium: "Message description: Decentralized Environmental Notification Message", Version 1.0. [i.4] ETSI TS 101 539-1: "Intelligent Transport Systems (ITS); V2X Applications; Part 1: Road Hazard Signalling (RHS) application requirements specification". [i.5] ETSI TS 101 539-2: "Intelligent Transport Systems (ITS); V2X Applications; Part 2: Intersection Collision Risk Warning (ICRW) application requirements specification". [i.6] ETSI TS 101 539-3: "Intelligent Transport Systems (ITS); V2X Applications; Part 3: Longitudinal Collision Risk Warning (LCRW) application requirements specification". [i.7] ETSI EN 302 895: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Local Dynamic Map (LDM)". [i.8] ETSI EN 302 636-4-1: "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-multipoint communications; Sub-part 1: Media-Independent Functionality". [i.9] ETSI EN 302 636-5-1: "Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking; Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol". [i.10] TISA specification TAWG11071 (2011-11-07, drafted to potentially become ISO/TS 21219 Part 15): "Intelligent Transport Systems (ITS) - Traffic and Travel Information (TTI) via Transport Protocol Experts Group, Generation 2 (TPEG2) - Part 15: Traffic Event Compact
(TPEG2-TEC-3.1/001)". [i.11] ISO EN 17419: "Intelligent Transport Systems - Cooperative Systems - Classification and management of ITS applications in a global context". [i.12] ETSI TS 102 723-5: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 5: Interface between management entity and facilities layer". [i.13] ETSI TS 102 723-8: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 8: Interface between security entity and network and transport layer". [i.14] ETSI TS 102 723-11 (V1.1.1): "Intelligent Transport Systems (ITS); OSI cross-layer topics;
Part 11: Interface between networking and transport layer and facilities layer". [i.15] ISO 3779 (2011-07): "Road vehicles - Vehicle identification number (VIN) Content and structure". [i.16] ETSI TS 102 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic Service". [i.17] ETSI TS 103 097 (V1.3.1): "Intelligent Transport Systems (ITS); Security; Security header and certificate formats". [i.18] ETSI TR 102 965 (V1.1.1): "Intelligent Transport Systems (ITS); Application object identifier (ITS-AID); Registration list". SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 11 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in SAE J2735 [1], ETSI EN 302 665 [2],
ETSI EN 302 895 [i.7] and the following apply: actionID: identifier of an detected event
à la carte container: container of DENM that includes information of the detected event in addition to management container, situation container and location container NOTE: Due to coding constraints in programming language, the term "alacarte" is also used. basic set of applications: group of applications, supported by the vehicular communication system NOTE: The BSA is defined in ETSI TR 102 638 [i.1]. cancellation Decentralized Environmental Notification Message (DENM): DEN message type generated by the ITS-S, which originated the new DENM, indicating the event termination Decentralized Environmental Notification (DEN) basic service: facility at the facilities layer to support ITS-S applications, DENM management and DENM dissemination Decentralized Environmental Notification Message (DENM): ITS facilities layer PDU providing event information Decentralized Environmental Notification Message (DENM) protocol: ITS facilities layer protocol that operates the DENM transmission, forwarding and reception destination area: geographical area for DENM dissemination NOTE: The destination area is specified in ETSI EN 302 931 [4]. downstream traffic: direction from the event position towards the departing traffic on the same carriageway event: road hazard, driving environment, or traffic condition facility: functionality, service or data provided by the ITS facilities layer forwarding Intelligent Transport System Station (ITS-S): ITS-S that forwards DENMs and implements the DENM protocol location container: container of DENM that includes location data of the detected event management container: container of DENM that includes management data for DENM protocol negation Decentralized Environmental Notification Message (DENM): DEN message type generated by an ITS-S other than the ITS-S, which originated the new DENM, indicating the event termination new Decentralized Environmental Notification Message (DENM): DEN message type indicating that the event is detected for the first time originating Intelligent Transport System Station (ITS-S): ITS-S that generates DENMs and implements the DENM protocol receiving Intelligent Transport System Station (ITS-S): ITS-S that receives DENMs from the ITS networking & transport layer and implements the DENM protocol relevance area: geographic area in which information concerning the event is identified as relevant for use or for further distribution situation container: container of DENM that includes data related to the detected event update Decentralized Environmental Notification Message (DENM): DEN message type indicating the evolution of the event SIST EN 302 637-3 V1.3.1:2019

ETSI ETSI EN 302 637-3 V1.3.1 (2019-04) 12 upstream traffic: direction from the event position towards the approaching traffic on the same carriageway 3.2 Symbols For the purposes of the present document, the following symbols apply: actionID
Identifier of an event that is detected by an ITS-S appDENM_trigger
Application request type to generate a new DENM for a newly detected event appDENM_update
Application request type to generate an update DENM for an update of the event appDENM_termination
Application request type to generate a cancellation or negation DENM for termination
of the event detectionTime
Timestamp at which an event or event update/termination is d
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