ISO 14813-6:2009

INTERNATIONAL ISO
STANDARD 14813-6
First edition
2009-09-15

Intelligent transport systems —
Reference model architecture(s) for the
ITS sector —
Part 6:
Data presentation in ASN.1
Systèmes intelligents de transport (ITS) — Architecture(s) de modèle de
référence pour le secteur ITS —
Partie 6: Présentation de données dans ASN.1




Reference number
ISO 14813-6:2009(E)
©
ISO 2009

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ISO 14813-6:2009(E)
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ISO 14813-6:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Requirements.4
4.1 General requirements .4
4.2 ASN.1 syntax.5
4.3 Determining context.5
4.4 Using ASN.1 to define ITS data concepts.6
4.5 Module definition using ASN.1 .7
Annex A (informative) Simplified context negotiation .10
Annex B (informative) Examples .11
Bibliography.15

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ISO 14813-6:2009(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 14813-6 was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
This first edition of ISO 14813-6 cancels and replaces ISO/TR 14813-6:2000.
ISO 14813 consists of the following parts, under the general title Intelligent transport systems — Reference
model architecture(s) for the ITS sector:
⎯ Part 1: ITS service domains, service groups and services
⎯ Part 2: Core TICS reference architecture [Technical Report]
⎯ Part 3: Example elaboration [Technical Report]
⎯ Part 4: Reference model tutorial [Technical Report]
⎯ Part 5: Requirements for architecture description in ITS standards
⎯ Part 6: Data presentation in ASN.1
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ISO 14813-6:2009(E)
Introduction
This part of ISO 14813 is one of a series of documents to provide a form and structure to the reference
architectures for intelligent transport systems (ITS). Specifically, this part of ISO 14813 is intended to enable
conformance with a resolution of ISO/TC 204, a determination for the consistent use and elaboration of
Abstract Syntax Notation One [ASN.1 (ISO/IEC 8824-1, ISO/IEC 8824-2, ISO/IEC 8824-3 and
ISO/IEC 8824-4)] within ITS International Standards.
ISO/TR 14813-6:2000 was developed following the decision of the ISO Technical Committee ISO/TC 204 to
adopt ASN.1 as its normal syntax notation for data definitions within ITS International Standards and to
provide instructions and rules to facilitate interoperability and mobility of data. This part of ISO 14813
represents a revision of ISO/TR 14813-6:2000, clarifying and updating it by setting the use of ASN.1 in context
with the use of other notations within ITS International Standards.
To be explicit, the ISO/TC 204 decision does not require that all ITS International Standards and systems shall
use ASN.1 as their only means of encoding and transfer. In many cases other methods will be used because
of industry practices or efficiency in certain situations. The ISO/TC 204 decision requires only that
⎯ where data is defined within an ITS International Standard or data registry, it is elaborated in a consistent
form within all ITS International Standards as an ASN.1 module to promote interoperability and reuse,
and
⎯ where ASN.1 is the chosen method for encoding, that it is consistently defined according to ISO/IEC 8825.
ASN.1 and its encoding rules provide a means of achieving interoperability of otherwise incompatible data
concepts. In order to achieve this, levels of identification are required to precede certain data elements, to
enable the comprehension of data messages.
Within the ASN.1 data definition there may be a requirement to use other notations or encoding rules in the
transfer of information within a system specified within an ITS International Standard.
ISO 14817 defines the format of data dictionaries and data registries and is consistent to this document in
requiring the definition of data according using ASN.1.

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INTERNATIONAL STANDARD ISO 14813-6:2009(E)

Intelligent transport systems — Reference model
architecture(s) for the ITS sector —
Part 6:
Data presentation in ASN.1
1 Scope
This part of ISO 14813 provides an 'enabling' structure for use in the ITS sector. It provides a formal means to
enact the ISO/TC 204 decision by resolution to use ASN.1 for data definitions within ITS International
Standards. This provides a common message form to enable interoperability and reuse. It provides
consistency of use so that where other aspects of ASN.1 (defined within ISO/IEC 8824 and ISO/IEC 8825),
such as transfer rules, are selected to be used, they are used in a common and consistent way in order to
maximize interoperability and reuse.
It is important to note that this part of ISO 14813 does not require the use of ASN.1 for anything other than
providing a common and flexible form of data definition and this document makes specific provision for the
support of use of other extant standardized syntax notations (EDIFACT, XML, etc.) whilst maintaining
interoperability and reuse by defining these practices within an ASN.1 data definition.
Specific implementation requirements, other than those determined in the syntax notations identified above,
are beyond the scope of this document.
This part of ISO 14813 also provides a means where particular ITS sector requirements, or existent
International Standards, that require particular message forms and procedures that are expressed in other
notations (EDIFACT, XML, etc.), may be referenced and reused by other ITS applications. Thus it presents an
unambiguous system for identifying all the different data types and describing them in ITS International
Standards in a common way.
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/IEC 8824-1:2002, Information technology — Abstract Syntax Notation One (ASN.1): Specification of basic
notation
ISO/IEC 8824-2, Information technology — Abstract Syntax Notation One (ASN.1): Information object
specification
ISO/IEC 8824-3, Information technology — Abstract Syntax Notation One (ASN.1): Constraint specification
ISO/IEC 8824-4, Information technology — Abstract Syntax Notation One (ASN.1): Parameterization of ASN.1
specifications
ISO/IEC 8825-1, Information technology — ASN.1 encoding rules: Specification of Basic Encoding Rules
(BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)
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ISO 14813-6:2009(E)
ISO/IEC 8825-2, Information technology — ASN.1 encoding rules: Specification of Packed Encoding Rules
(PER)
ISO/IEC 8825-3, Information technology — ASN.1 encoding rules: Specification of Encoding Control Notation
(ECN)
ISO/IEC 8825-4, Information technology — ASN.1 encoding rules: XML Encoding Rules (XER)
ISO/IEC 9834-1, Information technology — Open Systems Interconnection — Procedures for the operation of
OSI Registration Authorities: General procedures and top arcs of the ASN.1 Object Identifier tree
ISO 14817, Transport information and control systems — Requirements for an ITS/TICS central Data Registry
and ITS/TICS Data Dictionaries
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
ASN.1 type
ASN.1 type definition
definition of a type that conforms to ISO/IEC 8824
NOTE This is a data type, type definition (or type for short) that represents in a formalized way a class of information
(for example, numerical, textual, still image or video information). The representation is conformant to definitions given in
ISO/IEC 8824-1.
3.2
associated ASN.1 type
type which is used only for defining the value and subtype notation for a type
NOTE Associated types are defined when it is necessary to make it clear that there may be a significant difference
between how the type is defined in ASN.1 and how it is encoded. Associated types do not appear in user specifications.
3.3
data element
some single unit of information of interest (such as a fact, proposition, observation, etc.) about some (entity)
class of interest (e.g. a person, place, process, property, concept, association, state, event, etc.) considered to
be indivisible in a particular context
[ISO 14817:2002, definition 4.7]
3.4
data frame
data concept; grouping of data elements primarily for the purpose of referring to the group with a single name
and thereby efficiently reusing groups of data elements that commonly appear together (e.g. ASN.1
SEQUENCE, SEQUENCE OF, SET OF or CHOICE) in a message specification
[ISO 14817:2002, definition 4.9]
3.5
data primitive
data element that cannot be further subdivided meaningfully within the context of ASN.1
3.6
(data) type
named set of values
[ISO/IEC 8824-1:2002, definition 3.6.74]
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ISO 14813-6:2009(E)
3.7
EDI
electronic data interchange
passing of a message, or series of messages, between computers and/or between different software systems
[4]
NOTE Within this context an EDI message is normally compatible with the form specified in ISO/IEC 9897 .
3.8
EDIFACT
electronic data interchange for administration, commerce and transport
[3]
specific message format for the sector in question as specified in ISO 9735
3.9
information object
instance of some information object class, being composed of a set of fields which conform to field
specification of the class
[ISO/IEC 8824-2:2002, definition 3.4.9]
3.10
information object class
set of fields, forming a template for the definition of a potentially unbounded collection of information objects,
the instances of the class
[ISO/IEC 8824-2:2002, definition 3.4.10]
3.11
interface dialogue
bi-directional communication sequence between two parties in accordance with predetermined protocols and
sequences
3.12
level of identification
position within ASN.1 OBJECT IDENTIFIER (ISO/IEC 9834-1)
3.13
message
information in a defined form sent from a source to a receiver; data concept, grouping of data elements and/or
data frames, as well as associated message metadata, that is used to convey a complete unit of information
NOTE Adapted from ISO 14817.
3.14
module
one or more instances of the use of the ASN.1 notation for type, value, value set, information object class,
information object, and information object set (as well as the parameterized variant of those), encapsulated
using the ASN.1 module notation
[ISO/IEC 8824-1:2002, definition 3.6.43]
3.15
module identifier
instance of an object identifier type which relates to an associated module
NOTE In ISO/IEC 8824 a module identifier is defined as:
ModuleIdentifier::=
modulereference
DefinitiveIdentifier
If the "DefinitiveIdentifier" is not empty, the denoted object identifier value unambiguously and uniquely identifies the
module being defined. No defined value may be used in defining the object identifier value.
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ISO 14813-6:2009(E)
3.16
non-ASN.1 type
type definition that does not conform to ISO/IEC 8824
3.17
object identifier
globally unique value associated with an object to unambiguously identify it
[ISO/IEC 8824-1:2002, definition 3.6.47]
3.18
object identifier type
simple type whose values are the set of all object identifiers allocated in accordance with the rules of the
ISO/IEC 9834 series
[ISO/IEC 8824-1:2002, definition 3.6.48]
3.19
simple (data) type
type defined by directly specifying the set of its values
[ISO/IEC 8824-1:2002, definition 3.6.66]
3.20
value domain
data concept; expression of a specific and explicit representation of some information about something of the
interest within the ICT/ITS domain
[ISO 14817:2002, definition 4.29]
4 Requirements
4.1 General requirements
ISO/TC 204 has resolved to use Abstract Syntax Notation.1 (ASN.1), as defined in ISO/IEC 8824-1,
ISO/IEC 8824-2, ISO/IEC 8824-3 and ISO/IEC 8824-4, where there is a requirement to elaborate syntax
notation of data definitions within ITS International Standards. This ITS International Standard provides a
normative means to achieve this objective.
This requirement is particularly important for data reuse and interoperability now that ISO 14817 is approved
and countries and regions are beginning to implement data registries and data dictionaries according to its
requirements.
The requirement affects only
⎯ data definitions in ITS International Standards, and
⎯ the method of use of ASN.1 where ASN.1 has been selected for other syntax notation aspects (such as
data transfer).
Where extant practice or desirability to achieve interoperability with other (non ITS) systems has caused an
ITS International Standard to use other notations to transfer or format data, there is no limitation on this
whatsoever and there is no requirement to use ASN.1 transfer encodings, etc. The sole requirement is that
data definition within the ITS International Standard provides conversion to data module definitions in ASN.1.
Annex B provides examples for ASN.1 type definitions.
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ISO 14813-6:2009(E)
4.2 ASN.1 syntax
As stated in its defining document (ISO/IEC 8824-1), ASN.1 is a standard notation used for the formal
definition of data types, values, and constraints on data types. An important feature of ASN.1 as it relates to
the exchange of information regarding ITS is its ability to enable separation of the specification of message
content (e.g. data elements, data frames) from the specification of the encoding or syntax of messages (e.g.
EDI, EDIFACT, XML).
As presented in Reference [7], “the following advantages of formal and separate definitions can be cited.
⎯ Easy mapping to different syntaxes, including mapping to programming language data structures for easy
implementation and mapping to compact binary forms for both security and bandwidth purposes.
⎯ Provision of tools for validation of message syntax and processing of message content, including
application-independent encode/decode libraries.
⎯ Automatic generation of test-suites.
⎯ Checking for completion and validity”.
4.3 Determining co
...