ISO 21219-21:2025

International
Standard
ISO 21219-21
First edition
Intelligent transport systems —
2025-01
Traffic and travel information (TTI)
via transport protocol experts
group, generation 2 (TPEG2) —
Part 21:
Geographic location referencing
(TPEG-GLR)
Systèmes intelligents de transport — Informations sur le trafic
et le tourisme via le groupe expert du protocole de transport,
génération 2 (TPEG2) —
Partie 21: Information géographique (TPEG-GLR)
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 2
5 Toolkit specific constraints. 2
5.1 Version number signalling .2
5.2 Extendibility .2
6 GLR toolkit structure . 2
6.1 General .2
6.2 Geographic bounding box location reference .5
6.3 Geographic bounding circle or sector of circle location reference .5
6.4 Geographic point location reference .7
6.5 Geographic line location reference .7
6.6 Geographic area location reference .8
7 GLR toolkit components . 9
7.1 GeographicLocationReference .9
8 GLR Datatypes . 10
8.1 GeographicAreaReference .10
8.2 GeographicAreaWithHolesReference .10
8.3 GeographicBoundingBox .11
8.4 GeographicBoundingCircleSector .11
8.5 GeographicLineReference . 12
8.6 GeographicPointReference . 12
8.7 CircleSector . 13
8.8 Coordinate . 13
8.9 HierarchicalAreaName .14
8.10 Polygon .14
Annex A (normative) TPEG application, TPEG-binary representation .16
Annex B (normative) TPEG application, tpegML representation.23
Bibliography .29

iii
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
This first edition cancels and replaces the first edition of ISO/TS 21219-21:2018, which has been technically
revised.
The main changes are as follows:
— the document status has been changed from Technical Specification (TS) to International Standard (IS).
A list of all parts in the ISO 21219 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
0.1  History
TPEG technology was originally proposed by the European Broadcasting Union (EBU) Broadcast
Management Committee, who established the B/TPEG project group in the autumn of 1997 with a brief to
develop, as soon as possible, a new protocol for broadcasting traffic and travel-related information in the
multimedia environment. TPEG technology, its applications and service features were designed to enable
travel-related messages to be coded, decoded, filtered and understood by humans (visually and/or audibly
in the user’s language) and by agent systems. Originally, a byte-oriented data stream format, which can be
carried on almost any digital bearer with an appropriate adaptation layer, was developed. Hierarchically
structured TPEG messages from service providers to end-users were designed to transfer information from
the service provider database to an end-user’s equipment.
One year later, in December 1998, the B/TPEG group produced its first EBU specifications. Two documents
were released. Part 2 (TPEG-SSF, which became ISO/TS 18234-2) described the syntax, semantics and
framing structure which was used for all TPEG applications. Meanwhile, Part 4 (TPEG-RTM, which became
ISO/TS 18234-4) described the first application for road traffic messages.
Subsequently, in March 1999, CEN/TC 278, in conjunction with ISO/TC 204, established a group comprising
members of the former EBU B/TPEG and this working group continued development work. Further parts
were developed to make the initial set of four parts, enabling the implementation of a consistent service.
Part 3 (TPEG-SNI, ISO/TS 18234-3) described the service and network information application used by all
service implementations to ensure appropriate referencing from one service source to another.
Part 1 (TPEG-INV, ISO/TS 18234-1) completed the series by describing the other parts and their relationship.
It also contained the application IDs used within the other parts. Additionally, Part 5, the public transport
information application (TPEG-PTI, ISO/TS 18234-5), was developed. The so-called TPEG-LOC location
referencing method, which enabled both map-based TPEG-decoders and non-map-based ones to deliver
either map-based location referencing or human readable text information, was issued as ISO/TS 18234-6
to be used in association with the other applications of parts of the ISO 18234 series to provide location
referencing.
The ISO 18234 series has become known as TPEG Generation 1.
0.2  TPEG Generation 2
When the Traveller Information Services Association (TISA), derived from former forums, was inaugurated
in December 2007, TPEG development was taken over by TISA and continued in the TPEG applications
working group.
It was about this time that the (then) new Unified Modelling Language (UML) was seen as having major
advantages for the development of new TPEG applications in communities who would not necessarily have
the binary physical format skills required to extend the original TPEG TS work. It was also realized that the
XML format for TPEG described within the ISO 24530 series (now superseded) had a greater significance
than previously foreseen, especially in the content-generation segment, and that keeping two physical
formats synchronized, in different standards series, would be rather difficult.
As a result, TISA set about the development of a new TPEG structure that would be UML-based. This has
subsequently become known as TPEG Generation 2.
TPEG2 is embodied in the ISO 21219 series and it comprises many parts that cover introduction, rules, toolkit
and application components. TPEG2 is built around UML modelling and has a core of rules that contain the
modelling strategy covered in ISO 21219-2, ISO 21219-3 and ISO 21219-4 and the conversion to two current
physical formats: binary (see Annex A) and XML (see Annex B); others could be added in the future. TISA
uses an automated tool to convert from the agreed UML model XMI file directly into an MS Word document
file that forms the annex for each physical format.
TPEG2 has a three-container conceptual structure: message management (ISO 21219-6), application (several
parts) and location referencing (ISO 21219-7). This structure has flexible capability and can accommodate

v
many differing use cases that have been proposed within the TTI sector and more broadly for hierarchical
message content.
TPEG2 also has many location referencing options as required by the service provider community, any of
which may be delivered by vectoring data included in the location referencing container.
The following classification provides a helpful grouping of the different TPEG2 parts according to their
intended purpose. Note that the list below is potentially incomplete, as it is possible that new TPEG2 parts
will be introduced after publication of this document.
— Toolkit parts: TPEG2-INV (ISO 21219-1), TPEG2-UML (ISO 21219-2), TPEG2-UBCR (ISO 21219-3), TPEG2-
UXCR (ISO 21219-4), TPEG2-SFW (ISO 21219-5), TPEG2-MMC (ISO 21219-6), TPEG2-LRC (ISO 21219-7).
— Special applications: TPEG2-SNI (ISO 21219-9), TPEG2-CAI (ISO 21219-10), TPEG2-LTE (ISO/TS 21219-24).
— Location referencing: TPEG2-OLR (ISO/TS 21219-22), TPEG2-GLR (ISO 21219-21 – this document),
TPEG2-TLR (ISO 17572-2), TPEG2-DLR (ISO 17572-3).
— Applications: TPEG2-PKI (ISO 21219-14), TPEG2-TEC (ISO 21219-15), TPEG2-FPI (ISO 21219-16),
TPEG2-TFP (ISO 21219-18), TPEG2-WEA (ISO 21219-19), TPEG2-RMR (ISO/TS 21219-23), TPEG2-EMI
(ISO 21219-25), TPEG2-VLI (ISO/TS 21219-26).
TPEG2 has been developed to be broadly (but not totally) backward compatible with TPEG1 to assist in
transitions from earlier implementations, while not hindering the TPEG2 innovative approach and being
able to support many new features, such as dealing with applications with both long-term, unchanging
content and highly dynamic content, such as parking information.
This document is based on the TISA specification technical/editorial version reference:
SP22005_2.1_002
vi
International Standard ISO 21219-21:2025(en)
Intelligent transport systems — Traffic and travel information
(TTI) via transport protocol experts group, generation 2
(TPEG2) —
Part 21:
Geographic location referencing (TPEG-GLR)
1 Scope
This document establishes a method of using geographic location referencing (GLR) that can be used by
relevant TPEG applications. The GLR type, defined in this document, is used for defining geographic
location references (points, polylines and geographical areas). The GLR method is intended to be one of the
methods that can be transported inside a TPEG-Location Referencing Container (TPEG-LRC) for those TPEG
applications providing information for primarily geographical locations (e.g. weather).
The GLR specification is deliberately kept basic and compact, so that it can also be employed advantageously
in non-navigation devices, for simple TPEG services such as weather information, safety alerts, etc. As such,
the GLR location referencing method is intended to be complementary to map-related location referencing
methods, where the focus is on the referencing of anthropogenic artefacts such as roads and highways.
For this reason, the scope of GLR is limited to geographic locations on the Earth’s surface.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 21219-1, Intelligent transport systems — Traffic and travel information (TTI) via transport protocol experts
group, generation 2 (TPEG2) — Part 1: Introduction, numbering and versions (TPEG2-INV)
ISO 21219-9, Intelligent transport systems — Traffic and travel information (TTI) via transport protocol experts
group, generation 2 (TPEG2) — Part 9: Service and network information (TPEG2-SNI)
ISO 21219-14, Intelligent transport systems — Traffic and travel information (TTI) via transport protocol
experts group, generation 2 (TPEG2) — Part 14: Parking information (TPEG2-PKI)
ISO 21219-16, Intelligent transport systems — Traffic and travel information (TTI) via transport protocol
experts group, generation 2 (TPEG2) — Part 16: Fuel price information and availability (TPEG2-FPI)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

3.1
point of interest
specific point location that someone may find useful or interesting
EXAMPLE 1 A point on the Earth representing the location of the Eiffel Tower, in Paris, France.
EXAMPLE 2 The location of a weather station on top of Mount Washington in New Hampshire, VT, USA.
EXAMPLE 3 The location of a fuel station.
4 Abbreviated terms
For the purposes of this document, the abbreviated terms in ISO 21219-1, ISO 21219-9, ISO 21219-14,
ISO 21219-16 shall apply.
5 Toolkit specific constraints
5.1 Version number signalling
Version numbering is used to track the separate versions of an application through its development and
deployment. The differences between these versions could have an impact on client devices.
The version numbering principle is defined in ISO 21219-1.
Table 1 shows the current version numbers for signalling GLR versions within the SNI application.
Table 1 — Current version numbers for signalling of GLR
Major version number 2
Minor version number 1
5.2 Extendibility
Future toolkit extensions may insert new components or may replace existing components by new ones
without losing backward compatibility. This means that a TPEG2-GLR decoder shall be able to detect and
skip unknown components.
6 GLR toolkit structure
6.1 General
The GLR toolkit provides a component for simple geographic location references. This component can be
inserted in an LRC inside a TPEG message, when this type of location reference is relevant and suitable for
the particular TPEG application.
Figure 1 shows the structure of GeographicLocationReference in the GLR toolkit. Other classes used in the
toolkit are shown in Figure 2, Figure 3, Figure 4 and Figure 5. The GLR location reference offers several
variants of geographic location references. However, each instance shall contain only a single type of the
provided various types of geographic location references.
The binary format and XML format of the TPEG2-SNI application for use in transmission shall be in
accordance with Annexes A and B, respectively.

Figure 1 — GLR toolkit structure

Figure 2 — CircleSector
Figure 3 — Coordinate
Figure 4 — HierarchicalAreaName
Figure 5 — Polygon
In a GLR location reference, coordinates are specified in the WGS84 geodetic system, unless explicitly
signalled otherwise at service level or service component level (see also 8.8).

The GLR toolkit contains two versions of bounding areas, and point, line and area location references.
Subclauses 6.2 – 6.6 explain each of these variants of geographic location references in more detail.
6.2 Geographic bounding box location reference
A geographic bounding box location reference defines a rectangular area to indicate, for example, a search
area or encompassing area of a collection of features, e.g. fuel stations or other points of interest (POIs).
Figure 6 shows a bounding box, with its defining north-west (NW) and south-east (SE) corners. For example,
this bounding box location reference delineates the locations of a collection of fuel stations in Manhattan,
NY, USA.
Key
1 NW corner
2 SE corner
Figure 6 — Example of a geographic bounding box indicating a delineating search area for a set of
fuel stations
Geographic bounding box location references may indicate the altitude above mean sea level (MSL) of the
area, and may have an area name as descriptor.
6.3 Geographic bounding circle or sector of circle location reference
A geographic bounding circle location reference is very similar in nature to the geographic bounding box
location reference. The main difference is the definition of the encompassing area: in this case it is a circle
rather than a rectangle. This circle is defined by a centre point and a radius (see Figure 7).

Key
1 centre point
2 radius
Figure 7 — Example of a geographic bounding circle location reference
Geographic bounding circle location references may indicate the altitude above MSL of the area, and may
have an area name as descriptor.
When geographic bounding is to be limited to only a sector of a circle with a defined radius, this is specified
through two azimuth angles. These angles specify the angular start and angular end of the sector (in
clockwise direction) respectively. Both these angles are measured with respect to the geographic north (see
Figure 8).
Key
1 centre point
2 radius
3 sectorStartAngle
4 geographic north
5 sectorEndAngle
Figure 8 — Definition of a sector of a circle with sectorStartAngle and sectorEndAngle
6.4 Geographic point location reference
A geographic point location reference references the location of a point-type feature, e.g. a weather station,
a theatre, or one of the individual fuel stations in Figure 6 and Figure 7. If the location is approximate,
e.g. the location of a highway intersection, the location reference can indicate this through an attribute
"isFuzzyPoint" (see Figure 1).
Furthermore, for geographic location references of features close to roads, the road name of the adjacent
road may optionally be indicated, and optionally the direction one travels on that road, leading to the
primary entry point of that feature. Geographic point location references may also optionally indicate the
altitude above MSL of the area, and optionally contain a point feature name as descriptor.
6.5 Geographic line location reference
A geographic line location reference references the location of a line-type feature, e.g. a squall line or the
San Andreas Fault line in California, USA. If the location is approximate (e.g. the location of a squall line), the
location reference can indicate this through an attribute "isFuzzyLine" (see Figure 1).
Geographic line location references may also indicate the altitude above MSL of the area, and may have a line
feature name as descriptor.
SOURCE Reference [3], reproduced with the permission of the authors.
Figure 9 — Tornado watch location indication
6.6 Geographic area location reference
A geographic area location reference references the location of an area-type feature, e.g. the location of a
forest fire, or a tornado warning. If the location is approximate, such as the location of a forest fire, the
location reference can indicate this through an attribute "isFuzzyArea" (see Figure 1). Geographic area
location references may also optionally indicate the altitude above MSL of the area.
Furthermore, geographic area location references may include an area feature name as descriptor, or one
or more hierarchical area names as descriptor. Hierarchical area names are used in situations such as a
weather report for a tornado watch, for example (see Figure 9).
For the tornado watch example shown in Figure 9, the hierarchical name descriptor is composed of two
states (USA), Louisiana and Mississippi, and for each of these two states, the following parishes/counties,
indicating the parts of that state for which the tornado watch is issued:
— Louisiana Ascension, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee, St.
Helena, St. Tammany, Tangipahoa, Washington, West Baton Rouge, West Feliciana
— Mississippi Adams, Amite, Claiborne, Clarke, Copiah Covington, Forrest Franklin, Hinds, Jasper,
Jefferson, Jefferson Davis, Jones, Lamar, Lauderdale, Lawrence, Lincoln, Madison,
Marion, Newto, Pearl River, Pike, Rankin Scott, Simpson, Smith, Walthall, Warren,
Wilkinson
In the geographic area location reference for this example tornado watch, these composite locations can be
encoded with two HierarchicalAreaName data structures, one for each state.
Geographic area location references may also be indicated as polygonal shapes. These polygonal shapes may
even have holes in them, e.g. to indicate an applicable area, but at the same time to exclude some part of this
area. Figure 10 shows an example of an area with a “hole” in it. This area with a hole is constructed with an
outer, exterior polygon, and an interior polygon representing the hole (i.e. the part of the area that is “cut-out”).

Figure 10 — Polygonal area location reference with hole inside
7 GLR toolkit components
7.1 GeographicLocationReference
GLR is the top-level toolkit component for simple geographic location references. This component shall
contain only one single type of the various types of geographic location reference provided.
Table 2 defines the GeographicLocationReference component.
Table 2 — GeographicLocationReference
Name Type Multiplic- Description
ity
geographicBoundingBox GeographicBoundingBox 0.1 BoundingBox-type
geographic location
reference.
geographicBoundingSector GeographicBoundingCircleSector 0.1 Bounding area
geographic location
reference as sector of
a circle or complete
circle.
geographicPointReference GeographicPointReference 0.1 Point-type geographic
location reference.
geographicLineReference GeographicLineReference 0.1 Line-type geographic
location reference.
geographicAreaReference GeographicAreaReference 0.1 Area-type geographic
location reference.
geographicAreaWithHolesReference GeographicAreaWithHolesReference 0.1 Area-type geographic
location reference.
8 GLR Datatypes
8.1 GeographicAreaReference
GeographicAreReference denotes a geographic area specified as a polygon. A GeographicAreaReference shall
include at most one of the attributes "areaFeatureName" and "hierarchicalAreaFeatureName", but not both.
Table 3 defines the GeographicAreaReference datatype.
Table 3 — GeographicAreaReference
Name Type Multiplic- Description
ity
polygonPoints Coordinate 3.* A sequence of points forming a closed, sim-
ple (i.e. non-self-intersecting) contour of a
geographic polygon.
The polygon contour is formed by line seg-
ments connecting the successive points, and
finally the polygon contour is closed by the
line segment connecting the last point to
the first point.
The resulting area polygon shall be
non-self-intersecting.
A counter-clockwise order of the coordi-
nates in a (exterior) polygon is recommend-
ed.
It is recommended to limit the number of
points of the polygon to 32 or less.
isFuzzyArea Boolean 1 If set, the "isFuzzyArea" attribute indicates
that the polygon shape represents a fuzzy
area, i.e. the polygon shape is an approx-
imate description of the location of the
referenced feature.
altitudeMSL IntSiLoMB 0.1 Average elevation of location in metres
above/below MSL.
areaFeatureName LocalisedShortString 0.* Feature name of the area reference in the
local languages of interest.
hierarchicalAreaFeatureName HierarchicalAreaName 0.* Attribute to express area name(s) as hier-
archical feature name. Several hierarchical
area names are allowed to express a region
of a number of countries, or a number of
states, for example.
Each such hierarchical area name structure
indicates the local language of interest.
Multiple hierarchical area names in a single
local language may be supplied.
8.2 GeographicAreaWithHolesReference
GeographicAreaWithHolesReference denotes a geographic area with holes specified as an exterior polygon
and interior polygons representing the holes. A GeographicAreaWithHolesReference shall include at most
one of the attributes "areaFeatureName" and "hierarchicalAreaFeatureName", but not both.
Table 4 defines the GeographicAreaWithHolesReference datatype.

Table 4 — GeographicAreaWithHolesReference
Name Type Multiplic- Description
ity
exteriorPolygon Polygon 1 Exterior polygon of the geographic area.
The recommended order of the coordinates
is counter-clockwise for this exterior poly-
gon.
interiorPolygons Polygon 1.* Interior polygon of the geographic area, in-
dicating a hole in the area. The recommend-
ed order of the coordinates is clockwise for
the interior polygon. Interior polygons (if
more than one present) shall not intersect
or touch another.
isFuzzyArea Boolean 1 If set, the "isFuzzyArea" attribute indicates
that the polygon shape represents a fuzzy
area, i.e. the polygon shape is an approx-
imate description of the location of the
referenced feature.
altitudeMSL IntSiLoMB 0.1 Average elevation of location in metres
above/below MSL.
areaFeatureName LocalisedShortString 0.* Feature name of the area reference in the
local languages of interest.
hierarchicalAreaFeatureName HierarchicalAreaName 0.* Attribute to express area name(s) as hier-
archica
...