ISO/TS 21176:2020

TECHNICAL ISO/TS
SPECIFICATION 21176
First edition
2020-09
Cooperative intelligent transport
systems (C-ITS) — Position, velocity
and time functionality in the ITS station
Systèmes de transport intelligents coopératifs (STI-C) –
Fonctionnalités de position, de vitesse et de temps dans la station STI
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 4
5 Conformance . 5
6 PVT service in the ITS station and communication architecture. 5
6.1 ITS station and communication architecture . 5
6.2 ITS-S application processes (ITS-S-APs) . 6
6.3 ITS-S facilities layer services . 6
6.4 PVT service provided by the ITS-S facilities layer . 8
6.5 Access to the PVT service. 8
6.6 PVT-augmented ADUs . 9
7 PVT service . 9
7.1 PVT service reference model . 9
7.2 PVT-related input parameters .10
7.3 PVT output parameters .11
7.3.1 General.11
7.3.2 PvtInfoEcdd .12
7.3.3 PvtInfoEcdd-PosVelocityTime .16
7.3.4 PvtInfoEcdd-PosTime .16
7.3.5 PvtInfoEcdd-VelocityAccelerationTime .16
7.3.6 PvtInfoEcdd-VelocityTime .16
7.3.7 PvtInfoEcdd-SpeedTime .16
7.3.8 PvtInfoNmeaData .17
8 PVT-SAP service primitives .17
8.1 General .17
8.1.1 Overview .17
8.1.2 PVTinit .18
8.1.3 Return codes .18
8.2 Get-PVT .18
8.3 Subscribe-PVT-related service primitives .19
8.3.1 Subscribe-PVT .19
8.3.2 Notify-PVT .20
8.3.3 Cancel-PVT .20
9 PVT capability .20
Annex A (normative) PVT data type specifications .22
Annex B (normative) Implementation conformance statement proforma .23
Bibliography .27
Foreword
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This document was prepared by Technical Committee ISO/TC 204, Intelligent transport systems, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC
278, Intelligent transport systems, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
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iv © ISO 2020 – All rights reserved

Introduction
Context of C-ITS
This document is part of a family of deliverables from Standard Development Organizations (SDOs)
for Cooperative Intelligent Transport Systems (C-ITS), a subset of standards for Intelligent Transport
Systems (ITS).
ITS aims at improving surface transportation in terms of:
— safety, e.g. crash avoidance, obstacle detection, emergency call, dangerous goods;
— efficiency, e.g. navigation, green wave, priority, lane access control, contextual speed limits, car
sharing;
— comfort, e.g. telematics, parking, electric vehicle charging, infotainment;
by applying information and communication technologies (ICT).
To support interoperability, C-ITS specifications are developed to exchange and share information
within a given ITS application domain, or between ITS application domains.
C-ITS services are based on the exchange of data between vehicles of any category, the roadside and
urban infrastructure (e.g. traffic lights, road tolls, variable message signs), control and services centres
(e.g. traffic control centre, map providers), and other road users (e.g. pedestrians, cyclists).
Many ITS services require the cooperation of vehicles with their surrounding environment (e.g.
other vehicles, other road users, roadside and urban infrastructure), whilst other services require
connectivity to remote service platforms (e.g. road traffic control centres, map providers, service
providers, fleet managers, equipment manufacturers).
In order to support:
— a large variety of C-ITS services with diverging requirements, and
— efficient sharing of information maintained by individual service applications,
it is necessary to combine multiple access technologies and communication protocols with distinct
performance characteristics (communication range, available bandwidth, end-to-end transmission
delay, quality of service, security, etc.).
Combining multiple access technologies and communication protocols requires a common approach
to the way communications and data are managed in a secure way. A functional architecture (the ITS
station architecture) has therefore been specified to manage security, communications and data related
to C-ITS services.
For more detail on C-ITS, see the ITS station and communication architecture specified in ISO 21217,
and the multi-part technical report CEN/TR 21186 providing guidelines on the usage of C-ITS; see also
https:// www .itsstandards .eu/ cits.
Need for position, velocity and time (PVT) information in C-ITS
Many ITS services, particularly those where vehicles or other mobile devices such as smartphones are
involved, require position, velocity and time (PVT) information. Such PVT information is needed for
various purposes. It is notably used by navigation systems, any related ITS service where position is
needed (e.g. car-sharing, taxi ride booking, fleet management), advanced driver assistance or automated
driving systems. The information transmitted between ITS stations or between components of an ITS
station can be required to be marked with position or time information (geo- or time stamping).
PVT-related information can originate from various sources, such as a global navigation satellite system
or systems (GNSSs). Accuracy and reliability can be improved by usage of serval sources, such as anti-
spoofing flags used for GNSS signal authentication, inertial measurement units (IMUs), light detection
and ranging (LIDAR)-based sensors, video camera-based sensors, digital maps and differential
correction systems. Input from the various sources needs to be properly merged and the output be
associated with a defined accuracy.
The provision of PVT information in a standardized form that can be used by all types of C-ITS services
(e.g. road safety, traffic efficiency, public transport, freight and logistics, emergency call and other
value-added services) is urgently needed, particularly in pilots and pre-deployment of C-ITS standards
in Europe (e.g. ITS Corridor, ECo-AT, SCOOP@F, C-Roads), North America (e.g. Connected Vehicle Pilot
Deployments) and Asia (e.g. Anting Project). In addition, PVT information is applicable to forthcoming
deployments of the European emergency call (eCall) service. Further, high resolution and accurate PVT
information is essential for automated driving.
High availability, precision and integrity of PVT information is essential for some C-ITS services, notably
for advanced driver assistance or automated driving (e.g. lane keeping, platooning).
A major challenge in defining and assessing the (GNSS) positioning performance, is that it is highly
influenced by the environment and the operational scenario. Research projects, standardization
activities and pilot projects are on-going to address open issues and to define a common and broadly
adopted framework, including the definition of relevant quality parameters and associated test
procedures for conformance assessment.
SaPPART, an Action under the European Cooperation in Science and Technology programme, brought
together experts in GNSSs, ITS and mobility to address the open issues. SaPPART defined a framework
[22][23][24]
for the assessment of the performances of GNSS-based positioning terminals , whose concepts
have been integrated in leading ongoing research projects (e.g. inLANE and ESCAPE).
Context of use of this document
This document aims to define a functionality providing the PVT information and the interface between
this new functionality and other existing functionalities of the ITS station so that it can be used in a
uniform, flexible and future-proof extensible way by ITS-S application processes complying with the
ITS station and communication architecture and related standards.
This document makes provision for any kind of quality parameter definitions, for example, the accuracy
levels for predefined confidence levels, associated with PVT information.
It is outside the scope of this document to define the associated conformance evaluation test procedures.
[11]
The EN 16803 series defines a framework for assessing the performance of ITS GNSS-based
terminals. It defines so-called protection levels of position and velocity (i.e. error bounds around
the estimated position and velocity provided by the positioning module), of which each is associated
with an integrity risk (i.e. probability that the actual error for a given position or velocity exceeds
[11]
the associated protection level). EN 16803-2 defines a test methodology based on replay in the
laboratory of real data sets recorded during fields tests. It may be used to assess the accuracy of the
position and velocity of the positioning terminal and underpin the confidence levels of the position and
the velocity as defined in this document.
vi © ISO 2020 – All rights reserved

TECHNICAL SPECIFICATION ISO/TS 21176:2020(E)
Cooperative intelligent transport systems (C-ITS) —
Position, velocity and time functionality in the ITS station
1 Scope
This document specifies a generic position, velocity and time (PVT) service. It further specifies
the PVT service within the ITS station (ITS-S) facilities layer (ISO 21217) and its interface to other
functionalities in an ITS-S such as:
— ITS-S application processes (ITS-S-APs), defined in ISO 21217;
— the generic facilities service handler (FSH) functionality of the ITS station facilities layer, defined in
ISO/TS 17429.
This document specifies:
— a PVT service which, dependent on a specific implementation, uses a variety of positioning-related
sources such as global navigation satellite systems (GNSSs, e.g. GALILEO, GLONASS and GPS),
roadside infrastructure, cellular infrastructure, kinematic state sensors, vision sensors;
— a PVT service which merges data from the above-mentioned positioning-related sources and
provides the PVT output parameters (carrying the PVT information) including the associated
quality (e.g. accuracy);
— how the PVT service is integrated as an ITS-S capability of the ITS station facilities layer;
— the interface function calls and responses (Service Access Point – service primitives) between the
PVT ITS-S capability and other functionalities of the ITS station architecture;
— optionally, the PVT service as a capability of the ITS-S facilities layer; see ISO 24102-6;
— an ASN.1 module C-itsPvt, providing ASN.1 type and value definitions (in Annex A);
— an implementation conformance statement proforma (in Annex B), as a basis for assessment of
conformity to this document.
NOTE It is outside the scope of this document to define the associated conformance evaluation test
procedures.
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/IEC 8824-1, Information technology — Abstract Syntax Notation One (ASN.1): Specification of basic
notation
ISO 17423, Intelligent transport systems — Cooperative systems — Application requirements and objectives
ISO/TS 17429, Intelligent transport systems — Cooperative ITS — ITS station facilities for the transfer of
information between ITS stations
ISO 17575-1:2016, Electronic fee collection — Application interface definition for autonomous systems —
Part 1: Charging
ISO 21217, Intelligent Transport Systems — Communications access for land mobiles (CALM — Architecture
ISO 24102-6:2018, Intelligent Transport Systems — Communications access for land mobiles (CALM) — ITS
station management — Part 6: Path and flow management
EN 16803-1, Space — Use of GNSS-based positioning for road Intelligent Transport Systems (ITS) — Part 1:
Definitions and system engineering procedures for the establishment and assessment of performances
ETSI TS 102 894-2 V1.3.1 (2018-08), Intelligent Transport Systems (ITS) — Users and applications
requirements — Part 2: Applications and facilities layer common data dictionary
1)
ETSI prEN 302 890-2 , Intelligent Transport Systems (ITS); Facilities Layer function Part 2: Facility
Position and Time management (POTI)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
acceleration
rate of change of velocity (3.19) of an object with respect to time
Note 1 to entry: Acceleration is a physical vector quantity; both magnitude and direction are needed to define it.
The unit of the scalar absolute value (magnitude) of acceleration is measured in the international system of units
as metres per second squared (m/s ).
3.2
confidence level
probability that the actual PVT information (3.15) is within the error bounds of the estimated PVT
information
Note 1 to entry: Confidence level represents the confidence that the estimated position does not exceed the error
bounds, referred to as protection level (3.13) in EN 16803-1.
Note 2 to entry: Confidence level, the term used in ETSI TS 102 894-2 V1.3.1 (2018-08), is the complementary
probability of the integrity risk (3.3) (i.e. confidence level = 1 – integrity risk).
3.3
integrity risk
probability that, for positioning terminals providing a protection level (3.13) as integrity-related
quantity, the actual error on a given output component exceeds its associated protection level
Note 1 to entry: Integrity risk is the complementary probability of the confidence level (3.2) (i.e. integrity risk =
1 – confidence level).
[SOURCE: EN 16803-1:2020, 3.2.8]
3.4
ITS-S application
ITS-S application process (3.5) residing in the ITS-S application entity
[SOURCE: ISO 21217:2014, 3.18]
1) Under preparation.
2 © ISO 2020 – All rights reserved

3.5
ITS-S application process
ITS-S-AP
element in an ITS station that performs information processing for a particular application and uses
ITS-S services to transmit and receive information
[SOURCE: ISO 21217:2014, 3.19]
3.6
ITS-S capability
uniquely addressable protocol or functionality that is part of an ITS-S managed service entity (3.8)
Note 1 to entry: Examples of ITS-S capabilities in the ITS station facilities layer are generic ITS-S facilities
layer services specified in ISO/TS 17429 (Communication Profile Handler, Facilities Services Handler, Content
Subscription Handler), the position and time service defined in ISO/TS 21176, the security service defined in
ISO/TS 21177; examples of ITS-S capabilities in the ITS-S networking and transport layer are IPv6 functionalities
defined in ISO 21210 (IPv6 neighbour discovery, IPv6 forwarding, IPv6 mobility support, .), the fast service
announcement protocol defined in ISO 22418, etc.
[SOURCE: ISO 24102-6:2018, 3.6]
3.7
ITS-S facilities layer protocol data unit
ITS-FPDU
protocol data unit exchanged between peer ITS-S facility layers
[SOURCE: ISO 21217:2014, 3.23]
3.8
ITS-S managed service entity
ITS-S MSE
uniquely addressable entity in an ITS-S layer comprised of a set of related ITS-S capabilities
Note 1 to entry: Examples of ITS-S managed service entities are: a communication module in the ITS-S access
technologies layer (M5, cellular, etc.), a protocol suite in the ITS-S networking and transport layer (IPv6, FNTP,
GeoNetworking, 6LoWPAN, etc.), the generic facilities MSE at the ITS-S facilities layer.
[SOURCE: ISO 24102-6:2018, 3.14]
3.9
ITS-S facilities header
header used to form an “ITS-S facilities layer protocol data unit”
[SOURCE: ISO/TS 17429:2017, 3.13]
3.10
ITS-S facilities service
ITS-S capability of the ITS-S facilities layer providing a service that may be applied to ADUs at the
request of the source ITS-S-AP
Note 1 to entry: Examples of ITS-S facilities services are “time stamping”, “geo-stamping”.
[SOURCE: ISO/TS 17429:2017, 3.14]
3.11
kinematics
motion of an object
Note 1 to entry: Kinematics does not consider the forces that cause an object to move.
3.11.1
kinematics state vector
set of parameters describing the kinematics (3.11) of an object, including its position
3.12
position
terrestrial absolute geographical location
Note 1 to entry: The absolute geographical location is defined according to a global coordinate reference system,
[25] [26]
such as the World Geodetic System 84 (WGS84) or the International Terrestrial Reference System (ITRS) .
Note 2 to entry: The CEN/TR 17297 series presents a tutorial on location referencing methods, applicable location
[12]
systems and translation methods between different system .
3.13
protection level
estimation of an upper bound for the error made on a position (3.12) or velocity (3.19) component (e.g.
the plane position) associated with a given probability called integrity risk (3.3)
[SOURCE: EN 16803-1:2020, 3.2.18]
3.14
PVT capability
ITS-S capability of the ITS-S facilities layer providing the PVT service
3.15
PVT information
information related to kinematics (3.11) of an ITS-SU
Note 1 to entry: Examples of such information are position, velocity, speed or acceleration as a function of time.
3.16
PVT service
station-internal service providing PVT information (3.15)
3.17
PVT stamp
addendum of PVT information (3.15) to the ADUs, by the ITS-S facilities layer, for each FPDU of a specific
ITS-S flow
Note 1 to entry: This feature by which the ITS-S facilities layer augments ADUs by adding data to FPDUs is defined
in ISO 24102-6.
3.18
speed
rate of change of an object's position with respect to a frame of reference
Note 1 to entry: Speed is a function of time.
3.19
velocity
an object's speed (3.18) and direction of motion
Note 1 to entry: Velocity is a physical vector quantity; both magnitude and direction are needed to define it.
The scalar absolute value (magnitude) of velocity is called speed (3.18), a unit whose quantity is measured in the
international system of units as metres per second (m/s).
4 Abbreviated terms
ADU Application Data Unit (ISO 21217)
C-ITS Cooperative ITS (ISO 21217)
CPH Communication Profile Handler (ISO/TS 17429)
4 © ISO 2020 – All rights reserved

CSH Content Subscription Handler (ISO/TS 17429)
FA-SAP Service access point between facilities and application layer (ISO 21217)
ITS-FSDU ITS Station Facility layer Service Data Unit (ISO 21217)
FSH Facilities Service Handler (ISO/TS 17429)
Galileo A Global Navigation Satellite System (GNSS) by the European Global Navigation Satellite
Systems Agency (GSA)
GLONASS Globalnaja nawigazionnaja sputnikowaja Sistema – a GNSS operated by the Russian
Federal Space Agency
GNSS Global Navigation Satellite System
GPS Global Positioning System – a GNSS operated by the Air Force of the United States of
America
LDM Local Dynamic Map (ISO 18750)
ICS Implementation Conformance Statement
ITS Intelligent Transport Systems (ISO 21217)
ITS-S MSE ITS-S Managed Service Entity (ISO/TS 17429)
ITS-S ITS Station (ISO 21217)
ITS-S-AP ITS Station Application Process (ISO 24102-6)
PVT Position, Velocity and Time
SAP Service Access Point (ISO 21217)
SBAS Satellite-Based Augmentation System
5 Conformance
To evaluate conformance of an implementation to this document, it is necessary to have an
implementation conformance statement (ICS), i.e. a statement of which capabilities and options have
been implemented. Annex B provides an ICS proforma that shall be completed by an implementer or its
representative that claims that its implementation conforms with requirements of this document.
The evaluation of an implementation for conformance to this document shall be based on the ICS and
the execution of the associated conformance evaluation test procedures.
NOTE It is outside the scope of this document to define the associated conformance evaluation test
procedures.
6 PVT service in the ITS station and communication architecture
6.1 ITS station and communication architecture
The PVT service is a station-internal service in support of C-ITS services that depend on the availability
and accuracy of position, velocity, time or other kinematics characteristics of the station. A widely
supported approach in C-ITS is to build on stations conformant with the station and communication
reference architecture specified in ISO 21217 and illustrated in Figure 1.
Figure 1 — Simplified ITS-S reference architecture according to ISO 21217
A physical implementation of an ITS station conformant with ISO 21217 is named ITS Station Unit
(ITS-SU). According to ISO 21217, these C-ITS services are provided by ITS-S Application Processes
(ITS-S-AP). An ITS-S-AP requests PVT information from the local PVT service, and may use this
information locally and also in protocol data units (PDUs) exchanged with other stations. The exchange
of information between ITS-SUs is performed using the set of functionalities and protocols supported
by the ITS station and communication architecture.
6.2 ITS-S application processes (ITS-S-APs)
ITS station application processes (ITS-S-APs) are the entities of the ITS station that perform information
processing and PDU exchanges with other stations for a particular ITS application in support of a
particular ITS service.
6.3 ITS-S facilities layer services
The ITS-S facilities layer comprises functionalities that provide generic ITS-S facilities services to ITS-S-
APs; see ISO 21217. Examples of such ITS-S facilities services are geo- and time stamping, local dynamic
map and service announcement.
6 © ISO 2020 – All rights reserved

The functionalities providing such services are referred to as ITS-S capabilities as specified in
ISO 24102-6.
Each ITS-S capability and each ITS-S facilities service is identified by a globally unique identifier; globally
[4]
unique identifiers are specified in ISO 17419 and recorded in a global registry. New ITS-S facilities
services and ITS-S capabilities compatible with the ITS station and communication architecture and its
functionalities can thereby be added to meet the needs of all or a specific set of stakeholders.
NOTE Details of a registration mechanism of globally unique identifiers are out of scope of this document
and are currently being developed in ISO/TC 204.
These ITS-S facilities services can be invoked either by other services in the ITS-S facilities layer or
directly by ITS-S-APs:
— Performing a generic service by the ITS-S facilities layer (e.g. those specified in ISO/TS 17429 - see
below) may add content to a PDU. E.g. the Facilities Services Handler (FSH), specified in ISO/TS 17429,
may add a PVT stamp.
— Access to these services directly by the ITS-S-APs is e.g. made by usage of service primitives at the
service access point between facilities and application layer (FA-SAP), as defined in ISO 21217 and
ISO 24102-3.
ISO/TS 17429 defines a set of generic functionalities of the ITS-S facilities layer. Two of these
functionalities are considered within the context of this document:
— The Communication Profile Handler (CPH): This ITS-S capability processes ITS-S facility layer
service data units (ITS-FSDUs) transmitted by an ITS-S-AP. It checks whether there is a valid
communication profile (ITS-SCP) corresponding to the ITS-S flow identifier associated with the
ITS-FSDU. The CPH triggers the appropriate actions to be performed according to the given ITS-S-
FlowID, including the processing by the FSH (see below).
— The Facilities Services Handler (FSH): This ITS-S capability provides a mechanism for applying
generic ITS-S facilities services to ADUs transmitted by ITS-S-APs upon their request, made at the
time of flow type registration (as per ISO 17423, ISO 24102-6 and ISO/TS 17429). This capability
appends an ITS-S facilities header to the ADU whenever ITS-S facilities services are requested by
the transmitting ITS-S-AP and require treatment of the ADU at both the sender and the recipient(s)
of the packet containing the ADU.
Figure 2 illustrates the ITS stations facilities layer functionalities in the context of the ITS station and
communication architecture; more details are presented in ISO/TS 17429.
Figure 2 — PVT service as an ITS station facility based on ISO/TS 17429
6.4 PVT service provided by the ITS-S facilities layer
The PVT service is basically defined independently of any station architecture. In addition, PVT
specifications are provided in accordance with the ITS station and communication architecture as
defined in ISO 21217 and related standards.
In order that the PVT service can be used by ITS-S-APs relying on the path and flow management
specified in ISO 24102-6, in accordance with the ITS station and communication architecture as
specified in ISO 21217, the functionality providing PVT information (PVT service) is defined as an ITS-S
capability.
NOTE 1 Facilities can also be defined as ITS-S-APs. In this case, such an ITS-S-AP is referred to as ITS-S facility
application, as specified in ISO 21217.
NOTE 2 Defining the PVT service associated with an ITS-S capability simplifies its specification and use. The
PVT functionality complies with the requirements that apply to ITS-S capabilities and ITS-S facilities services,
as defined in ISO 17423, ISO 24102-6 and ISO/TS 17429. This does not preclude usage of the PVT service in a
different station context, as the SAP of the PVT service is specified independently of any station architecture; a
mapping of the PVT-SAP service primitives to SAPs of any station architecture can be achieved in the form of a
non-standardized implementation.
6.5 Access to the PVT service
The PVT information can be accessed by an ITS-S-AP in two ways:
— directly upon request of PVT information ("pull method");
— directly upon subscription to the reception of PVT information ("subscription push method");
8 © ISO 2020 – All rights reserved

see the PVT services presented in Table 2.
NOTE 1 Another usage of the PVT service is specified in ISO/TS 17429, which defines an ITS-S facility service
(FSH) that appends information to an ADU (e.g. geo- and time stamping) of a specific flow ("PVT-augmented
ADUs push method"). See 6.6 for further details.
NOTE 2 ITS-S-APs include:
— ITS-S-APs located in the ITS-S application entity, also referred to as ITS-S application in ISO 21217;
[8]
— ITS-S-APs located in the ITS-S management entity: e.g. remote ITS station management [ISO 24102-2 ], the
[10]
ITS station internal management communication [ISO 24102-4 ], also referred to as ITS-S management
application in ISO 21217;
[5]
— ITS-S-APs located in the ITS-S facilities layer: e.g. LDM [ISO 18750 ], CAM, also referred to as ITS-S facility
applications in ISO 21217.
6.6 PVT-augmented ADUs
PVT-augmented ADUs ("PVT stamping"), i.e. appending PVT information to the ADUs, can be performed
e.g. by the ITS-S facilities layer for each ITS-facilities protocol data unit (FPDU) of a given ITS-S flow (as
defined in ISO 24102-6) for which the ITS-S-AP had requested to apply PVT stamping to its ADUs.
In order to perform PVT-augmented ADUs by the ITS-S facilities layer, one of the services presented in
Table 2 and Table 11 is used.
7 PVT service
7.1 PVT service reference model
The PVT service reference model adheres to the GNSS-based positioning terminal model in accordance
with EN 16803-1, which decomposes the generic architecture of intelligent road transport systems into
two systems as illustrated in Figure 3:
— the positioning system, encompassing the sensors and the positioning module, provides the PVT
information,
— the road ITS application system processes this PVT information, together with other data, to provide
the final service to the end-user.
Figure 3 — GNSS-based positioning terminal model in its context according to EN 16803-1
NOTE 1 Adhering to the GNSS-based positioning terminal model does not preclude other PVT estimation
technologies to be included in a sensor fusion process designed to provide accurate and trustable PVT
information.
In the context of this document, the positioning system provides the PVT service and is located in
the ITS-S facilities layer. It includes a piece of software, referenced in Figure 3 as Positioning module,
that uses PVT input parameters to determine the PVT output parameters. The PVT-related input
(sensor data) and output parameters of the positioning module in Figure 3 are defined in 7.2 and 7.3,
respectively.
NOTE 2 It is outside the scope of this document to define how the positioning system and which PVT sensors
are implemented. The implementation of a positioning system in an ITS-SU generally includes a GNSS receiver as
a primary PVT sensor, notably in a vehicle ITS-SU.
7.2 PVT-related input parameters
The PVT service may use various information sources. These sources can either be internal to the
ITS-S, such as digital map information, or be external, such as differential corrections provided by the
roadside infrastructure network.
Possible sources of PVT-related input information include:
— PVT input information provided by a GNSS receiver, for instance in the form of a standardized
[15]
NMEA 0183 sentence (message), which provides 3D position, coordinated universal time and
accuracy data (number of satellites being tracked and horizontal dilution of precision, HDOP). The
position and velocity are provided in a global coordinate reference system (CRS) such as the World
[25] [26]
Geodetic System 84 (WGS84) or the International Terrestrial Reference System (ITRS) .
10 © ISO 2020 – All rights reserved

— PVT-related input information provided by an inertial measurement unit (IMU), an electronic
device that measures and reports the vehicle's specific force (typically along 3 axes), angular rate,
and sometimes the magnetic field surrounding the vehicle, using a combination of accelerometers
and gyroscopes, sometimes also magnetometers.
— The vehicle ground speed, or travelled distance provided by the odometer of the vehicle.
EXAMPLE 1 The number of pulses associated to the left and right wheels, available from the controller
area network (CAN) bus, can be used to determine the vehicle's ground speed and its heading.
— Light detection and ranging (LIDAR)-based sensor data, providing distances to objects in the
environment of the vehicle.
— Video camera-based sensor data, providing distances and directions between a given reference
point of the vehicle and road markings, landmarks or points of interest in the environment of the
vehicle.
— Any a priori information, such as a digital map, that can be used for data fusion purposes.
— Differential corrections for improving the accuracy of GNSS receivers, transmitted by any data
transmission channel, for instance, the roadside infrastructure network or the cellular network.
[17]
EXAMPLE 2 RTCM 10403.3 , designed specifically for the transmission of differential corrections
coming from terrestrial networks of GNSS reference stations.
EXAMPLE 3 Corrections provided by a satellite-based augmentation system (SBAS), such as the European
[16]
Geostationary Navigation Overlay Service (EGNOS) or the Wide Area Augmentation System (WAAS) .
These are generally provided by ground stations and geostationary satellites.
— PVT-related input information provided by the roadside and its environment (e.g. vehicles) or
infrastructure, respectively.
EXAMPLE 4 PVT-related input information provided through V2X communications. For instance,
the cooperative awareness message (CAM) generated by vehicles for traffic-safety applications, the SPaT
[13]
information transmitted by the roadside infrastructure and LDM data as defined in ETSI EN 302 637-2 ,
[6] [5]
ISO/TS 19091 , ISO 18750 , respectively.
EXAMPLE 5 PVT-related input information provided by the cellular network as defined in
[12]
ETSI TS 136 455 . ®
EXAMPLE 6 Bluetooth low energy beacon transmits a universally unique identifier, as defined in
® [27]
Bluetooth Core Specification , which can be used by the ITS-SU to determine its position.
7.3 PVT output parameters
7.3.1 General
The PVT output parameters encompass part or all of the kinematics state vector of an ITS-SU providing
the PVT service, e.g. the following parameters:
— position: the absolute geographical reference position of an object carrying an ITS-SU that
provides the PVT service, where the reference position for different vehicles, roadside equipment
2)
and pedestrians shall be as defined in ETSI prEN 302 890-2 ;
— velocity; the speed together with the heading associated with an ITS-SU;
— acceleration; the acceleration associated with an ITS-SU;
— time: the time associated with the position, velocity, acceleration or/and speed event of an ITS-SU.
2) Under preparation.
Table 1 provides an overview of the sets of PVT information specified in this document. Each set of PVT
information, including provisions for the associated accuracy and PVT-related information, is specified
in the subsequent subclauses. The complete associated ASN.1 type and value definitions to be used are
specified in Annex A.
Table 1 — Sets of PVT information
PVT info set PVT info Description
set ID
PvtInfoEcdd 1 Position, velocity, acceleration and time.
Position and time according to ETSI TS 102 894-2 V1.3.1 (2018-
08), also known as the ETSI Common Data Dictionary (ECDD).
The definition of acceleration in this document is based on the
definitions in the ECDD, the combination of lateral, longitudinal
and vertical acceleration as defined in the ECDD, whilst noting
that the ECDD does not explicitly define acceleration (with these
three elements) as a data set.
The definition of velocity in this document is based on definitions
in the ECDD, the combination of speed together with heading as
defined in the ECDD, whilst noting that the ECDD does not explic-
itly define velocity.
PvtInfoEcdd-PosVelocityTime 2 Position, velocity and time. It is a subset of pvtInfoEcdd.
PvtInfoEcdd-PosTime 3 Position and time according to ETSI TS 102 894-2 V1.3.1 (2018-
08). It is a subset of pvtInfoEcdd.
PvtInfoEcdd-VelocityAccelera- 4 Velocity, acceleration and time. It is a subset of pvtInfo
...