ISO/TR 17427-2:2015

TECHNICAL ISO/TR
REPORT 17427-2
First edition
2015-11-01
Intelligent transport systems —
Cooperative ITS —
Part 2:
Framework overview
Systèmes intelligents de transport — Systèmes intelligents de
transport coopératifs —
Partie 2: Aperçu général du cadre de travail
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Terms and definitions . 1
3 Abbreviated terms . 4
4 Overview of components of a C-ITS enabled system . 4
4.1 Specific service features characterizing C-ITS . 4
4.2 Actors involved in C-ITS service provision . 6
5 Framework overview for C-ITS enabled systems . 9
5.1 Communications . 9
5.2 Vehicle systems .10
5.2.1 General.10
5.2.2 Vehicle gateway .11
5.2.3 In-vehicle control .12
5.2.4 Sensors and data collectors .12
5.2.5 Data storage and access .12
5.3 Roadside systems .13
5.3.1 Roadside host .13
5.3.2 Roadside gateway .13
5.3.3 Access router .13
5.3.4 ITS border router .13
5.4 ‘Core’ systems.13
5.4.1 Core system overview .13
5.4.2 Single core systems .14
5.4.3 Multiple core systems .15
5.4.4 Other “Central” systems .15
5.4.5 Core system functions .15
5.4.6 Control/Service centre .15
5.4.7 Home agent .16
5.4.8 Authority/Jurisdiction databases.16
5.5 Personal Systems .16
5.5.1 Personal mobile .16
5.5.2 Personal SatNav .16
5.5.3 Mobility assistance . .16
5.5.4 Intermodal connection/display .17
6 Summary of Framework overview .17
6.1 General .17
6.2 Cooperative Vehicle and Highway Systems safety applications .18
6.3 Vehicle to infrastructure Communications for Safety .18
6.4 Real-Time Data Capture and Management .18
6.4.1 Dynamic Mobility Applications .18
6.5 Cooperative Vehicle and Highway Systems Technology Policy and Institutional Issues .18
6.6 Cooperative Vehicle and Highway Systems Policy and Institutional Issues .18
Annex A (informative) ISO 14813-1 ITS Service domains and services .20
Bibliography .27
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 documents 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).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 204, Intelligent transport systems.
ISO 17427 consists of the following parts, under the general title Intelligent transport systems —
Cooperative ITS:
— Part 2: Framework overview [Technical Report]
— Part 3: Concept of operations (ConOps) for ‘Core’ systems [Technical Report]
— Part 4: Minimum system requirements and behaviour for core systems [Technical Report]
— Part 6: Core systems risk assessment methodology [Technical Report]
— Part 7: Privacy aspects [Technical Report]
— Part 8: Liability aspects [Technical Report]
— Part 9: Compliance and enforcement aspects [Technical Report]
— Part 10: Driver distraction and information display [Technical Report]
The following parts are under prepartion:
— Part 1: Roles and responsibilities in the context of co-operative ITS architechtures(s)
— Part 5: Common approaches to security [Technical Report]
— Part 11: Compliance and enforcement aspects [Technical Report]
— Part 12: Release processes [Technical Report]
— Part 13: Use case test cases [Technical Report]
— Part 14: Maintenance requirements and processes [Technical Report]
iv © ISO 2015 – All rights reserved

This Technical Report provides an informative ‘framework overview’ of Cooperative Intelligent
Transport Systems (C-ITS). It is intended to be used alongside ISO 17427-1, ISO/TR 17465-1 and other
parts of ISO 17465, and ISO 21217. Detailed specifications for the application context will be provided
by other ISO, CEN and SAE deliverables, and communications specifications will be provided by ISO,
IEEE and ETSI.
Introduction
Intelligent transport systems (ITS) are transport systems in which advanced information,
communication, sensor and control technologies, including the Internet, are applied to increase safety,
sustainability, efficiency, and comfort.
A distinguishing feature of ‘ITS’ are their communication with outside entities.
Some ITS systems operate autonomously, for example, ‘adaptive cruise control’ uses radar/lidar and/or
video to characterize the behaviour of the vehicle in front and adjust its vehicle speed accordingly. Some
ITS systems are informative, for example, ‘Variable Message Signs’ at the roadside, or transmitted into
the vehicle, provide information and advice to the driver. Some ITS systems are semi-autonomous, in
that they are largely autonomous, but rely on ‘static’ or ‘broadcast’ data, for example, GNSS (3.9) based
‘SatNav’ systems operate autonomously within a vehicle but are dependent on receiving data broadcast
from satellites in order to calculate the location of the vehicle.
Cooperative Intelligent Transport Systems (C-ITS) are a group of ITS technologies where service provision
is enabled by, or enhanced by, the use of ‘live’, present situation related, dynamic data/information from
other entities of similar functionality [for example, from one vehicle to other vehicle(s)], and/or between
different elements of the transport network, including vehicles and infrastructure [for example, from the
vehicle to an infrastructure managed system or from an infrastructure managed system to vehicle(s)].
Effectively, these systems allow vehicles to ‘talk’ to each other and to the infrastructure. These systems
have significant potential to improve the transport network.
A distinguishing feature of ‘C-ITS’, is that data is used across application (3.1)/service boundaries.
ISO/TR 17465-1 provides a summary definition of C-ITS as a ‘subset paradigm of overall ITS that
communicates and shares information between ITS stations to give advice or facilitate actions with
the objective of improving safety, sustainability, efficiency and comfort beyond the scope of stand-
alone systems’.
The benefits of Intelligent Cooperative Systems stem from the increased information that is available
from the vehicle and its environment and from other vehicles. The same set of information can be used
to extend the functionality of the in-vehicle safety systems, and through vehicle-to-infrastructure
communications for more efficient traffic control and management. The benefits include the following:
— improved safety;
— increased road network capacity;
— reduced congestion and pollution;
— shorter and more predictable journey times;
— improved traffic safety for all road users;
— lower vehicle operating costs;
— more efficient logistics;
— improved management and control of the road network (both urban and inter-urban);
— increased efficiency of the public transport systems;
— better and more efficient response to hazards, incidents and accidents.
(source: EC project CVIS)
The difference between any ‘ITS system’ and a ‘C-ITS system’ is that C-ITS systems are dependent from
the interaction with other vehicles and or the infrastructure, and the exchange of dynamic data, to
receive data to enable their function, or conversely to provide data to other vehicles/infrastructure to
enable their C-ITS systems to function.
vi © ISO 2015 – All rights reserved

C-ITS as an entity, is therefore the functionality that enables such ‘cooperative’ and collaborative
exchange of data, and in some cases, collaborative control, or subservient decision making, in order to
provide an application service to one or more actors. Descriptions of the roles and responsibilities of
those actors can be found in ISO 17427-1.
It is important to understand that C-ITS is not an end in itself, but a combination of techniques, protocols,
systems and sub-systems to enable ‘cooperative’/collaborative service provision.
This Technical Report describes and specifies the framework which enables such collaborative and
cooperative systems to operate. It is agnostic in respect of technology, and operates with whatever
communications and hardware technologies can support its functionalities. Other deliverables in this
family of C-ITS standards will define specific aspects of technology and behaviour, and the roles and
responsibilities within the context of C-ITS.
This Technical Report may therefore be seen as an ‘overview’ of the features and physical and functional
architecture elements that comprise C-ITS.
This Technical Report is a ‘living document’ and as our experience with C-ITS develops, it is intended that
it will be updated from time to time, as and when we see opportunities to improve this Technical Report.
Further technical reports in this series are expected to follow.
Please note that these TRs are expected to be updated from time to time as the C-ITS evolves.
TECHNICAL REPORT ISO/TR 17427-2:2015(E)
Intelligent transport systems — Cooperative ITS —
Part 2:
Framework overview
1 Scope
This Technical Report characterizes and provides an overview of the framework which enables
collaborative and cooperative ITS to operate and defines the characteristics and components of a
Cooperative-ITS (C-ITS), its context and relevance for ITS service provision, and provides references
to International Standards deliverables where specific aspects of C-ITS are defined. The objective of
this Technical Report is to raise awareness of and consideration of such issues and to give pointers,
where appropriate, to International Standards deliverables existing that provide for all or some of these
aspects. This Technical Report does not provide specifications for solutions of these issues.
This Technical Report is agnostic in respect of technology and operates with whatever communications
and hardware technologies can support its functionalities.
NOTE Other deliverables in this family of C-ITS standards will define specific aspects of technology and
behaviour and the roles and responsibilities within the context of C-ITS.
2 Terms and definitions
2.1
application
app
software application
2.2
application programming interface
API
set of routines, protocols, and tools for building software applications
[SOURCE: ISO 17627:2009, 2.4, modified]
Note 1 to entry: An API expresses a software component in terms of its operations, inputs, outputs, and
underlying types; it defines functionalities that are independent of their respective implementations, which
allows definitions and implementations to vary without compromising the interface. An API can also assist
otherwise distinct applications with sharing data, which can help to integrate and enhance the functionalities of
the applications.
Note 2 to entry: APIs often come in the form of a library that includes specifications for routines, data structures,
object classes, and variables. In addition to accessing databases or computer hardware, such as hard disk drives
or video cards, an API can be used to ease the work of programming graphical user interface components.
2.3
application service
service provided by a service provider accessing data from the IVS (2.11) in a vehicle in the case of
C-ITS, via a wireless communications network, or provided on-board the vehicle as the result of
software (and potentially also hardware and firmware) installed by a service provider or to a service
provider’s instruction
2.4
bounded secure managed domain
BSMD
secure peer-to-peer communications between entities (ITS-stations (2.17)) that are themselves capable
of being secured and remotely managed; the bounded nature is derived from the requirement for ITS-
stations to be able to communicate amongst themselves, i.e. peer-to-peer, as well as with devices that
are not secured (referred to as ‘other ITS-stations’), and realizing that to achieve this in a secure manner
often requires distribution and storage of security-related material that must be protected within the
boundaries of the ITS-stations, leads to the secured nature of the entity, as there is great flexibility to
achieve desired communication goals, there is a requirement that this flexibility be managed
Note 1 to entry: Within C-ITS and ISO 21217, such ITS-stations are defined as operating within bounded secured
managed domains (BSMD), or outside of the BSMD.
2.5
Cooperative ITS
C-ITS
use of ITS technologies where service provision is enabled, or enhanced by, the use of ‘live’, present
situation related, data/information from other entities (for example, from one vehicle to other
vehicle(s)), and/or between different elements of the transport network, including vehicles and
infrastructure (for example, from the vehicle to an infrastructure managed central system (2.6) or from
a central infrastructure managed system to vehicle(s))
2.6
central system
service centre system that provides/supports application service(s) (2.3) managed through a central
facility
2.7
Controller Area Networking bus
CAN bus
network designed for use in automotives, which:
a) uses a single terminated twisted pair cable;
b) is multi master;
c) uses a maximum signal frequency used is 1 Mbit/sec;
d) has a typical length of 40 M at 1 Mbit/sec up to 10 KM at 5 Kbits/sec;
e) has high reliability with extensive error checking;
f) has a typical maximum achieveable data rate of 40 KBytes/sec;
g) has a maximum latency of high priority message <120 µsec at 1 Mbit/sec
Note 1 to entry: CAN is unusual in that the entities on the network, called nodes, are not given specific addresses.
Instead, it is the messages themselves that have an identifier which also determines the messages’ priority. For
this reason, there is no theoretical limit to the number of nodes, although in practice it is ~64.
2.8
‘Core’ system
combination of enabling technologies and services that will provide the foundation for the support
of a distributed, diverse set of applications (2.1)/application transactions, which work in conjunction
with ‘External Support Systems’ such as ‘Certificate Authorities’; the system boundary for the core
system is not defined in terms of devices or agencies or vendors, but by the open, standardized interface
specifications that govern the behaviour of all interactions between core system users
2 © ISO 2015 – All rights reserved

2.9
global navigation satellite system
GNSS
comprises several networks of satellites that transmit radio signals containing time and distance data
that can be picked up by a receiver, allowing the user to identify the location of its receiver anywhere
around the globe
2.10
host management centre
HMC
service gateway that supervises the secure provision of software and services for C-ITS service provision
2.11
in-vehicle system
hardware, firmware and software on board a vehicle that provides a platform to support C-ITS service
provision, including that of the ITS-station (2.17) (ISO 21217), the facilities layer, data pantry and on-
board ‘apps’ (2.1)
2.12
intelligent transport systems
ITS
transport systems in which advanced information, communication, sensor and control technologies,
including the Internet, are applied to increase safety, sustainability, efficiency, and comfort
2.13
ITS application
functionality that either completely provides what is required by an ITS service (2.16) or works in
conjunction with other ITS applications (2.1) to provide one or more ITS services
2.14
ITS border router
ITS-s router with additional functionality that provides connectivity to other ITS communication nodes
over external networks
2.15
ITS mobile router
ITS-s border router (2.14) with additional functionality that allows a change of point of attachment to
an external network while maintaining session continuity
2.16
ITS service
functionality provided to surface transport users
2.17
ITS-station
entity in a communication network (comprised of application (2.1), facilities, networking and access
layer components) that is capable of executing ITS-s application processes (sometimes within a bounded,
secured, managed domain), comprised of an ITS-s facilities layer, ITS-s networking and transport layer,
ITS-s access layer, ITS-s management entity and ITS-s security entity, which adheres to a minimum set
of security principles and procedures so as to establish a level of trust between itself and other similar
ITS stations with which it communicates
2.18
wireline
traditional permanent ‘wired’ connection (although may in reality include microwave and other
wireless connections)
3 Abbreviated terms
2G second-generation cellular phone technology e.g. GSM
3G third-generation mobile phone technology e.g. UMTS
API application programming interface (2.2)
BSMD bounded secure managed domain
C-ITS cooperative intelligent transport systems, cooperative ITS
CALM Communications Access for Land Mobiles
CAM Cooperative Awareness Message
CVIS Cooperative Vehicle Infrastructure Systems
GNSS global navigation satellite systems (2.9)
GSM Global System for Mobile Communication (2G mobile communications)
HMC host management centre (2.10)
IPv6 Internet Protocol version 6
ITS intelligent transport systems (2.12)
IVS in-vehicle system (2.11)
NEMO Network Mobility (NEMO) Basic Support Protocol (IETF) RFC 3963
4 Overview of components of a C-ITS enabled system
4.1 Specific service features characterizing C-ITS
ISO 14813-1 describes the ITS service (2.16) groups and services that are generally considered
to comprise the realm of ITS. From ISO 14813-1, we can establish that ITS services can operate in
different paradigms, and some application services operate autonomously (see examples given in the
introduction).
Some ITS systems are semi-autonomous, in that they are largely autonomous, but rely on ‘static’ or
‘broadcast’ data (see examples given in the introduction).
Cooperative Intelligent Transport Systems (C-ITS) are a group of ITS technologies where service
provision is enabled by, or enhanced by, the use of ‘live’, dynamic, present situation related,
data/information from other entities (for example, from one vehicle to other vehicle(s)), and/or between
different elements of the transport network, including vehicles and infrastructure [for example, from
the vehicle to an infrastructure-managed system or from an infrastructure-managed system to
vehicle(s)]. Effectively, these systems allow vehicles to ‘talk’ to each other and to the infrastructure.
These systems have significant potential to improve the transport network. See also ISO/TR 17465-1
and ISO 17427-1.
For specifications regarding C-ITS terms, definitions and guidance for standards documents, see
ISO/TR 17465-1.
For specifications regarding the structure of specific C-ITS Standards deliverables, and general C-ITS
definitions, see ISO/TR 17465-2.
4 © ISO 2015 – All rights reserved

For specifications regarding ‘Release’ procedures for consistent groups of C-ITS Standards, see
ISO/TR 17465-3.
The difference between any ‘ITS system’ and a ‘C-ITS system’ is that C-ITS systems are dependent on the
interaction with other vehicles and or the infrastructure to receive data/sometimes make decisions,
to enable their function, or conversely to provide data to other vehicles/infrastructure to enable their
C-ITS systems to function.
‘Cooperative’, in the context of C-ITS, implies cooperation within the following contexts:
a) Direct communication and exchange of relevant information between entities,
b) Dynamic interaction between road users, or between road users and the transport infrastructure
for the benefit of road users, and may also mean
c) Use of data provided for one purpose to be (anonymously) collated and managed to bring benefits
to other users (example: probe data).
C-ITS as an entity, is therefore the functionality that enables such ‘cooperative’ and collaborative
exchange of data, and in some cases, collaborative control, or subservient decision making, in order to
provide an application service to one or more actors.
It is important to understand that C-ITS is not an end in itself, but a combination of techniques, protocols,
systems and functions to enable ‘cooperative’/collaborative service provision. What separates C-ITS
from any other ITS communication is the sharing and exchange of data to provide information, and in
some cases control, cooperatively between actors in the road network.
However, C-ITS cannot in itself be described as a single mode of operation. C-ITS itself can operate in at
least five modes:
a) direct vehicle-to-vehicle;
b) ITS-station (2.17) to any other ITS-station;
c) vehicle to application service provider/application service;
d) via a ‘core’ backbone, back office;
e) between ‘core’ systems or ‘applications’ (2.1).
a) and b) in communication terms are identical; however, for time critical safety applications (2.1) such
as car-to-car ‘collision avoidance’, there are some special ‘time critical’ requirements that do not apply,
for example, in exchanges with ITS-stations such as ‘personal’ phone-based applications, or exchanges
with application service providers. These two use cases, though similar, are therefore considered in this
deliverable as separate sub-classes.
b) and c) are again identical in communications terms, but functionally, sub-class c) includes many
services that may be provided in a C-ITS context, sharing data with other sources in order to
provide the service; however, similar services may also be provided in an ITS context that do not
include the ‘cooperative’/‘collaborative’ aspects that characterize C-ITS (albeit with inferior levels
of quality of service).
Sub-class d) is an important and separate class, even though the communication is likely to be between
two or more peer ITS-stations, as with sub classes a), b) and c) (and therefore identical in nature in
respect of communications). However, where certification or the involvement or approval of the
Jurisdiction is involved, or some form of permissions or payments are involved, there needs to be the
presence and involvement of a ‘back office’, in the context of C-ITS most commonly referred to as a
‘Central system’ (2.6). ISO/TR 17427-3 will define the concept of operations for “core” systems, and
ISO/TR 17427-4 will describe the minimum operating requirements and behaviour of such systems, and
ISO/TR 17427-1 explains the roles and responsibilities for such systems. ISO/TR 17427-5 will describe
and provide references to standards deliverables to assure C-ITS common approaches to security, while
ISO/TR 17427-6 will provide a basis for C-ITS risk assessment.
Further, while some C-ITS services can be provided in a vehicle-to-vehicle context (for example, ‘Ice Alerts’,
‘Obstacle Alerts’, and other road condition alerts), they may be provided more efficiently if the detecting
vehicle passes the data to a ‘core’ system, which is then in a more selective and better position to alert
other vehicles, as it is a constant within the area (as opposed to a vehicle whose presence in any location
is transient). Some other services, such as safe dynamically controlled ramp access (ingress to and egress
from highways), and railway (so called ‘grade’) crossings, which, in the C-ITS context will be part managed
by a central road management system, and in part by dynamic collision avoidance data from vehicles in
the zone, may be more efficient when provided under the control of a central ‘core’ system.
Within most administrations currently considering the introduction of support for C-ITS assisted
applications (2.1), the ‘core’ system is seen to be an important component, and a component that can
accelerate the business case for C-ITS implementation, by spreading many of its benefits beyond just
C-ITS equipped vehicles, at an early stage.
Finally, there are C-ITS services, whose data may originate from road users, but process and provide
their application (2.1) between road managers, administrations and jurisdictions via mainstream so
called ‘wireline’ (2.18) communications networks, or the Internet, that do not require the use of ITS-
station communications.
4.2 Actors involved in C-ITS service provision
Figure 1 shows a high level view of actors and objects in an ITS service provision use case. In this
scenario, ITS-stations lie at the core of most, but not all, ITS service provision. The ITS-station may be
connected over a variety of wireless media, and through them, or directly, via the Internet.
6 © ISO 2015 – All rights reserved

Figure 1 — Functions and actors in an ITS service provision use case
However, while appropriate in the context of ‘ITS’, Figure 1 is an over simplification in the context of
C-ITS, as any ITS-station can talk to any other ITS station, and will exchange and share data, and in
some circumstances control, based on that shared information. There will certainly be multiple, indeed
many, ‘vehicle systems’, in a world where all or part of the vehicle park is C-ITS capable, there will be
as many ITS-stations as there are C-ITS capable vehicles. In the C-ITS world, vehicles can exchange
data, even control mechanisms, with other vehicles. There will be multiple roadside stations (either
permanent or temporary), and many personal ITS stations. There will often also be multiple ‘core
systems’ (2.8), all of which can connect and interact with each other. Figure 2 therefore represents
the C-ITS world more realistically, though all of the possible interactions are not shown, in order not to
overload comprehension of the figure.
Figure 2 — Functions and actors in a C-ITS multiple instantiation service provision use case
Now both Figure 1 and Figure 2 could arguably just reflect ordinary ITS data exchanges; however, we
have established above what it is that differentiates C-ITS from other ITS, is that service provision
is enabled, or enhanced, by obtaining or providing relevant dynamic ITS application (2.13) service
data/decision making to/from/with other ITS-stations, or other ITS applications.
We could, more pictorially visualize the C-ITS paradigm as shown in Figure 3, which is an update
and enhancement of a figure used in the CVIS project, and the authors acknowledge that work in the
development of this Technical Report, and the same figure is used in ISO 21217.
8 © ISO 2015 – All rights reserved

Figure 3 — High level C-ITS connectivity paradigm
In order to achieve C-ITS service provision, a combination of applications (2.1), services and systems
are therefore necessary to provide safety, mobility and environmental benefits through the exchange
of data between mobile and fixed transportation users. The principal system components are therefore
the following:
— Applications — that provide functionality to realize safety, mobility and environmental benefits;
— Equipped vehicles — vehicles equipped with the communications and data collection and
processing capacity to perform in the C-ITS context;
— Equipped persons — persons with mobile phones, tablets or similar communications and data
collection and processing capacity to perform in the C-ITS context;
— Communications — that facilitate data exchange, including roadside ITS-stations where appropriate;
— Core Systems — which provide the functionality needed to enable data exchange between and
among mobile and fixed transportation users;
— Support Systems — including security credentials certificate and registration authorities that
allow devices and systems to establish trust relationships.
5 Framework overview for C-ITS enabled systems
5.1 Communications
For a high level overview of how ITS-stations communicate within the context of C-ITS service provision,
see ISO/TR 17465-1, and in particular consider ISO/TR 17465-1, 5.3.5.
Communication requirements to enable and support C-ITS can be as simple as a one-way broadcast
of basic status information that can be received and interpreted by other system users, or as complex
as a number of two-way dialogues and shared Internet connection amongst an ever-changing ad hoc
network of vehicles within a specific area or zone of operation.
To enable maximum flexibility for C-ITS providers and users to configure relationships between actors
in the service chain, at the communications level, networks supporting C-ITS will be peer-to-peer where
no particular operational, business or legal hierarchy is built-in: any entity can communicate with
any other entity, and a vehicle can at one moment be a service provider for a data centre, and the next
moment be the client for a traffic information service. Since all system entities are equal in respect of
communications, the same platform can be used for all types of ITS-station. (However, at the application
(2.1) level, a Jurisdiction may require certain behaviour or communication). An ideal ITS application
service, particularly in the C-ITS context, needs a communication sub system that
— is available wherever and whenever a vehicle is present in a traffic situation,
— can communicate vehicle-vehicle and vehicle-roadside in a transparent way,
— relieves the applications (2.1) from the need to know about communications setup and
management, and
— uses modern Internet techniques and standards for global usability (IPv6); provides a range of different
possibilities related to data speeds, communication distance, cost, and many other parameters.
In the ITS-station communications environment, communications between ITS-stations are peer-to-
peer relationships. In the context of the communications protocols, the functionality that an ITS-station
is performing (vehicle, personal, roadside, core system) is not directly relevant.
However, in terms of security, all systems are not equal. Some ITS systems can utilize security from the
communications network over which their wireless communication is made, which provides adequate
security for the provision of their service, and others can control their data so it is only provided
to a legitimate source, indeed some data may not be sensitive to misuse. But most data in the C-ITS
context has some sensitivity, and therefore will have to be effected within layers of security, and some
C-ITS communications will have to be effected within the high levels of security that ISO 21217 calls a
“Bounded Secure Management Domain” (2.4) (see ISO 21217).
While the functionality of an ITS-station is communications medium agnostic (i.e. it provides both
direct and networked connectivity using the most appropriate medium available in a given situation),
it will have to support one or more appropriate communications media. Some are specific to ITS,
some are public networks suitable for supporting some or all types of C-ITS application services.
C-ITS as implemented through the ITS-station architecture, separates applications from underlying
communications technologies using the Communications Access for Land Mobiles (CALM) concept.
CALM comprises a number of standards for vehicle communication management.
See ISO 21217, ISO 21210, ISO 29281-1, ISO 29281-2, ISO 21212, ISO 21213, ISO 21214,ISO 21215,
ISO 21216, ISO 21218, ISO 24102, ISO 24103, ISO 25111, ISO 25112, ISO 25113, ISO 29282, ISO 29283,
and ISO 17515.
Other communications standards will be developed according to need.
The standard networking protocol for most C-ITS systems will be IPv6 (Internet protocol version 6),
although provision for rapid safety critical communications are provided in ISO 29281-1 and ISO 29281-2.
5.2 Vehicle systems
5.2.1 General
For a vehicle to be able to support C-ITS functionality, it requires more than just an ITS-station. It requires
a processing capability (which may or may not be a separate physical device) to support the following:
— platform core functions;
— middleware;
— applications facilities;
10 © ISO 2015 – All rights reserved

— applications;
— native/realtime application support.
The “In-Vehicle System” (IVS) (2.11) has to be able to prove that it is able to perform the program of
operations required in order to fulfil regulated service provision. This normally implies the combination
of the following:
— a processor;
— volatile memory (RAM/DRAM/SRAM etc.);
— recognized operating system (e.g. LINUX®).
Functionality tests for such systems are widely available and easily devised.
Testing of the central processing unit should be completely independent of any envisaged application
service.
5.2.1.1 Platform core functions
Comprise the physical (ITS-station communications medium, or media), network and transport layers
used by the vehicle system and core functionality of the In-vehicle system (IVS) (for example, a Java
virtual machine).
5.2.1.2 ITS-station
Comprises communications and processing facilities for one or more media, compliant with ISO 21217.
5.2.1.3 ITS mobile router
Comprises an ITS-s border router (2.14) with additional functionality that allows a change of point of
attachment to an external network while maintaining session continuity, containing the appropriate
communications implementation and IPv6, NEMO (IETF network mobility support protocol) and non IP
networking support.
5.2.1.4 Middleware
Provides the runtime environment for applications which can be added or removed in controlled
circumstances.
5.2.1.5 Applications facilities
Comprises application programming interfaces (API) to features of the platform.
5.2.1.6 Applications
Comprises applications running within the IVS .
5.2.1.7 Native/realtime application support
Comprises specific application support software and provisioning for applications that are tied to native
hardware (for example, ‘tolling’ and other payment systems).
5.2.2 Vehicle gateway
The vehicle gateway provides
— translation between vehicle-proprietary format and open ‘standard’ format,
— firewall to protect both sides from unauthorised data access, and
— access to the CAN bus (2.7) and other OEM sensor data,
via an ITS-s node in the IVS used to interconnect two different OSI protocol stacks at layers 5 through to 7.
5.2.3 In-vehicle control
This provides the means of physical access to data and to any ‘control’ features that are driven by C-ITS
inputs and associated on board ‘apps’.
5.2.4 Sensors and data collectors
Comprises sensing equipment (additional to that within the CAN bus) on board and its connection and
integration into C-ITS service provision.
5.2.5 Data storage and access
The IVS has a means of non-volatile data storage that can retain the stored information even when not
powered (such as hard disc, flash memory, etc.).
The IVS has a means to receive inputs both from auxil
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