Standards for Cooperative and Urban Intelligent Transport Systems
- C-ITS / U-ITS -


Cooperative ITS (C-ITS) is a feature of ITS rather than something different:

  • applications share information, both inside an ITS station unit, and accross several such units. Thus C-ITS "breaks" with the traditional "silo-thinking". Standardization of C-ITS is mainly done at CEN/ISO.

Urban ITS (U-ITS) is simply ITS applied in an urban context.


ESF News on C-ITS

You want to subscribe to our ITS news? CALM

ISO and CEN are leading advocates for technologies improving safety, security, efficiency and comfort of the world's transportation system. ISO TC204 and CEN TC278 work jointly together.



Seminars on C-ITS
- Information on Interest groups, Standards, Testing, Deployment -
not necessarily politically correct - but true

Temporarily no public seminars are scheduled.
Please contact us to arrange for your private briefing.


ESF GmbH, with support from other independent experts on Intelligent Transport Systems and the CALM concept of an ITS station with hybrid communications, is disclosing its knowledge in a series of seminars.


We are involved in standardization at governmental SDOs (Standard Development Organizations),


non-governmental SDOs,


and NGOs, e.g. SAE.

We have experience from testing, field trials, and deployment activities.

We contributed to the CVIS project that invented the "cooperative" feature of ITS.

RechtsBeiRotWe know about traditional Intelligent Transport systems (formerly referred to as Road Transport Traffic Telematics) including electronic road tolling, digital tachograph, and e-call,

Cooperative ITS, Urban ITS, ... C-ITS

A major focus of our activities is on support of road operators and city authorities.


Please contact Dr. Fischer from ESF GmbH to arrange your private briefing, e.g. a seminar in your own premises..



Release 2 C-ITS standards

The development of Release 1 standards for Cooperative Intelligent Transport Systems is done. Deployment projects started. Early experience with real operation of C-ITS triggered development of Release 2 standards for C-ITS.


The set of Release 2 standards will be based on the revision of Release 1 standards, and missing complementary standards. If you are interested in learning about Release 2, please contact us.


ITS Application Identifier

ITS application identifiers (ITS-AID) are precisely specified in EN ISO 17419:2018. The specifications given there support the needs of CEN, ETSI, and ISO. The primary purpose of ITS-AID is identification of an ITS application, and at least one of its related ITS-S application processes, e.g. in a service advertisement message and for security purposes.

As a result of the IEEE/ISO harmonization on LM and SAM (see below), the Provider Service Identifer (PSID) used in IEEE shares a number space with ITS-AID. This sharing of the number space means that PSID and ITS-AID are synonyms, i.e. identifying the same technical meaning. However reality shows that IEEE / SAE experts have slightly different understandings of what is meant with PSID, and these understandings so far are nowhere standardized.

Careful observation of the various thoughts on PSID show that likely most of these thoughts can be managed by the set of specifciations from EN ISO 17419.

It is important to clarify that ITS-AID is not to be used

  • to distinguish different versions of the same ITS application object,
  • to identify C-ITS messages,
  • to identify communication protocols / features!

The following definitions exist:

  • ITS-AID: globally unique, registered number identifying an ITS application object
  • ITS application object: ITS application or ITS application class
  • ITS application class: ITS application designed for operation in different contexts involving real-time negotiation of the appropriate context
  • ITS application: instantiation of an ITS service that involves an ITS-S application process, or an association of complementary ITS-S application processes
  • ITS-S application process: element in an ITS station unit that performs information processing for a particular application, and may use ITS-S services to transmit and receive information
  • ITS-S application: ITS-S application process residing in the ITS-S application entity

Now about the technical details:

ITS-AID is just a non-negative Integer number with unlimited number range. So far two presentations in ASN.1 and two encodings are specified and used in standards, i.e. the p-encoding and the o-encoding.

P-encoding is based on a complex ASN.1 type with variable length, applying unaligned PER. This presentation is used in LM (WSMP / FNTP) and SAM/SRM (WSA / FSAP) resulting in fields of one up to four octets (larger numbers are possible, but not supported). The first 32 numbers of ITS-AID point to ISO 15628 "application classes". An "application class" - in simple words - can be understood as a Super-Application that requires upon start initial negotiation of an operational context (known from CEN DSRC as BST/VST exchange).

O-encoding is based on the simple ASN.1 Integer type, applying OER. This presentation is used in IEEE 1609.2, i.e. for security purposes.


IEEE / ISO harmonization of Localized Messages and Service Advertisement Messages

Harmonization of message formats

  • IEEE WAVE Short Message Protocol (WSMP) with ISO Fast Networking & Transport Protocol (FNTP)
  • IEEE WAVE Service Advertisement (WSA) with ISO Fast Service Advertisement (FSAP)

is finished since 2016!


ISO TS 16460:2016 is published; ASN.1 modules are available for free download. The revised IEEE standards 1609..3:2016, 1609.4:2016, and 1609.2:2016 are published. ISO 22418 is in publication. ISO 29281-1 and ISO 21215 will be published in Q2/2018.

There is an interoperability mode for the localized message (LM) and the service advertisment message (SAM). ISO specifies enhancements, i.e. additional modes of LM (networking and transport features), enhanced SAM functionality, and the functionality of SRM. The enhanced features are used in FNTP and FSAP, and can be activated in WAVE without breaking binary backward compatibility. Whilst WAVE only supports IEEE 802.11 @ 5,9 GHz communications, FNTP and FSAP are agnostic to the underlying access technology.


Services and tools


ESF GmbH is maintaining an international virtual enterprise with experts covering all parts of C-ITS and all kinds of engineering services and consultancy. Please feel free to contact us.

ASN.1 Tools


TTCN-3 Tools




Some hyperlinks



25. January 2018