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Specialist Task Force 420:
ITS G5 Channel Configuration, Channel selection, Link Layer Control, and interfaces between the Access Layer and Network & Transport Layer

Who we are:

Team Leader: Fritz Kasslatter, Siemens,
Team Members: Friedbert Berens, FBConsulting,
Härri Jerome, Eurécom,
Jan De Jongh, TNO, Jan.DeJongh@TNO.NL
Paul Spanderman, TNO/PaulsConsultancy,  

What we do:

In order to control the access to the medium various methods are used. These methods are described by the term Medium Access Control (MAC). The requirements for MAC methods to be used in this context is particularly challenging since the amount of stations that are within range of one another is constantly changing and is indeed different from station to station. Each station sees a different ad-hoc network. There cannot be any restrictions on the number of participating stations in the vehicular ad-hoc network and therefore the MAC method must be able to handle overloaded situations with graceful degradation.

For more details, see our Terms of Reference

Why we do it:

ITS for road safety in the 5.9 GHz range contributes to the general goal of reducing accidents and fatalities.

The expectation is that the market for ITS safety systems will be established. An important prerequisite is the scalability of the systems, i.e. the systems should work in low and dense traffic scenarios, with only a few or many ITS stations sharing the communication channel(s).

A common channel configuration, channel selection policies and logical link layer control implemented in ITS G5 will facilitate the market introduction of the cooperative ITS systems, since new users can be assured that their system will continue working if the number of participants in the VANET increases. It is also important to provide an open interface between the radio access layer and the network & transport layer to enable modular design in ITS solutions and foster competition in the market.

A poor initial policy with regard to channel configuration, channel selection and logical link layer control can dramatically decrease the acceptance and efficiency of the ITS cooperative systems for road safety related ITS applications. In addition, the performance or the reliability of the system may drop dramatically.

How we do it:

The work will be carried out in close cooperation with the relevant WG within ETSI TC ITS. Liaison to CEN TC 278 WG16 (under mandate M/453), the Car-2-Car Communication Consortium and other relevant stakeholders and standardization organizations as well as ITS related EU and National R&D projects will be established. The STF will also provide contributions to relevant ITS workshops and conferences ensuring detailed contacts with stakeholders in the STF process.

The Link Layer Control will be crucial as the link between the ‘radio module’ and the network – between radio and the data plane. In addition early ITS implementation will be a bit simplified compared to possible later solutions. This ETSI process is quite complex and really now. It will be important to ensure contacts with a lot of global stakeholders, probably even including overseas travels. 


ETSI DTS/ITS-0040016 providing the specifications for operation in the 5 GHz range to satisfy the harmonised usage of the designated spectrum by control and service channels including usage of channels for road- safety related ITS applications. This will also include transmit and receive restrictions, channel selection and channel configuration. Reference usage scenarios and parameters will be depicted that justify the specifications. Adjacent channel interference considerations will be encompassed.

ETSI DTS/ITS-0040018 containing the specification of the interface(s) between Access Layer and Network & Transport Layer. It will include the specification of, for example, SAP services and service primitives which are extendible in order to achieve general applicability and related procedures as well as Link Layer Control. 

Time plan:

The STF activity will be divided into the following sub-phases to produce the expected deliverables in accordance with the indicated time scales:

Sub-phase 1:    Investigation and ranking of techniques and information that lead to the development of  channel configuration,

                       channel selection policies and logical link layer control and interface between access layer and network &

                       transport layers; further requirements if identified.

Sub-phase 2:    Preparation of first draft documents for WG comment.

Sub-phase 3:    Interim Report to the EC/EFTA.

Sub-phase 4:    Performance evaluation.

Sub-phase 5:    Recommended parameters and settings for co-operative ITS.

Sub-phase 6:    Document refinement and TC ITS approval of the final ETSI TSs.

How to contact us:


This information is based upon STF working assumptions.
The views expressed do not necessarily represent the position of ETSI in this context.

Last updated: 2013-04-13 17:33:40