Towards Standardized Channel Models for Short-range Vehicular Communications.

David G. Michelson*, David Matolak**, John Wang*, and Alexander Corbett*

*University of British Columbia, Dept. of Electrical and Computer Engineering, Vancouver, BC, Canada

**Ohio University, School of Electrical Engineering and Computer ScienceAthens, OH, USA

Why are standardized channel models important?

• Channel models capture our knowledge and understanding of the manner in which propagation impairments manifest themselves in a particular environment in a form useful in design and simulation.

• Standardized channel models permit fair comparison of alternative PHY, MAC and network layer schemes across a representative range of channel conditions.

How are standardized channel models developed?

• A channel modeling committee works with PHY. MAC and network developers to determine:- the channel impairments to which the proposed PHY,

MAC and network layer schemes are likely sensitive, and,

- the range of environments and scenarios within which the proposed systems will likely be delpoyed

• The channel modelling committee reviews the published literature and identifies relevant works.

- If the published works are inadequate, the committee may put out a call for submissions based upon work either recently completed or in progress

• The committee proposes and evaluates alternative forms for the standardized channel models based upon a tradeoff between model accuracy, computation efficiency and the cost and availability of increasing levels of detail concerning the environment.

• The committee recommends parameters for the standardized channel models based upon results presented in published works and recent submissions.

• The committee may recommend test suites that permit implementations of the standardized channel models to be validated.

• The committee releases a channel modelling report that summarizes the results of their work in order to provide guidance to system designers and simulation tool developers.

Vehicle Unit

Roadside Unit 1

What are some common VANET (Vehicular Ad hoc NETwork) simulation tools?

• NS-2

• GloMoSim

• OMNeT++

• JiST/SWANS

Are standardized channel models available for short-range vehicular networks?

• No. As a result,

- simulation tool developers must use their own best judgement when selecting or implementing channel models

- there are significant differences between the channel models incorporated into today’s VANET simulation tools and

- fair comparison between results obtained using different simulation tools is difficult.

How is the IEEE VT-S Propagation Committee proceeding to develop standardized channel models for short-range vehicular networks?

• The Short-Range Vehicular Channel Modelling Initiative will be launched at IEEE VTC Fall 2011.

• The VANET community will be engaged at other events such as the 2011 NSERC DIVA Workshop and the IEEE ICC 2012 Workskop on Intelligent Vehicular Networking.

• VANET simulation tool developers will be engaged directly and their feedback sought.

• The results will be released at a special session or workshop at IEEE VTC Fall 2012.

How will a given simulation tool’s compliance be verified?

• A test suite will be released that will allow a given simulator’s compliance with the channel modelling standard to be verified.

• A compliant simulation tool will be allowed to display a logo that shows that it is compliant with the IEEE VT-S standardized short-range vehicular channel model.

Will compliance require that the developer exclude alternative channel models models?

• No. Compliant simulators will be encouraged to implement alternative channel models but must provide a simple method for invoking the IEEE VT-S standardized channel models.

• TraNS• OPNET Modeler

• QualNet

• J-Sim