1. Jérôme Härri, Fethi Filali, Christian Bonnet
On Meaningful Parameters for Routing in VANETs Urban Environments under Realistic Mobility Patterns
Jérôme Härri, Fethi Filali, Christian Bonnet
Institut Eurécom
Mobile Communications Department
Sophia Antipolis, France
Eurécom Seminar Series
Sophia-Antipolis
January 18st 2007

2. Agenda Motivation New Parameters for Performance evaluation
VanetMobiSim: Realistic Mobility Simulator
Incidence on Vehicular Mobility Patterns
New Parameters for Performance evaluation
Incidence on the Performance of Routing Protocols
Conclusion et Future Work

3. Motivation
VANETs in urban areas have special characteristics that make standard wireless protocols inefficient or unusable
higher speed
non-uniform distribution of vehicles and speed
short transmission range
non random mobility patterns
Many academic researches carried on routing protocols have been done using random mobility models and uniform distribution of speed and vehicles.
Routing Performance is greatly dependent to the availability and the stability of wireless links
Closely tied to the mobility model
Can we assume that the performance of routing protocols will be identical to that under random mobility patterns ?
Can we actualy use the same performance evaluation parameters ?

4. Agenda Motivation New Parameters for Performance evaluation
VanetMobiSim: Realistic Mobility Simulator
Incidence on Vehicular Mobility Patterns
New Parameters for Performance evaluation
Incidence on the Performance of Routing Protocols
Conclusion et Future Work

5. VanetMobiSim [1] Stepanov et al., Universitat Stuttgart, CANU project
Written in JAVA
Platform independent
Configured by XML files
Produces traces for different network simulators (ns-2, QualNet..)
Simulator independent
Compatibility with a ns-2 module for realistic radio propagation model in presence of buildings1
Graphically displays vehicles mobility
Publicly available at :
[1] Stepanov et al., Universitat Stuttgart, CANU project

6. Features Macroscopic Features: Microscopic Features:
Random or Imported Topological Maps (TIGER, GDF)
Stops and Traffic lights-based Intersections
Bi-directional roads
Single lane and multi-lanes roads
Microscopic Features:
Car-to-car interaction
Acceleration, deceleration based on the Intelligent Driver Model (IDM)
Intelligent Driver Model with Lane Changing (IDM-LC) based on the MOBIL model
Car-to-road infrastructure interaction
Interactions with traffic and stop signs based on the Intersection management (IDM-IM)
[1] Treiber, Helbing, Universitat Dresden, Physical Review Aug 2000
[2] Treiber, Helbing, Universitat Dresden, ASIM 2002

7. Agenda Motivation New Parameters for Performance evaluation
VanetMobiSim: Realistic Mobility Simulator
Incidence on Vehicular Mobility Patterns
New Parameters for Performance evaluation
Incidence on the Performance of Routing Protocols
Conclusion et Future Work

8. Non Uniform Position Distribution
Vehicular distribution on an urban topology with RWM

9. Non Uniform Position Distribution
Vehicular distribution on an urban topology with VMM

10. Non Uniform Speed Distribution
Vehicular speed distribution on an urban topology with VMM

11. Speed Decay Speed decay as a function of the average velocity
Speed decay as a function of the density of vehicles

12. Agenda Motivation New Parameters for Performance evaluation
VanetMobiSim: Realistic Mobility Simulator
Incidence on Vehicular Mobility Patterns
New Parameters for Performance evaluation
Incidence on the Performance of Routing Protocols
Conclusion et Future Work

13. Realistic Mobility Models for Vanets
Are the vehicles’ positions uniformly distributed ?
NO !
Is the speed uniformly distributed ?
Do we actually get the speed we configured ?
Again NO !
Are we even in control here ?

14. New Parameters for Performance evaluation
What is really controlling the mobility patterns ?
Nodes average density ?
Not Really !
Nodes average velocity ?
So, what else ?
Road Segment length
Acceleration
Cluster Effect

15. Speed Decay
Speed decay as a function of the length of the road segments
Speed decay as a function of the acceleration

16. True Vehicular Speed on a Single Trip
Average length of the road segments: 100m
Average length of the road segments: 250m

17. Agenda Motivation New Parameters for Performance evaluation
VanetMobiSim: Realistic Mobility Simulator
Incidence on Vehicular Mobility Patterns
New Parameters for Performance evaluation
Incidence on the Performance of Routing Protocols
Conclusion et Future Work

18. Scenarios Characteristics
Micro-model Parameters
Simulation Parameters
Macro-model Parameters

19. Scenarios Characteristics
Simulation Scenarios
Simulation Environment

20. Performance Evaluation
Packet Delivery Ratio (PDR) as a function of the average velocity

21. Performance Evaluation
Route hop-length as a function of the average velocity

22. Performance Evaluation
End-to-end delay as a function of the average velocity

23. Performance Evaluation
Packet Delivery Ration as a function of the length of the road segments

24. Performance Evaluation
Route hop-length as a function of the length of the road elements

25. Performance Evaluation
Packet Delivery Ratio as a function of the cluster effect

26. Performance Evaluation
Route hop-length as a function of the cluster effect

27. Performance Evaluation
End-to-end delay as a function of the cluster effect

28. Conclusion
We illustrated how a realistic mobility model for VANETs impacts vehicular mobility patterns
We evaluated the performance of AODV under realistic mobility patterns.
Some parameters have no influence in VANET with realistic mobility patterns.
New parameters has been proposed that have a more significant influence
We compared those results with non realistic random motion patterns.
Realistic mobility patterns has major influence on the performance
all performance metrics are improved
network connectivity is not fair
Good connectivity in clusters
Connectivity between clusters depends on the inter-distance between clusters
shorter route length
But longer hop length

29. Conclusion Future Work
We illustrated some effects of realistic mobility patterns on evaluation parameters
Velocity is not a good performance evaluation metric
We should better choose
Road segment length
Acceleration
Cluster effect
Intersection distribution
Intersection policy
Future Work
Radio Obstacles
New universal metric that controls the large configuration parameters of VanetMobiSim.

30. Questions ?
Jérôme Härri