Routing in Vanet

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Routing in Vanet

• Improvement of CAR

Cardone Martina Farucci Savino Hours Hadrien
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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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IntroductionVANET definition

• A Vehicular Ad-Hoc Network, or VANET, is a form
  of Mobile ad-hoc network, to provide
  communications among nearby vehicles and between
  vehicles and nearby fixed equipment, usually
  described as roadside equipment
• (http//en.wikipedia.org/wiki/Vehicular_ad-hoc_net
  work)

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Discussion

• All usual protocols
• Dont take roads topology into account
• Dont use density of nodes
• An improving solution
• CAR Connectivity Aware Routing

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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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CAR

• Vector and Anchor based protocol
• Source creates a path list of anchor nodes (PGB)
• Intermediate nodes follow the anchor list
• Improvements
• Adapt beaconing to the number of neighbors
• Use Guards to maintain the path

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CAR
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Intersection
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5
2
1
3
4
source
dest
Curve
anchor
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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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Motivation

• Improving the route discovering process
• Reducing delay
• Reduce overhead
• Localize destination

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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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Problem Statement

• Flooding in the route discovery initial phase
• Wasted Bandwidth
• Delay
• Increasing Network congestion
• External source for destination location
• Bad performances for long distance between source
  and destination

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Ideas to improve CAR

• Use Road Signs Units (Curves, Traffic lights)
• Caching
• Fixed Anchor Node
• Communication among RSU
• CAR routing information
• Hierarchical routing
• Rendez-vous

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Assumptions

• RSUs have higher coverage
• RSUs may communicate between themselves
• RSUs have a high computational power
• RSUs know area topology
• RSUs cache information
• RSUs have memory

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Agenda

• Introduction and discussion
• Context of CAR
• Motivation
• Problem statement
• Improvements
• Conclusion and references

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Improvements

• Flooding in the route discovery initial phase
• External sources for destination location
• Bad performances for long distance between source
  and destination

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Implementation of improvements CAR functioning
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Implementation of improvements RSU usage
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RSU behavior

• When receiving a PD
• If first PD
• Make the list of RSUs to reach destination area
• Send a new Path Discovery which have to go
  through the RSUs
• If not the first
• Check for improvement (number of hops)
• If improve forward PD

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Explanations

• RSUs are preferred to other nodes to be used as
  fixed anchor nodes
• Know topology
• Know routes from area to area
• Generate Optimal Path using their knowledge
• May exchange information with other RSUs
• Timers to keep table on date
• If no RSU, PGB flooding is used.

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Special Cases

• RSU further than the potentially next hop
• Several RSUs in the range

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Improvements

• Flooding in the route discovery initial phase
• External sources for destination location
• Bad performances for long distance between source
  and destination

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Rendez-vous

• Reuse HIP (Host Identity Protocol) rendez-vous
  idea
• HIT attached to the cluster in which the node
  is
• Update position, keep node ID
• Information stored in Global Data Base and Local
  Data base
• Clusters f(number of RSUs)

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Rendez-vous

• Node
• Entering new Cluster Update its location
• Update its location on GDB and on LDB
• Cluster Head
• Has a local view of nodes in its cluster
• Interact with Rendez-vous server (GDB)
• (HLR VLR analogy)

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Special Cases

• Too many nodes inside the cluster
• Take too much time to find the location (in LDB)
• Moving too often from a cluster to another
  (Clusters big enough)
• Node knows it is moving from Clusterold
  Clusternew

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Improvements

• Flooding in the route discovery initial phase
• External sources for destination location
• Bad performances for long distance between source
  and destination

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Hierarchy prevents from Anarchy

• When a node starts PD
• Asks to communicate with HIT to CH
• CH look for
• Presence in its database
• If not ask GDB for ClusterID of the destination
• Compute distance, decide to
• Use basic CAR
• Use inter CHs communication then CAR locally
• CAR with RSUs as anchor nodes locally

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Hierarchy prevents from Anarchy
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Special Cases

• Inter/ Intra Cluster
• Depends on inter RSUs links
• How to find list of RSUs to dest
• Third routing table for RSUs
• Two scopes RSUs
• Cluster Head
• Fixed anchor nodes

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Example inter-cluster
GDB
Cache
Cluster
LDB
Cache
Cache
Cluster
Routing table
LDB
LDB
Cache
Routing table
Routing table
LDB
RSU
Routing table
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Example intra-cluster
Anchor nodes
Find RSU list
talk to D
Dest
talk to D
Src
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Conclusions

• Many ideas proposed
• Many limitations exist and risk to lose the
  benefits of the improvements made with CAR
• Some or all the solutions can be improved and
  implemented
• NO PERFECT SOLUTION EXISTING
• RSU repartition
• Capacity
• Topology
• Cost

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References

• Wikipedia
• (http//en.wikipedia.org/wiki/Vehicular_ad-hoc_ne
  twork)
• Connectivity-aware Routing (CAR) in Vehicular Ad
  Hoc Networks
• Valery Naumov, Thomas R. Gross
• Greedy Routing Protocols for Vehicular Ad Hoc
  Networks
• James Bernsen, D.Manivannam

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Questions ?