Connectivity-Aware Routing (CAR) in Vehicular Ad Hoc Networks Valery Naumov, Thomas R. Gross ETH Zurich, Switzerland IEEE INFOCOM 2007

Outline Introduction Connectivity-Aware Routing (CAR) Performance evaluation Conclusion

Introduction Ad hoc networks operate without a predefined fixed infrastructure. Vehicular ad hoc networks using based WLAN technology have recently received considerable attention in many projects

Introduction - Related Work Geographic Routing (GR) –GPSR Non-GR –AODV

Introduction - AODV AODV (Ad-hoc On-demand Distance Vector) s d b a f e c Destination Node Source

Introduction - Motivation SE A B D

Introduction - Goal Present a novel position-based routing scheme –Find connected paths between source and destination pairs –Locate position of destination

Connectivity-Aware Routing (CAR) Neighbor tables and adaptive beaconing Destination location discovery Path maintenance Routing error recovery

Neighbor tables and adaptive beaconing all nodes include in the periodic HELLO beacons information about –moving directions –Speeds A B Neighbor Table B A

Neighbor tables and adaptive beaconing

Scenario S D

S D

Anchor Point A BB Anchor Hello Beacon

A Destination location discovery B C Neighbor Table B, C Source Node

Destination location discovery A Anchor

Path Maintenance S E A D

S E A D

If an end point node (Source or Destination) changes its direction End Point Node Standing Guards

Path Maintenance If an end point node (Source or Destination) changes its direction End Point Node Standing Guards

Path Maintenance If an end point node (Source or Destination) changes its direction End Point Node Standing Guards

Path Maintenance End Point Node Traveling Guards

Path Maintenance End Point Node Traveling Guards

Routing error recovery Gap

Routing error recovery Timeout Algorithm Gap AA Temporary Destination

Routing error recovery Timeout Algorithm AA Temporary Destination

Routing error recovery If an end point node (Source or Destination) changes its direction End Point Node

Routing error recovery End Point Node Anchor Node Walk-Around Error Recovery

Performance evaluation Simulatorns-2 Communication range - city scenarios Communication range - highway scenarios 400 meters 500 meters Vehicle Density less than 15, 30-40, more than 50 vehicles/km Data Rate 2 Mbps

Packet Delivery Ratio GPSR GPSR+AGF CAR CAR+WA Low (<15) Medium High >50 Packet Delivery Ratio

GPSR GPSR+AGF CAR CAR+WA Low (<15) Medium High >50 Packet Delivery Ratio

Average Data Packet Delay GPSR GPSR+AGF CAR CAR+WA Low (<15) Medium High >50 Average Data Packet Delay (s)

Average Data Packet Delay GPSR GPSR+AGF CAR CAR+WA Low (<15) Medium High >50 Average Data Packet Delay (s)

Routing Overhead GPSR CAR CAR+WA Low (<15) Medium High >50 Routing Overhead in Packets

Routing Overhead GPSR CAR CAR+WA Low (<15) Medium High >50 Routing Overhead in Packets

Conclusion A new Connectivity-Aware Routing protocol for VANETs –A scalable low overhead routing algorithm –Find connected paths between source and destination pairs –Locate position of destination

Thank You!!!