An Improved Vehicular Ad Hoc Routing Protocol for City EnvironmentsMoez Jerbi, Sidi-Mohammed Senouci, and Rabah MeraihiFrance Telecom R&D, Core Network LaboratoriesYacine Ghamri-DoudaneNetworks and Multimedia Systems Research GroupIEEE International Conference on Communications, ICC 2007

OutlineIntroductionImproved Greedy Traffic Aware Routing Protocol (GyTAR)SimulationConclusion

IntroductionMany potentially useful applications have been envisioned in vehicular networks.Safety applicationsReal-time traffic informationMedia content sharingInternet service

IntroductionRouting is the fundamental component for the success of these VANET applications.

GoalPropose a routing protocol suitable for city environments.Efficiently relay data in the network.Considering the real time road traffic variation and the characteristics of city environments.Efficiently use the network resources.Reduced end-to-end delay.Improve packet delivery ratio.

Network AssumptionVehicleEach vehicle is equipped with GPS devices used for obtaining vehicle Location, Speed, and direction.Each vehicle maintains a neighbor table.Each vehicle can determine the location of its neighboring junctions.

J1J2J3J4J1J4J3J3

Network AssumptionRoadEach junction deploy a static node.Each static node can communication with the neighbor static nodes.Determine the vehicle traffic between two junction.Get the current geographical location of the destination

J1J2J3J4

Overview

J1J4J8J5J7

DA

J1static node()*

ProblemHow to know the current geographical location of the destinationHow to know the vehicle traffic between two junctionsHow to select the best next junction to forward packetHow to forwarding data between two junction

1.destinationVANET topology2. 3.4.*

ProblemHow to know the current geographical location of the destinationHow to know the vehicle traffic between two junctionsHow to select the best next junction to forward packetHow to forwarding data between two junction

*

How to know the current geographical location of the destinationProvided by a location service - GLS (Grid Location Service)A scalable location service for geographic ad hoc routingMobiCom 2000

location servicedestination*

How to know the current geographical location of the destination

J1Level 1Level 2Level 3

location servicedestination*

How to know the current geographical location of the destination

J1(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)Level 1Level 2Level 3

location servicedestination*

How to know the current geographical location of the destination

J1(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)(VD , J1)J2

location servicedestination*

How to know the current geographical location of the destination

J2(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)

location servicedestination*

How to know the current geographical location of the destination

J2(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)J3

location servicedestination*

How to know the current geographical location of the destination

J2(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)(VD , J2)J3J4J5

location servicedestination*

ProblemHow to know the current geographical location of the destinationHow to know the vehicle traffic between two junctionsHow to select the best next junction to forward packetHow to forwarding data between two junction

*

How to know the vehicle traffic between two junctionsV1V1V1

J2J3J4J5J1J2J2J1J1J3J3J1J1J4J4J1J1J5J5J1

Static nodeIDstatic nodestatic node*

How to know the vehicle traffic between two junctionsV1

J2J3J4J5J1J2J2J1J1J3J3J1J1J4J4J1J1J5J5J1

*

How to know the vehicle traffic between two junctions

V1V2V3V4V5V6V1V2V3V4V5V6V7V8V9V10V11V12V7V8V9V10V11V12

J2J1J2J2J1

J1J2J1J1J2

static nodestatic nodeJ1J2static nodestatic node()static nodeJ1J2J1J2*

How to know the vehicle traffic between two junctionsV1V2V3V4V5V6V1V2V3V4V5V6V7V8V9V10V11V12V7V8V9V10V11V12

V1V2

J2J1J2J2J1

J1J2J1J1J2

J1J2J2J1*

ProblemHow to know the current geographical location of the destinationHow to know the vehicle traffic between two junctionsHow to select the best next junction to forward packetHow to forwarding data between two junction

*

How to select the best next junction to forward packetDJ1J4J8SDiThe curvemetric distance from the current junction to the destination.DjThe curvemetric distance from the current junction to the destination.DpDj / Di (Determines the closeness of the candidate junction to the destination.)

17

20

11

171.1760.6471

DiDjJ3J1J4J8

Dp

*

How to select the best next junction to forward packetDJ1J4J8SNvTotal number of vehicles between i and j.NcNumber of transmission range between i and j.Navg Nv / Nc (Average number of vehicles per transmission range.)NconThe ideal connectivity degree within in a transmission range.2671.53.541.3331.7141.751.5

J1J4J8NvNcNavgNcon

*

How to select the best next junction to forward packetDJ1J4J8S

J1J4J8Nv267Nc1.53.54Navg1.3331.7141.75Ncon1.5

DiDjJ3J1J4J817201117

Dp1.1760.6471

Dp1.1760.6471

Navg1.3331.7141.75Ncon1.5

J1J4J8Dp1.1760.6471Navg1.3331.7141.75Ncon1.5

*

How to select the best next junction to forward packetDJ1J4J8S = 0.5 , = 0.50.35650.67650.50.6765

J1J4J8Dp1.1760.6471Navg1.3331.7141.75Ncon1.5

J1J4J8score

*

0.6765How to select the best next junction to forward packetDJ4S = 0.5 , = 0.50.35650.5J5J6

J1J4J8score

J1J4J8Dp1.1760.6471Navg1.3331.7141.75Ncon1.5

J5J6DpNavgNcon

J5J6score

*

ProblemHow to know the current geographical location of the destinationHow to know the vehicle traffic between two junctionsHow to select the best next junction to forward packetHow to forwarding data between two junction

*

How to forwarding data between two junctionV1

*

How to forwarding data between two junctionV1

V2V6V4V8V10V7V9V5V3

V1IDLocationDirectionVelocityUpdate timeV2LV2DV2VV2TV2V3LV3DV3VV3TV3

V3IDLocationDirectionVelocityUpdate timeV1LV1DV1VV1TV1V2LV2DV2VV2TV2V4LV4DV4VV4TV4V5LV5DV5VV5TV5

V5IDLocationDirectionVelocityUpdate timeV3LV3DV3VV3TV3V4LV4DV4VV4TV4V6LV6DV6VV6TV6V7LV7DV7VV7TV7

V7IDLocationDirectionVelocityUpdate timeV5LV5DV5VV5TV5V6LV6DV6VV6TV6V8LV8DV8VV8TV8V9LV9DV9VV9TV9V10LV10DV10VV10TV10

*

How to forwarding data between two junctionV1V2V6V4V8V10V7V9V5V3

V7IDLocationDirectionVelocityUpdate timeV5LV5DV5VV5TV5V6LV6DV6VV6TV6V8LV8DV8VV8TV8V9LV9DV9VV9TV9V10LV10DV10VV10TV10

*

How to forwarding data between two junctionV1V2V4V8V10V9V5V3

*

Performance Evaluation

SimulationSimulatorQualnetComparisonB-GyTAR (Basic GyTAR)GyTARGSR (Geographic Source Routing - AODV)LAR (Location Aided Routing - GPSR)Simulation Time200 s

Performance Evaluation

Simulation scenarioMap Size2500 2000 m2Number of Intersections16Number of Roads26Number of Vehicles100 ~ 300Vehicle Velocity30 ~ 50 5 Km/h

Performance Evaluation

Simulation parameterMAC Protocol802.11 DCFChannel Capacity2 MbpsTransmission Range~266 mPacket Sending Rate0.1 ~ 1 secondData Packet Size128 bytesWeighting Factors = 0.5 = 0.5

Performance Evaluation

Performance metrics1.Packet Delivery Ratio2.End-to-End Delay3.Routing Overhead

Performance Evaluation

Packet delivery ratioNumber of vehicles300 vehiclesPacket sending rate0.2 s

Performance Evaluation

End-to-End DelayNumber of vehicles300 vehiclesPacket sending rate0.2 s

Performance Evaluation

Routing OverheadNumber of vehicles300 vehiclesPacket sending rate0.2 s

ConclusionThis paper proposed a novel geographical routing protocol for VANET in city environments.Considering the real time road traffic variation and the characteristics of city environments.Efficiently use the network resources.Reduced end-to-end delay.Improve packet delivery ratio.

J1static node()*1.destinationVANET topology2. 3.4.*

*location servicedestination*location servicedestination*location servicedestination*location servicedestination*location servicedestination*location servicedestination*location servicedestination*

*Static nodeIDstatic nodestatic node*

*static nodestatic nodeJ1J2static nodestatic node()static nodeJ1J2J1J2*J1J2J2J1*

*

*

*

*

*

*

*

*

*

*

*[

]

+

-

1

,

min

1

con

avg

p

N

N

D

b

a