Modeling of a Virtual Track Modeling of a Virtual Track Based Group Mobility Model Based Group Mobility Model

for Ad Hoc Networksfor Ad Hoc Networks

Kelvin Biao Zhou

Tutor: Kaixin Xu

MotivationMotivation Importance of Mobility Models for Ad Hoc Networks

– Topology and movement of the nodes are key factors in the performance of the network protocol

– Mobility model dictates the movement of the nodes To simulate dynamic and group movement in reality

– Typical scenario: Highway System To study the impact of the VT mobility model on the

performance of routing protocol Implemented in QualNet

Related WorkRelated Work Random Mobility Model

– Random Waypoint(RWP) Model One of the most popular mobility model Nodes move independently and randomly

Group Mobility Model– Reference Point Group Mobility(RPGM) Model

Two components of movement: group movement plus individual movement Group movement: shared by all nodes in the same group

– Based on the Random Waypoint Model Individual movement: based on the Random Waypoint Model

Realistic Mobility Model– Obstacle Mobility Model

Including obstacles and based on RWP models

DesignDesign

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Users will pre-define the following:Total City Number,City Positions,Track Width,Allowed Track Length,Horizontal MinSpeed,Horizontal MaxSpeed,Vertical MinSpeed,Vertical MaxSpeed.

Example Topology of Cities and Tracks

Design (Cont.)Design (Cont.)

Design Procedure: 1. Get topology of cities and track requirement from

configuration file: like city position, track width, allowed track length, etc.

2. Node Initial Distribution Nodes will initially distribute in cities randomly

3. Define all possible tracks from current city Read all city positions If the distance(from current city to city k) is less than allowed track

length, then the city k is next possible destination city, recording this possible track

Design(Cont.)Design(Cont.)

4. Randomly choose a track Randomly choose the track among these possible tracks, which

defines next destination city, track length, track angle, and node movement direction

5. Node moving in a selected track Initialize moving parameters Get intermediate destination in the track (details in next slide) Keep movement direction: horizontal movement is toward to

next city, vertical movement can be up or down(simulating the lane change)

Obey track limitation: like track Width & track Length• By controlling the horizontal speed and the vertical speed

6. Repeat step 3-5 when reach trackDest (next city)

horizDist

How to get an intermediate Dest point in a track ?

Design (Cont.)Design (Cont.)

trackOrigin(current city)

trackDest(next city)

Dest

horizDest1) Initilization:Current = trackOrigin;horizCurrent = trackOrigin;verticalCurrentPartial = 0.0;

horizCurrent

Current

2) Loop (to get horizDest):horizDist = horizSpeed * time;horizDest.x = horizCurrent.x +horizDist*cos ;horizDest.y = horizCurrent.y +horizDist*sin ;

verticalDist

3) Loop(Cont., to get Dest):verticalDist = verticalSpeed * time;verticalDistPartial = verticalDist/(trackWidth/2);verticalDestPartial = verticalCurrentPartial + verticalDistPartial;Dest.x = horizDest.x – verticalDestPartial * (trackWidth/2)*sin ;Dest.y = horizDest.y + verticalDestPartial * (trackWidth/2)*cos ;

SimulationSimulation

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Dimensions (2200, 2200)

City1 (400, 600)City2 (400, 1600)City3 (1200, 100)City4 (1200, 1100)City5 (1200, 2100)City6 (2000, 600)City7 (2000, 1600)trackWidth = 100mAllowedTrackLength = 1200m

Node Number = 100Tested Routing Protocol: AODV

Simulation Scenario

Simulation ResultsSimulation Results

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RWP(UniformDistribution)

RWP(RandomDistribution)

VT Model

Delivery Ratio vs Node Speed(ClientOfferLoad=16.73kbps)

Node Speed (m/s)

Node Number: 100Routing Protocol: AODV

Del

iver

y R

atio

Simulation Results (Cont.)Simulation Results (Cont.)

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RWP(UniformDistribution)

RWP(RandomDistribution)

VT Model

Throughput vs Node Speed(ClientOfferLoad=16.73kbps)

Node Speed (m/s)

Thr

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put (

kbps

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Node Number: 100Routing Protocol: AODV

Simulation Results (Cont.)Simulation Results (Cont.)

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120150180210240270300330360

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RWP(UniformDistribution)

RWP(RandomDistribution)

VT Model

End-to-End Delay vs Node Speed(ClientOfferLoad=16.73kbps)

Node Speed (m/s)

End

-to-

End

Del

ay (

mse

c)

Node Number: 100Routing Protocol: AODV

Conclusion and Future WorkConclusion and Future Work Simulate realistic, dynamic and group movement

– Nodes move under virtual tracks Obey the limitation of the track, like track width & length, and

track direction, etc

– Easily simulate node joining and leaving group The VT model has significant impact on the

performance of routing protocol (AODV) Future Plan:

– Group Discovery, Formation, Splitting, Join and Merging– Partition Problem in the VT model