General Ripple Mobility Model Chun-Hung Chen Dept. of CSIE National Taipei University of Technology

Introduction

RMM-Previous Work

The problem with RMM It can be described as the combination of two RWP mobility patterns It can be described as the combination of two RWP mobility patterns The average speed can not be spread wide The average speed can not be spread wide Uniform Index (UI) is not a good index for spatial distribution Uniform Index (UI) is not a good index for spatial distribution There is a limitation for extension There is a limitation for extension

Procedure of GRMM 1. Given V min, V max, R min, and R max 2. Randomly choose a speed v within [V min, V max ] 3. r = f(v, λ, V min, V max ) 4. Uniformly pick up a destination within the disk of radius r and the disk centering at the node position 5. The node moves toward the destination, and if it reaches the wall or boundary, it will bounce off and maintain the same speed. Bouncing action is set according to the rule that incidence angle is equal to the reflection angle.

Flexible Average Speed (FAS) In RMM, V min <V LS <V max In RMM, V min <V LS <V max g(λ,v) = 0 if v ≦ V LS g(λ,v) = 0 if v ≦ V LS g(λ,v) = 1 if v > V LS g(λ,v) = 1 if v > V LS If we want the lower speed node with shorter distance, we can assign g(λ,v) as a monotone increasing function. If we want the lower speed node with shorter distance, we can assign g(λ,v) as a monotone increasing function. g(λ,v)=v λ is proposed here and it is an instance of GRMM g(λ,v)=v λ is proposed here and it is an instance of GRMM

V min =1, V max =20, R min =50, R max =1000 and g(λ,v)=v λ

Evaluation Metrics Average Speed Average Speed –Results of Flexible Average Speed Average Number of Links Average Number of Links –Given Effective Range D, if there exists a link between A and B, Distance from A to B is smaller than or equal to D Average Duration of Links Average Duration of Links –Once the link is established, we observe how long it lasts Spatial Distribution Spatial Distribution –Moving area is divided into several 100x100 sections. Accumulating how many nodes being in the sections. Spatial Entropy Spatial Entropy –

Simulation Parameters X Coordinate1000 meters Y Coordinate1000 meters Number of Nodes (N)50 Simulation Time120 minutes V min 1 m/s V max 20 m/s R min 50 meters R max 1000 meters Effective Range (D)300 meters

Flexible Average Speed

Average Number of Links

Average Duration of Links

Spatial Distribution

Spatial Entropy

Conclusions GRMM maintains the simplicity and the understandable of RWP GRMM maintains the simplicity and the understandable of RWP It is the first time of Flexible Average Speed (FAS) mentioned in mobility models. It is the first time of Flexible Average Speed (FAS) mentioned in mobility models. There are still some analytic works which can be done There are still some analytic works which can be done