Vehicular Ad-hoc Networks Joint Transport and Communication Model for Vehicular Ad-hoc Networks Ivan Ho Supervisors: Prof. Kin K. Leung and Prof. John W. Polak

Background Mobile Ad hoc NETwork (MANET): A collection of wireless nodes communicating with each other in the absence of any infrastructure Vehicular Ad hoc NETwork (VANET): A subclass of MANET, which would perform crucial functions in road safety, detection of traffic accidents and reduction of traffic congestions. However, driver behaviour, mobility constraints and high speeds create unique characteristics in VANET. Mobile sensor network in MESSAGE However, automotive ad hoc networks will behave in fundamentally different ways than the predominated models in MANET research…

Background Joint Transport and Communication Model: to adequately capture spatial and temporal details and accuracy of vehicle propagation, link condition, node connectivity and network protocol operations Key Question: How different characteristics of mobility affect the performance of wireless communication protocols? To ensure the design feasibility of the mobile sensor network, modelling and design tools are needed…

Research Framework Protocol Mobility Model Spatial Dependence Temporal Dependence Relative Speed Geographic Restrictions Protocol Throughput Routing Overhead

Research Framework The focus of this research work Mobility Model Spatial Dependence Temporal Dependence Relative Speed Geographic Restrictions Connectivity Link Duration Path Availability Protocol Throughput Routing Overhead

Mobility Model Random Waypoint Model Reference Point Group Mobility (RPGM) Model Freeway Mobility Model Manhattan Mobility Model Objective: To establish a general transport model that can well describe the real-world environment These models are insufficient to capture the major characteristics of the real-world transport systems! For instance, previous works show that the results obtained from different models vary widely and do not realistically represent vehicular traffic speeds, directions and trips. Moreover, none of them consider mobile nodes as scheduled transport systems (e.g. Bus, tube) other than private vehicles, and traffic delays caused by congestions and traffic control through traffic lights or stop signs are also neglected. Therefore, our first objective is to establish an arbitrary transport model that can well describe the real-world environment. T. Camp, J. Boleng, V. Davies, "A Survey of Mobility Models for Ad Hoc Network Research," Wireless Communications & Mobile Computing, Vol. 2, No. 5, 2002.

Propagation Model Shadowing, attenuations of signal at obstacles NLOS LOS Objective: To identify the propagation model that could accommodate the environment of vehicle networks NLOS In an urban environment, the signal may reach the receiver via non-line-of-sight (NLOS) propagation mechanisms, such as reflection, diffraction, and scattering.

Joint-Transport- Communication Model What is the impact of the mobility model on the connectivity graph, which in turn influences the protocol performance? e.g. Relationship between node density and connectivity Node density Connectivity Degree of connectivity = F(node density, velocity, mobility pattern)

Simulators Area of Interest Traffic Model VisSim, Paramics, SUMO GrooveNet More sophisticated NS-2, QualNet, Opnet Communication Model We are going to figure out which is the most efficient and cost effective way for achieving our goal. More sophisticated R. Mangharam, D. Weller, R. Rajkumar, P. Mudalige and F. Bai, "GrooveNet: A Hybrid Simulator for Vehicle-to-Vehicle Networks," V2VCOM, Jul 2006.

Summary - Develop appropriate mobility and communication models Communication connectivity among vehicles Verify and optimize efficiency of vehicular ad hoc networks Mobility Model Spatial Dependence Temporal Dependence Relative Speed Geographic Restrictions Protocol Throughput Routing Overhead Connectivity Link Duration Path Availability The Joint Model acts as a framework for future VANET design - understand and exploit dynamics between vehicle movement and communication capability - enable efficient design of vehicular ad hoc network for transport systems control/management

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