A Novel mobility model for realistic behavior in Vehicular Ad hoc Network Dhananjay S. Gaikwad Computer Engineering Department, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat India-395007 dhananjayg63@gmail.com , g.dhananjay@coed.svnit.ac.in Mukesh Zaveri Computer Engineering Department, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat India-395007 mazaveri@coed.svnit.ac.in Abstract— Mobility models or the movement patterns of nodes communicating wirelessely, play a vital role in the simulation- based evaluation of vehicular Ad Hoc Networks (VANETs). Even though recent research has developed models that better corresponds to real world mobility, we still have a limited understanding of the level of the required level of mobility details for modeling and simulating VANETs. In this paper, we propose a new mobility model for VANETs that works on the city area. In this model we map the topology of streets and behavior of vehicles at the intersection of roads. In our proposed model, we change the speed of nodes after some specific distance in accordance to neighboring nodes, so this will lead a realistic situation on the roads. Our new proposed model accounts the various characteristics of VANETs such as traffic lights, acceleration/deceleration due to nearby vehicles, attraction points where maximum numbers of vehicle tends to go. Using the real and controlled map of street, we compare our mobility model with the random direction mobility model. Our result demonstrates that probability of link availability in VANETs is more sensitive to the vehicles waiting at intersections and acceleration/deceleration of vehicles. We also found that probability of link availability suffers at the intersection of the roads, because some nodes cross the signal continue movement in horizontal direction while some nodes change the direction of traveling to vertical. Keywords- Vehicular Ad Hoc Network (VANETs), Mobile Ad Hoc Network (MANETs). 1. INTRODUCTION Ad hoc network is a collection of wireless mobile nodes without any fixed base station infrastructure and centralized management. Each node acts as both host and router, which moves arbitrarily and communicates with each other via multiple wireless links. It is a multi-hop wireless network, where packets need to pass through several nodes to reach destination [2]. Vehicular Ad Hoc Network (VANETs) are a special case of Mobile Ad Hoc Network (MANETs) and consist of a number of vehicles traveling on urban streets capable of communicating with each other without fixed infrastructures. VANETs are expected to benefit safety applications, gathering and disseminating real-time traffic congestion and routing information, information services such as transparent connection to internet etc [3]. One critical aspect of VANETs simulation is the movement pattern of vehicles, also called mobility models. Mobility model determine the location of nodes in the topology at any given instant, which strongly affects network connectivity and throughput [5]. There are several mobility models such as random pattern, graph constrained commonly used in popular wireless simulators such as ns2 [16] by VANET researchers [4]. But one problem with these models is that they ignores some critical aspects of the real world traffic such as queuing of vehicles at road intersection, traffic lights and traffic signs, acceleration and deceleration according to neighbor vehicles. Mobility models should reflect as possible as the real behavior of vehicular traffic on the road [1]. In this paper, we propose a new mobility model, which incorporates important features of mobility model on the road, such as presence of traffic light on the road, node movement is restricted to the road structure and speed changes in accordance to the neighboring vehicle. The rest of paper is organized as follows: section 2 describes some currently used mobility models and some tools for generation of mobility models. Section 3, describes our new proposed mobility model and simulation of our model. Finally Section 4 concludes the paper. 2. MOBILITY MODEL OVERVIEW Mobility model reflects the behavior of the nodes throughout the simulation time. It shows how the nodes change their speed and direction in accountancy to the neighboring vehicles and according to the traffic rule. Following are some important factors those affect the mobility of nodes in VANETs. • Street structure: Streets force nodes to conne their movements to well-defined paths. This constrained movement pattern determines the spatial distribution of nodes and their connectivity. Streets can have either single or multiple lanes and can allow either one-way or two-way traffic. • Block size: A city block can be considered the smallest area surrounded by streets. The block size determines the number of intersections in the area, which in turn determines the frequency with which a vehicle stops. 2011 11th IEEE International Conference on Computer and Information Technology 978-0-7695-4388-8/11 $26.00 © 2011 IEEE DOI 10.1109/CIT.2011.70 597 2011 11th IEEE International Conference on Computer and Information Technology 978-0-7695-4388-8/11 $26.00 © 2011 IEEE DOI 10.1109/CIT.2011.70 597