World Applied Sciences Journal 7 (11): 1341-1352, 2009 ISSN 1818-4952 © IDOSI Publications, 2009 Corresponding Author: Dr. Laiq Khan, Associate Professor, Head of Graduate Programme, Department of Electrical Engineering, COMSATS IIT Abbottabad, Pakistan 1342 Anycast Based Routing in Vehicular Adhoc Networks (VANETS) using Vanetmobisim Laiq Khan, Nohman Ayub and Aamir Saeed Department of Electrical Engineering, COMSATS IIT Abbottabad, Pakistan Abstract: Vehicular Adhoc Networks (VANETS) is an emerging flavor of Mobile Adhoc Networks (MANETS) to improve intelligent Inter Vehicle and Vehicle to Vehicle communication without any fixed infrastructure. VANETS can be used to improve the Comfort Applications such as traffic information, weather information, gas station/restaurant location information or interactive communication such as Internet access and downloads. As these networks have no fixed communication structure and may vary heavily due to which routing of data packets through VANETS is very crucial. To evaluate the performance of Adhoc routing protocol in realistic urban vehicular motion pattern to make an improvement in providing Comfort Applications, this study proposes MANET anycast AODV routing protocol to make it adaptive for VANETS using VanetMobisim (a generator for vehicular mobility traces) under different matrices such as varying node maximum speed, varying number of nodes and with varying number of Constant Bit Rate (CBR) Sources. Key words: Any-cast routing  VANETs  vanetMobisim  performance metrics INTRODUCTION Vehicular Adhocnetworks emerge as a new technology that integrates existing wireless networks to radio enabled vehicles. The basic idea is to provide ubiquitous connections to mobile users on the road [1] and enable efficient Intelligent Transportation System (ITS) [2] between vehicles via vehicle to vehicle communication (V2V) depicted in Fig. 1 or Inter Vehicle Communication (IVC) system. In Comparison to cellular system this communication system has three main advantages [3]: Lower Latency, Brooder Coverage, and No Service Fee. In recent years, collaborative efforts of Government, Industries, Car Manufacturers Standardization Bodies and World Wide Research Centers opened a lots of interest for ITS. US FCC allocated 75 MHz of spectrum in the 5.9 GHz Band to improve Nation's Transportation System [3, 4]. In addition to this, other countries outside the us like: internet ITS [5] Consortium in Japan, Networks on Wheels [6] in Germany and PreVENT [7] Project in Europe are few research projects to support inter vehicle and vehicle to vehicle applications and services. However, due to dynamic network topology, frequent disconnected networks, varying communication conditions and hard delay constraints VANETS can be distinguished from other kinds of Adhoc networks. FCC frequency allocation categorizes two main areas/applications of vehicular Adhoc networks i.e., Safety Applications and Comfort Applications. First category as its name suggests improves safety levels of passengers via IVC or V2V Communication depicted in Fig. 1. Some common examples of this application are: signal violation warning, road condition warning, intersection coordination and emergency warning systems. Second kind of applications improves passengers comfort level through optimized route to destination, traffic information, weather information, gas station or restaurant location and price information are good examples of comfort applications. In both classes of applications data messages or control messages should be continuously exchanged between mobile nodes or vehicles. Four services that have immediate applications for comfort issues are unicast, multicast, anycast and scan [8]. This paper evaluates an anycast AODV On Demand Routing Protocol for comfort applications such as gas station and restaurant locations services with unicast on demand routing protocol in realistic urban mobility pattern. Rest of this paper is organized as follows: Section 2 presents routing protocols in general and then specific routing protocol used for evaluation section 3 contains introduction to VanetMobisim. Section 4, describes Mobility Model used for this simulation. Section 5 presents design methodology. Section 6 shows simulation scenarios and evaluation Results. Finally this paper is concluded in section 7.