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PERFORMANCE EVALUATION OF DATA DISSEMINATIONS 
FOR VEHICULAR AD HOC NETWORKS IN HIGHWAY SCENARIOS 
XIONG Wei a ’ *, LI Qing-Quan b 
a School of Electronic Information (EIS), Wuhan University, Wuhan, 430079, China - beargolden@tom.com 
^National Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing (LIESMRS), Wuhan 
University, Wuhan, 430079, China - qqli@whu.edu.cn 
Commission I, ThS-1 
KEY WORDS: Data Dissemination, Network Simulation, Performance Evaluation, Routing Protocols, Vehicular Ad Hoc 
Networks 
ABSTRACT: 
A vehicular ad hoc network (VANET) is a relatively new term for an old technology - a network that does not rely on pre-existing 
infrastructure. When integrated into the intelligent transportation systems (ITS), it can provide direct vehicle-to-vehicle (V2V) and 
vehicle-to-infrastructure (V2I) communications, thereby can greatly improve the safety and efficiency of road traffic. The emerging 
and promising VANET technology is distinguished from mobile ad hoc networks (MANET) and wireless sensor networks (WSN) by 
large-scale deployed autonomous nodes with abundant exterior assisted information, high mobility with an organized but 
constrained pattern, frequently changed network topology leading to frequent network fragmentation, and varying drivers behavior 
factors. Without the presence of centralized entities such as base stations, mobile hosts also need to operate as routers in order to 
maintain network connectivity. Therefore, various ad hoc routing protocols have been proposed, but there have previously been few 
studies on how the specific mobility patterns of vehicles may influence the protocols performance and applicability. In this paper, 
we compare and evaluate the performance of following routing protocols: AODV, DSDV, and DSR. A variety of highway scenarios, 
characterized by the mobility, load, and size of the network were simulated. Our results indicate that those routing protocols 
dedicated for MANET is unsuitable for VANET scenarios in terms of packet delivery ratio, routing load, and end-to-end delay. 
1. INTRODUCTION 
A vehicular ad hoc network (VANET) is a specific form of 
packet radio networks (PRNET), as the practical application of 
mobile ad hoc networks (MANET) and wireless sensor 
networks (WSN) on intelligent transportation systems (ITS), it 
can provide direct communications among nearby vehicles, 
referred to as vehicle-to-vehicle (V2V) communications, and 
between vehicles and nearby fixed equipment, referred to as 
vehicle-to-infrastructure (V2I) communications, thereby can 
rapidly deploy a self-organizing, non-infrastructure, multi-hop, 
cost-free, open, and distributed inter-vehicle communication 
(IVC) networks based on pre-established road layouts. 
The emerging and promising VANET technology, which has 
drawn tremendous attention from government, academics, and 
industry in the past few years, has been envisioned as one of the 
forefront research hotspots and increasingly available for a 
large number of cutting-edge applications as diverse as 
imminent collision warning and avoidance, forward obstacle 
detection and avoidance, emergency message dissemination, 
intersection decision support, cooperative driving assistance, 
traffic congestion advisory, dynamic route update, traveler and 
tourist information, automated toll collection and parking 
services, interactive multimedia and internet access. 
Most of concerns of interest to MANET are of interest in 
VANET; however, when compared to the former, the latter has 
several salient characteristics, such as, large-scale deployed 
autonomous nodes or terminals with abundant exterior assisted 
* XIONG Wei (phone: +86-27-68778035, fax: +86-27-68778043) 
information (e.g., in-vehicle global positioning system (GPS), 
geographic information system (GIS), lidar, and video camera), 
high mobility with an organized but constrained pattern (e.g., 
by being restricted to follow a paved highway), frequently 
changed network topology leading to frequent network 
fragmentation, and varying drivers behavior (e.g., direction/lane 
changing or overtaking). Furthermore, the on-board unit (OBU) 
and roadside unit (RSU), by which may provide mobile ad hoc 
inter-connectivity, generally do not have distinct energy 
constraints due to their access to external power supply systems. 
Therefore, the conventional research dedicated for MANET 
cannot be directly applied to VANET since those afore 
mentioned characteristics are not well considered. 
To facilitate the safe, secure, efficient, clean, and comfortable 
mobility of people and goods, advanced communication and 
information exchange between the key elements of the mobility 
sector - the user, the infrastructure, and the vehicle - are 
required. Nodes in VANET can communicate with each other at 
any time and without any restriction, except for connectivity 
limitations and subject to security provisions. Different mobility 
patterns and radio propagation conditions can result in a space- 
time varying network topology. A VANET, other than legacy 
client-server (C/S) communications, is a peer-to-peer (P2P) 
network which allows direct communications between any two 
nodes. If there is no direct link between the source and the 
destination, multi-hop routing is used. Various ad hoc network 
routing protocols have been proposed in the literature, and can 
be coarsely classified into topology-based and position-based 
approaches (Mauve et al., 2001).