1 Performance Analysis of XOR-based Flat Routing Protocols in High Mobility Vehicular ad hoc Networks Rodolfo Oliveira *† , Andr´ e Garrido * , Miguel Lu´ ıs † , Rafael Pasquini § , Luis Bernardo *† , Rui Dinis *‡ Paulo Pinto *† , * Departamento de Engenharia Electrot´ ecnica, Faculdade de Ciˆ encias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal † UNINOVA, 2829-516 Caparica, Portugal ‡ IT, Instituto de Telecomunicac ¸˜ oes, Portugal § State University of Campinas 13083-970 - Campinas - SP - Brazil Abstract The routing strategy is an important issue in Vehicular ad hoc Networks since the shared nature of the wireless medium, the time-varying capacity of the links and the highly dynamic network topology due to vehicle’s mobility severely restrict the choices available for the creation of the paths. These issues influence the availability of the path and its long-term duration. In this report we present a performance analysis of XOR 1 -based flat routing protocols in high mobility conditions, considering a vehicular ad hoc network (VANET) formed in a highway scenario. First, we propose an XOR-based protocol that incorporates several adaptations of the existing XOR-based routing algorithms, in order to cope with the network mobility. Then we propose an improved version of it, XORi, which modifies the protocol’s information gathering process to accommodate the specific dynamic nature of VANETs topology. Finally, we evaluate the performance of XOR-based protocols with other topology-based routing protocols. Simulation results allow us to characterize the performance of this class of protocols through the comparison of the packet delivery ratio, end-to- end path delay and average number of path hops 2 . When a moderate density of nodes is considered, simulations show that XOR-based algorithms achieve almost the same packet delivery rate as link state algorithms, such as OLSR, while for high density of nodes XOR-based algorithms scale better in terms of delay when compared to source routing algorithms, such as DSR. Keywords: XOR-based Routing Protocols, Flat Routing Protocols, Vehicular ad hoc Networks. 1 Exclusive-or logical operator. 2 The source code of the simulated XOR-based protocols was written for the network simulator ns-2.34 and is available to download at http://tele1.dee.fct.unl.pt/people/rado/html/downloads .html, allowing the community to evaluate their own scenarios and compare it with other protocols. February 28, 2010 DRAFT Preliminary TR#02_10