The convergence of telecommunication, computing, wireless, and transportation technologies facilitates that our roads and highways can be both our communications and transportation platforms. These changes will completely revolutionize when and how we access services, communicate, commute, entertain, and navigate, in the coming future. Vehicular ad hoc networks (VANETs) are wireless communication networks that do not require any fixed infrastructure, and support cooperative driving among communicating cars on the road. Vehicles act as communication nodes and relays, forming dynamic vehicular networks together with other near-by vehicles on the road and highways.
The specific characteristics of vehicular networks favor the development of attractive and challenging services and applications. In this thesis we focus on safety applications. Specifically, we develop and evaluate a novel protocol to improve safety on the road. Our proposal combines location information of vehicles, and roadmap scenario characteristics, to improve warning message dissemination. In safety-based applications for vehicular networks our approach is able to reduce the broadcast storm problem while maintaining a high message dissemination effectiveness towards surrounding vehicles.
Since deploying and testing VANETs involves high cost and intensive labor, simulation is a useful alternative prior to actual implementation.  However, unlike other previous works, we seek to fully address the peculiarities of vehicular mobility and urban radio transmission, especially when buildings interfere with radio signal propagation. With this purpose, we develop more accurate and realistic VANET simulation tools by improving both the radio propagation and the mobility models, achieving a solution that allows integrating real roadmaps into the simulation framework. Finally, we assess the performance of our proposed protocol using our enhanced simulation platform, evidencing the importance of an adequate simulation framework to achieve more realistic results and draw more meaningful conclusions.