Optimizing reactive routing over virtual nodes in VANETs

© 1967-2012 IEEE. The virtual node layer (VNLayer) is a cluster-based approach to handle communications in mobile ad hoc networks (MANETs), furnishing an abstraction of fixed geographical regions served by virtual nodes (VNs) as a means to tackle the challenges raised by the mobility of the physical nodes (PNs). Several studies have proved that the VNLayer constructs can be applied to improve the performance of existing routing algorithms, i.e., most notably Ad hoc On-Demand Distance Vector Routing (AODV) in general MANET scenarios. In this paper, however, we show that the same mechanisms do not work well in the more specific and demanding realm of vehicular ad hoc networks (VANETs). In response to this, we present several enhancements to the reference implementations of the VNLayer and the adaptation of AODV to work with VNs, proving by means of mathematical analysis and simulation experiments that our solutions achieve better performance in terms of overhead, packet delivery fraction, and latencies in VANET scenarios.