  A number of geolocation-based Delay Tolerant Networking (DTN) routing
protocols have been shown to perform well in selected simulation and mobility
scenarios. However, the suitability of these mechanisms for vehicular networks
utilizing widely-available inexpensive Global Positioning System (GPS) hardware
has not been evaluated. We propose a novel geolocation-based routing primitive
(Centroid Routing) that is resilient to the measurement errors commonly present
in low-cost GPS devices. Using this notion of Centroids, we construct two novel
routing protocols and evaluate their performance with respect to positional
errors as well as traditional DTN routing metrics. We show that they outperform
existing approaches by a significant margin.
