Rethinking the overhead of geo-localization information for vehicular communications

Geo-localization informations is a key component for providing locationbased services for Intelligent Transportation Systems (ITS). Mostly obtained by GPS devices and transmitted by Wireless Vehicular Communications, geo-localization in ITS represents a promising approach to reach objectives such as an increased road safety, transport efficiency, or on-the-road services. Despite its popularity, the issue of the overhead generated by the transmission of geo-localization data has not been addressed the ITS community. In this paper, we first discuss the format of the information provided by GPS devices and propose a flexible message structure for exchanging geolocalization data. Then, we illustrate the significant overhead generated by the transmission of such information and propose a compression method which achieves up to 70% overhead reduction without loss of precision. We finally test our method on the OLSR routing protocol.