Risa: Distributed Road Information Sharing Architecture

With the advent of the new IEEE 802.11p DSRC/WAVE radios, Vehicle-to-Vehicle (V2V) communications is poised for a dramatic leap. A canonical application for these future vehicular networks is the detection and notification of anomalous road events (e.g., potholes, bumps, icy road patches, etc.). We present the Road Information Sharing Architecture (RISA), the first distributed approach to road condition detection and dissemination for vehicular networks. RISA provides for the in-network aggregation and dissemination of event information detected by multiple vehicles in a timely manner for improved information reliability and bandwidth efficiency. RISA uses a novel Time-Decay Sequential Hypothesis Testing (TD-SHT) approach in which event information from multiple sources is combined with time-varying beliefs. We describe our implementation of RISA which has been deployed and tested on a fleet of vehicles on-site at the GM Warren Technical Center in Michigan. We further provide a comprehensive evaluation of the aggregation mechanism using emulation of the RISA code on real vehicular mobility traces.