A directional geocast warning dissemination protocol for vehicular ad hoc NETworks (VANETs)

Multi-hop broadcasting is commonly used by safety applications in Vehicular Ad Hoc Networks (VANETs). By using a multi-hop technique and relay nodes, a sender in VANET can reach all other nodes outside of its communication range. A major problem with this well-known flooding approach is the congestion it causes on the network. Recently proposed protocols aim to reduce congestion by decreasing the number of relaying nodes. However, performing broadcast at each hop causes the same message to be received multiple times at the nodes located between two relays (intermediate nodes). To deal with this problem, we propose a Directional Geocast (DGcast) dissemination protocol aimed at distributing warning messages in VANET. The proposed protocol filters data according to the region it is addressed. We evaluated the performance of DGcast and compared the results with those obtained with previous protocols. DGcast outperforms its peers in term of latency and redundancy.