On the Use of Control Packets for Intelligent Flooding in VANETs

Broadcasting will be extensively used in Vehicular Ad Hoc Networks (VANET), mainly for spreading out safety messages. A number of Intelligent Flooding Schemes (IFSs) have been recently proposed to optimize message dissemination. Some of them exploit a distributed timer-based contention mechanism in order to allow the most suitable nodes to forward the packet and to suppress other potential forwarders. This paper deals with those schemes which are based on a handshake similar to RTS/CTS. This helps in avoiding potential forwarders, which should be suppressed, to uselessly rebroadcast a data packet. We aimed at identifying main problems which these schemes may encounter in optimizing message dissemination. To this objective, an analysis of the events which can cause the failure of the forwarding election procedure has been carried out. The analysis has also been the starting point for devising some different design choices.