A timer-based intelligent flooding scheme for VANETs

A number of timer-based intelligent flooding schemes have been recently proposed to optimise message dissemination in Vehicular Ad-hoc NETworks. Unfortunately, most of them are not able to completely avoid useless copies of the message to be broadcast. Moreover, some schemes determine when the message has to be rebroadcast, thus thwarting the application in processing it. The use of a Medium Access Control (MAC) layer control packet handshake allows mitigating the issues above, but it could lead to an unacceptable overhead and to a high probability of dissemination interruption. The proposed Data-Ack Scheme (DAS) allows to reduce the overhead by exploiting only one control packet and makes the dissemination interruption most unlikely. By simulation, DAS performance has been compared with that obtained when either a MAC layer handshake-based scheme or a scheme which does not provide the use of control packets is adopted. Simulation results have shown that DAS performs better in those scenarios in which the Message Delivery Ratio values are not critical.