A message propagation model for hybrid vehicular communication protocols

This paper addresses a hybrid approach on message propagation in vehicular networks. Short-range Vehicle-to-Vehicle (V2V) communications cannot always guarantee connectivity to the network cloud, especially when traffic density is very low. By utilizing existing wireless network infrastructure it is possible to greatly enhance the capabilities of short range V2V technologies. Such existing and future communications infrastructure includes UMTS, HSDPA, Wi-Fi, and WiMax. For this multi-network environment we analyze how messages are forwarded by vehicles communicating via a hybrid protocol exploiting both short-range V2V communication schemes and Vehicle-to-Infrastructure (V2I) concepts. The protocol switching from V2V to V2I, and vice versa, occurs through a decision algorithm that considers observed network state. We characterize the bounds of information propagation and compare performance with traditional message propagation based on opportunistic networking. Simulation results show the effectiveness of the proposed hybrid vehicular communication protocol.