The minimum delay relay optimization based on nakagami distribution for safety message broadcasting in urban VANET

For safety applications of Vehicular ad-hoc Network (VANET), many valuable broadcast protocols have been proposed nowadays, most of which are based either on sender or receiver. In fact, sender-based protocols would fall into invalidation owing to high mobility of vehicles, while receiver-based ones would generate extra delay. Combining both, this paper proposes a broadcast protocol with the minimum delay forwarding (BP-MDF) optimization for disseminating safety messages in city scenario. Based on the presented delay model, considering both of the static and dynamic routing attributes of urban road, BP-MDF firstly specifies the only one neighbor node as forwarder at sending end, and other receivers assist in forwarding if specified forwarder rebroadcasts unsuccessfully. Consequently, both reliability and timeliness performance of broadcast are satisfied. The simulation results show that the delay and dissemination efficiency of BP-MDF outperforms Slotted-1 protocol, accompanying with the achievement of more than 95% packet delivery ratio.