Enhancement and Analysis of VANET One-Hop Event-Driven Emergency Services

In this paper, we propose a reliable dual-radio based DSRC channel assignment scheme and a new application- level based receiver-oriented repetition (AROR) scheme for one-hop event-driven emergency message broadcast in vehicular ad hoc networks (VANETs). The new scheme takes advantage of DSRC dual-radio devices to provide preemptive access for one-hop event-driven safety services without conflicts with basic safety message (BSM) based services. Furthermore, an application-level concept of region of interest (ROI) is introduced in selecting nodes for rebroadcast and repetitions of one-hop emergency warning message. In this way, both the reliability and transmission delay can be significantly improved. Additionally, we investigate and compare the reliability and performance of the proposed scheme and other broadcast schemes for DSRC VANET safety services on highway analytically and by simulations. The new analytic model accounts for the impact of the Nakagami fading channel with distance dependent path loss on the reliability and performance. The numerical results verify effectiveness of the new proposed schemes and correctness of the analytic model.