Latency performance analysis for safety‐related information broadcasting in VeMAC

Abstract

AbstractThe performance analysis is a powerful tool to reveal the features of protocols. We can find hints to optimize protocols through performance analysis. Ultralow latency transmission is one of stringent requirements for event‐driven safety‐related message transmission in vehicular medium access control (VeMAC) protocol. In this paper, we focus on analyzing the latency performance for event‐driven safety‐related application in VeMAC. As analyzed, the optimization of MAC layer latency depends on minimization of the slot acquisition latency. Then, we derive the mean slot acquisition latency according to the behavior of nodes. There are two typical protocol versions, with the split parameter equals to zero and infinity, respectively. From the analytical model, although the protocol version with split parameter equal to infinity can reduce the merge collision through split slots with in a frame, it prolongs the mean slot acquisition latency since the block‐wised slots placement. Then, we develop an interleaved frame structure that can reduce the mean slot acquisition latency and merge collision simultaneously. The interleaved frame structure can adapt to various vehicular densities through the proposed slots allocation algorithm. The derived theoretical mean latency shows the advantages of the proposed frame structure. At last, we present simulation results to verify the analytical model and show that the proposed scheme can provide desired performance.