To Cluster or not to Cluster: A VRU Clustering Based on V2X Communication

Vulnerable Road Users (VRU) clustering in ITS-G5 promises to design a communication environment with high QoS and available bandwidth for V2X nodes to communicate, even in the case of VRU high-density conditions. On the other hand, grouping VRUs might increase the Age of Information (AoI) from a VRU, i.e. the receiver might be warned later of a VRU's presence in the vicinity. This work implemented simulation-based VRU clustering methods based on standardization by ETSI and proposes some improvements. The metrics applied to measure the impact in the wireless network were Channel Busy Ratio, the queuing and latency caused by Decentralized Congestion Control, Packet Error Rate, and VRU's position error. Intending to assess these effects, a high-density crossing traffic scenario has been simulated. In the first approach, VRUs broadcast only individual messages, and in the second approach, VRUs were able to transmit cluster-VAMs as also the cluster operations VAMs. Simulation results not only showed that clustering provides more radio resources for the transmission nodes, i.e. a lower CBR has been observed, but also revealed that the position error minimizes under the cluster scenario, when a motion prediction algorithm is implemented.