Study of BSM Inter-Packet Gap Tails in C-V2X Networks

TL;DR

This paper analyzes the tail behavior of inter-packet gaps in C-V2X networks, demonstrating how one-shot transmissions improve reliability and proposing an analytical model validated by high-fidelity simulations.

Contribution

It introduces an analytical model for IPG tail behavior in C-V2X mode 4 and evaluates the impact of one-shot SPS transmissions through detailed simulations.

Findings

Significant reduction in IPG tail distribution with one-shot SPS.

Analytical model accurately characterizes IPG tail behavior.

Simulation results validate the model's asymptotic accuracy.

Abstract

Cellular vehicle-to-everything (C-V2X) enables safety-critical connected vehicular service by exchanging basic safety messages (BSMs) among nearby vehicular users (VUEs). Timely transmission of BSMs is crucial to avoid stale information at VUEs. However, successive packet losses can lead to large inter-packet gaps (IPGs), reducing the BSMs' reliability. This paper investigates the tail behavior of IPG and information age (IA) distributions in C-V2X mode 4, a decentralized resource allocation method based on semi-persistent scheduling (SPS). We study the improvements and trade-offs introduced by SAE one-shot transmission to decrease the number of successive BSM losses at destination VUEs. The study employs high-fidelity system-level simulations that closely follow the SPS process of CV2X mode 4 to evaluate the performance of interleaved one-shot SPS transmissions. The numerical results demonstrate significant improvement in the IPG and IA tail distributions in various simulation scenarios. Additionally, we propose an accurate analytical model to characterize the IPG tail behavior of C-V2X BSM transmissions. The proposed model is validated by comparing its results with those obtained using the system-level simulations. Our validation shows that the proposed model generates analytical results that coincide with the asymptotic slopes of IPG distribution in different BSM transmission modes.