Performance Analysis of Sensing-Based Semi-Persistent Scheduling in C-V2X Networks

TL;DR

This paper introduces an open-source ns-3 simulator for C-V2X Mode 4, analyzing how resource configuration and SPS parameters affect scheduling performance in vehicular networks, highlighting the importance of proper parameter tuning.

Contribution

It presents the first open-source C-V2X simulator and provides insights into how SPS parameter settings impact performance in congested environments.

Findings

Resource reservation interval greatly affects packet data rate.

Resource reselection probability has minimal impact in dense scenarios.

Proper scheduling parameter configuration can significantly enhance performance.

Abstract

The 3rd Generation Partnership Project released the cellular vehicular-to-everything (C-V2X) specifications as part of the LTE framework in Release 14. C-V2X is the alternative to dedicated short range communications and both are specifically designed for V2X control signaling. C-V2X extends the device-to-device specifications by adding two more modes of operation targeting the vehicular environment in coverage and out of coverage of LTE base stations. Vehicle-to-vehicle communications (V2V) is established with Mode 4, where the devices schedule their transmissions in a distributed way employing sensing-based semi-persistent scheduling (SPS). Research is needed to assess the performance of SPS, especially in congested radio environments. This paper presents the first open-source C-V2X simulator that enables such research. The simulator is implemented in ns-3. We analyze the effect of the Mode 4 resource pool configuration and some of the key SPS parameters on the scheduling performance and find that the resource reservation interval significantly influences packet data rate performance, whereas resource reselection probability has little effect in dense vehicular highway scenarios. Our results show that proper configuration of scheduling parameters can significantly improve performance. We conclude that research on congestion control mechanisms is needed to further enhance the SPS performance for many practical use cases.