ATOMIC: Adaptive Transmission Power and Message Interval Control for C-V2X Mode 4

Abstract

To support the emerging vehicle-to-everything (V2X) communication for autonomous vehicles and smart transportation services, 3rd Generation Partnership Project (3GPP) has recently introduced cellular V2X (C-V2X) standards. In C-V2X, radio resources can be managed not only centrally by the cellular network base station, but also in a completely distributed manner (Mode 4) without any cellular support. However, Mode 4 may suffer significant collisions and interference in a dense environment since each vehicle selects its own resources to transmit V2X messages autonomously without adapting appropriately to vehicle density. To address this challenge, we propose ATOMIC, an Adaptive Transmission pOwer and Message Interval Control scheme for C-V2X Mode 4, in which each vehicle utilizes real-time channel sensing and neighbor information to reduce channel contention for improved reliability and latency. Through analysis and extensive simulations, we show that ATOMIC outperforms the standard Mode 4 in both urban and highway scenarios especially in highly dense environments.

Keywords

• Vehicle-to-vehicle (V2V) communication
• vehicle-to-everything (V2X)
• cellular V2X (C-V2X) mode 4
• TX power adaptation
• rate control