Is 30 MHz Enough for C-V2X?

TL;DR

This paper investigates whether a 30 MHz spectrum allocation is sufficient for vehicle-to-everything (V2X) communications, focusing on safety message support and latency requirements amid spectrum reallocation.

Contribution

The study provides an extensive analysis of safety message types, latency needs, and simulation results assessing the adequacy of the reduced 30 MHz spectrum for V2X.

Findings

30 MHz spectrum may be sufficient for certain safety messages

Latency requirements can be met within the 30 MHz band under specific conditions

Spectrum reallocation impacts V2X safety message support

Abstract

Connected vehicles are no longer a futuristic dream coming out of a science fiction, but they are swiftly taking a bigger part of one's everyday life. One of the key technologies actualizing the connected vehicles is vehicle-to-everything communications (V2X). Nonetheless, the United States (U.S.) federal government decided to reallocate the spectrum band that used to be dedicated to V2X uses (namely, the ``5.9 GHz band'') and to leave only 40\% of the original chunk (i.e., 30 MHz of bandwidth) for V2X. It ignited concern of whether the 30-MHz spectrum suffices key V2X safety messages and the respective applications. We lay out an extensive study on the safety message types and their latency requirements. Then, we present our simulation results examining whether they can be supported in the 30-MHz spectrum setup.