Is 30 MHz Enough for C-V2X?

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 present a comprehensive investigation into various safety message types and their corresponding latency requirements. Our study encompasses an extensive study of Packet Delivery Rates (PDR) and latency across varying vehicular densities and quantities of Road Side Units (RSUs). Furthermore, we provide simulation outcomes that scrutinize the feasibility of accommodating these rates within the 30-MHz spectrum configuration.