Coexistence of DSRC and C-V2X communication: modeling a competing scenario

Vehicular communications has steadily grown in the last years playing a key role in the development of road safety applications, assisting users to improve traffic efficiency, or providing infotainment systems. There are two main Radio access technologies (RATs) that support vehicular communications: the Dedicated Short Range Communication (DSRC) and the Cellular vehicle-to-everything (C-V2X) standard. Among its use cases, the C-V2X technology allows communication between users, that is, vehicle-to-vehicle (V2V) communication, but also the vehicle-to-infrastructure (V2I) communication. In our work, we focus on enhancing the quality of the V2I link through V2V communications. We use idle users to boost the signal coming from the Base Station (BS) and therefore to improve the coverage of the overall network. Furthermore, we analyze a scenario where both standards coexist: the cellular users enhance the signal from the BS while DSRC users act as interferes in the relay-assisted link. To model the interference of the DSRC users, we consider both perfect and imperfect Carrier Sense Multiple Access (CSMA). Our scenario is a 2-dimensional (2D) Manhattan grid where BSs, vehicular users, and streets are placed randomly. We provide analytical expressions of the coverage probability for the direct link and the individual parts of the relay-assisted link by leveraging tools from stochastic geometry (SG). We compare the analytical results to Monte Carlo system-level simulations in order to validate our model.