Co-Existence of ITS-G5 and C-V2X at an Urban Road Intersection

High mobility, low latency and high throughput requirements in intelligent transport systems (ITS) have paved the way for the development of new wireless communication technologies. Therefore, the 5.9 GHz band has been assigned to ITS applications under two main technologies. Europe's ITS-G5 is one such technology, which is based on IEEE 802.11p. The other alternative technology is 3GPP's cellular vehicle-to-everything (C-V2X). Both of these technologies have their inherent advantages and disadvantages due to dissimilarities in their physical (PHY) and media access control (MAC) layer architectures. Therefore, the applicability of each technology will vary depending on the situation. While previous work has been mainly focused on the comparison of two technologies, in this paper, we investigate the benefit of the co-existence of both of these technologies for a V2I downlink scenario in a road-side unit (RSU) placed at the center of an urban road intersection. We propose an optimization scheme to achieve the best minimum signal-to-interference-plus-noise ratio (SINR) performance for the RSU while providing connectivity to the maximum possible number of vehicles. Our analysis shows that ITS-G5 should be given priority when communicating with larger number of vehicles while C-V2X should be given priority when less number of vehicles are requesting to connect with the RSU.