Home > Technical Articles > V2X Communication Towards 5G
In the past decade, the automotive industry is evolving toward connected and autonomous vehicles that offer many benefits, such as improved safety, less traffic congestion, less environmental impact, and lower capital expenditure. A key enabler for the evolution is the vehicle-to-everything (V2X) communication, which allows a vehicle to communicate with other vehicles, pedestrians, road-site equipment, and the Internet so that critical information can be shared to improve situation awareness and thus to avoid accidents. The goal of V2X is to guarantee driving safety in 100% no matter it is operated by a driver or navigated by self-driving, while at the same to maximizing convenience and comforts to drivers and passengers inside the vehicle. It is estimated that V2X technology could eliminate or mitigate the severity of up to 80 percent of non-impaired crashes, especially crashes at the intersections or while changing lanes.
Before deep-diving into technology, it is beneficial to clarify the terms used during the evolution of the technology. The emergence of the concepts in-vehicle communications has experienced many stages for many years, from V2V (Vehicle-to-Vehicle), to V2I (Vehicle-to-Infrastructure), V2N (Vehicle to-Network), V2P (Vehicle-to-Pedestrians), and finally to V2X (Vehicle-to-Everything). 802.11p-based V2V, or DSRC-based V2V, is the earliest technology dated back to 2009 that has promoted to use of IEEE 802.11p for V2V communications. As indicated by its name, DSRC, short for Dedicated Short Range Communication, can only work under a comparably limited range: about 300 meters. Though a number of standards and applications have been developed in the automotive industry since its first release, DSRC has its weakness in evolution path and deployment cost. By contrast, Cellular V2X, often referred to as C-V2X, is to compensate for the weakness of the DSRC-based V2V in large deployment, by leveraging the ubiquitous cellular LTE or 5G technologies. 4G-based V2X also called LTE V2X, or Rel14 C-V2X is the first standardized C-V2X communication based on LTE release 14. LTE-V2X is stated to support V2X communication for basic safety use cases. 5G-based V2X, or 5G V2X, NR V2X, is the second phase of the V2X stated in the releases 15, 16, and in the future release that enables advanced use cases for data exchange but will not duplicate 4G-based V2X functionality.
The use cases for V2X communication have also been evolving along with the maturity of the C-V2X technology. TR 22.285 in 3GPP Release 14 has identified up to 27 user cases that are possible in LTE, including V2V Emergency Stop Use Case, Automated Parking System, Wrong-way driving warn ing, V2X Road safety services via infrastructure, Waring to Pedestrian against Pedestrian Collision even when out of line sight (Fig. ).