Introduction

Abstract

Next generation of vehicle safety applications will hinge on connectivity. It is also widely accepted notion that connectivity will be key enabling technology for autonomous driving. That connectivity may include Vehicle to Vehicle (V2V), Vehicle to Infrastructure (V2I), and Vehicle to Pedestrian (V2P) communications. One of the questions is “what technology will prevail?” Lower layers of Dedicated Short Range Communication (DSRC) are defined in IEEE 802.11. The automotive industry, academia, and government have been evaluating DSRC since late 1990s. On the other side, recently the cellular industry has taken an interest in developing standards for vehicular usage. DSRC is based on relatively old physical layer protocol. But, it has been tested and proven to meet requirements for the vast majority of the cooperative safety applications in term of range and latency. The newer 5G cellular approach is not thoroughly tested for cooperative vehicle safety. It does offer potentially better communication performance and a path for system upgradeability. Whichever technology prevails, safety communication requirements will remain unchanged: high availability and low latency. Vehicle to everything (V2X) communications needs to accommodate fast-moving vehicles. Vehicles in various traffic situations need to communicate with low latency. End to end latency should be in the order of 100 ms. It is necessary for V2X communications to be highly available. In other words, V2X is not to compete with other crowded communications networks such as WiFi and cellular networks.