 as mode 3) via control signaling over the Uu interface. The eNB assigns the resources that are used for V2V signaling in a dynamic manner. The goal of the next-generation V2X communication is to enable accident-free cooperative automated driving by efficiently using the available roadways. To achieve this goal, the communication system will need to enable a diverse set of use cases, each with a specific set of requirements. The V2X feature was initially introduced with IEEE 802.11p and sup- ported a limited set of basic safety services. IEEE 802.11 group has initiated a new project called IEEE 802.11bd which is tasked to enhance IEEE 802.11p and develop similar fea- tures as NR V2X, while backward compatible to IEEE 802.11p [28]. 3GPP Rel-14 V2X supported a wider range of applications and services, including low-bandwidth safety Vehicle-to-Everything (V2X) Communications Advanced V2X 3GPP C-V2X Rel-15 and NR-V2X Rel-16 (Self-driving vehicles) Longer range, higher density Very high throughput, very high reliability Wideband ranging and positioning Very low latency Enhanced V2X 3GPP C-V2X Rel-14 Network coverage Long range Multimedia services Basic V2X IEEE 802.11p, DSRC ETSITS V2V,V2P,V2I Safety Figure 7.4 V2X technology evolution [13,14,25]. Table 7.2: High-level comparison of attributes for DSRC, LTE V2X, and NR V2X [13,14]. Features DSRC/IEEE 802.11p Rel-14 LTE C-V2X (5G) (Rel-15/16) C-V2X Out-of-network operation Support for V2V Support for safety-critical uses Support for V2P Support for V21 Limited Support for multimedia services Network coverage support Limited Global economies of scale Regulatory/testing efforts Limited Very high throughput Very high reliability applications and high-bandwidth applications such as infotainment. 3GPP Rel-15 and 16 enable even more V2X services by providing longer range, higher density, very high throughput and reliability, accurate positioning, and ultra-low latency. Fig. 7.4 summarizes these features and shows the evolution of V2X technologies and how IEEE 802.11p, LTE- b