Connected Vehicle Communication

Connected vehicle communication serves as the technical backbone for Internet of Vehicles (IoV) functionality, enabling vehicles to exchange real-time data with their surrounding environment and the cloud via wireless communication technologies. By overcoming the sensing constraints of onboard vehicle sensors, this communication infrastructure forms a core foundation for intelligent connected vehicles and autonomous driving.

💡 Two Mainstream Technological Approaches: DSRC and C-V2X

Globally, connected vehicle communication has largely developed along two distinct technical paths, with C-V2X emerging as the prevailing standard:

• Dedicated Short-Range Communications (DSRC): An earlier, more mature technology based on the IEEE 802.11p standard, DSRC is primarily designed for direct, short-range communication between vehicles (V2V) and roadside infrastructure (V2I). While it benefits from a longer track record of technical maturity, its coverage and bandwidth remain relatively limited, making it inadequate to meet the demands of advanced autonomous driving.

• Cellular Vehicle-to-Everything (C-V2X): Developed on cellular mobile network architecture, this solution has become the prioritized development pathway globally and in China. Its primary strength lies in its dual-mode communication capability, where both modes complement each other seamlessly.

⚙️ Core Operating Principles: Dual Communication Modes

The technical edge of C-V2X lies in its integration of two complementary communication methods:

1. Direct Communication: Operating via the PC5 interface, this mode enables direct communication across Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), and Vehicle-to-Pedestrian (V2P) links. Operating independently of cellular base stations, it ensures critical safety data (such as emergency braking alerts) is transmitted with ultra-low latency (typically within milliseconds), even in areas without cellular coverage.

2. Network-Based Communication: Utilizing the Uu interface, vehicles connect directly to 4G/5G cellular networks for Vehicle-to-Network (V2N) communication. This mode caters to high-bandwidth, wide-area coverage demands, such as real-time traffic updates, high-definition map downloads, over-the-air (OTA) software updates, and in-car infotainment services.

In terms of technological progression, C-V2X has evolved from 4G-based LTE-V2X to 5G New Radio-based NR-V2X, delivering higher data throughput, lower latency, and enhanced reliability required for high-level autonomous driving systems.

📡 Key Application Scenarios

This robust communication framework supports a broad spectrum of connected vehicle applications:

• Enhancing Driving Safety: It delivers Forward Collision Warnings via V2V and protects vulnerable road users via V2P in scenarios where pedestrians suddenly step out from blind spots. These safety features demand ultra-low latency, typically requiring response times within 100 ms or as fast as 20 ms.

• Optimising Traffic Efficiency: Interfacing with smart traffic light systems via V2I enables Green Light Optimal Speed Advisory (GLOSA), helping reduce junction wait times by around 30%, while V2N delivers comprehensive traffic conditions for dynamic route optimisation.

• Supporting Autonomous Driving: It equips autonomous vehicles with beyond-line-of-sight sensing capabilities, allowing them to detect hidden hazards around blind corners or obstructed views, combining cloud and roadside infrastructure data to make safer driving decisions.