Vehicle-to-Pedestrian (V2P) Communication

Vehicle-to-Pedestrian (V2P) communication serves as a vital component within the broader Vehicle-to-Everything (V2X) ecosystem. Utilising wireless communication technology, it facilitates real-time data exchange between vehicles and pedestrians (particularly those carrying smart devices such as smartphones), aimed at providing proactive safety alerts for vulnerable road users (VRUs) to effectively mitigate collision risks.

Working Principle: How the "Human-Vehicle Dialogue" Works

Unlike conventional driver-assist sensors (such as cameras and radar), V2P communication does not rely on direct line of sight, instead conducting this "dialogue" via wireless signals. When both the vehicle and the pedestrian carry V2P-enabled devices, critical data such as real-time position, speed, and direction of travel can be seamlessly exchanged.

Its typical operational workflow is as follows:

1. Real-Time Positioning and Broadcasting: The vehicle via its onboard system and the pedestrian via a smartphone app determine their precise coordinates utilising positioning technologies like GPS.

2. Short-Range Communication: Both parties broadcast and receive low-latency data packets over dedicated frequency bands, such as 5.9 GHz, utilising technologies such as Dedicated Short-Range Communications (DSRC) or Cellular Vehicle-to-Everything (C-V2X).

3. Collision Risk Assessment: The system continuously computes the trajectory paths of both the vehicle and pedestrian. Should a collision risk be detected within a critical timeframe (such as within a few seconds), simultaneous alerts are issued to the driver (via the instrument cluster or head-up display) and the pedestrian (via smartphone screen pop-ups, haptic vibrations, or audible warnings).

Key Technical Requirements

V2P communication is governed by stringent technical standards to guarantee immediate alert delivery during critical split-second scenarios:

• Ultra-Low Latency: Standard V2P communication mandates an end-to-end latency of under 100 milliseconds, while critical pre-collision sensing scenarios require latency compressed to just 20 milliseconds.

• High Reliability: Data transmission must deliver exceptional reliability without depending on application-layer message retransmissions, ensuring time-critical safety packets arrive without fail.

• Universal Compatibility: Factoring in the wide diversity of pedestrian devices (smartphones across various makes and models) and resource constraints (such as battery life), the communication network must offer robust compatibility and power-efficient management.

Core Value and Practical Applications

The primary value of V2P technology lies in bridging the sensory limitations of conventional onboard sensors, highlighted across two major aspects:

1. Eliminating Visual Blind Spots: It enables vehicles to "detect" pedestrians obscured behind other vehicles, roadside infrastructure, or blind corners, effectively mitigating sudden hazards such as blind-spot dash-outs.

2. Bidirectional Warnings: The alert mechanism works two-ways—not only alerting the driver, but also directly warning distracted pedestrians (such as those wearing earphones or looking down at their phones) of impending danger via smartphone apps and connected devices.

Real-world deployment data further substantiates its safety efficacy. For instance, a pilot V2X deployment in Tampa, Florida, successfully prevented 24 pedestrian collisions, whilst a smart-intersection project in Texas enhanced the perceived safety of pedestrians and cyclists by up to 88% through C-V2X technology.