Design and performance analysis of an IEEE 802.15.4 V2P pedestrian protection system

Vulnerable Road User protection systems leveraging V2P (Vehice-to-pedestrian) communications require low-power, low-cost, small size radio communication hardware in order to be suitable for a future mass-market introduction. This paper therefore proposes a Low Power Pedestrian Protection System (LP³S) based on IEEE802.15.4. It is composed of a retrofit warning unit installed in the vehicle and a miniaturized active Tag-solution with very long battery lifetime to be worn by children, bicycle riders or other endangered persons. A lean protocol design allows for a reliable detection of pedestrians within a critical distance. A comprehensive performance evaluation based on detailed, stochastic system simulation demonstrates the high potential as well as the drawbacks of this solution. The performance indicators focus on the reasonability of alarming messages, with the aim to reduce false alarms to a minimum. Therefore, several solutions for optimizing the warning trigger algorithm are proposed including protocol optimization and incorporation of radio-based distance measurements. The most promising system options are validated in a large-scale simulation containing several hundred vehicles and pedestrians in a realistically modeled environment. The results show a high reasonability for alarming messages inside the vehicle and demonstrate the feasibility and reliability of the proposed pedestrian detection system.