A Scalable VRU Protection System Based on Edge Servers

Various vulnerable road user (VRU) protection systems have been proposed based on the edge server paradigm to take advantage of the reduced latency as well as computational offloading to servers. In most existing studies, the authors presume that each edge server receives data from its associated users and takes care of the collision risks among them. Because of this presumption, the collision risks between users associated with different edge servers can be overlooked until one of the users at risk crosses the boundary of the server. Therefore, users located at or near the boundary of the edge server domain can receive late alerts or, more seriously, miss the alert entirely until a collision occurs. To address this hazardous scenario, we propose a scalable VRU protection system (SVPS) with an edge server cooperation mechanism. SVPS minimizes additional communication and computational overhead while maintaining satisfactory service accuracy even if users are moving. The numeric results demonstrate that SVPS effectively predicts users' risks associated with different edge servers. Furthermore, SVPS is demonstrated to be scalable: The larger the edge server coverage area, the lower the overhead. Therefore, the coverage area should be set as large as possible while still satisfying latency requirements.