Child Guard System: A Cross-Platform Mobile Child Monitoring System Using Global Positioning System Tracking, Geofencing, and Firebase Cloud Messaging

Abstract

This study proposes a child guard system (CGS), a mobile-based solution that supports real-time location monitoring and emergency communication between parents and children. The proposed system adopts a client–server architecture that integrates a global positioning system (GPS), Wi-Fi positioning, RESTful communication, and Firebase Backend-as-a-Service to ensure scalable and reliable data synchronization. Location data collected from the child’s smartphone are transmitted to a cloud-based backend, enabling near-real-time monitoring through a mobile application. The CGS provides several key functionalities, including real-time location tracking, geofencing alerts, emergency notifications, location history, and a built-in chat feature for direct parent–child communication. Unlike many existing solutions that require additional hardware devices, the proposed system operates entirely using smartphones and cloud services, reducing system complexity and deployment cost. Experimental evaluation demonstrated an average GPS positioning accuracy of approximately 5–10 m, a location update latency of 1.25–2.8 s, an average notification delivery time of 1.85 s, and an overall user satisfaction score of 4.7/5, highlighting the effectiveness of the proposed system for child monitoring apps.