An Agile Real-Time Location System (RTLS) for Missing Persons Using IoT Technology

Ana María Zambrano Vizuete, Eduardo Luis Ortiz Mejía, Oscar Marcelo Zambrano Vizuete, Xavier Alexander Calderón Hinojosa


This article presents the QSSC (Quito Smart Safe City), a prototype system for locating and issuing early warnings about missing persons. The city of Quito is used as a case study. QSSC is a system that integrates the community and the agents responsible for monitoring and solving the missing persons problem within a shared collaborative space. The system uses a mobile distributed architecture that allows users to report any disappearances and, if possible, to upload multimedia evidence that helps identify and locate the victims and the circumstances under which the disappearance occurred. It employs IoT communications using the Message Queuing Telemetry Transport (MQTT) protocol to exchange information. Together with various advantages provided by the Amazon Web Services (AWS) cloud, MQTT enables communications in real-time among all participating rescue parties focused on the kidnapping (indispensable given the importance of response time). The RTLS is an opportunistic, light application that minimizes resource consumption on the host mobile device and manages information efficiently. QSSC is based on crowdsensing, which allows it to support decision-making processes that result in quick and effective solutions to events. The viability and operability of the prototype described in this article have been tested against several kidnapping simulations in the city of Quito.


MQTT, Cloud Computing, Smartphone

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