Reliable emergency communication in maritime environments remains challenging due to the limited availability of cellular networks and the high cost of satellite services, particularly for small vessels. To address this gap, a low-cost prototype combining Raspberry Pi 4, LoRa (Long Range) wireless technology, and a GPS (Global Positioning System) module was developed to provide an accessible and energy-efficient emergency alerting solution. The system supports both predefined hardware buttons for specific alerts and a voicetriggered mode in which spoken input is transcribed locally and enriched with real-time geolocation before transmission. Messages are sent via LoRaWAN to an Arduino-based receiver, which forwards them to a Telegram channel for immediate distribution and situational awareness. Laboratory evaluation demonstrated stable operation, acknowledgment-based delivery, and consistent end-to-end transmission delays ranging from 1.3 to 1.8 seconds, confirming the feasibility of integrating multimodal inputs, GPS tagging, and cloud-based messaging within a compact and affordable design. The prototype highlights potential use cases for small fishing vessels, coastal monitoring, inland waterways, and other off-grid safety scenarios in which traditional communication infrastructure is unavailable. Overall, the results illustrate how open-source hardware and lightweight IoT technologies can enable reliable, low-cost emergency communication for maritime workers operating in remote, resource-constrained, or high-risk environments.
Keywords
LoRaWANGPSRaspberry PiArduinoEmergency CommunicationMaritime IoTLow-cost IoTSearch and Rescue (SAR)Telegram Integration.
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