2025/09/26 by Khamaisi, Karim, Kamer, Oliver, Rodrigues, Bruno +2
#Computers and Society (cs.CY) #Cryptography and Security (cs.CR) #Emerging Technologies (cs.ET) #FOS: Computer and information sciences #Networking and Internet Architecture (cs.NI)
paper · doi:10.48550/arxiv.2509.22568
During large-scale crises disrupting cellular and Internet infrastructure, civilians lack reliable methods for communication, aid coordination, and access to trustworthy information. This paper presents a unified emergency communication system integrating a low-power, long-range network with a crisis-oriented smartphone application, enabling decentralized and off-grid civilian communication. Unlike previous solutions separating physical layer resilience from user layer usability, our design merges these aspects into a cohesive crisis-tailored framework. The system is evaluated in two dimensions: communication performance and application functionality. Field experiments in urban Zürich demonstrate that the 868 MHz band, using the LongFast configuration, achieves a communication range of up to 1.2 km with 92% Packet Delivery Ratio, validating network robustness under real-world infrastructure degraded conditions. In parallel, a purpose-built mobile application featuring peer-to-peer messaging, identity verification, and community moderation was evaluated through a requirements-based analysis.