Resilient Multi-hop LoRa Communication System for Post-Disaster Environments

During disasters, conventional communication infrastructure may become unavailable, damaged, or congested, making rescue coordination and emergency response difficult. This project presents a resilient multi-hop LoRa communication system designed to provide an independent, low-power, long-range communication network for post-disaster environments. The proposed system supports emergency messaging, location sharing, rescue coordination, and structural health monitoring (SHM) data transmission using LoRa relay nodes, end nodes, rescue nodes, and a disaster management gateway. The project investigates multi-hop routing strategies for LoRa mesh networks under realistic disaster conditions, including node mobility, random node failures, and varying traffic loads. Reactive routing using Ad hoc On-Demand Distance Vector (AODV), proactive routing using Destination Sequenced Distance Vector (DSDV), and Smart Flooding were implemented and evaluated using OMNeT++/FLoRa simulations. Performance was analyzed using packet delivery ratio, latency, energy consumption, and routing overhead. Based on the simulation results, AODV was selected for physical implementation due to its reliable performance, especially under high-traffic and dynamic network conditions. A physical LoRa prototype network was developed and tested using LoRa hardware to validate multi-hop communication, route recovery, and practical disaster communication functionality. In addition, the system was extended to support SHM data transmission by using MiniSEED compression, fragmentation, acknowledgements, retransmission handling, and security mechanisms. Since raw structural health data is too large for direct LoRa transmission, MiniSEED compression was used to reduce the data size before transmission. A TDD-aware Block ACK ARQ scheme was introduced to improve large-data transfer performance by reducing retransmission overhead compared with Stop-and-Wait ARQ. The results show that multi-hop LoRa networks can provide a practical and reliable alternative communication method during disasters. The developed system demonstrates the feasibility of combining emergency communication, rescue coordination, location sharing, and SHM data transfer within a low-power ad-hoc LoRa network.