Maritime monitoring through LoRaWAN: Resilient decentralised mesh networks for enhanced data transmission

Resilient communication networks from ocean-deployed buoys are crucial for maritime applications. However, wireless data transmission in these environments faces significant challenges due to limited buoy battery capacity, harsh weather conditions, and potential interference from maritime vessels. LoRaWAN technology, known for its low power consumption and long-range communication capabilities, presents a promising solution. Nevertheless, the standard LoRaWAN framework lacks native support for multi-hop routing, which is essential for enhancing network efficiency by relaying data between buoys. This paper introduces two novel multi-hop routing protocols designed for resilient LoRaWAN mesh networks in maritime environments. The first, Opportunistic Smart Routing over a Decentralised LoRaWAN Mesh (OSR-DLM), employs a cross-layer design with a hybrid routing strategy and balanced metric selection. The second, Beacon-Forwarding LoRaWAN with Channel-Aware Path Selection (BF-LoRaCAPS), maintains continuous device awareness using a scheduling mechanism and integrates the OSR-DLM strategy for further optimisation. We evaluate these protocols through extensive simulations that model the detrimental effects of severe weather on data transmission, validated by analysing varied parameter settings in massive Maritime of Things (MoT) scenarios. Key performance metrics, including packet delivery ratio, end-to-end latency, throughput, and traffic intensity for each hop-ratio, are analysed. The results show the superiority of both OSR-DLM and BF-LoRaCAPS over conventional Geographic Routing Protocol (GRP) variants under realistic marine channel conditions. Notably, BF-LoRaCAPS exhibits superior network coverage and resilience, outperforming both OSR-DLM and GRP variants, albeit with slightly increased latency.