LoRaWAN deployments follow an ad-hoc deployment model that has organically led to overlapping communication networks, sharing the wireless spectrum, and completely unaware of each other. LoRaWAN uses ALOHA-style communication where it is almost impossible to schedule transmission between networks belonging to different owners properly. The inability to schedule overlapping networks will cause inter-network interference, which will increase node-to-gateway message losses and gateway-to-node acknowledgement failures. This problem is likely to get worse as the number of LoRaWAN networks increase. In response to this problem, we propose IRONWAN, a wireless overlay network that shares communication resources without modifications to underlying protocols. It utilises the broadcast nature of radio communication and enables gateway-to-gateway communication to facilitate the search for failed messages and transmit failed acknowledgements already received and cached in overlapping network's gateways. IRONWAN uses two novel algorithms, a Real-time Message Inter-arrival Predictor, to highlight when a server has not received an expected uplink message. The Interference Predictor ensures that extra gateway-to-gateway communication does not negatively impact communication bandwidth. We evaluate IRONWAN on a 1000-node simulator with up to ten gateways and a 10-node testbed with 2-gateways. Results show that IRONWAN can achieve up to 12\% higher packet delivery ratio (PDR) and total messages received per node while increasing the minimum PDR by up to 28\%. These improvements save up to 50\% node's energy. Finally, we demonstrate that IRONWAN has comparable performance to an optimal solution (wired, centralised) but with 2-32 times lower communication costs. IRONWAN also has up to 14\% better PDR when compared to FLIP, a wired-distributed gateway-to-gateway protocol in certain scenarios.

翻译：LORAWAN 部署将遵循一个自动同步部署模式,该模式有机地导致通信网络重叠,共享无线频谱,并且完全互不知情。 LoRAWAN 使用ALOHA 式通信, 几乎无法正确安排属于不同所有者的网络之间的传输。 无法安排重叠网络将引发网络间干扰, 这会增加节点到端的电文丢失和网到节点的识别失败。 这个问题可能会随着LORAWAN网络数量的增加而恶化。 为了应对这一问题, 我们提议 IRONWAN, 一个无线超线超线连接网络, 在不修改基本协议的情况下共享通信资源。 它使用无线电通信的广播性质, 并允许开关到门户的通信便利搜索错误信息, 并传送已经收到并隐藏在重叠的网络网关口中的错误确认。 ICRONWAN 使用两种新算法, 即实时信息到节点快速发送信息, 在服务器没有收到预期的节点信息时, 这一问题可能会变得更糟。 Inference Sillence Sildorning 确保超网到端通信的通信不会对内进行负面通信, 同时提升。