This work deals with the management of sporadic and rare events linked with emergency situations in wireless Internet-of-Things (IoT) scenarios. The goal is to increase the performance of the emergency communication, when low-power wide area networks (LPWANs) are used as IoT backbone. In the proposed approach, a device usually operates as a normal node but, in case of emergency, can use the novel LoRa-REP access method. In this work, the LoRa-REP, based on message replication, is discussed focusing on its capability of reducing average transaction time and increasing success probability. Two operational paradigms have been considered and tested: public LoRaWAN infrastructure with cloud-based backend, and private LoRaWAN networks with local backend (edge/fog computing). Typical examples of public networks are smart cities, whereas local networks are often used in industry or building automation. Additionally, two real use cases (for public and local scenarios) are provided to show the effectiveness of the proposed approach. The experimental results (with a prototype device implementing LoRa-REP and named eNode) show that the success probability of the emergency communication can be increased up to 99.5%, and the average transaction time can be reduced up to 15% with respect to LoRaWAN without retries or up to 50% with respect to LoRaWAN with retries.

中文翻译：

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通过透明的LoRaWAN增强功能实现物联网场景中的紧急通信

这项工作涉及在无线物联网（IoT）场景中与紧急情况相关的偶发事件和罕见事件的管理。当低功率广域网（LPWAN）用作IoT骨干网时，目标是提高紧急通信的性能。在提出的方法中，设备通常作为正常节点运行，但是在紧急情况下可以使用新颖的LoRa-REP访问方法。在这项工作中，讨论了基于消息复制的LoRa-REP，着眼于其减少平均交易时间和增加成功概率的能力。已经考虑并测试了两个操作范例：具有基于云的后端的公共LoRaWAN基础架构，以及具有本地后端（边缘/雾计算）的私有LoRaWAN网络。公共网络的典型示例是智慧城市，而本地网络通常用于工业或楼宇自动化。此外，还提供了两个实际用例（针对公共和本地场景），以展示所提出方法的有效性。实验结果（使用实现LoRa-REP的原型设备并命名为eNode）表明，与不使用LoRaWAN的情况相比，紧急通信的成功概率可以提高到99.5％，平均事务处理时间可以减少15％。重试或相对于LoRaWAN最多重试的50％。