The employment of Low-Power Wide Area Networks (LPWANs) has proven quite beneficial to the advancement of the Internet of Things (IoT) paradigm. The utilization of low power but long range communication links of the LoRaWAN technology promises low energy consumption, while ensuring sufficient throughput. However, due to LoRa’s original scheduling process there is a high chance of packet collisions, compromising the technology’s reliability. In this paper, we propose a new Medium Access Control (MAC) protocol, entitled the FCA-LoRa leveraging fairness and improving collision avoidance in LoRa wide-area networks. The novel scheduling process that is introduced is based on the broadcasting of beacon frames by the network’s gateway in order to synchronize communication with end devices. Our results demonstrate the benefits of FCA-LoRa over an enhanced version of the legacy LoRaWAN employing the ALOHA protocol and an advanced adaptive rate mechanism, in terms of throughput and collision avoidance. Indicatively, in a single gateway scenario with 600 nodes, FCA-LoRa can increase throughput by nearly 50% while in a multiple gateway scenario, throughput reaches an increase of 49% for 500 nodes.

事实证明，低功耗广域网（LPWAN）的使用对物联网（IoT）范式的发展非常有利。LoRaWAN技术的低功耗，远距离通信链路的使用保证了低能耗，同时确保了足够的吞吐量。但是，由于LoRa的原始调度过程，发生数据包冲突的可能性很高，从而损害了该技术的可靠性。在本文中，我们提出了一种新的媒体访问控制（MAC）协议，名为FCA-LoRa，它利用公平性并改善了LoRa广域网中的冲突避免。引入的新颖的调度过程是基于网络网关对信标帧的广播，以便与终端设备同步通信。我们的结果证明，在吞吐量和避免冲突方面，FCA-LoRa优于采用ALOHA协议和高级自适应速率机制的传统LoRaWAN增强版。示意性地，在具有600个节点的单网关方案中，FCA-LoRa可以将吞吐量提高近50％，而在多网关方案中，对于500个节点，吞吐量可以达到49％的增长。