Kim Seungku, Lee Heonkook, Jeon Sungho
School of Electronics Engineering, Chungbuk National University, Cheongju 28644, Korea.
ESS R&D Center, LG Chem Ltd., Daejeon 34122, Korea.
Sensors (Basel). 2020 Feb 13;20(4):1008. doi: 10.3390/s20041008.
When the low power wide area network (LPWAN) was developed for the internet of things (IoT), it attracted significant attention. LoRa, which is one of the LPWAN technologies, provides low-power and long-range wireless communication using a frequency band under 1 GHz. A long-range wide area network (LoRaWAN) provides a simple star topology network that is not scalable; it supports multi-data rates by adjusting the spreading factor, code rate, and bandwidth. This paper proposes an adaptive spreading factor selection scheme for corresponding spreading factors (SFs) between a transmitter and receiver. The scheme enables the maximum throughput and minimum network cost, using cheap single channel LoRa modules. It provides iterative SF inspection and an SF selection algorithm that allows each link to communicate at independent data rates. We implemented a multi-hop LoRa network and evaluated the performance of experiments in various network topologies. The adaptive spreading factor selection (ASFS) scheme showed outstanding end-to-end throughput, peaking at three times the performance of standalone modems. We expect the ASFS scheme will be a suitable technology for applications requiring high throughput on a multi-hop network.
当低功耗广域网（LPWAN）被开发用于物联网（IoT）时，它引起了广泛关注。LoRa作为LPWAN技术之一，利用1GHz以下频段提供低功耗、远距离的无线通信。远距离广域网（LoRaWAN）提供一种简单的星型拓扑网络，该网络不可扩展；它通过调整扩频因子、编码率和带宽来支持多数据速率。本文提出了一种针对发射机和接收机之间相应扩频因子（SF）的自适应扩频因子选择方案。该方案使用廉价的单通道LoRa模块，实现了最大吞吐量和最小网络成本。它提供了迭代SF检查和SF选择算法，允许每个链路以独立的数据速率进行通信。我们实现了一个多跳LoRa网络，并在各种网络拓扑中评估了实验性能。自适应扩频因子选择（ASFS）方案显示出出色的端到端吞吐量，性能峰值达到独立调制解调器的三倍。我们预计ASFS方案将成为多跳网络上需要高吞吐量的应用的合适技术。
