Nowadays, Low-power Wide Area Networks (LPWANs) hold much promise, due to their low-power, low-cost, and low throughput nature. The very long range of LPWA technologies enables devices to spread and move over large geographical areas, thus creating excellent opportunities for new IoT technologies and for Wireless Sensor Networks (WSNs) in general. In this context, LoRa (Long Range) technology represents a highly important example of wireless technology working in high-density networks. LoRa Wide-Area Networks (LoRaWANs) are characterised by low data rate requirements per device, large cells and heterogeneous application domains, which can lead to extremely high numbers of devices coexisting in the same cell. The coexistence of other technologies operating in the same ISM (Industrial Scientific and Medical) band may lead to increased interference. In this paper an overview of interference management in LoRaWANs is performed, encompassing different approaches, methods and algorithms to deal with interference in the ISM band. We focus on the so-called Co-Spreading Factor Interference (CSFI) and Inter-Spreading Factor Interference (ISFI) occurring when the useful and interference signal use the same or different SFs. We aim to show via link-level simulations the impact of coding rate and bandwidth on this imperfect orthogonality-based CSFI and ISFI.

• Viktor Stoynov
• Vladimir Poulkov
• Zlatka Valkova-Jarvis

Proceedings of Advances in Wireless and Optical Communications (RTUWO), Riga, Latvia, November 2018.

https://ieeexplore.ieee.org/document/8587904