On the Interference between LoRa and Bluetooth in the 2.4 GHz Unlicensed Band
Ladislav Polák, Filip Paul, Marek Šimka, Radim Zedka, Jan Kufa, Roman Šotner
Abstract
Long-Range (LoRa) is one of the most employed technologies in the Low Power Wide Area Networks (LPWANs), primarily developed for sub-1 GHz radio frequency (RF) band. Nowadays, mainly thanks to hardware support from company Semtech, LoRa-based wireless links can be also realized in the 2.4 GHz unlicensed band. However, this RF band is dominantly utilized by other systems (e.g. Wi-Fi and Bluetooth). Thereby, issues with coexistence between them and LoRa can arise. This paper investigates the influence of Bluetooth (as an interfere) on the LoRa-based 2.4 GHz wireless link at co-channel and in-band coexistence scenarios. A laboratory-based measurement setup is created to measure the immunity of LoRa against Bluetooth in terms of protection ratio (PR). The evaluated results show high robustness of LoRa in the studied scenarios, but this robustness is highly depending on the used LoRa system configuration.