On Spatial Diversity for LoRaWAN: Experimental Evaluation of Performance of a Dual-Gateway Network With and Without Downlink

The Low Power Wide Area Networks (LPWANs) is today seen as one of the key connectivity enablers for the massive Internet-of-Things (IoT) applications. In this paper, we experimentally study the performance of a LoRaWAN network composed of multiple end devices and two independently operating gateways (GW) for the case of uplink-only and uplink- downlink traffic. Our results demonstrate that even though the spatial diversity due to the use of multiple GWs improves the performance of the network for the packet error rate, it still does not guarantee low packet loss under heavy uplink network traffic. Nonetheless, when the downlink traffic is present, a second GW operating in the uplink-only mode can dramatically increase the uplink packets delivery rate in the network. Therefore, we consider that spatial decoupling of receiver and transmitters, or addition of uplink-only GWs may become an efficient way to improve the performance of LoRaWAN networks with downlink traffic. Even though the limited laboratory environment might have affected the results of our measurements, we expect that many of the observed trends will also stand for the real-life LoRaWAN deployments. For this reason, the presented results might be interesting both for analysts and practitioners working in the field.