Fundamental Study of a Monitoring System for Clinical Settings Using LoRaWAN

We investigated the application of long-range wide area network (LoRaWAN) in medicine and its associated challenges. First, we developed a prototype system that can remotely monitor the environment (temperature, humidity, and illuminance) and pulse rate of patients. This system consists of a gateway and an end node. The gateway receives sensor data from the end node via LoRaWAN communication. The received data are sent from a network server on the cloud to an application server. Users can access the data on the application server via an external line. Through simulation, we investigated whether LoRaWAN communication could be received when the transmission data rate and payload frame value were changed. The reception was good on the same floor of a building, even with obstructions and radio wave diffraction and reflection. Moreover, we evaluated the effective data reception rate while changing the data rate (spreading rate and transmission output) and payload size in LoRaWAN communication between an end node and a gateway. LoRaWAN uses frequency-spreading technology for long-distance transmission; however, increasing the spreading rate makes it impossible to transmit large amounts of data. In contrast, sensor data require only one byte if it is a two-digit integer value; therefore, even if multiple sensor data are sent from a single device, the amount of data is not considerably large. We believe that for low-volume data such as sensor data, highly reliable communication can be achieved by maximizing the spreading factor and improving reception characteristics.