# A Long-Distance Communication Architecture for Medical Devices Based on LoRaWAN Protocol
## 3 The Proposed Medical Device Architecture Based on LoRaWAN Protocol  
In [23; 28], the authors have proposed a solution for an Internet of m-health things system for remote ECG monitoring. The device allows connection to a central server through the USB, Bluetooth, and GSM interfaces, but this article proposes a new and efficient solution based on LoRa. However, the applicability of the system proposed in [23] can be improved, by integrating the concept into a new perspective of data acquisition and communication such as LoRa technology, which will be the scope of this paper. Nowadays, there are developed and used new efficient technologies having as the main concern the power efficiency and transmission of data at long distances, named LPWANs. This paper improves the device proposed in [23] by integrating the LoRa technology. In this new context, the device integrates into a medical system that uses the LoRaWAN protocol for long-distance data transmission. The general architecture of the hardware-software system used for validation and testing of long-distance communication of medical devices based on LoRaWAN protocol is presented in Figure 1.  
In the proposed architecture (see Figure 1), a device is used with three electrodes that are connected to the Internet through three interfaces: Wi-Fi, Bluetooth, and LoRa (for the first two a smartphone can be used as a gateway). To transmit data on the Internet, the LoRaWAN gateway is used. The data are stored in the Cloud (Server from Figure 1) and can be viewed by the patient, family members, and the doctor via a GUI interface (via HTTP requests or MQTT subscriptions using a smartphone/tablet/mobile device). Basically, the device proposed in this article is an update of the device presented in [23]. Through this update, the device can send data over long distances without having  
Figure 1: The functional architecture of the proposed medical demonstrative experimental device based on Long Range Wide-Area Network (LoRaWAN). an Internet connection or without the use of a smartphone. Instead, a LoRaWAN gateway is needed to transmit the data on the Cloud server and send any alarms that can be generated by the device. The solution of the proposed architecture is the use of the LoRaWAN technology in the medical field for remote monitoring of patients without additional costs given by the Internet connections. The feasibility and performance of the functional architecture of the proposed medical demonstrative experimental device based on LoRaWAN for validation and testing on medical long-distance communication devices (see Figure 1) will have a huge impact, not only for the medical field as presented in this article but also for fields such as aviation, automotive, industrial, academic, monitoring, management, and so on. The proposed device can be integrated into an m-IoT system via LoRaWAN protocol. The stack of LoRa consists of _the application_ that is in the top level of the stack and includes applications, possible cloud services, and databases; the _Medium Access Control_ (_MAC_) layer is the high-level LoRaWAN protocol; and the _LoRa modulation_ that is the physical layer and which is modulated onto the regional ISM bands. Figure 2 presents the architecture of the m-IoT system proposed, and it is organized on four levels such as Thing/Sensing, Edge/Fog Computing, Cloud, and Applications/Services. At the lower level are the devices that can purchase medical parameters at the home's patients without the assistance of qualified personnel. They will send the acquired data to the Fog/Edge computing level via LoRaWAN. At the Fog/Edge computing level, there are LoRaWAN gateways that receive data from the acquisition devices, perform local processing, and then save the data in the Cloud. At the higher-level are the applications/services that can be used by doctors or other dedicated hospital systems to analyze data saved in the Cloud. Based on these analyzes, the decision can be made to call the patient for a consultation with professional medical devices.