## 4 Results
### Examined Works
The LoRa network allowed several months of autonomy with transmission rates near to 100% and very low latency, even with the gateway locked inside a shelter with metallic walls for protection against meteorological conditions. In [76], [PERSON] et al. developed an innovative open CPS to monitor and control human exposure to ionizing radiation tested with a PIN Diode Radiation Sensor (RN53 from Teviso Sensor Technologies) and front-end electronics. Each prototype node realized in a printed circuit board (PCB) has an intelligent component with inherent physical sensing and actuation capabilities in real-time, as well as mature communication resources. The recent IoT and CPS technologies allow interaction with the monitored environment to implement various policies to mitigate radon gas concentration. It has an open architecture that permits integration with several data sources, and easy adaptation of the services as well as the interface area, according to the different users' requirements. The main com-ponents involve various sensor/actuator nodes twinned with a virtual software agent in cyberspace for data transmission into databases and policy negotiation with the service providers. The processing unit is an SBC to handle the sampling process and timestamps. The data are sent to the application server by 4G modem or Wi-Fi network, using a client/server socket application on TCP/IP connection. In the interface area, there's a versatility to adapt various codes of signs, including a specific mobile app for the evaluation of personal risks related to radon exposition. This interface intends to deal with the lack of involvement of the scientific community in achieving appropriate language codes that can support recognizable and effective communication. In [77], [PERSON] et al. carried out a radon gas monitoring campaign based on a case study to obtain real-time radon measurements and display the results on a website, through a novel IoT architecture based on ITU-T Recommendations Y.4113 [78] and Y.4208 [79], lightweight messaging protocol MQTT, and Node-RED for managing data flows. It is noteworthy, a brief survey of the most popular elements that apply to each of the referred components. The proposed IoT system architecture includes the Radon Scout sensor interfaced to a USB port on a Raspberry Pi 3, a lightweight open-source message broker (Mosquito), tools for data flow, a management database, and a web server. The authors emphasize that the system supports any type of sensor and combines different measurements on a map and allows the monitoring of many sensors spread across a territory or city with automated measurements. Radon concentrations are stored on the webserver and the web application can sign up and log in, visualize the data in real-time and the sensor locations, and query the radon measurements stored in the database. In [80], [PERSON] et al. developed an easy to install, simple to use, and secure IoT platform, aimed at small and medium enterprises (SME) for fast and easy product development, recurring to cheap off the shelf hardware, and standardized protocols. The platform provides means for monitoring sensors on the devices as well as for sending com-mands to actuators. The generic implementation includes a Raspberry Pi computer, an Internet connection, and a ready-to-use open-source solution, prepared by the authors to be downloaded into an SD-card. The edge devices communicate via Wi-Fi using the MQTT protocol, and the messages are handled by a Mosquito broker that utilizes OpenSSL for TLS-PSK encryption. The platform was tested and evaluated with sensors and actuators in 2 real-world specific use cases: the first one being a radon sensor from MidDec Scandinavia AB attached to a Raspberry Pi 3 A+ to connect to Wi-Fi and persistently save data to an SD-card. The second case was tested with an actuator that includes a ventilation unit from Air Green Sweden AB with a built-in micro-controller and heat exchange system that can keep the warmth indoors but still exchange stale air for fresh air.