## 3 Overview of IoT System Security Applications in the Industrial Field
Similarly, in [56], the authors introduce geofencing technology to implement a digital boundary around selected geographic locations; this last can be based on several technologies, like the global positioning system (GPS) or radio frequency identification (RFID) [57], enabling the implementation of several strategies, such as zone-based safety alert, equipment safety, emergency response, site-access control, etc. Geofencing technology can improve worker security, area-based alerts, and activity monitoring within the framework of the construction  
Figure 8: The overview of the smart occupational safety monitoring system [53]. industry. Also, [PERSON] et al. developed a helmet as a protective device to improve miners' health management and prevent injuries [58]. The STM32 module uses multiple sensors to continuously analyze, i.e., the environment's temperature, humidity, and toxic gases. It also constantly analyzes the operator's health, including heart rate and vibrations from blasting and excavation. Next, a Bluetooth Low Energy (BLE) module transmits the data to the control center. Their proposed device also has an anti-panic button that alerts the control unit in the event of an emergency for the operator. They also installed a helmet camera to monitor and recognize the operator's gestures; they used the Advanced RISC Machine (ARM) Cortex-M platform and the TensorFlow Lite microframework to execute Python programs. The safety of mine workers is not the only area where the IoT has contributed to numerous innovations; in the construction sector, the IoT has allowed other different solutions to improve the safety of the construction worker. In the literature, there are other studies in which the concept of smart technology has been widely integrated into the design of wearable applications [59]. For workers operating in dangerous environments, smart vests were created to be worn for their greater safety. The vast monitors the environmental and biophysical parameters (heart rate, temperature, etc. ); it is also able to self-power by storing energy from movements (piezoelectric transducers), from the sun, and thermoelectric generators [60]. In the event of an alarm, the information is sent to a cloud database and then consulted via a web app. For this reason, [PERSON] et al. have developed a helmet and smart band by implementing different sensors that monitor the safety and health of workers using heart rate sensors, temperature sensors, accelerometers, and IR sensors to track the vital parameters of the operator [61]. The authors have used mobile phones for communication and data exchange, which quickly send SMSs through the Global System Mobile (GSM) module to inform the assigned personnel about any incidents. The technology also uses an algorithm associated with an accelerometer that allows predicting the fall of the operator. Similarly, the authors in [62] developed a creative plan for an independent system that monitors, locates, and alerts construction site workers in dangerous areas with IoT-based construction vehicles [63]. Their technology combines three techniques, directional antennas, 40 kHz ultrasonic waves, and 868 MHz radio frequency, to locate and identify construction workers precisely. A collection of parts comprises the wearable device's design: a General Packet Radio Service (GPRS) module, an activation sensor, an alert actuator, and a radio transceiver (transmitter/receiver). The wearable gadget has a low-power consumption power-saving strategy that prolongs battery life by keeping it in deep sleep mode until a radio frequency (RF) field is detected. In Figure 9, the architecture chosen by the authors is shown. To monitor the health of construction workers, [PERSON] et al. also realized an IoT-based platform using a smart band ready-to-use wearable [64]. The created platform is intended for builders who work in high temperatures.