# Review of Monitoring and Control Systems Based on Internet of Things
## 4 Discussion
They have a transmission range of up to 50 km in rural areas and 3-10 km in cities, and the devices used for transmission are not too expensive. The disadvantages, however, are low bandwidth of up to 12 bytes per message and transmission mainly in one direction (from the device to the cloud). Yet another LPWAN solution is NB-IoT. Narrowband IoT technology was developed within 3 GPP standards and operates in licensed frequency bands. It uses narrowband radio channels (200 kHz), which allows for high spectral efficiency and high signal penetration inside buildings. The advantages of this solution include long-range and deep penetration through building walls, the ability to support many devices in a small area, and two-way transmission. The disadvantages of this technology are the need to have a license to use the frequency and slightly higher energy consumption than in the case of LoRa or Sigfox. LPWAN is the foundation of modern IoT monitoring systems. It offers reliable, long-distance communication with low power consumption, making it ideal for various monitoring applications. Thanks to its unique properties, LPWAN will play a key role in further developing the IoT and creating more intelligent, effective, and sustainable monitoring systems. Also, based on our findings and thoughts, we identified seven fields of challenges and potential solutions in IoT-based monitoring and control systems. We summarized them in Table 4.  
We also identified possible future research directions in IoT-based monitoring and control systems that can help further develop this technology. Future research should focus on creating and developing new system architectures, including hybrid solutions. Developing more flexible and modular architectures will enable easier scaling and integration of new technologies. Such architectures will allow for the dynamic adaptation of IoT systems to changing conditions and requirements. In turn, introducing hybrid architectures that combine the advantages of cloud computing, edge computing, and fog computing can increase the efficiency and flexibility of IoT systems. The second research direction may concern autonomous IoT systems that can independently monitor, diagnose, and repair their components without human intervention. Such systems can optimize their operations with artificial intelligence and machine learning algorithms. Issues related to autonomous energy and resource management will also be exciting areas for research, as they will allow for the optimization of devices in real time and their adaptation to changing environmental conditions and application requirements. Another direction of research in the case of monitoring and control systems concerns the use of artificial intelligence and machine learning methods. Here, research can focus on advanced analysis of data generated by IoT devices or making autonomous decisions based on real-time data analysis. Additionally, the methods mentioned above can be used to detect and counteract cyber threats in IoT systems (network monitoring, identifying anomalies, and automatically responding to threats). In addition, essential areas of research that combine the IoT and artificial intelligence are smart cities and smart agriculture. Within smart cities, IoT systems are integrated with urban infrastructure, managing traffic, energy consumption, waste management, and other resources in an automated and optimized way. Developing methods designed for this field will undoubtedly contribute to its evolution in various aspects of urban life. A similar situation occurs in the case of agriculture. These monitoring systems dedicated to agriculture (monitoring soil condition, irrigation, plant growth, or animal health) can lead to more precise and efficient agricultural production methods. In the context of the IoT-based monitoring and control systems discussed, it is also necessary to mention the security aspects of these environments related to data, users, or the entire network to which devices are connected.