## 4 The Architecture of IoT  
The paradigm of the Internet of Things (IoT) connects \"living and non-living things\" through the \"Internet\", referring to the objects as smart objects, which allows them to communicate with each other through Internet technologies. This means the connection of a huge number of end devices that require a clear and consistent architectural design to form a whole operating unit of smart objects. Services and smart solutions brought about by IoT can be utilized in pretty much an industry from energy and automation to financial management and health. In the automotive industry, for instance, an IoT use case might be when clients need the digital experiences of their vehicles. In such a case, the vehicle becomes an integral part of the interconnected web of information, which turns data into actionable insights about the  
Figure 6: The architecture of NB-IoT. The communication of eNodeB with IoT services through EPC interfaces. Figure 7: User plane CIoT EPS 3 GPP LTE protocol stack from the sensor to eNodeB. Communication interfaces from eNodeB to the Internet services. driving experience. Power grids also consist of countless sensors sharing data in real-time to help distribute energy efficiently. Thanks to IoT, it is possible to enable energy consumers, businesses, and service providers to obtain timely information on power consumption. With the emergence of the COVID-19 pandemic in 2020, the need for remote patient monitoring in the healthcare industry to decrease the infection risk has been emphasized. This concept is achievable via IoT in order to improve the treatment outcomes, make the personalization of the treatments possible, and reduce costs. Additionally, wearable sensors that work in ultrasound frequencies enable older citizens to live longer and be self-reliant through the real-time monitoring of their activities and vital signs. Manufacturers can harness the large amounts of data gathered using equipment or from suppliers to gain insights into every link of the production chain, helping them to increase the efficiency and reduce costs. IoT can be used for retail management to create personalized experiences that keep shoppers coming back. The core part of this use case is the process of data gathering and organization. However, as the data grow, analyzing, understanding, and extracting value from the data become more challenging [3]. When it comes to defining the architecture of IoT, it is important to make a distinction between the terms \"machine-to-machine\" connection or M2M and Internet of Things (IoT), as the two are often used interchangeably. The concept of M2M involves independent devices that directly communicate. There is no need for human intervention in such a connection. Depending on the application, the M2M communication form (the used services and topology) may differ. M2M devices may connect through non-IP communication channels (such as a custom-made protocol or port). However, IoT systems can combine M2M end-points by using a Bluetooth mesh over non-IP channels. In this way, the IoT system collects data through a gateway or a router that represents the Internet entries. In IoT systems, the networking layers in a sensor that work on significant calculations are pushed onto the sensor. The method of tying into the Internet fabric is what defines IoT [36]. Keeping the distinction between M2M and IoT in mind, we can say that IoT represents a whole ecosystem that embraces numerous fields of computer science and technology, computing and security, communication, and data analytics.