An IoT (Internet of Things) network comprises interconnected IoT nodes, including sensors, actuators, and fog nodes. Each IoT node typically includes several key components: a power supply system, a processing unit (such as microprocessors, microcontrollers, or specialised hardware like digital signal processors), communication units (including radio, Ethernet, or optical interfaces), and additional electronic elements (e.g., sensors, actuators, and cooling mechanisms). These components work in unison to enable the node to collect, process, and transmit data effectively, supporting various IoT applications.
The architecture of a typical IoT network is structured into four main layers: the perception layer, the fog layer, the Internet core network (transport layer), and the cloud data centre (cite fig.). This multi-layered structure allows for scalability, efficiency, and optimised data processing.
IoT network Layer: This foundational layer consists of IoT devices, such as sensors and actuators, responsible for collecting data from their surrounding environment. These devices can range from simple temperature and humidity sensors in smart homes to complex monitoring systems in industrial settings. Depending on their configuration, these devices may perform preliminary data processing to filter or compress data before transmission. For example, motion sensors in a security system might only transmit data when movement is detected, thereby conserving energy and bandwidth. This layer consists primarily of a network of IoT nodes connected directly to each other or an access point, depending on the network topology chosen for the given IoT network deployment scenario. The IoT nodes are connected directly to each other or an access point via low-power wireless communication technologies.
Fog computing Layer: The fog computing layer acts as an intermediary between the IoT devices at the IoT network layer and the cloud. It provides localised, lightweight processing capabilities that help reduce latency and bandwidth usage. The fog layer can handle real-time data analysis, decision-making, and local storage tasks by processing data closer to the source. This is particularly useful in applications requiring immediate responses, such as autonomous vehicles, healthcare monitoring, and smart manufacturing systems. Fog computing enhances the network's overall performance and reduces the burden on centralised cloud resources.
Transport Layer (Internet Core Network): This layer transmits data between the perception and fog layers and the cloud data centre. It is the backbone of IoT communication, leveraging various networking technologies such as wireless networks (e.g., Wi-Fi, LTE, 5G), wired connections (e.g., Ethernet), and even optical networks for high-speed data transfer. The transport layer ensures reliable and secure data flow, using protocols that safeguard data integrity and reduce transmission errors. This layer's efficiency directly impacts the overall responsiveness and performance of the IoT network.
Cloud Data Center layer: The cloud data centre layer represents the centralised processing hub where advanced data analytics, complex computation, and long-term data storage occur. It can handle vast amounts of data from IoT devices across the network. The cloud layer employs powerful data analytics tools, machine learning algorithms, and big data technologies to extract insights and generate actionable outcomes. For instance, data collected from smart grids can be analysed to optimise energy distribution, while data from medical sensors can support remote patient monitoring and predictive healthcare interventions. The processed information is returned to users or devices to facilitate informed decision-making or automated physical responses (control of physical systems).
In an IoT network, the seamless integration of these layers enables efficient data collection, processing, and transmission. This layered approach supports diverse applications, from smart homes with automated climate control and security systems to large-scale industrial automation, smart cities, and agricultural monitoring. The robust structure of IoT networks allows for scalable solutions that can adapt to the needs of various industries, enhancing productivity, efficiency, and quality of life.
Details on networks are presented in the following chapters: