Introduction to IoT

The Internet of Things (IoT) refers to a network of interconnected physical objects that can communicate and exchange data with each other over the internet. These objects, embedded with sensors, software, and other technologies, collect and transmit data, enabling intelligent systems to interact with the physical world.

As of recent estimates, the number of IoT devices has far surpassed the global human population. For example, in 2021, there were more than 40 billion IoT devices compared to the world population of around 7.8 billion. This trend is expected to accelerate, with projections suggesting that by 2025, there could be over 80 billion connected devices globally.

Figure 4‑1: IoT devices projection vs Population

The proliferation of IoT devices is driven by advancements in technology and increasing demand for smart solutions in various sectors, including healthcare, manufacturing, transportation, and home automation. As IoT continues to evolve, it is anticipated to bring even more innovative applications and significant improvements in quality of life, efficiency, and productivity.

4.1       History of IoT

The era of the Internet of Things (IoT) is widely recognized to have begun between 2008 and 2009 when the number of devices connected to the Internet surpassed the global human population. This milestone marked the onset of a new age where “things” were more connected than people, heralding a significant technological shift. The term “Internet of Things” was coined in 1999 by Kevin Ashton, who was working at Procter & Gamble at the time. Ashton introduced this phrase to describe the concept of linking the company’s supply chain to the Internet, envisioning a system where objects could communicate and share data autonomously.

Figure 4‑2: Kevin Ashton

Ashton further elaborated that IoT involves adding senses to computers. In the twentieth century, computers were akin to “brains without senses,” processing only the information that humans input through methods like typing and barcodes. However, in the twenty-first century, IoT has revolutionized this paradigm by enabling computers to sense their environment independently. This advancement allows devices to collect, interpret, and act on data without human intervention, fundamentally transforming our interaction with technology.

The transition to IoT represents a major technological shift, creating a tighter integration between the physical world and digital systems. This integration has led to significant improvements in efficiency, accuracy, and automation across various applications, from smart homes to industrial automation and healthcare, highlighting the profound impact of IoT on modern life.

4.2       IoT reference model

The IoT World Forum’s 2014 architectural committee, led by Cisco, IBM, Rockwell Automation, and others, introduced a seven-layer IoT architectural reference model. This model aims to clarify various aspects of IoT architecture, addressing ambiguities by defining specific functions for each layer. Figure 4-2 in their publication illustrates this comprehensive IoT Reference Model, helping to navigate complexities in IoT system design. This IoT architecture proposed to includes the following layers: physical devices and controller layer, connectivity layer, edge computing layer, data accumulation layer, data abstraction layer, application layer, and collaboration and processes layer. Here is a detailed explanation of each layer:

Figure 4‑3: IoT reference Architecture

1. Physical Devices and Controller Layer
2. Function: This layer encompasses physical devices equipped with sensors and actuators, along with controllers that manage these devices.
3. Components:
   1. Sensors and Actuators: Devices that sense and act upon the physical environment.
   1. Controllers: Devices or systems that manage and control the operation of sensors and actuators.
4. Explanation: The physical devices and controller layer forms the foundation of the IoT system, responsible for collecting data from the physical world and initiating actions based on commands from higher layers. Sensors capture environmental data, while actuators perform tasks based on instructions received from controllers.

2. Connectivity Layer

• Function: Facilitates communication between IoT devices, sensors, actuators, and higher layers of the IoT architecture.
• Components:
  • Communication Protocols: MQTT, CoAP, HTTP, Zigbee, Bluetooth, Wi-Fi, cellular networks.
  • Gateways: Devices that enable communication between IoT devices and the network.
• Explanation: The connectivity layer ensures seamless and reliable data transmission across the IoT ecosystem. It supports various communication protocols and employs gateways to bridge different network technologies. This layer enables IoT devices to transmit data to edge computing resources or directly to cloud services for further processing.

3. Edge Computing Layer

• Function: Provides real-time data processing and analysis capabilities close to the data source, reducing latency and bandwidth usage.
• Components:
  • Edge Devices: Microcontrollers, edge servers, gateway devices.
  • Local Storage: Temporary storage for caching data and executing edge analytics.
• Explanation: Edge computing enhances the efficiency of IoT systems by processing data locally, closer to where it is generated. This layer performs tasks such as data filtering, aggregation, and preliminary analysis, enabling faster response times for time-sensitive applications. It also reduces the volume of data that needs to be transmitted to the cloud, optimizing bandwidth usage.

4. Data Accumulation Layer

• Function: Collects, stores, and manages data generated by IoT devices and edge computing resources.
• Components:
  • Databases: SQL, NoSQL databases for storing structured and unstructured data.
  • Data Lakes: Scalable storage systems for storing large volumes of raw data.
• Explanation: The data accumulation layer acts as a centralized repository for IoT data, ensuring it is securely stored and accessible for further analysis. It integrates data from various sources, including edge devices and sensors, and supports scalable storage solutions like data lakes for managing big data. This layer enables historical data analysis and long-term storage of IoT-generated data.

5. Data Abstraction Layer

• Function: Processes raw data into meaningful information and insights for decision-making and application development.
• Components:
  • Data Processing Tools: ETL (Extract, Transform, Load) tools, data integration platforms.
  • Data Models: Structured representations of data for analytics and visualization.
• Explanation: The data abstraction layer transforms raw IoT data into structured formats suitable for analysis and application development. It performs tasks such as data cleansing, normalization, and integration, ensuring data quality and consistency. This layer supports the creation of data models and provides APIs for accessing processed data, enabling advanced analytics, machine learning, and visualization.

6. Application Layer

• Function: Provides interfaces and tools for end-users to interact with IoT systems, visualize data, and control devices.
• Components:
  • User Interfaces: Web applications, mobile apps, dashboards.
  • APIs: Application Programming Interfaces for integrating IoT data and functionality with other systems.
• Explanation: The application layer delivers IoT insights and functionalities to end-users in a user-friendly manner. It enables monitoring and management of IoT devices, visualization of real-time and historical data, and control of connected devices through intuitive interfaces. APIs facilitate integration with third-party applications and services, extending the functionality of IoT systems and supporting custom applications and solutions.

7. Collaboration and Processes Layer

• Function: Orchestrates workflows, manages interactions between IoT components, and supports collaboration among users and systems.
• Components:
  • Workflow Management Systems: Tools for defining, automating, and optimizing IoT workflows.
  • Collaboration Platforms: Communication and collaboration tools for stakeholders and IoT systems.

Explanation: The collaboration and processes layer ensures seamless integration and coordination across different IoT components and processes. It manages workflows, automates tasks, and facilitates communication among stakeholders, enhancing operational efficiency and decision-making. This layer supports real-time collaboration, alerts, notifications, and event-driven actions, enabling adaptive and responsive IoT systems