The Internet of Things (IoT) is a network of physical objects — called 'things' — that are embedded with sensors, software, and connectivity technologies. These objects collect and exchange data with other devices and systems over the internet, often without any direct human intervention.
Examples of IoT devices include smart thermostats, fitness trackers, smart door locks, industrial sensors, and connected vehicles.
| Component | Role |
|---|---|
| 1. Sensors / Devices | Collect data from the physical environment (e.g., temperature, motion, humidity) |
| 2. Connectivity | Transmit collected data to the cloud or processing centre via Wi-Fi, Bluetooth, 4G/5G, etc. |
| 3. Data Processing | Software (often cloud-based) analyses the data and makes decisions or triggers actions |
| 4. User Interface | Presents information to the user or allows them to send commands (e.g., a mobile app) |
Example: A water-leak sensor detects flooding → sends signal to cloud → cloud instructs the actuator → actuator closes the water valve automatically.
IoT networks must support billions of connected devices simultaneously. Two key network properties are therefore critical:
The choice of network topology directly affects scalability and reliability:
| Topology | Scalability | Reliability | Notes |
|---|---|---|---|
| Star | Moderate | Low (single point of failure at hub) | Simple but hub failure brings down the network |
| Mesh | High | High (multiple paths available) | Ideal for large IoT deployments; self-healing |
| Bus | Low | Low | Simple but not suitable for large IoT networks |
For large-scale IoT deployments (e.g., smart cities, industrial IoT), mesh topology is preferred because it eliminates single points of failure and allows the network to reroute data automatically.
Because IoT devices continuously collect and transmit sensitive personal and environmental data, cybersecurity is a critical concern.
| Method | Description |
|---|---|
| Encryption | Converts data into an unreadable format during transmission (e.g., AES, TLS/SSL) so only authorised parties can read it |
| Authentication | Verifies the identity of devices and users before granting access |
| Firewalls | Filter incoming and outgoing network traffic to block unauthorised access |
| Regular Updates | Firmware/software patches fix known security vulnerabilities |
Key Point: Without proper encryption and authentication, an attacker could intercept IoT data or take control of connected devices (e.g., unlocking smart locks, accessing security cameras).
| Domain | Example |
|---|---|
| Smart Home | Smart thermostat, smart lighting, connected security cameras |
| Healthcare | Wearable heart-rate monitors, remote patient monitoring |
| Agriculture | Soil moisture sensors that automatically trigger irrigation |
| Industry (IIoT) | Predictive maintenance sensors on factory machines |
| Smart Cities | Connected traffic lights, smart waste management |