Internet of Things (IoT)
The Internet of Things (IoT) is a network of physical devices that use sensors, software, and communication technologies to collect data, exchange information, and, when necessary, interact with the physical world. These devices include sensors, household appliances, industrial machines, medical equipment, vehicles, and many other systems.
The basic idea behind IoT is that devices can collect information about their surroundings, exchange it with other devices or computer systems, and use the resulting data to monitor processes, automate tasks, and support decision-making.
How Does the Internet of Things Work?
In an IoT system, devices collect information, exchange it through an appropriate network, and use the resulting data for monitoring or controlling processes. Depending on the application, data can be processed directly on the device, by a local computer or network gateway, or on remote server infrastructure.
For example, a temperature sensor can measure the temperature of a room. A microcontroller processes the measured value, compares it with the target temperature, and switches on an air conditioner when necessary. If the system is connected to a network, the user can monitor the temperature and control the device through an app.
A typical workflow consists of the following steps:
- Data collection: sensors measure physical quantities or detect events.
- Data processing: a microcontroller or another computer processes the data and applies a control algorithm.
- Communication: data is sent, when necessary, to other devices, a local computer, or a remote server.
- Decision-making: the system determines whether an action should be performed or the user should be notified.
- Action: an actuator executes the command, for example by starting a motor, opening a valve, or switching on a heating system.
These steps do not always take place in a single location or in a strictly sequential order. Some systems respond locally while simultaneously sending data to a remote server for storage, analysis, or presentation to the user.
Main Components of an IoT System
The Internet of Things is more than a collection of devices connected to the Internet. To perform a particular function, a system must integrate sensors, a control unit, communication, software, and, when necessary, actuators.
1. Sensors
Sensors measure physical quantities or detect changes in the surrounding environment. They convert a measured quantity into a signal that an electronic system can process.
Examples of sensors include:
- temperature sensors;
- pressure sensors;
- air or soil moisture sensors;
- light sensors;
- motion and distance sensors;
- acceleration and angular velocity sensors;
- flow and liquid-level sensors.
2. Control Unit
The control unit processes sensor data and executes the program that determines the system's behavior. It can be a microcontroller, an embedded computer, or another computing system.
A microcontroller is particularly suitable for small embedded systems because it combines a processor, memory, and peripheral interfaces needed to control devices on a single chip.
Arduino and ESP32 are examples of development platforms used to build IoT projects. Their capabilities depend on the particular model: some microcontrollers have built-in wireless communication, while others require an additional communication module.
3. Communication Module and Network
A communication module allows a device to exchange data with other devices or systems. The connection can be wireless or wired, depending on the requirements of the project.
Devices can communicate directly, through a router or a network gateway, or through another intermediary unit that connects different networks.
Every device does not need its own public IP address. Some devices use local network addresses or communicate through an intermediary device. What matters is that the system provides a way to identify devices and exchange data.
4. Software and Data Processing
Software processes measured values, checks conditions, and determines how the system should behave. Depending on the application, data can be processed directly on a microcontroller, by a local computer, or on a remote server.
More complex systems may use databases, analytical software, and, when appropriate, artificial intelligence algorithms. Artificial intelligence is not a mandatory part of every IoT system: a simple control algorithm is often sufficient.
5. Actuators
Actuators convert control signals into physical actions. They allow a system not only to observe its environment but also to affect it.
Examples of actuators include:
- electric motors and servo motors;
- relays used to switch electrical devices on and off;
- solenoid valves and solenoids;
- heaters and cooling devices;
- mechanisms for opening doors or moving mechanical parts.
6. User Interface
Users can monitor the system and change its settings through a mobile phone, tablet, desktop computer, or dedicated control panel. The interface may display current measurements, historical data, alerts, and the status of connected devices.
Smart Devices and Control Algorithms
When we describe a device as "smart", it generally means that the device contains an electronic control unit and software that enable it to respond automatically to certain conditions or user commands.
A control algorithm is a set of rules or procedures used by a system to process input data and determine the appropriate output commands.
For example, a temperature control system can compare the temperature measured by a sensor with the target temperature. If a room is too cold, the system switches on the heating. When the desired temperature is reached, it switches the heating off or reduces its output.
Such a system can operate without an Internet connection. Connecting it to an IoT network adds further capabilities, such as remote adjustment, monitoring through an app, and access to historical measurements.
Applications of the Internet of Things
Smart Homes
In a smart home, sensors and control devices can monitor temperature, lighting, the presence of people, door openings, and electricity consumption. Based on this information, the system can automatically regulate heating, switch on lights, send alerts, or allow users to control devices remotely.
For example, a motion sensor can detect someone entering a room and activate the lighting. A smart thermostat can adjust the heating according to a target temperature and a schedule defined by the user.
The Internet of Things in Healthcare
In healthcare, connected devices can collect and transmit patient data, enable remote monitoring, and help medical staff access important information more quickly. Reliability, data protection, and appropriate medical supervision are especially important in these systems.
Consider the following example. Mira is a nurse working in an emergency medical service. After an emergency call, the team at the scene uses medical equipment to measure important patient parameters. If the equipment and information systems support connectivity, selected data can be transmitted to the hospital during transport.
Hospital staff can then receive information needed to prepare equipment and organize the patient's arrival. Software can display changes in measurements and alert staff when values exceed predefined limits. Decisions about diagnosis and treatment remain the responsibility of qualified healthcare professionals.
The Internet of Things in Automotive Engineering
Modern motor vehicles contain numerous sensors, electronic control units, and actuators. Sensors can measure temperature, intake manifold pressure, engine speed, throttle position, and other quantities relevant to vehicle operation.
The measured data is sent to the engine electronic control unit (ECU), which processes the information and sends appropriate control signals. Depending on the system, these commands control fuel injectors, relays, solenoid valves, and other actuators.
The objective is to achieve appropriate engine operating conditions, efficient combustion, favorable fuel consumption, and stable operation. This is an example of an embedded control system, also known as a mechatronic system.
However, engine control using sensors and an ECU does not by itself mean that the vehicle is connected to the Internet. When a vehicle exchanges data with a remote service, an app, or external infrastructure—for example, for remote diagnostics or fleet monitoring—it becomes part of a broader IoT system.
Industry and Manufacturing
In industrial facilities, sensors can measure temperature, pressure, vibration, and other machine parameters. The data can be used to monitor equipment condition, detect unusual behavior, and plan maintenance.
For example, increased vibration in a bearing may indicate the development of a fault. The system can alert an operator and store measurements for later analysis. This makes it possible to schedule maintenance before a more serious breakdown occurs.
Smart Cities and Traffic
Connected sensors can monitor traffic, parking availability, street lighting, and air quality. Processing this information helps manage urban systems and provide useful information to citizens.
A navigation system can use available traffic data to suggest an alternative route. Such a service may combine information from multiple sources rather than relying only on sensors in a single vehicle.
Main Characteristics of IoT Systems
Connectivity and Data Exchange
Connectivity allows devices to exchange information with other devices and computer systems. Depending on the project, communication may take place over a local network, the Internet, or a network gateway.
Automation
A system can perform repetitive actions without requiring constant user intervention. For example, an automatic irrigation system can switch on a pump when soil moisture falls below a predefined threshold.
Data Collection and Analysis
Data collected over time can reveal patterns, help plan maintenance, or improve system performance. Large amounts of data are often processed using databases and analytical tools, but not every device requires complex analysis or artificial intelligence.
Remote Monitoring and Control
If a system has a suitable network connection and an application, users can check device status remotely, change settings, or receive notifications. Available functions depend on the system's design and connectivity.
Small and Energy-Efficient Devices
Many IoT devices use small microcontrollers and sensors designed for a specific purpose. For battery-powered devices, low power consumption, efficient communication, and the ability to enter a low-power mode when active operation is unnecessary are particularly important.
Artificial Intelligence as an Additional Capability
Artificial intelligence can be used when a system needs to recognize complex patterns or make predictions based on large amounts of data. For example, it can help predict failures in industrial machinery or analyze energy consumption. However, simple IoT systems often operate using predefined rules without artificial intelligence.
IoT Hardware
A specific IoT implementation may contain sensors, a microcontroller or embedded computer, a communication module, a power supply, and an actuator. More complex systems may also use gateways, servers, and dedicated monitoring or control equipment.
Standard Devices as a Control Center
Desktop computers, tablets, and mobile phones often serve as user interfaces for monitoring and controlling IoT systems. They can display current measurements, historical data, the status of connected devices, and notifications.
These devices are not necessarily part of the direct control loop. A device may continue operating according to its local algorithm even when the user is not using the app, provided the system has been designed for that mode of operation.
Communication Technologies and Protocols
IoT uses a variety of technologies to connect devices. The choice depends on range, data volume, power consumption, connection reliability, cost, and security requirements. No single technology is best for every application.
Wi-Fi and Ethernet
Wi-Fi provides wireless connectivity within a local network and is often used when higher data rates and a direct connection to a home or business network are required.
Ethernet provides a wired network connection. It is used when connection stability and reliable data transmission are important, for example in industrial equipment and stationary devices.
Bluetooth Low Energy (BLE)
Bluetooth Low Energy is designed for communication with low power consumption. It is suitable for devices that exchange relatively small amounts of data, such as certain sensors, wearable devices, and accessories that communicate with a mobile phone.
Zigbee
Zigbee is a wireless technology that supports communication in low-power networks, including networks in which devices can relay data to one another. It is used, among other applications, in building automation and smart homes.
Thread and Matter
Thread is an IP-based, low-power wireless networking technology designed to connect devices in a mesh network. Such a network allows devices to relay data between one another and extend coverage.
Matter is an interoperability standard for smart home devices. It defines how compatible devices and systems exchange commands and information, while the underlying network communication can use supported technologies such as Wi-Fi and Thread.
Z-Wave
Z-Wave is a wireless technology used in home automation, for example to control lighting, sensors, and smart locks. As with other technologies, its actual capabilities depend on the devices, network configuration, and supported standards.
RFID and NFC
RFID (Radio-Frequency Identification) is a technology used to identify objects through radio-frequency communication. An RFID system typically consists of a tag and a reader, which uses radio waves to read identification data from the tag.
NFC (Near Field Communication) enables communication over a very short distance. It is used, for example, for contactless tag reading and data exchange between compatible devices.
RFID and NFC can be part of a broader IoT solution, but they do not, by themselves, mean that a tag or device has a direct Internet connection. The data is usually read by a compatible reader, which can then forward it to another system.
Cellular Networks: LTE, LTE-A, LTE-M, NB-IoT, 4G, and 5G
Cellular networks allow devices to connect when they are away from a local network, including devices installed in vehicles, in the field, or at remote measurement sites.
LTE and LTE Advanced (LTE-A) are part of the evolution of mobile broadband networks. LTE-M and NB-IoT are designed for different types of low-power device communication, while 4G and 5G networks support a wide range of mobile applications. The appropriate choice depends on system requirements, network coverage, and the services available from the network operator.
Wi-Fi Direct
Wi-Fi Direct allows compatible devices to connect directly without using a conventional wireless access point. It can be useful when devices need to exchange data directly, but it is not a mandatory component of every IoT system.
Protocols for Data Exchange
In addition to the technology used to connect devices, communication protocols define the format and method used by applications and devices to exchange messages.
- HTTP/HTTPS: commonly used for communication between devices, web services, and applications. HTTPS provides an encrypted connection using TLS.
- MQTT: a lightweight messaging protocol based on the publish/subscribe model. It is often used when multiple devices exchange telemetry through an intermediary server known as a broker.
- CoAP: a protocol designed for communication involving constrained devices and networks, with a lower communication overhead than some conventional web approaches.
It is important to distinguish communication technologies from messaging protocols. For example, Wi-Fi defines how devices connect wirelessly to a network, while MQTT defines how applications exchange messages. An IoT system can use several technologies and protocols at the same time.
Cloud Computing and On-Device Data Processing
IoT systems with many devices can generate large amounts of data. Remote servers and cloud platforms can be used to store this data, analyze it, present information to users, and manage large numbers of devices.
However, cloud computing is not essential for every IoT system. A simple device can process data locally and respond immediately without sending information to a remote server.
Edge computing refers to processing data on the device itself or close to its source. This can reduce latency, limit the amount of data sent over the network, and reduce dependence on a continuous connection to a remote server. In practice, local processing and cloud computing are often used together.
Benefits and Challenges of IoT Systems
Benefits
- Automation: repetitive tasks can be performed without constant user intervention.
- Remote monitoring: device status can be checked from another location.
- Faster response: alerts can be generated when an unusual value or event is detected.
- Improved analysis: data collected over time can help identify patterns and plan maintenance.
- More efficient resource use: systems can adapt their operation to energy consumption, environmental conditions, or equipment status.
Challenges and Limitations
- Security: unauthorized access can lead to misuse or disruption of a device or system.
- Privacy: data about people, locations, or habits must be handled responsibly.
- Connection reliability: a network failure can limit remote monitoring or control.
- Power consumption: battery-powered devices must manage their energy use carefully.
- Compatibility: devices from different manufacturers may not work together automatically.
- Maintenance: software updates, repair of faulty components, and long-term support must be provided.
A secure IoT system should use appropriate authentication, up-to-date software, protected communications, and restricted access permissions. Security should be considered from the beginning of a project rather than added only after devices are connected to a network.
Conclusion
The Internet of Things connects physical devices, sensors, control units, and computer systems to collect and exchange data, monitor conditions, and automate processes. Its foundation consists of hardware, software, and suitable network communication.
IoT is used in smart homes, healthcare, industry, transportation, agriculture, and many other fields. A successful implementation depends on selecting appropriate sensors and actuators, choosing how data is processed, selecting a communication technology, and ensuring adequate system security.