Ch 15: Internet of Things | Exam Fusion Prep

What is the Internet of Things?

Source states that in 1999, Kevin Ashton first coined the concept “Internet of Things”.
It describes IoT as a concept in which devices such as phones, cars, lamps and coffee machines can be connected to the Internet or to each other.
IoT is described as a network that connects objects capable of storing and exchanging data.
Two main parts are named: Internet = basis of connectivity; Thing = objects/devices.
Intro definition: a system in which various devices are connected to each other and exchange data via the Internet.

English Summary

IoT is a system in which different devices connect to one another and to the Internet to exchange data. The source gives examples such as phones, cars, lamps, coffee machines, smartphones, smart-home devices and fitness trackers.

Source visual extracted from the supplied PDF: IoT with accelerometer, infrared, pressure, temperature, smoke, proximity, gyroscope and motion sensors.

Internet + Thing

Internet

The basis of connectivity — it connects devices to a network.

Thing

Objects or devices that can store or exchange data.

One-Line Recall

IoT = connected things + Internet + data exchange.

Core Components of IoT

Diagram built only from the component names and roles listed in the source.

Sensors

Collect data from the environment and transmit it over a network; can be embedded in the IoT device or positioned remotely.

Actuators

Mechanical devices that receive data signals and perform actions based on those signals.

Connectivity

Allows IoT devices to communicate with each other over the Internet.

IoT Gateway

Central hub connecting IoT devices to cloud services; collects data, creates alerts and moves data to the cloud.

IoT Cloud

Secure centralized system that stores, analyzes and shares IoT data and provides a platform for access/analysis.

Data Processing

Turns raw information into actionable insights.

User Interface

Allows intuitive interaction with the system.

Revision note

A common functional grouping is devices/sensors, connectivity, processing and user interface. Actuators, gateways and cloud services are implementation components; a separate gateway or cloud is not mandatory for every IoT system.

How IoT Works

Four-step flow exactly based on the supplied source.

1. Data Collection

Sensors collect physical-environment data such as temperature, humidity and motion.

2. Transmission

Data goes through connectivity protocols such as Wi-Fi or Bluetooth to cloud/local servers.

3. Data Processing

Software or AI processes/analyzes received data to derive useful insights.

4. Action

Processed data may trigger actions such as turning on heating or sending alerts.

IoT Architecture

Device → Network → Processing → Application, as listed in the PDF.

Layer	Role from source
Device Layer	Sensors and devices collect raw data.
Network Layer	Communication between devices through Wi-Fi, 4G/5G, Zigbee, etc.
Processing Layer	Data processed in cloud or at the edge, near devices.
Application Layer	User interfaces such as mobile apps for interaction and monitoring.

Applications of IoT

Smart Homes

Smart thermostats, lights and security cameras; convenience and energy efficiency.

Healthcare

Wearable devices such as fitness trackers and heart monitors for health metrics.

Industrial IoT

Manufacturing sensors/devices for predictive maintenance, automation and efficiency optimization.

Smart Cities

IoT systems for traffic, waste and energy management to improve urban living.

Agriculture

Precision farming; monitoring soil moisture, weather and crop health.

Hindi Recall

Smart Home → convenience and energy efficiency • Healthcare → wearable monitoring • IIoT → predictive maintenance/automation • Smart City → traffic/waste/energy • Agriculture → soil/weather/crop monitoring

Connectivity technologies and protocol stacksol stacks

Technology	Use Case stated in source
Wi-Fi	Primarily home and office IoT devices.
Bluetooth / BLE	Short-range communication, especially personal IoT devices such as wearables and smartphones.
Zigbee	Home automation and industrial IoT, including smart lighting and security systems.
LoRaWAN	Remote, long-range IoT applications such as agriculture, smart cities and utility monitoring.
Z-Wave	Home automation, primarily smart homes.
5G	High-performance IoT requiring real-time data, such as autonomous vehicles, smart cities and healthcare.

Network Layer / IoT-Specific Protocols

6LoWPAN

IPv6 over Low-Power Wireless Personal Area Networks. Source use case: lets IoT devices use IPv6 in low-power, low-bandwidth environments.

RPL

Routing Protocol for Low Power and Lossy Networks. Used in low-power, lossy networks (LLNs) with limited resources.

Transport & Application Layer Protocols

Protocol groups and names taken from the supplied source.

Transport Layer

TCP

Source lists TCP as reliable and connection-oriented.

UDP

UDP is connectionless; it does not guarantee delivery, ordering or retransmission. Applications can add reliability mechanisms when needed.

Source wording

UDP has low overhead; “unreliable” means no built-in delivery guarantee, not that every UDP packet fails.

Application Layer

Protocol	Use Case from source
HTTP	Communication between web servers and IoT devices, particularly RESTful APIs.
CoAP	Designed for low-power, low-bandwidth IoT devices such as smart sensors and actuators.
MQTT	Real-time messaging and telemetry; smart homes, industrial systems, connected vehicles.
AMQP	Applications requiring high reliability and security, including enterprise and industrial IoT.
DDS	Real-time, mission-critical uses such as autonomous vehicles, robotics and military.
XMPP	Chat applications; can also support IoT messaging.

Security Protocols

Why security matters

Source says IoT security is crucial for data integrity, privacy and device authentication.

TLS

Used to secure data transmissions, especially over HTTP (HTTPS) or MQTT.

SSL

Similar use to TLS; source explicitly notes SSL is now considered obsolete and replaced by TLS.

PKI

Public Key Infrastructure — device authentication and secure communication in IoT systems.

OAuth & OpenID Connect

OAuth 2.0 is an authorization framework; OpenID Connect adds authentication on top of OAuth 2.0.

Exam Trap

TLS / SSL are transport-security terms in this source; PKI is tied to authentication/secure communication; OAuth/OpenID Connect to authorization/authentication.

Sensors, Actuators & Transducer

Concept diagram built from the source comparison.

Sensor

Physical device that measures/detects a physical quantity and converts it into a signal for processing/control analysis.

Actuator

A device that converts a control signal and available energy into physical action, such as motion, switching or heating; actuators may be electrical, hydraulic or pneumatic.

Transducer

Converts a signal from one physical structure to another — one type of energy into another; may be used as an actuator in various systems.

Different Types of Sensors

Temperature Sensor

Image Sensor

Gyro Sensor

Obstacle Sensor

RF Sensor

IR Sensor

MQ-02/05 Gas Sensor

LDR Sensor

Ultrasonic Distance Sensor

Sensor vs Actuator

Sensor	Actuator
Receives input from the environment and senses surrounding conditions.	Receives a command or input from the system and produces a physical output in the environment or load.
Converts physical quantities or characteristics into electrical signals.	Converts electrical signals into physical action, force or motion.
Provides the system with information about environmental conditions for monitoring or control.	Acts as an output device in a control system.
Source uses: pressure, temperature, fluid levels, flow, vibration, speed etc.	Source uses: control valves, dampers, guide vanes, moving objects/conveyor belts/robotic arms etc.
Examples: Thermocouple, photo cell, RTD, LVDT, strain gauge, load cell, hall sensors, differential flow meters, speed probes, pH meter.	Examples: motor actuator, servo motor, stepper motor, heaters, electro-pneumatic, electro-hydraulic and magnetic actuators.

Quick Recall

Core Formula

IoT = Things + Connectivity + Data + Processing + Action.

Term	Recall cue from source
1999	Kevin Ashton coined the concept “Internet of Things”.
Sensor	Collects/measures environment data; converts physical quantity to signal.
Actuator	Receives signal and performs physical action.
Gateway	Central hub connecting IoT devices to cloud services.
IoT Cloud	Stores, analyzes and shares IoT data.
4-layer architecture	Device → Network → Processing → Application.
BLE	Short-range personal IoT, wearables/smartphones.
LoRaWAN	Remote/long-range IoT.
6LoWPAN	IPv6 in low-power, low-bandwidth environments.
RPL	Routing for low-power and lossy networks.
MQTT	Real-time messaging and telemetry.
CoAP	Low-power, low-bandwidth IoT devices.
TLS	Secure data transmission; source mentions HTTPS/MQTT.
PKI	Device authentication and secure communication.
Transducer	Converts one signal/energy form into another.

Exam Trap

Sensor ≠ Actuator: Sensor senses/input; actuator performs physical output/action.

Exam Trap

IoT architecture in source: Device → Network → Processing → Application.

Exam Trap

MQTT = real-time messaging/telemetry; CoAP = constrained low-power/low-bandwidth devices; LoRaWAN = long-range use cases.