MQTT - Messaging and Acknowledgment Mechanism

Relevance

IoT is no longer just a trend; it is a necessity for businesses, industries, and even individual users. From building automation to

remote monitoring systems and intelligent sensor networks, connectivity is shaping the future of technology.

The challenge? Finding efficient, scalable, and secure solutions to ensure that IoT growth is sustainable and manageable. MQTT and other optimized protocols play a fundamental role in this scenario.

The Internet of Things (IoT) is revolutionizing the way devices, machines, and people interact. In a world where connectivity is increasingly demanded and resources (bandwidth, energy, hardware) are limited, efficient and scalable solutions like MQTT are becoming the backbone of the IoT industry.

Why is IoT becoming dominant?

1️. Exponential growth of connected devices: It is estimated that by 2030, there will be over 25 billion IoT devices in operation.

2️. Resource optimization: Lightweight protocols like MQTT enable efficient communication even over unstable networks or with low bandwidth.

3️. Development of Smart Cities and Industry 4.0: Automated systems for environmental monitoring, intelligent transportation,

and industrial production are already a reality.

4️. Increasing demand for automation and data analytics: IoT is at the core of artificial intelligence and machine learning, improving

decision-making processes and optimizing resource consumption.

5️. Transition towards sustainable solutions: IoT helps reduce energy waste, improve resource management, and optimize production processes.

Abstract

MQTT (Message Queuing Telemetry Transport) is a lightweight, efficient protocol designed specifically for resource-constrained devices and unreliable networks, prevalent in the IoT (Internet of Things) ecosystem. This course covers MQTT’s fundamental concepts, including its publish/subscribe architecture, detailed message types, and critical message properties such as Quality of Service (QoS)and the Last Will and Testament (LWT).

MQTT plays a crucial role in smart home and building automation due to its inherent advantages, such as minimal bandwidth usage, scalability, reliability, and real-time communication capabilities.

This three-part training series provides a comprehensive introduction to the MQTT protocol, a lightweight and efficient communication standard widely used in IoT and distributed automation systems.

Part 02 – Messaging and Acknowledgment Mechanism

This module focuses on the MQTT message types and communication flow. It details the function and structure of CONNECT, PUBLISH, SUBSCRIBE, and acknowledgment packets (e.g., CONNACK, PUBACK, SUBACK). The concept of Quality of Service (QoS) levels is introduced to explain how MQTT ensures reliable message delivery. Additional topics include retained messages, session persistence, and authentication mechanisms.