MQTT Protocol in Smart Home Environments: Principles of Operation and Application

Internet of Things as a revolutionary concept in technology of modern days has led to the popularization of “smart” things. It introduces low-cost and reliable solutions to provide independent operations of devices and machines. Smart home systems have become one of the most important implementations as they significantly improve the quality of people’s lives. Since communication plays a key role in these systems, this article provides insights into Message Queuing Telemetry Transport protocol application in smart home systems. Although it is not the only protocol used, MQTT stands out in terms of reliability, efficiency, and simplicity. The article provides major MQTT characteristics, advantages and its application in a particular smart home system for ambient parameters monitoring and control. The system integrates NodeMCU based sensor node with mobile and web applications via MQTT protocol. Results of the performance analysis of MQTT use in this system are given. Tests have shown great connection establishment speed, a high percentage of successfully sent messages, and a large number of messages sent per minute. Thanks to the flexibility of the MQTT protocol, the system is easy to upgrade and expand.