MQTT is a Chinese translation of the OASIS MQTT 3.1.1 protocol specification for developers working with messaging, machine-to-machine systems, and the Internet of Things. It explains MQTT as a lightweight client-server publish-and-subscribe transport designed for constrained devices and networks. The documentation covers protocol concepts, control packet formatting, operational behavior, security, WebSocket transport, and conformance requirements. Individual chapters describe connection, publication, subscription, acknowledgment, heartbeat, and disconnection packets in detail. ...