MQTT协议是为大量计算能力有限，且工作在低带宽、不可靠的网络的远程传感器和控制设备通讯而设计的协议，它具有以下主要的几项特性：
1、使用发布/订阅消息模式，提供一对多的消息发布，解除应用程序耦合；
2、对负载内容屏蔽的消息传输；
3、使用 TCP/IP 提供网络连接；(MQTT protocol is a protocol designed for large amounts of computing power and communication between remote sensors and control devices in low bandwidth and unreliable networks. It has the following main characteristics.
1. Use the publish / subscribe message mode to provide more than one message release and release the application coupling.
2. Message transmission of the shielding of the content of the load;
3, the use of TCP/IP to provide network connections;)