Communication method, device and system

Provided are a communication method, device and system, the communication method being applied to a first device, the communication method comprising: sending a first message to a second device, the first message carrying first device data, a first receiving state identifier and a first device queue length, the first receiving state identifier is used for identifying whether the first equipment successfully receives a message sent by the second equipment in the last round or not; and receiving a response message sent by the second device for the first message, the response message carrying second device data, a second receiving state identifier and a second device queue length, and the second receiving state identifier being used for identifying whether the second device successfully receives the first message. According to the invention, the device data, the receiving state identifier and the queue length are carried in the sent message, so that the technical problem of low communication efficiency in relate