Rate adaptation method and device between RRU (Radio Remote Unit) and BBU (Building Base band Unit)

The invention provides a rate adaptation method and device between RRU (Radio Remote Unit) and BBU (Building Base band Unit), comprising: RRU (Radio Remote Unit) connecting to the base station through Slave interface, the Master interface connecting to the Slave interface at the lowest grade rate; the BBU (Building Base band Unit) of the base station querying rate level information from the RRU (Radio Remote Unit), and receiving the feedback rate grade of the RRU (Radio Remote Unit); the BBU (Building Base band Unit) determining corresponding rate and notifying the RRU (Radio Remote Unit) according to the attributes of Master side device, the Master interface communicating with the Slave interface at a corresponding rate. The invention is characterized by querying rate level respectively supported by the Master and the Slave interface through the base station initiates, effectively realizing rate adapting of the Master and the Slave interface, full use of the Master and the Slave interface bandwidth, and avoiding waste of resource of the bandwidth.