The embodiments of the present invention provide a method, apparatus, and system. The method comprises: sending, by a centralized processing node, control information containing address information of a service ERRU and the transmission mode of ERRUs to the ERRUs in a COMP set; receiving the compressed uplink COMP frequency domain data sent by the service ERRU according to the transmission mode, wherein the compressed uplink COMP frequency domain data are data obtained by the service ERRU by compressing the original uplink COMP frequency domain data sent by the non-service ERRUs and the original uplink COMP frequency domain data of the service ERRU, and receiving the original uplink COMP frequency domain data sent by at least one ERRU according to the transmission mode. In the present invention, the data are compressed to reduce the uplink transmission flow between the ERRUs in the COMP set and the centralized processing node.