An operation method of a first communication node in a communication network, which supports a radio link control (RLC) function among functions of a base station, may comprise receiving a first message from a second communication node supporting a packet data convergence protocol (PDCP) function among the functions of the base station; processing the received first message by performing the RLC function; and transmitting the processed first message to a third communication node supporting a medium access control (MAC) function and physical (PHY) functions among the functions of the base station.