Patent ID: 8817806

Claim:
A method for flow control between a Packet Data Convergence Protocol (PDCP) layer and a Radio Link Control (RLC) layer in a communication system, the method comprising: storing mirrored Service Data Units (SDUs) indicating SDUs corresponding to PDUs already transferred to the RLC layer, in a first area of a buffer of the PDCP layer; storing SDUs to be transferred to the RLC layer, in a second area of the buffer separated from the first area of the buffer of the PDCP layer; receiving information on a capacity that is currently unused in a total capacity of a buffer of the RLC layer from the RLC layer; generating Packet Data Units (PDUs) from SDUs in accordance with a capacity of which corresponds to the information, among SDUs stored in the second area of the buffer of the PDCP layer; and transferring the generated PDUs to the RLC layer.