Patent ID: 8804742

Claim:
A method for transmitting a Packet Data Convergence Protocol (PDCP) packet, the method comprising: receiving a PDCP Service Data Unit (SDU) from an upper layer; determining whether a Next-PDCP_TX_SN minus a sequence number of a last PDCP SDU completely and successfully transmitted from a lower layer is greater than a predetermined number that is determined based on half a PDCP sequence number space; associating a PDCP sequence number that corresponds to the Next-PDCP_TX_SN with the received PDCP SDU if the Next-PDCP_TX_SN minus the sequence number of the last PDCP_SDU completely and successfully transmitted from the lower layer is determined as greater than the predetermined number; and setting the Next-PDCP_TX_SN to a new value and associating a PDCP sequence number that corresponds to the new value with the received PDCP SDU if the Next-PDCP_TX_SN minus the sequence number of the last PDCP SDU completely and successfully transmitted from the lower layer is determined as not greater than the predetermined number.