Method and apparatus for communication in wireless communication system

A method performed by a receiving device in a wireless communication system, the method comprising:

• receiving, from a transmitting device, a radio link control (RLC) protocol data unit (PDU) for an RLC service data unit (SDU), the RLC PDU including an RLC header;
• and
• identifying the RLC header from the RLC PDU,
• wherein the RLC header includes a segmentation information (SI) field and a sequence number (SN) field, in case that the RLC PDU includes an RLC SDU segment which is a segment of the RLC SDU, and
• wherein the RLC header includes the SI field and does not include the SN field, in case that the RLC PDU includes a complete RLC SDU which is the RLC SDU.

A transmitting device in a wireless communication system, the transmitting device comprising:

• a transceiver;
• and
• a controller configured to:
• obtain a radio link control (RLC) service data unit (SDU) from an upper layer,
• generate an RLC protocol data unit (PDU) for the RLC SDU, the RLC PDU including an RLC header, and
• transmit the RLC PDU to a receiving device via the transceiver,
• wherein the RLC header includes a segmentation information (SI) field and a sequence number (SN) field, in case that the RLC PDU includes an RLC SDU segment which is a segment of the RLC SDU, and
• wherein the RLC header includes the SI field and does not include the SN field, in case that the RLC PDU includes a complete RLC SDU which is the RLC SDU.

A receiving device in a wireless communication system, the receiving device comprising:

• a transceiver;
• and
• a controller configured to:
• receive, from a transmitting device via the transceiver, a radio link control (RLC) protocol data unit (PDU) for an RLC service data unit (SDU), the RLC PDU including an RLC header, and
• identify the RLC header from the RLC PDU,
• wherein the RLC header includes a segmentation information (SI) field and a sequence number (SN) field, in case that the RLC PDU includes an RLC SDU segment which is a segment of the RLC SDU, and
• wherein the RLC header includes the SI field and does not include the SN field, in case that the RLC PDU includes a complete RLC SDU which is the RLC SDU.