Apparatus for transmitting MAC PDU with a fragmentation and packing extended header and method thereof

A receiver for receiving data from a transmitting side in a wireless communication system, the receiver comprising:

• a receiving module configured to receive a medium access control protocol data unit (MAC PDU) from the transmitting side, the MAC PDU including:
• at least one of the two or more fragments fragmented from a data block by the transmitting side,
• a first header containing control information about the MAC PDU which includes the at least one of the two or more fragments, and
• a fragmentation extended header (FEH) providing information on the data packet fragment,
• wherein the first header contains an indicator indicating that the FEH is present following the first header,
• wherein the FEH contains a type field identifying a type of the FEH and the FEH has a variable length depending on whether the fragmented data packet is a real-time data packet or not, and
• wherein the FEH has a shorter length when the fragmented data packet is the real-time data packet than when the fragmented data packet is a non-real-time data packet;
• and
• a processor configured to perform a signal processing operation on the received MAC PDU.