Patent ID: 8743874

Claim:
A method of transmitting data by a transmitting side in a wireless communication system, the method comprising: fragmenting a data packet into two or more fragments; forming a medium access control protocol data unit (MAC PDU), the MAC PDU including at least one of the two or more fragments, 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 transmitting the formed MAC PDU to a receiving side.