Patent ID: 7675941

Claim:
A method of transmitting data in a mobile communication system, comprising: receiving a service data unit (SDU) from a higher layer and determining whether the SDU can be comprised in one protocol data unit (PDU); if the SDU is not comprised in one PDU, segmenting the SDU into a plurality of segments according to a transmittable PDU size, and constructing one or more PDUs, each PDU comprising a header and a data field, wherein the data field comprises a segment of the SDU, wherein the header comprises a serial number (SN) field, a one-bit field indicating that the PDU does not contain an entire SDU in the data field and at least one Length Indicator (LI) field, wherein if the data field of the PDU contains an intermediate segment of the SDU, the LI field in the PDU contains the intermediate segment of the SDU is set to a predefined value indicating that the PDU contains neither a first segment nor a last segment of the SDU; and sending the PDUs to a receiver.