Methods and apparatuses are provided for generating a protocol data unit (PDU). An apparatus may comprise a processor configured to provide a medium access control (MAC) entity and a segmentation entity. The MAC entity may indicate an amount of data associated with the segmentation entity to be multiplexed by the MAC entity. The segmentation entity may segment, based on the indicated amount of data, a service data unit (SDU) into a segment, and the MAC entity may multiplex the segment into a MAC protocol data unit (PDU). The MAC PDU may include a field that indicates whether the segment is included and whether the segment is a last segment. The apparatus may further comprise a transmitter configured to transmit the MAC PDU.