An improved method for packet transmission scheduling and an improved packet transmission scheduling system in mobile telecommunication systems. Both the improved method and the system especially adapted to be used for UMTS systems. A quality of service scheduling of multiple data flows in a mobile telecommunication system is proposed, wherein a priority order of protocol data units (PDU) of multiple data flows with regard to predefined flow's quality of service requirements is determined, a serving of the protocol data units (PDU) is performed by dynamically determining transport blocks (TB) to be transmitted by the physical layer (PHY-layer) with regard to the defined priority order and in dependence of allocated radio resource constraints, by assigning to each transport block (TB) a respective associated transport format (TF), and by creating transport block sets (TBS) with the determined transport blocks (TB) to be transmitted by the physical layer (PHY-layer) by using the respective associated transport format (TF) as assigned.