In the present invention, a radio link control (RLC) entity of the receiving device receives an RLC service data unit (SDU) segment of a first RLC SDU. The RLC entity starts a first reassembly timer for the first RLC SDU if the RLC SDU segment of the first RLC SDU is the first one received for the first RLC SDU at the RLC entity. The receiving device uses a reassembly timer per RLC SDU segmented.