A radio link control (RLC) entity can be used for multiple radio bearers (RBs). In other words, one RLC entity can be associated with multiple packet data convergence protocol (PDCP) entities, where the multiple PDCP entities are associated with the multiple RBs, respectively. An identifier of a PDCP or RB can be provided with a PDCP PDU in order to inform the RLC entity or a receiving device which RB or which PDCP entity the PDCP PDU is associated with. The RLC entity shared by more than one RB can be configured according to configuration information for RB(s).