A method performed by a wireless device in a wireless communication system, includes receiving a threshold value and a hysteresis value from a network; while in a radio resource control (RRC) idle mode, detecting that a measured quality of a cell is below the threshold value by the hysteresis value; establishing an RRC connection with the network to enter an RRC connected mode; and performing relaying operation between the network and a remote wireless device, upon establishing the RRC connection with the network.