A method of supporting a user equipment (UE) to UE (UE-to-UE) communication by a network in a wireless communication system, the method includes transmitting a system information block associated with the UE-to-UE communication, wherein the system information block contains a period parameter indicating a periodicity at which a relay UE transmits discovery announcement, wherein the system information block contains a high threshold value and a low threshold value, wherein the relay UE is not allowed to transmit the discovery announcement if a reference signal received power (RSRP) measured by the relay UE is above the high threshold value, and wherein the relay UE is not allowed to transmit the discovery announcement if the RSRP measured by the relay UE is below the low threshold value.