A method includes receiving, by a user equipment (UE) and through Radio Resource Control (RRC) signaling, information of a resource pool for a D2D communication, wherein the information of the resource pool comprises information of a discovery subframe in which a D2D discovery signal is to be communicated, determining that in the discovery subframe, the D2D discovery signal is prioritized over a communication with an evolved NodeB (eNB) unless the communication with the eNB is associated with a random access (RA) procedure, transmitting a RA preamble through a Physical Random Access Channel (PRACH), determining whether the discovery subframe corresponds to a RA subframe in which a RA response for the UE is to be monitored, and in response to determining that the discovery subframe corresponds to the RA subframe, monitoring, by the UE, the RA response during the discovery subframe.