A method for communicating by a first terminal, the method comprising: determining whether a device-to-device, D2D, communication is triggered; identifying, when the D2D communication is triggered, whether information indicating that a first cell of a first base station supports the D2D communication is configured in first system information broadcasted in the first cell, the first cell being a serving cell and associated with a first frequency serving the D2D communication; identifying, when the information indicating that the first cell supports the D2D communication is not configured in the first system information, whether information indicating that a second cell of a second base station adjacent to the first base station supports the D2D communication is configured in second system information broadcasted in the second cell, the second cell being associated with a second frequency serving the D2D communication; determining, when the information indicating that the second cell supports the D2D communication is configured in the second system information, whether the first terminal is able to perform the D2D communication by using a D2D resource of the second cell while communicating with the first cell; determining, based on the first terminal being not able to perform the D2D communication by using the D2D resource of the second cell while communicating with the first cell, priorities of a 3GPP network service and the D2D communication; performing a cell reselection to the second cell, based on a priority of the D2D communication being higher than a priority of the 3GPP network service; and transmitting a first control message for requesting the D2D communication to the second cell to perform the D2D communication with a second terminal. determining whether a device-to-device, D2D, communication is triggered; identifying, when the D2D communication is triggered, whether information indicating that a first cell of a first base station supports the D2D communication is configured in first system information broadcasted in the first cell, the first cell being a serving cell and associated with a first frequency serving the D2D communication; identifying, when the information indicating that the first cell supports the D2D communication is not configured in the first system information, whether information indicating that a second cell of a second base station adjacent to the first base station supports the D2D communication is configured in second system information broadcasted in the second cell, the second cell being associated with a second frequency serving the D2D communication; determining, when the information indicating that the second cell supports the D2D communication is configured in the second system information, whether the first terminal is able to perform the D2D communication by using a D2D resource of the second cell while communicating with the first cell; determining, based on the first terminal being not able to perform the D2D communication by using the D2D resource of the second cell while communicating with the first cell, priorities of a 3GPP network service and the D2D communication; performing a cell reselection to the second cell, based on a priority of the D2D communication being higher than a priority of the 3GPP network service; and transmitting a first control message for requesting the D2D communication to the second cell to perform the D2D communication with a second terminal. <EOS>