The present disclosure provides a method of performing up-link transmission at a reduced power. According to the method, system information may be received from a base station. The system information may include one or more of first information on an operating band and second information on an up-link bandwidth. Also, according to the method, a network signal for an additional power reduction may be received from the base station. Also, according to the method, when an operating band indicated by the first information is within a range of 777 MHz to 787 MHz and a bandwidth indicated by the second information is 5 MHz, namely, 777 MHz to 782 MHz, an additionally required power reduction may be determined in order to decrease interference to the band of an adjacently located public safety network according to the network signal, and up-link transmission at the reduced power may be performed.