One disclosure of the present specification provides a terminal capable of simultaneously performing a cellular communication and a D2D communication. The terminal comprises: a first duplexer for separating a transmission signal and a reception signal in a first band for LTE/LTE-Advanced based cellular communication; a second duplexer for separating a transmission signal and a reception signal in a second band; a third duplexer for separating a transmission signal and a reception signal in a third band; and a first band switch for selecting one of the first duplex, the second duplex and the third duplex, wherein when the first band is only used for the cellular communication and the second band is disabled, the second duplex uses the second band for device to device (D2D) communication, and the first band and the second band may correspond to a different inter-band to each other.