A mobile communication method for transmitting and receiving a data signal and a control signal through a radio base station interface (Uu) between a first mobile station (UE#1) and a second mobile station (UE#2) and a radio base station (eNB), and for transmitting and receiving a data signal through an inter-mobile station interface (Ud) between the first mobile station (UE#1) and the second mobile station (UE#2), wherein the first and second mobile station (UE#1, UE#2) are allocated a common identification information, X-RNTI, the mobile communication method comprising using a first carrier employing a first frequency for downlink through the radio base station interface (Uu); using a second carrier employing a second frequency for uplink through the radio base station interface (Uu); using either one of the first carrier or the second carrier for transmitting and receiving the data signal through the inter-mobile station interface (Ud); a) by the radio base station (eNB), notifying the first mobile station (UE#1) and the second mobile station (UE#2) that an opportunity (Ud Tx, Ud Rx) to transmit and receive the data signal through the inter-mobile station interface (Ud) is allocated through a physical downlink control channel (PDCCH) using the first carrier in which the common identification information, X-RNTI on the first and second mobile station (UE#1, UE#2) is used; b) by the radio base station(eNB), transmitting transmission direction information (UE#1->UE#2; UE#1<-UE#2) through RRC signaling, for notifying of a direction in which the data signal should be transmitted in the allocated opportunity, to the first mobile station (UE#1) and the second mobile station (UE#2); and by the radio base station (eNB), transmitting time division information necessary to transmit and receive the data signal and the control signal through the radio base station interface (Uu) and transmit and receive the data signal through the inter-mobile station interface (Ud) in a time division manner, through RRC signaling. using a first carrier employing a first frequency for downlink through the radio base station interface (Uu); using a second carrier employing a second frequency for uplink through the radio base station interface (Uu); using either one of the first carrier or the second carrier for transmitting and receiving the data signal through the inter-mobile station interface (Ud); a) by the radio base station (eNB), notifying the first mobile station (UE#1) and the second mobile station (UE#2) that an opportunity (Ud Tx, Ud Rx) to transmit and receive the data signal through the inter-mobile station interface (Ud) is allocated through a physical downlink control channel (PDCCH) using the first carrier in which the common identification information, X-RNTI on the first and second mobile station (UE#1, UE#2) is used; b) by the radio base station(eNB), transmitting transmission direction information (UE#1->UE#2; UE#1<-UE#2) through RRC signaling, for notifying of a direction in which the data signal should be transmitted in the allocated opportunity, to the first mobile station (UE#1) and the second mobile station (UE#2); and a) by the radio base station (eNB), notifying the first mobile station (UE#1) and the second mobile station (UE#2) that an opportunity (Ud Tx, Ud Rx) to transmit and receive the data signal through the inter-mobile station interface (Ud) is allocated through a physical downlink control channel (PDCCH) using the first carrier in which the common identification information, X-RNTI on the first and second mobile station (UE#1, UE#2) is used; b) by the radio base station(eNB), transmitting transmission direction information (UE#1->UE#2; UE#1<-UE#2) through RRC signaling, for notifying of a direction in which the data signal should be transmitted in the allocated opportunity, to the first mobile station (UE#1) and the second mobile station (UE#2); and by the radio base station (eNB), transmitting time division information necessary to transmit and receive the data signal and the control signal through the radio base station interface (Uu) and transmit and receive the data signal through the inter-mobile station interface (Ud) in a time division manner, through RRC signaling.