A communication apparatus comprising: a receiver configured to receive information of a first resource pool of two or more resource pools being indicated by a dedicated Radio Resource Control, RRC, signaling from an eNode B and a second resource pool of the two or more resource pools being indicated by a System Information Block, SIB, transmitted from the eNode B; and a transmitter configured to transmit a device to device, D2D, signal using one of the two or more resource pools; characterized in that the receiver is configured to receive information of a third resource pool of the two or more resource pools being indicated by a physical device-to device shared channel, PD2DSCH, transmitted by user equipment(s), UE(s), a fourth resource pool of the two or more resource pools is a pre-configured resource pool, and wherein, when determining the one of the two or more resource pools: • if the communication apparatus is in an RRC_CONNECTED state, the first resource pool, the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority, and • if the communication apparatus is in an RRC_IDLE state , the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority; and wherein the communication apparatus is in mode 2, the mode 2 being a transmission mode in which the communication apparatus autonomously schedules resources for D2D communication. a receiver configured to receive information of a first resource pool of two or more resource pools being indicated by a dedicated Radio Resource Control, RRC, signaling from an eNode B and a second resource pool of the two or more resource pools being indicated by a System Information Block, SIB, transmitted from the eNode B; and a transmitter configured to transmit a device to device, D2D, signal using one of the two or more resource pools; characterized in that the receiver is configured to receive information of a third resource pool of the two or more resource pools being indicated by a physical device-to device shared channel, PD2DSCH, transmitted by user equipment(s), UE(s), a fourth resource pool of the two or more resource pools is a pre-configured resource pool, and wherein, when determining the one of the two or more resource pools: • if the communication apparatus is in an RRC_CONNECTED state, the first resource pool, the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority, and • if the communication apparatus is in an RRC_IDLE state , the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority; and • if the communication apparatus is in an RRC_CONNECTED state, the first resource pool, the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority, and • if the communication apparatus is in an RRC_IDLE state , the second resource pool, the third resource pool, and the fourth resource pool are in descending order in priority; and wherein the communication apparatus is in mode 2, the mode 2 being a transmission mode in which the communication apparatus autonomously schedules resources for D2D communication. <EOS>