A user equipment, UE,, configured to select at least one resource across a plurality of carriers (CC1 to CC3) for transmitting at least one packet in sidelink, comprising: a sensor, adapted to sense a plurality of resource pools of the plurality of carriers within a sensing window to obtain a sensing result, wherein a length of the sensing window is configurable or preconfigured; a resource selector, adapted to obtain a plurality of available resources (R 1-t, R 1-n1, R 1-n2, R 2-n1, R 2-t, R 2-n2, R 3-n1, R 3-n2, R 3-t) of the plurality of carriers within a resource selection window in which the resource selector obtains the plurality of available resources for further selection, according to the sensing result, wherein the plurality of available resources are included in at least one resource pool of the plurality of carriers within the resource selection window and the at least one resource pool is included in the sensed plurality of resource pools of the plurality of carriers, wherein the resource selector is further adapted to: - select at least one resource (R 1-t; R 2-t; R 3-t) from the plurality of available resources of the plurality of carriers within the resource selection window in accordance with a priority of the at least one resource pool, wherein a length of the resource selection window is determined according to a desired latency so as to ensure a Quality of Service, QoS, - select a resource pool in accordance with a relationship between the priority of the at least one resource pool and a priority of the at least one packet, wherein the resource selector selects, as at least one selected resource pool, a resource pool whose priority is not higher than the priority of the at least one packet, and - select the at least one resource from the at least one selected resource pool to transmit the at least one packet, wherein the priority of the at least one packet is indicated by a priority of a logical channel of the at least one packet or a priority of a layer of the at least one packet, said layer being higher than layer 3 of the at least one packet; and a transmitter, adapted to transmit the at least one packet on the at least one resource (R 1-t; R 2-t; R 3-t) which is selected by the resource selector. a sensor, adapted to sense a plurality of resource pools of the plurality of carriers within a sensing window to obtain a sensing result, wherein a length of the sensing window is configurable or preconfigured; a resource selector, adapted to obtain a plurality of available resources (R 1-t, R 1-n1, R 1-n2, R 2-n1, R 2-t, R 2-n2, R 3-n1, R 3-n2, R 3-t) of the plurality of carriers within a resource selection window in which the resource selector obtains the plurality of available resources for further selection, according to the sensing result, wherein the plurality of available resources are included in at least one resource pool of the plurality of carriers within the resource selection window and the at least one resource pool is included in the sensed plurality of resource pools of the plurality of carriers, wherein the resource selector is further adapted to: - select at least one resource (R 1-t; R 2-t; R 3-t) from the plurality of available resources of the plurality of carriers within the resource selection window in accordance with a priority of the at least one resource pool, wherein a length of the resource selection window is determined according to a desired latency so as to ensure a Quality of Service, QoS, - select a resource pool in accordance with a relationship between the priority of the at least one resource pool and a priority of the at least one packet, wherein the resource selector selects, as at least one selected resource pool, a resource pool whose priority is not higher than the priority of the at least one packet, and - select the at least one resource from the at least one selected resource pool to transmit the at least one packet, wherein the priority of the at least one packet is indicated by a priority of a logical channel of the at least one packet or a priority of a layer of the at least one packet, said layer being higher than layer 3 of the at least one packet; and - select at least one resource (R 1-t; R 2-t; R 3-t) from the plurality of available resources of the plurality of carriers within the resource selection window in accordance with a priority of the at least one resource pool, wherein a length of the resource selection window is determined according to a desired latency so as to ensure a Quality of Service, QoS, - select a resource pool in accordance with a relationship between the priority of the at least one resource pool and a priority of the at least one packet, wherein the resource selector selects, as at least one selected resource pool, a resource pool whose priority is not higher than the priority of the at least one packet, and - select the at least one resource from the at least one selected resource pool to transmit the at least one packet, wherein the priority of the at least one packet is indicated by a priority of a logical channel of the at least one packet or a priority of a layer of the at least one packet, said layer being higher than layer 3 of the at least one packet; and a transmitter, adapted to transmit the at least one packet on the at least one resource (R 1-t; R 2-t; R 3-t) which is selected by the resource selector.