e, if it detects a cell providing resource configuration or inter-carrier resource con- figuration for V2X sidelink communication. An RRC_IDLE UE may prioritize the frequency that provides cross-carrier resource configuration for V2X sidelink communication over other choices during cell reselection. If the UE supports multiple transmission chains, it may simul- taneously transmit on multiple carriers via PC5. In that case, a mapping between V2X service types and the suitable V2X frequencies is configured by upper layers. For scheduled resource allocation, the eNB can schedule a V2X transmission on a frequency based on the sidelink buffer status report, in which the UE includes the destination index uniquely associated with a frequency reported by the UE to the eNB in sidelink UE information message [6,8]. The UE may receive the V2X sidelink communication of other PLMNs. The serving cell can directly signal the resource configuration for V2X sidelink communication in an inter- PLMN operation or indirectly via the frequency on which the UE may acquire the inter- PLMN resource configuration. Note that the V2X sidelink communication transmission in other PLMNs is not permissible. When uplink transmission overlaps in time domain with V2X sidelink transmission on the same frequency, the UE prioritizes the latter over the for- mer, if the PPPP of sidelink MAC PDU is lower than a (pre-)configured PPPP threshold; otherwise, the UE prioritizes the uplink transmission over the V2X sidelink transmission. When uplink transmission overlaps in time domain with V2X sidelink transmission in dif- ferent frequency, the UE may prioritize the V2X sidelink transmission over the uplink trans- mission or may reduce uplink transmission power, if the PPPP of sidelink MAC PDU is lower than a (pre-)configured PPPP threshold; otherwise, the UE prioritizes the uplink trans- mission over the V2X sidelink transmission or reduces V2X sidelink transmission power. However, if uplink transmission is prioritized by upper layer or random-access proce