A method performed by a WTRU may comprise determining application layer information and receiving QoS policy configuration information. A QoS mechanism may be determined based on the application layer information and the received QoS policy configuration information. A QoS value applicable to the determined QoS mechanism may then be determined for a data packet. Subsequently, the determined QoS value may be transmitted to another WTRU over a PC5 interface, with or without the data packet. The QoS mechanism may be determined as one of a PPPP mechanism or a QFI mechanism. The QoS policy configuration information may be received via a gNB. In an embodiment, the application layer information may include an application identifier, a PSID or an ITS-AID. The QoS policy configuration information may indicate a mapping of V2X application IDs to respective QoS mechanisms.