Methods of operating user equipment for device-to-device, D2D, communications are provided. Operations include transmitting a quality of service, QoS, flow establishment request, the flow establishment request indicating that the QoS flow is to be transmitted over a sidelink, responsive to a determination that a required QoS flow will be fulfilled, receiving a message indicating that a requested sidelink QoS flow will be supported and receiving mapping and configuration data corresponding to the sidelink QoS flow, and responsive to determining that the required QoS may not be fulfilled, receiving a message indicating that the requested sidelink QoS flow will not be established.