Systems, methods, and instrumentalities are disclosed to determine access control and channel and signaling priority. A wireless transmit/receive unit (WTRU) may comprise a processor configured, at least in part, to determine device-to-device (D2D) data to be transmitted. The WTRU may determine if the D2D data may be transmitted. The WTRU may determine available scheduling assignment (SA) resources used for priority based D2D data signals. The WTRU may select one or more available SA resources used for priority based D2D data signals. The WTRU may transmit the D2D data, wherein the D2D data may be transmitted on the selected SA resources.