A wireless transmit/receive unit (WTRU) may receive a first scheduling assignment that includes an indication of one or more first resources and an indication of a first priority for a first sidelink data transmission from another WTRU. The first WTRU may determine to send a second sidelink data transmission associated with a second priority that is lower than the first priority. The first WTRU may determine a signal strength associated with the first scheduling assignment and may select one or more resources for sending the second sidelink data transmission. The first WTRU may determine that one or more first resources are available for transmission of the second sidelink data transmission based on the signal strength associated with the first scheduling assignment being below a threshold. The first WTRU may send a second scheduling assignment including an indication of the selected one or more resources for the second sidelink data transmission.