A user equipment (UE) may, in a first discovery frame, determine whether a discovery resource is available for communication. If the discovery resource is available for communication, the UE may, in a second discovery frame following the first discovery frame, transmit a discovery signal using the discovery resource and puncture the discovery signal during a listening window. The UE may detect the energy of a received signal at the discovery resource during the listening window. The UE may abandon the discovery resource if the detected energy is above a threshold. In some example, the listening window may have a fixed duration and a beginning that is randomly selected from a predetermined set of values. In some example, the listening window may have a variable duration and an end that matches an end of the second discovery frame.