This disclosure provides systems, methods, apparatus, including computer programs encoded on computer storage media for one or more wireless devices to gain access to a wireless channel of a radio frequency spectrum band. In some aspects, a recurring coordinated medium interval is defined in the time domain and associated with the wireless channel. The coordinated medium interval includes a first time period, which may be referred to as a common reservation window, and a second time period, which may be referred to as a scheduled medium access window. During the first time period, access points (APs) attempting to gain access to the wireless channel may transmit reservation signals to reserve one or more scheduled service periods within the second time period of the same coordinated medium interval. The scheduled service periods reserved by an individual AP may be used for UL/DL communications between that AP and its associated stations (STAs).