Embodiments of an access point (AP), station (STA), and method of communication are generally described herein. The AP may perform channel sensing in a first channel of a first frequency band and a second channel of a second frequency band to obtain access for transmission of a physical layer convergence procedure (PLCP) protocol data unit (PPDU) that comprises multiple subframes. The transmission of the PPDU may be configurable to use a multi-band layer-1 aggregation of the first and second channels. While the second channel is unavailable, the AP may transmit one or more subframes on the first channel without usage of the multi-band layer-1 aggregation. When it is determined that the second channel has become available, the AP may switch to synchronized transmission of the subframes on the first and second channels in accordance with the multi-band layer-1 aggregation.