A relay receives a frame from a source, and based on state of a relayed frame bit within the frame, the relay selects an operational mode: implicit acknowledgement mode, first explicit acknowledgement mode, or second explicit acknowledgement mode. The relay sets the relayed frame bit in subsequent transmissions to indicate transmission opportunity (TXOP) control of the communication medium (e.g., whether under control of the relay or the source). The source may receive acknowledgement of the relay's successful receipt of the frame implicitly via the relay transmitting a relayed frame to the destination. Alternatively, the source may receive acknowledgement of the relay's successful receipt of the frame explicitly in a response frame from the relay. State of a more data bit in the frame receive from the source may indicate the source has one or more additional frames intended for the destination.