A scheduled transmission may be divided up into several segments so that a transmitting node may receive and transmit control messages between segments. In some implementations a monitoring period is defined after a scheduled transmission period to enable the transmitting node to acquire control information that may otherwise have been transmitted during the scheduled transmission period. In some implementations a wireless media access control supports asynchronous communication and overlapping transmissions. Here, a wireless node may determine whether to request or schedule a transmission based on control messages it receives from neighboring nodes. In some implementations data and control information are transmitted over different frequency division multiplexed channels to enable concurrent transmission of the data and control information.