A method includes receiving, by control circuitry, a received portion of a first data unit from a remote device and determining, by the control circuitry, a first duration of the first data unit based on the received portion. The method further includes generating, by the control circuitry, a second data unit with data to be transmitted and transmitting, by the control circuitry, the second data unit to the remote device while receiving the unreceived portion of the first data unit. The second data unit has a second duration equal to the remaining duration of an unreceived portion of the first data unit.