One embodiment relates to a method of processing data in a transmitter. In the method, a timestamp is generated for a data unit. The data unit is stored in a memory unit in the transmitter. The data unit is transmitted from the transmitter to a receiver. The transmitter waits up to a predetermined time measured with respect to the timestamp to receive an acknowledgement from the receiver. Based on whether the acknowledgement is received within the predetermined time, the transmitter selectively retransmits the data unit to the receiver. Other methods and systems are also disclosed.