Method of controlling a receiver and a transmitter in a wireless communication system to handle a transmission window size change procedure

A method of controlling a receiver and a transmitter to handle a transmission window size change procedure is disclosed. The method includes driving the receiver to deliver a control message having a window size parameter to the transmitter (100) for adjusting a transmission window size of the transmitter, and driving the transmitter to output an acknowledgement message to the receiver (106) and adjust the transmission window size according to the window size parameter when the transmitter receives the control message.