Patent ID: 6868064

Claim:
A method of confirming a receipt of protocol data unit in a mobile communication system, the method comprising a step of sending a polling signal to a receiving system during a transmission of protocol data units (PDU) when the following conditions are satisfied, (1) sequence number of the next PDU to be transmitted for a first time (VT(S)) and is smaller than the sequence number of the first PU not allowed by a peer receiver (VT(MS)) (2) window transmission percentage (X) is bigger than a parameter which indicates when the transmitter should poll the receiver in case of performing window-based polling(Poll_Window), wherein the equation for window transmission percentage (X) is a function of the sequence number of the next PU to be transmitted for the first time (VT(S)), and do not have maximum value when the sequence number of the next PU to be transmitted for the first time (VT(S)) equals to the sequence number of the first PU not allowed by the peer receiver (VT(MS)).