Method and apparatus for handling control PDUs during re-establishment of transmitting sides in wireless communications systems

1. A method of handling control PDUs in a wireless communications system having a communications device having an Radio Link Controller (RLC) entity having a transmitting side and a receiving side when reestablishing the transmitting side comprising:

only reestablishing the transmitting side in the Radio Link Controller (RLC) entity of the communications device;

discarding a first control Packet Data Unit (PDU) corresponding to the transmitting side:

retaining and not discarding a second control Packet Data Unit (PDU) corresponding to the receiving side: and

wherein the first control Packet Data Unit (PDU) corresponding to the transmitting side is a move receiving window (MRW) STATUS PDU.

2. A communications device utilized in a wireless communications system, an Radio Link Controller (RLC) entity of the communications system having a transmitting side and a receiving side, utilized for accurately reestablishing the transmitting side, the wireless communications device comprising:

a control circuit for realizing functions of the wireless communications device: a central processing unit for executing a program code to operate the control circuit; and

a memory for storing the program code;

wherein the program code comprises:

only reestablishing the transmitting side in the Radio Link Controller (RLC) entity of the communications device:

discarding a first control Packet Data Unit (PDU) corresponding to the transmitting side: and

retaining and not discarding a second control Packet Data Unit (PDU) corresponding to the receiving side; and

wherein the first control Packet Data Unit (PDU) corresponding to the transmitting side is a move receiving window (MRW) STATUS PDU.

3. The method of claim 1 , wherein the first control PDU corresponding to the transmitting side is a RESET PDU.

4. The method of claim 1 , wherein the second control PDU

corresponding to the receiving side is an acknowledged negatively acknowledged (ACK/NACK) STATUS PDU.

5. The method of claim 1 , wherein the second control PDL

corresponding to the receiving side is a change window size STATUS PDU.

6. The method of claim 1 , wherein the second control PDU corresponding to the receiving side is an MRW ACK/NACK STATUS PDU.

7. The method of claim 1 , wherein the second control PDU

corresponding to the receiving side is a RESET ACK PDU.

8. The method of claim 1 , wherein the wireless communications system operates in an acknowledged mode (AM).

9. The method of claim 1 , wherein the communications device is a mobile phone, a wireless mobile communications device, or a networking device.

10. The wireless communications device of claim 2 , wherein the first control PDU corresponding to tile transmitting side is a RESET PDU.

11. The wireless communications device of claim 2 , wherein the second control PDU corresponding to tile receiving side is an acknowledged/negatively acknowledged (ACK/NACK) STATUS PDU.

12. The wireless communications device of claim 2 , wherein the second control PDU corresponding to the receiving side is a change window size STATUS PDU.

13. The wireless communications device of claim 2 , wherein the second control PDU corresponding to the receiving side is an MRW ACK′NACK STATUS PDU.

14. The wireless communications device of claim 2 , wherein the second control! PDU corresponding to the receiving side is a RESET ACK PDU.

15. The wireless communications device of claim 2 , wherein the wireless communications system operates in an acknowledged mode (AM).

16. Tile wireless communications device of claim 2 , wherein the communications device is a mobile phone, a wireless mobile communications device, or a networking device.