LOCAL DROP CONTROL FOR A TRANSMIT BUFFER IN A REPEAT TRANSMISSION PROTOCOL DEVICE

• US 20090319850A1
• Filed: 06/24/2009
• Published: 12/24/2009
• Est. Priority Date: 06/24/2008
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Baek, Seung, Vedantham, Ramanuja
• Application Number:
  US12/490,587
• Publication Number:
  US 20090319850A1
• Time in Patent Office: Days
• US Class Current: 714/748
• CPC Class Codes: H04L 1/1874 Buffer management

Abstract

A wireless communication device includes a transmit buffer and control logic coupled to the transmit buffer. The control logic selectively implements an “ACK2 scheme” that drops a data block in the transmit buffer based on reception of two consecutive HARQ ACKs associated with the data block.

Claims

1. A wireless communication device, comprising:

a transmit buffer; and

control logic coupled to the transmit buffer, wherein the control logic selectively implements an “

ACK2 scheme”

that drops a data block in the transmit buffer based on reception of two consecutive HARQ ACKs associated with the data block.

2. The wireless communication device of claim 1 wherein the transmit buffer is sized based on the ACK2 scheme.

3. The wireless communication device of claim 2 wherein the transmit buffer is sized based on the buffer reduction formula:

[T_NACK2−

(α

*T_ACK2+β

*T_NACK2)]/T_NACK2, where T_NACK2=status report timing without the ACK2 scheme, T_ACK2=status report timing with the ACK2 scheme, α

=a percentage estimate of how often the ACK2 scheme is used, and β

=1−

α

.

4. The wireless communication device of claim 1 wherein the control logic selectively implements an “

ACK/NDI scheme”

that drops a data block in the transmit buffer based on reception of a HARQ ACK associated with the data block and reception of a new data indicator (NDI).

5. The wireless communication device of claim 4 wherein the transmit buffer is sized based on the ACK/NDI scheme.

6. The wireless communication device of claim 4 wherein the control logic implements both the ACK2 scheme and the ACK/NDI scheme.

7. The wireless communication device of claim 6 wherein the transmit buffer is sized based on the ACK2 scheme and the ACK/NDI scheme.

8. The wireless communication device of claim 1 wherein the transmit buffer is part of a Radio Link Control (RLC) layer.

9. The wireless communication device of claim 1 wherein the control logic is part of a Media Access Control (MAC) layer.

10. The wireless communication device of claim 1 wherein the control logic operates only during Acknowledged Mode (AM) operation of the wireless communication device.

11. A transmitter, comprising:

a Radio Link Control (RLC) layer with an RLC buffer, the RLC layer causes a data block in the RLC buffer to be dropped in response to a local RLC status report; and

a Media Access Control (MAC) layer coupled to the RLC layer, wherein the MAC layer generates the local RLC status report upon receipt of a HARQ ACK corresponding to the data block and a supplemental validity indicator for the data block.

12. The transmitter of claim 11 wherein the supplemental validity indicator is a subsequent HARQ ACK related to the data block.

13. The transmitter of claim 11 wherein the supplemental validity identifier is a new data indicator (NDI).

14. The transmitter of claim 11 wherein the RLC buffer is sized based on an estimation of how often local RLC status reports will be generated.

15. A method for a Long Term Evolution (LTE) device, comprising:

storing a data block in a transmit buffer;

dropping the data block from the transmit buffer before receipt of a remotely-generated status report related to the data block based on a locally-generated status report related to the data block.

16. The method of claim 15 further comprising generating the locally-generated status report upon receipt of two consecutive HARQ ACKs.

17. The method of claim 15 further comprising generating the locally-generated status report upon receipt of a HARQ ACK and a new data indicator (NDI).

18. The method of claim 15 further comprising further comprising generating the locally-generated status report by a Media Access Control (MAC) layer.

19. The method of claim 18 wherein further comprising forwarding the locally-generated status report from the MAC layer to a Radio Link Control (RLC) layer to enable said dropping.

20. The method of claim 15 wherein a size of the transmit buffer is selected based on an estimation of locally-generated status report parameters.