Enhanced acknowledgement and retransmission mechanism

• US 9,432,251 B2
• Filed: 03/08/2013
• Issued: 08/30/2016
• Est. Priority Date: 03/08/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Newman, Richard, Rajkotia, Purva R.
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Ajid, Abdeltif
• Application Number:
  US13/790,631
• Publication Number:
  US 20140254351A1
• Time in Patent Office: 1,271 Days
• Field of Search: 370/228, 370/229, 370/235, 370/242, 370469-473
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1864 ARQ related signaling H04L1/1607 takes precedence
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability
• CPC Class Codes: H04L 2001/0096 Channel splitting in point-to-point links
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities

Abstract

Protocol data units (PDUs) associated with a packet stream are transmitted with sequence numbers to support reordering and selective acknowledgement. A selective acknowledgement (SACK) message may be used to indicate at least one sequence number of a lost or corrupted PDU which was not properly received by the receiving device. Responsive to the SACK message, the lost or corrupted PDU is retransmitted via a different path of the network, different from the path used to transmit the original PDU. Lost or corrupted PDUs may not be retransmitted if the estimated retransmission delay is greater than a delay tolerance associated with the quality of service requirements of the application. Instead, a control message (i.e. “cut losses” message) may be transmitted to indicate that PDUs earlier than a particular sequence number will not be transmitted.

Claims

1. A method for communicating via a network, the method comprising:

transmitting, from a first device via at least a first path of the network to a second device, a series of protocol data units (PDUs), wherein each PDU of the series of PDUs includes an associated sequence number;

receiving a first selective acknowledgement (SACK) message from the second device indicating that at least one unacknowledged PDU of the series of PDUs was not properly received by the second device; and

transmitting a control indicator responsive to receiving the first SACK message, the control indicator including a first sequence number to indicate that the first device will not retransmit an unacknowledged PDU associated with a prior sequence number earlier than the first sequence number.

2. The method of claim 1, retransmitting, via a second path of the network, a first PDU indicated by the first SACK message responsive to receiving the first SACK message, wherein the second path has a lower latency relative to the first path.

3. The method of claim 1, further comprising:

determining whether to retransmit a first unacknowledged PDU indicated by the first SACK message based, at least in part, on an estimated retransmission delay for the first unacknowledged PDU and at least one quality of service requirement associated with the series of PDUs.

4. The method of claim 3, further comprising:

refraining from retransmitting the first unacknowledged PDU based, at least in part, on the estimated retransmission delay being greater than a delay tolerance threshold associated with the at least one quality of service requirement.

5. The method of claim 1,

wherein the control indicator comprises a control message.

6. The method of claim 1, wherein transmitting the control indicator comprises retransmitting a first unacknowledged PDU indicated by the first SACK message, and wherein the control indicator is included with the first unacknowledged PDU.

7. The method of claim 1, wherein the sequence numbers are useable by the second device to deliver data from the series of PDUs to upper layers in an order that the series of PDUs were transmitted.

8. The method of claim 1, wherein the series of PDUs transmitted via the first path comprise a first subset of PDUs associated with a packet stream, the method further comprising:

transmitting, from the first device via a second path to the second device, a second subset of PDUs associated with the packet stream, wherein each PDU of the second subset of PDUs includes an associated sequence number.

9. The method of claim 8, wherein sequence numbers associated with PDUs from the first subset of PDUs and the second subset of PDUs are unique among the PDUs for the packet stream.

10. The method of claim 8, wherein the first SACK message indicates sequence numbers of unacknowledged PDUs from both of the first subset of PDUs and the second subset of PDUs.

11. The method of claim 8, wherein the first SACK message is associated with acknowledgement feedback regarding the first subset of PDUs, the method further comprising:

receiving a second SACK message associated with other acknowledgement feedback regarding the second subset of PDUs.

12. The method of claim 11, wherein the first SACK message and the second SACK message are received at the first device via a same feedback path from the second device to the first device.

13. The method of claim 1, wherein the associated sequence number included in each PDU of the series of PDUs are included in a virtual local area network (VLAN) header that has been repurposed to include the associated sequence number.

35. The method of claim 1,

wherein transmitting the series of PDUs comprises transmitting a first subset of the series of PDUs via the first path of the network and transmitting a second subset of the series of PDUs via a second path of the network,

wherein the series of PDUs is associated with a packet stream, and

wherein the sequence numbers are unique among the series of PDUs associated with the packet stream regardless of which path a PDU of the series of PDUs traverses through the network.

36. The method of claim 35, wherein the sequence numbers included in the series of PDUs are assigned at a media access control (MAC) layer, and wherein the packet stream is associated with a higher layer than the MAC layer.

37. The method of claim 35, wherein transmitting the first subset and transmitting the second subset comprises:

determining latencies of the first path and the second path; and

scheduling transmission of the first subset and the second subset via the first path and the second path, respectively, based, at least in part, on the latencies of the first path and the second path such that the series of PDUs arrive in approximate order.

14. A first device comprising:

a network interface configured to transmit, from the first device via at least a first path of a network to a second device, a series of protocol data units (PDUs), wherein each PDU of the series of PDUs includes an associated sequence number; and

a selective acknowledgement (SACK) and retransmit (SACK/Retransmit) controller configured to receive a first SACK message from a second device indicating that at least one unacknowledged PDU of a series of protocol data units (PDU s) was not properly received by the second device and to transmit a control indicator responsive to receipt of the first SACK message, the control indicator including a first sequence number to indicate that the first device will not retransmit an unacknowledged PDU associated with a prior sequence number earlier than the first sequence number.

15. The first device of claim 14, wherein the SACK/Retransmit controller is further configured to:

retransmit, via a second path of the network, a first PDU indicated by the first SACK message responsive to the receipt of the first SACK message, wherein the second path has a lower latency relative to the first path.

16. The first device of claim 14, wherein the SACK/Retransmit controller is further configured to:

determine whether to retransmit a first unacknowledged PDU indicated by the first SACK message based, at least in part, on an estimated retransmission delay of the first unacknowledged PDU and at least one quality of service requirement associated with the series of PDUs.

17. The first device of claim 16, wherein the SACK/Retransmit controller is further configured to:

refrain from retransmission of the first unacknowledged PDU based, at least in part, on the estimated retransmission delay being greater than a delay tolerance threshold associated with the at least one quality of service requirement.

18. The first device of claim 16,

wherein the control indicator comprises a control message.

19. The first device of claim 14, wherein the SACK/Retransmit controller configured to transmit the control indicator comprises the SACK/Retransmit controller being further configured to retransmit a first unacknowledged PDU indicated by the first SACK message, and wherein the control indicator is included with the first unacknowledged PDU.

20. The first device of claim 14, wherein the sequence numbers are useable by the second device to deliver data from the series of PDUs to upper layers in an order that the series of PDUs were transmitted.

21. The first device of claim 14, wherein the series of PDUs transmitted via the first path comprise a first subset of PDUs associated with a packet stream, and wherein the SACK/Retransmit controller is further configured to:

transmit, from the first device via a second path to the second device, a second subset of PDUs associated with the packet stream, wherein each PDU of the second subset of PDUs includes an associated sequence number.

22. The first device of claim 21, wherein sequence numbers associated with PDUs from the first subset of PDUs and from the second subset of PDUs are unique among the PDUs for the packet stream.

23. The first device of claim 21, wherein the first SACK message indicates sequence numbers of unacknowledged PDUs from both of the first subset of PDUs and the second subset of PDUs.

24. The first device of claim 21, wherein the first SACK message is associated with acknowledgement feedback regarding the first subset of PDUs, and wherein the SACK/Retransmit controller is further configured to:

receive a second SACK message associated with other acknowledgement feedback regarding the second subset of PDUs.

25. The first device of claim 24, wherein the first SACK message and the second SACK message are received at the first device via a same feedback path from the second device to the first device.

26. A non-transitory computer readable medium having instructions stored therein which, when executed by a processor of a first device, cause the first device to:

transmit, from the first device via at least a first path of a network to a second device, a series of protocol data units (PDUs), wherein each PDU of the series of PDUs includes an associated sequence number;

receive a selective acknowledgement (SACK) message from the second device indicating that at least one unacknowledged PDU of the series of PDUs was not properly received by the second device; and

transmit a control indicator responsive to receipt of the SACK message, the control indicator including a first sequence number to indicate that the first device will not retransmit an unacknowledged PDU associated with a prior sequence number earlier than the first sequence number.

27. The non-transitory computer readable medium of claim 26, wherein the instructions, when executed by the processor of the first device, cause the first device to:

determine whether to retransmit a first unacknowledged PDU indicated by the SACK message based, at least in part, on an estimated retransmission delay of the first unacknowledged PDU and at least one quality of service requirement associated with the series of PDUs.

28. The non-transitory computer readable medium of claim 27, wherein the instructions, when executed by the processor of the first device, cause the first device to:

refrain from retransmitting the first unacknowledged PDU based, at least in part, on the estimated retransmission delay being greater than a delay tolerance threshold associated with the at least one quality of service requirement.

29. The non-transitory computer readable medium of claim 26, wherein the control indicator comprises a control message.

30. The non-transitory computer readable medium of claim 26, wherein the instructions, when executed by the processor of the first device, cause the first device to:

retransmit a first unacknowledged PDU indicated by the SACK message,

wherein the control indicator is included with the first unacknowledged PDU.

31. An apparatus for communicating via a network, the apparatus comprising:

means for transmitting, from a first device via at least a first path of the network to a second device, a series of protocol data units (PDUs), wherein each PDU of the series of PDUs includes an associated sequence number;

means for receiving a selective acknowledgement (SACK) message from the second device indicating that at least one unacknowledged PDU of the series of PDUs was not properly received by the second device; and

means for transmitting a control indicator responsive to receiving the SACK message, the control indicator including a first sequence number to indicate that the first device will not retransmit an unacknowledged PDU associated with a prior sequence number earlier than the first sequence number.

32. The apparatus of claim 31, further comprising:

means for determining whether to retransmit a first unacknowledged PDU indicated in the SACK message based, at least in part, on an estimated retransmission delay of the first unacknowledged PDU and at least one quality of service requirement of the series of PDUs.

33. The apparatus of claim 32 further comprising:

means for refraining from retransmitting the first unacknowledged PDU based, at least in part, on the estimated retransmission delay being greater than a delay threshold associated with the at least one quality of service requirement.

34. The apparatus of claim 32, wherein the control indicator is included in a control message or in a header of a retransmitted PDU.