Adding hybrid ARQ to WLAN protocols with MAC based feedback

• US 8,004,992 B2
• Filed: 03/03/2008
• Issued: 08/23/2011
• Est. Priority Date: 03/03/2008
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Nandagopalan, Saishankar, Sampath, Ashwin, Nanda, Sanjiv, Abraham, Santosh
• Primary Examiner(s): ABELSON, RONALD B
• Application Number:
  US12/041,525
• Publication Number:
  US 20090219851A1
• Time in Patent Office: 1,268 Days
• Field of Search: 370/229, 370/235, 370/236, 370/328, 370/395.53
• US Class Current: 370/236
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]

Abstract

A wireless node having a MAC layer configured to coordinate access to a shared wireless medium using a MAC protocol, a PHY layer configured to provide an interface to the shared wireless medium, and a HARQ layer between the MAC and PHY layers, the HARQ layer being configured to support HARQ using the MAC protocol.

Claims

1. An apparatus for communication, comprising:

a MAC layer configured to coordinate access to a shared wireless medium using a MAC protocol;

a PHY layer configured to provide an interface to the shared wireless medium; and

a HARQ layer between the MAC and PHY layers, the HARQ layer being configured to support HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.

2. The apparatus of claim 1 wherein the MAC protocol comprises an IEEE 802.11 protocol.

3. The apparatus of claim 1 wherein the apparatus comprises a transmitting node, the HARQ layer being further configured to communicate with the peer node to determine whether the peer node is HARQ capable.

4. The apparatus of claim 3 wherein the HARQ layer is further configured to set up a protocol and state machine to support HARQ if the peer node is HARQ capable.

5. The apparatus of claim 1 wherein the apparatus comprises a receiving node, the HARQ layer being further configured to receive a message from the peer node requesting HARQ and set up a protocol and state machine to support HARQ in response to the message.

6. The apparatus of claim 1 wherein the apparatus comprises a transmitting node, the HARQ layer being further configured to assign a HARQ session ID to each HARQ session it maintains with the peer node.

7. The apparatus of claim 1 wherein the apparatus comprises a receiving node, the HARQ layer being further configured to receive a plurality of data packets each having a HARQ session ID and use the HARQ session IDs to configure and identify the data packets.

8. The apparatus of claim 1 wherein the HARQ layer is further configured to communicate with the peer node to negotiate a coding scheme for the HARQ.

9. The apparatus of claim 8 wherein the negotiated coding scheme comprises turbo coding, LDPC, chase combining, or any combination thereof.

10. The apparatus of claim 1 wherein the HARQ layer is further configured to receive a data packet from the MAC layer for transmission to the peer node and determine whether the data packet has been previously transmitted.

11. The apparatus of claim 10 wherein the HARQ layer, if it determines that the data packet has not been previously transmitted, is further configured to encode the data packet to generate systematic and parity symbols, provide the systematic symbols to the PHY layer for transmission, and store at least a portion of the parity symbols.

12. The apparatus of claim 11 wherein the HARQ layer being further configured to remove said at least a portion of the parity symbols from storage in response to an acknowledgement received by the MAC layer indicating that the peer node has successfully decoded the data packet transmitted by the PHY layer.

13. The apparatus of claim 10 wherein the HARQ layer, if it determines that the data packet has been previously transmitted, is further configured to retrieve from storage at least a portion of parity symbols generated from encoding the data packet for a first one of the previous transmissions, and provide said at least a portion of the parity symbols to the PHY layer for transmission.

14. The apparatus of claim 13 wherein the HARQ layer is further configured to determine that the data packet has been previously transmitted in response to a block acknowledgement received by the MAC layer.

15. The apparatus of claim 1 wherein the HARQ layer is further configured receive from the PHY layer a data packet that was transmitted by the peer node, decode the data packet, and provide the decoded data packet to the MAC layer.

16. The apparatus of claim 15 wherein the data packet includes a plurality of symbols, the HARQ layer being further configured to decode the data packet by combining the symbols in the data packet with any symbol received by the HARQ layer associated with one or more previous transmissions of the data packet.

17. The apparatus of claim 16 wherein the HARQ layer is further configured to store the symbols in the data packet for combining with one or more future transmissions of the data packet in response to an indication from the MAC layer that the data packet was not successfully decoded by the HARQ layer.

18. The apparatus of claim 16 wherein the HARQ layer is further configured to remove from storage said any symbols received by the HARQ layer associated with said one or more previous transmissions of the data packet in response to an indication from the MAC layer that the data packet was successfully decoded by the HARQ layer.

19. The apparatus of claim 1 wherein the HARQ layer is further configured to support a HARQ header that is combined with a PHY layer header for a data packet, wherein the data packet conforms to the MAC protocol.

20. The apparatus of claim 1 wherein the HARQ layer is further configured to receive a data packet from the MAC layer for transmission to the peer node and generate a HARQ header for the data packet.

21. The apparatus of claim 20 wherein the HARQ header comprises a transmit number indicating the number of times the data packet has been previously transmitted.

22. The apparatus of claim 20 wherein the HARQ header comprises a length corresponding to the data packet.

23. A method for communication, comprising:

coordinating access to a shared wireless medium using a MAC protocol;

providing an interface to the shared wireless medium; and

supporting HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.

24. The method of claim 23 wherein the MAC protocol comprises an IEEE 802.11 protocol.

25. The method of claim 23 wherein the support of HARQ comprises communicating from a transmitting node to the peer node to determine whether the peer node is HARQ capable.

26. The method of claim 25 wherein the support of HARQ further comprises setting up a protocol and state machine at the transmitting node to support HARQ if the peer node is HARQ capable.

27. The method of claim 23 wherein the support of HARQ comprises receiving a message at a receiving node from the peer node requesting HARQ and setting up a protocol and state machine to support HARQ in response to the message.

28. The method of claim 23 wherein the support of HARQ comprises assigning at a transmitting node a HARQ session ID to each HARQ session maintained with the peer node.

29. The method of claim 23 wherein the support of HARQ comprises receiving a plurality of data packets at a receiving node, each of the data packets having a HARQ session ID, and wherein the support of HARQ further comprises using the HARQ session IDs to configure and identify the data packets.

30. The method of claim 23 wherein the support of HARQ comprises communicating with the peer node to negotiate a coding scheme for the HARQ.

31. The method of claim 30 wherein the negotiated coding scheme comprises turbo coding, LDPC, chase combining, or any combination thereof.

32. The method of claim 23 wherein the support of HARQ comprises receiving a data packet from a MAC layer for transmission to the peer node and determining whether the data packet has been previously transmitted.

33. The method of claim 32 wherein the support of HARQ further comprises determining that the data packet has not been previously transmitted, encoding the data packet to generate systematic and parity symbols, providing the systematic symbols to a PHY layer for transmission, and storing at least a portion of the parity symbols.

34. The method of claim 33 wherein the support of HARQ further comprises removing said at least a portion of the parity symbols from storage in response to an acknowledgement received by the MAC layer indicating that the peer node has successfully decoded the data packet transmitted by the PHY layer.

35. The method of claim 32 wherein the support of HARQ further comprises determining that the data packet has been previously transmitted, retrieving from storage at least a portion of parity symbols generated from encoding the data packet for a first one of the previous transmissions, and providing said at least a portion of the parity symbols to a PHY layer for transmission.

36. The method of claim 23 wherein the support of HARQ comprises determining that the data packet has been previously transmitted in response to a block acknowledgement received by a MAC layer.

37. The method of claim 23 wherein the support of HARQ comprises receiving from a PHY layer a data packet that was transmitted by the peer node, decoding the data packet, and providing the decoded data packet to a MAC layer.

38. The method of claim 37 wherein the data packet includes a plurality of symbols, the support of the HARQ further comprising decoding the data packet by combining the symbols in the data packet with any received symbols associated with on one or more previous transmissions of the data packet.

39. The method of claim 38 wherein the support of HARQ further comprises storing the symbols in the data packet for combining with one or more future transmissions of the data packet in response to an indication from the MAC layer that the data packet was not successfully decoded.

40. The method of claim 38 wherein the support of HARQ further comprises removing from storage said any received symbols associated with said one or more previous transmissions of the data packet in response to an indication from the MAC layer that the data packet was successfully decoded.

41. The method of claim 23 wherein the support of the HARQ comprises supporting a HARQ header that is combined with a PHY layer header for a data packet, wherein the data packet conforms with the MAC protocol.

42. The method of claim 23 wherein the support of the HARQ comprises receiving a data packet from a MAC layer for transmission to the peer node and generating a HARQ header for the data packet.

43. The method of claim 42 wherein the HARQ header comprises a transmit number indicating the number of times the data packet has been previously transmitted.

44. The method of claim 42 wherein the HARQ header comprises a length corresponding to the data packet.

45. An apparatus for communication, comprising:

means for coordinating access to a shared wireless medium using a MAC protocol;

means for providing an interface to the shared wireless medium; and

means for supporting HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.

46. The apparatus of claim 45 wherein the MAC protocol comprises an IEEE 802.11 protocol.

47. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for communicating with the peer node to determine whether the peer node is HARQ capable.

48. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for communicating with a receiving node to determine whether the peer node is HARQ capable.

49. The apparatus of claim 48 wherein the means for supporting HARQ further comprises means for setting up a protocol and state machine node to support HARQ if the peer node is HARQ capable.

50. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for receiving a message from the peer node requesting HARQ and means for setting up a protocol and state machine to support HARQ in response to the message.

51. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for assigning a HARQ session ID to each HARQ session maintained with a receiving node.

52. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for receiving a plurality of data packets at a receiving node, each of the data packets having a HARQ session ID, and means for using the HARQ session IDs to configure and identify the data packets.

53. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for communicating with the peer node to negotiate a coding scheme for the HARQ.

54. The apparatus of claim 53 wherein the negotiated coding scheme comprises turbo coding, LDPC, chase combining, or any combination thereof.

55. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for receiving a data packet from a MAC layer for transmission to the peer node and means for determining whether the data packet has been previously transmitted.

56. The apparatus of claim 55 wherein, if the data packet has not been previously transmitted, the means for supporting HARQ further comprises means for encoding the data packet to generate systematic and parity symbols, means for providing the systematic symbols to a PHY layer for transmission, and means for storing at least a portion of the parity symbols.

57. The apparatus of claim 56 wherein the means for supporting HARQ further comprises means for removing said at least a portion of the parity symbols from storage in response to an acknowledgement received by the MAC layer indicating that the peer node has successfully decoded the data packet transmitted by the PHY layer.

58. The apparatus of claim 55 wherein, if the data packet has been previously transmitted, the means for supporting HARQ further comprises means for retrieving from storage at least a portion of parity symbols generated from encoding the data packet for a first one of the previous transmissions, and means for providing said at least a portion of the parity symbols to a PHY layer for transmission.

59. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for determining that the data packet has been previously transmitted in response to a block acknowledgement received by a MAC layer.

60. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for receiving from a PHY layer a data packet that was transmitted by the peer node, means for decoding the data packet, and means for providing the decoded data packet to a MAC layer.

61. The apparatus of claim 60 wherein the data packet includes a plurality of symbols, the means for supporting HARQ further comprising means for decoding the data packet by combining the symbols in the data packet with any received symbols associated with one or more previous transmissions of the data packet.

62. The apparatus of claim 61 wherein the means for supporting HARQ comprises means for storing the symbols in the data packet for combining with one or more future transmissions of the data packet in response to an indication from the MAC layer that the data packet was not successfully decoded.

63. The apparatus of claim 61 wherein the means for supporting HARQ further comprises means for removing from storage said any received symbols associated with said one or more previous transmissions of the data packet in response to an indication from the MAC layer that the data packet was successfully decoded.

64. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for supporting a HARQ header that is combined with a PHY layer header for a data packet, wherein the data packet conforms with the MAC protocol.

65. The apparatus of claim 45 wherein the means for supporting HARQ comprises means for receiving a data packet from a MAC layer for transmission to the peer node and means for generating a HARQ header for the data packet.

66. The apparatus of claim 65 wherein the HARQ header comprises a transmit number which indicates the number of times the data packet has been previously transmitted.

67. The apparatus of claim 65 wherein the HARQ header comprises a length corresponding to the data packet.

68. A computer-program product for communication, comprising:

a machine-readable medium comprising instructions executable by a processing system to;

coordinate access to a shared wireless medium using a MAC protocol;

provide an interface to the shared wireless medium; and

support HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.

69. An access terminal, comprising:

a user interface;

an application layer configured to support the user interface;

a MAC layer configured to coordinate access to a shared wireless medium using a MAC protocol to support the application layer;

a PHY layer configured to provide an interface to the shared wireless medium; and

a HARQ layer between the MAC and PHY layers, the HARQ layer being configured to support HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.

70. An access point, comprising:

a wireless network adapter configured to support a backhaul connection for a peer node to a network;

a MAC layer configured to coordinate access to a shared wireless medium using a MAC protocol to support communications with the peer node;

a PHY layer configured to provide an interface to the shared wireless medium; and

a HARQ layer between the MAC and PHY layers, the HARQ layer being configured to support HARQ using the MAC protocol, wherein the HARQ layer is further configured to communicate with a peer node to determine whether the peer node is HARQ capable.