RANDOM ACCESS PROCEDURE ENHANCEMENTS FOR HETEROGENEOUS NETWORKS

• US 20110250913A1
• Filed: 04/12/2011
• Published: 10/13/2011
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Damnjanovic, Aleksandar, Luo, Tao, Wei, Yongbin, Malladi, Durga Prasad, Ji, Tingfang, Song, Osok, Vajapeyam, Madhavan Srinivasan, Barbieri, Alan
• Granted Patent: US 8,666,398 B2
• Time in Patent Office: Days
• US Class Current: 455/507
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Certain aspects of the present disclosure provide various mechanisms that allow a user equipment to convey information regarding one or more attributes to a base station during a random access (RA) procedure. The attributes may include, for example a capability of the UE (e.g., to support a particular feature or version of a standard) or a condition of the UE (e.g., if it is currently experiencing an interference condition).

Claims

1. A method for wireless communications, comprising:

receiving, by a user equipment (UE) from a base station, configuration parameters for performing different random access (RA) procedures; and

notifying the base station of an attribute of the UE by transmitting one or more RA messages in accordance with one of the RA procedures, wherein the attribute is indicated by the RA procedure used.

2. The method of claim 1, wherein:

the attribute comprises detection of an interference condition by the UE.

3. The method of claim 2, wherein:

a first RA procedure is used if an interference condition is not detected; and

a second RA procedure is used if an interference condition is detected.

4. The method of claim 2, further comprising:

determining the interference condition exists if at least one of a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement exceeds a threshold value.

5. The method of claim 4, further comprising receiving the threshold value from the base station.

6. The method of claim 5, wherein the threshold value is broadcast from the base station in a system information block (SIB).

7. The method of claim 2, further comprising:

determining resource partitioning information (RPI) that indicates subframes subject to cooperative partitioning of resources between a serving base station and one or more non-serving base stations; and

utilizing the RPI when performing the second RA procedure.

8. The method of claim 7, wherein utilizing the RPI when performing the second RA procedure comprises transmit messages to the serving Node B on subframes subject to cooperative partitioning.

9. The method of claim 8, wherein utilizing the RPI when performing the second RA procedure comprises transmitting a first message in a first subframe that is not subject to cooperative partitioning to ensure at least one second subsequent message is transmitted in a second subframe that is subject to cooperative partitioning.

10. The method of claim 9, wherein the second subsequent message is transmitted from the serving Node B.

11. The method of claim 7, further comprising:

transmitting a first RA message to the base station; and

attempting to decode a second RA message received from the base station, even if an acknowledgement if not received for the first RA message.

12. The method of claim 11, further comprising:

continuing a RA procedure if the second RA message is successfully decoded; and

re-starting the RA procedure if the second RA message is not successfully decoded.

13. The method of claim 2, further comprising:

determining the interference condition exists; and

sending a message, during a RA procedure, notifying a base station that the interference condition exists.

14. The method of claim 8, wherein the message comprises a bit indicating the interference condition exists.

15. The method of claim 8, further comprising:

receiving a message from the base station with a delay bit set; and

sending the message notifying the base station that the interference condition exists comprises, at a later time than if the delay bit was not set.

16. The method of claim 1, wherein:

the attribute comprises a capability of the UE; and

the UE notifies the base station of the capability by the RA procedure utilized.

17. The method of claim 16, further comprising:

receiving a message from the base station with a delay bit set; and

sending at least one message during the RA procedure at a later time than if the delay bit was not set.

18. The method of claim 16, wherein the RA procedures comprise:

a first RA procedure to indicate the UE is capable of complying with a first version of a standard; and

a second RA procedure to indicate the UE is capable of complying with a first version of a standard in accordance with a second version of the standard later than the first version.

19. The method of claim 1, wherein:

the UE transmits at least one preamble first and second preambles to indicate the attribute to the base station.

20. The method of claim 19, wherein the UE transmits first and second preambles to indicate the attribute.

21. The method of claim 19, wherein:

the UE transmits first and second preambles to indicate to the base station one or more RA procedures the UE is capable of performing

22. The method of claim 21, wherein the first and second preambles are transmitted in a same subframe but using different frequency resources.

23. The method of claim 21, wherein the first and second preambles are transmitted with different preamble IDs.

24. The method of claim 21, wherein the first and second preambles are transmitted in different subframes.

25. A method for wireless communications, comprising:

configuring a user equipment (UE) with parameters for performing different random access (RA) procedures;

receiving one or more RA messages sent in accordance with one of the RA procedures; and

identifying an attribute of the UE based on the RA procedure used.

26. The method of claim 25, wherein:

the attribute comprises detection of an interference condition by the UE.

27. The method of claim 26, wherein:

determining the UE has not detected the interference condition if the UE utilizes a first RA procedure; and

determining the UE has detected the interference condition if the UE utilizes a second RA procedure.

28. The method of claim 27, further comprising:

transmitting resource partitioning information (RPI) to the UE for use in performing the second RA procedure, the RPI indicating subframes subject to cooperative partitioning of resources between a serving base station and one or more non-serving base stations.

29. The method of claim 27, wherein the receiving comprises:

receiving a message comprising at least one of a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement.

30. The method of claim 29, further comprising:

transmitting a threshold value from the base station, wherein at least one of the received RA messages indicates at least one of a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement exceeds the threshold value.

31. The method of claim 30, wherein transmitting the threshold value comprises broadcasting the threshold value in a system information block (SIB).

32. The method of claim 26, wherein at least one of the RA messages comprises a bit indicating the interference condition exists.

33. The method of claim 26, further comprising:

transmitting a message from the base station with a delay bit set; and

receiving a message notifying the base station that the interference condition exists comprises, at a later time than if the delay bit was not set.

34. The method of claim 25, wherein:

the attribute comprises a capability of the UE; and

the UE notifies the base station of the capability by the RA procedure utilized.

35. The method of claim 34, wherein the RA procedures comprise:

a first RA procedure to indicate the UE is capable of complying with a first version of a standard; and

a second RA procedure to indicate the UE is capable of complying with a first version of a standard in accordance with a second version of the standard later than the first version.

36. The method of claim 25, wherein:

the receiving comprises receiving at least one preamble transmitted from the UE; and

the identifying comprises identifying the at least one attribute based on the at least one preamble.

37. The method of claim 36, wherein the at least one preamble comprises at least first and second preambles.

38. The method of claim 37, wherein the first and second preambles are received in a same subframe but using different frequency resources.

39. The method of claim 37, wherein the first and second preambles are received with different preamble IDs.

40. The method of claim 37, wherein the first and second preambles are received in different subframes.

41. The method of claim 37, wherein the receiving comprises:

concluding that the first and second preambles are received from the same UE if the first and second preambles are received with timing and power that differs less than a threshold amount.

42. The method of claim 34, wherein:

the attribute comprises whether or not the at least one UE is capable of being aware of subframes subject to cooperative partitioning of resources between a serving Node B and one or more non-serving Node Bs.

43. The method of claim 42, wherein the determining comprises:

determining the at least one UE is capable of being aware of subframes subject to cooperative partitioning if the at least one transmission comprises a defined sequence transmitted on a random access channel.

44. The method of claim 42, wherein the determining comprises:

determining the at least one UE is capable of being aware of subframes subject to cooperative partitioning if the at least one transmission is sent using predefined frequency resources.

45. The method of claim 42, wherein the determining comprises:

determining the at least one UE is capable of being aware of subframes subject to cooperative partitioning if the at least one transmission is sent in a predefined time location.

46. A method for wireless communications, comprising:

identifying one or more subframes subject to cooperative partitioning of resources between a serving Node B and one or more non-serving Node Bs; and

configuring a user equipment (UE) for performing a random access (RA) procedure utilizing the one or more subframes.

47. The method of claim 46, wherein the UE is not aware of the one or more subframes subject to cooperative partitioning.

48. The method of claim 46, further comprising:

reserving additional subframes for the UE to perform random access to the serving NodeB.

49. The method of claim 46, further comprising receiving, from the UE, one or more random access procedure messages transmitted in one or more subframes subject to cooperative partitioning as part of the RA procedure.

50. The method of claim 46, further comprising transmitting, to the UE, one or more random access procedure messages in one or more subframes subject to cooperative partitioning as part of the RA procedure.

51. An apparatus for wireless communications, comprising:

means for receiving, by a user equipment (UE) from a base station, configuration parameters for performing different random access (RA) procedures; and

means for notifying the base station of an attribute of the UE by transmitting one or more RA messages in accordance with one of the RA procedures, wherein the attribute is indicated by the RA procedure used.

52. The apparatus of claim 51, wherein:

the attribute comprises detection of an interference condition by the UE.

53. The apparatus of claim 52, wherein:

a first RA procedure is used if an interference condition is not detected; and

a second RA procedure is used if an interference condition is detected.

54. The apparatus of claim 52, further comprising:

means for determining the interference condition exists if at least one of a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement exceeds a threshold value.

55. The apparatus of claim 54, further comprising means for receiving the threshold value from the base station.

56. The apparatus of claim 55, wherein the threshold value is broadcast from the base station in a system information block (SIB).

57. The apparatus of claim 51, wherein:

the attribute comprises a capability of the UE; and

the UE notifies the base station of the capability by the RA procedure utilized.

58. The apparatus of claim 57, further comprising:

means for receiving a message from the base station with a delay bit set; and

means for sending at least one message during the RA procedure at a later time than if the delay bit was not set.

59. The apparatus of claim 57, wherein the RA procedures comprise:

a first RA procedure to indicate the UE is capable of complying with a first version of a standard; and

a second RA procedure to indicate the UE is capable of complying with a first version of a standard in accordance with a second version of the standard later than the first version.

60. The apparatus of claim 51, wherein:

the UE transmits at least one preamble first and second preambles to indicate the attribute to the base station.

61. The apparatus of claim 60, wherein the UE transmits first and second preambles to indicate the attribute.

62. An apparatus for wireless communications, comprising:

means for configuring a user equipment (UE) with parameters for performing different random access (RA) procedures;

means for receiving one or more RA messages sent in accordance with one of the RA procedures; and

means for identifying an attribute of the UE based on the RA procedure used.

63. The apparatus of claim 62, wherein:

the attribute comprises detection of an interference condition by the UE.

64. The apparatus of claim 63, comprising:

means for determining the UE has not detected the interference condition if the UE utilizes a first RA procedure; and

means for determining the UE has detected the interference condition if the UE utilizes a second RA procedure.

65. The apparatus of claim 62, wherein:

the attribute comprises a capability of the UE; and

the UE notifies the base station of the capability by the RA procedure utilized.

66. The apparatus of claim 65, wherein the RA procedures comprise:

a first RA procedure to indicate the UE is capable of complying with a first version of a standard; and

a second RA procedure to indicate the UE is capable of complying with a first version of a standard in accordance with a second version of the standard later than the first version.

67. The apparatus of claim 62, wherein:

the means for receiving comprises means for receiving at least one preamble transmitted from the UE; and

the means for identifying comprises means for identifying the at least one attribute based on the at least one preamble.

68. The apparatus of claim 67, wherein the at least one preamble comprises at least first and second preambles.

69. An apparatus for wireless communications, comprising:

means for identifying one or more subframes subject to cooperative partitioning of resources between a serving Node B and one or more non-serving Node Bs; and

means for configuring a user equipment (UE) for performing a random access (RA) procedure utilizing the one or more subframes.

70. The apparatus of claim 69, wherein the UE is not aware of the one or more subframes subject to cooperative partitioning.

71. The apparatus of claim 69, further comprising:

means for reserving additional subframes for the UE to perform random access to the serving NodeB.

72. The apparatus of claim 69, further comprising means for receiving, from the UE, one or more random access procedure messages transmitted in one or more subframes subject to cooperative partitioning as part of the RA procedure.

73. The apparatus of claim 69, further comprising means for transmitting, to the UE, one or more random access procedure messages in one or more subframes subject to cooperative partitioning as part of the RA procedure.

74. An apparatus for wireless communications, comprising:

at least one processor configured to receive, by a user equipment (UE) from a base station, configuration parameters for performing different random access (RA) procedures and notify the base station of an attribute of the UE by transmitting one or more RA messages in accordance with one of the RA procedures, wherein the attribute is indicated by the RA procedure used; and

a memory coupled with the at least one processor.

75. An apparatus for wireless communications, comprising:

at least one processor configured to configure a user equipment (UE) with parameters for performing different random access (RA) procedures, receive one or more RA messages sent in accordance with one of the RA procedures, and identify an attribute of the UE based on the RA procedure used; and

a memory coupled with the at least one processor.

76. An apparatus for wireless communications, comprising:

at least one processor configured to identify one or more subframes subject to cooperative partitioning of resources between a serving Node B and one or more non-serving Node Bs and configuring a user equipment (UE) for performing a random access (RA) procedure utilizing the one or more subframes; and

a memory coupled with the at least one processor.

77. A computer program product comprising a computer readable medium having instructions stored thereon, the instructions executable by one or more processors for:

receiving, by a user equipment (UE) from a base station, configuration parameters for performing different random access (RA) procedures; and

notifying the base station of an attribute of the UE by transmitting one or more RA messages in accordance with one of the RA procedures, wherein the attribute is indicated by the RA procedure used.

78. A computer program product comprising a computer readable medium having instructions stored thereon, the instructions executable by one or more processors for:

configuring a user equipment (UE) with parameters for performing different random access (RA) procedures;

receiving one or more RA messages sent in accordance with one of the RA procedures; and

identifying an attribute of the UE based on the RA procedure used.

79. A computer program product comprising a computer readable medium having instructions stored thereon, the instructions executable by one or more processors for:

identifying one or more subframes subject to cooperative partitioning of resources between a serving Node B and one or more non-serving Node Bs; and

configuring a user equipment (UE) for performing a random access (RA) procedure utilizing the one or more subframes.