USING IDENTIFIER MAPPING TO RESOLVE ACCESS POINT IDENTIFIER AMBIGUITY

• US 20100067371A1
• Filed: 09/16/2009
• Published: 03/18/2010
• Est. Priority Date: 09/18/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Nanda, Sanjiv, Sundarraman, Chandrasekhar T., Tinnakornsrisuphap, Peerapol, Gogic, Aleksandar M., Gupta, Rajarshi
• Granted Patent: US 8,379,512 B2
• Time in Patent Office: Days
• US Class Current: 370/216
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Ambiguity (e.g., confusion) associated with access point identifiers may be resolved by querying candidate target access points and/or by using historical records indicative of one or more access points that the access point has previously accessed. For example, messages may be sent to access points that are assigned the same identifier to cause the access points to monitor for a signal from an access terminal that received the identifier from a target access point. The target access point may then be identified based on any responses that indicate that a signal was received from the access terminal In some aspects the access points subject to being queried may be selected using a tiered priority. In addition, it may be determined based on prior handoffs of a given access terminal that when that access terminal reports a given identifier, the access terminal usually ends up being handed-off to a particular access point. Accordingly, a mapping may be maintained for that access terminal that maps the identifier to that access point so that the mapping may be used to resolve any future confusion associated with the use of that identifier by that access terminal.

Claims

1. A method of communication, comprising:

determining a mapping associated with an access terminal, wherein the mapping relates a first identifier used by the access terminal to identify a first access point to a second identifier assigned to the first access point; and

storing information indicative of the mapping.

2. The method of claim 1, wherein the determination of the mapping comprises determining that the access terminal previously accessed the first access point.

3. The method of claim 1, wherein the determination of the mapping is made upon resolving confusion associated with use of the first identifier by the access terminal.

4. The method of claim 1, wherein a second access point receives the first and second identifiers via a measurement report from the access terminal to determine the mapping.

5. The method of claim 1, wherein:

a second access point receives the first identifier from the access terminal; and

the second access point receives the second identifier via a message from the first access point that indicates that the access terminal accessed the first access point after a radio link failure.

6. The method of claim 5, wherein the message from the first access point comprises a request for access terminal context information to be relayed from the second access point to the first access point.

7. The method of claim 1, wherein:

the access terminal was previously handed-over to the first access point from a second access point; and

the second access point receives the second identifier via a message relating to the handover.

8. The method of claim 1, further comprising:

receiving a measurement report comprising the first identifier from the access terminal;

determining that there is access point confusion associated with the first identifier; and

using the stored information to resolve the confusion.

9. The method of claim 1, further comprising:

receiving, at a second access point, a measurement report from the access terminal comprising the first identifier;

using the stored information to determine that the access terminal should be handed-over from the second access point to the first access point; and

sending a message to prepare the first access point for handover of the access terminal

10. The method of claim 1, further comprising:

determining another mapping associated with the access terminal, wherein the another mapping relates the first identifier to at least one other identifier assigned to at least one other access point, and wherein the stored information is indicative of the another relationship;

identifying the first access point and the at least one other access point as candidate target access points for handover of the access terminal based on the stored information; and

sending messages to prepare the first access point and the at least one other access point for handover of the access terminal.

11. The method of claim 1, wherein the first identifier comprises a pilot pseudonoise offset or a physical cell identifier.

12. The method of claim 1, wherein:

the first identifier comprises a physical cell identifier; and

the second identifier comprises a global cell identifier.

13. The method of claim 1, wherein:

the first access point comprises a femto access point;

the determination of the mapping is performed at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

14. An apparatus for communication, comprising:

a mapping controller configured to determine a mapping associated with an access terminal, wherein the mapping relates a first identifier used by the access terminal to identify a first access point to a second identifier assigned to the first access point; and

a memory device configured to store information indicative of the mapping.

15. The apparatus of claim 14, wherein the determination of the mapping comprises determining that the access terminal previously accessed the first access point.

16. The apparatus of claim 14, wherein the determination of the mapping is made upon resolving confusion associated with use of the first identifier by the access terminal.

17. The apparatus of claim 14, further comprising:

a communication controller configured to receive a measurement report comprising the first identifier from the access terminal; and

a handover controller configured to determine that there is access point confusion associated with the first identifier, and further configured to use the stored information to resolve the confusion.

18. The apparatus of claim 14, wherein:

the first access point comprises a femto access point;

the determination of the mapping is performed at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

19. An apparatus for communication, comprising:

means for determining a mapping associated with an access terminal, wherein the mapping relates a first identifier used by the access terminal to identify a first access point to a second identifier assigned to the first access point; and

means for storing information indicative of the mapping.

20. The apparatus of claim 19, wherein the determination of the mapping comprises determining that the access terminal previously accessed the first access point.

21. The apparatus of claim 19, wherein the determination of the mapping is made upon resolving confusion associated with use of the first identifier by the access terminal.

22. The apparatus of claim 19, further comprising:

means for receiving a measurement report comprising the first identifier from the access terminal;

means for determining that there is access point confusion associated with the first identifier; and

means for using the stored information to resolve the confusion.

23. The apparatus of claim 19, wherein:

the first access point comprises a femto access point;

the determination of the mapping is performed at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

24. A computer-program product, comprising:

computer-readable medium comprising code for causing a computer to;

determine a mapping associated with an access terminal, wherein the mapping relates a first identifier used by the access terminal to identify a first access point to a second identifier assigned to the first access point; and

store information indicative of the mapping.

25. The computer-program product of claim 24, wherein the determination of the mapping comprises determining that the access terminal previously accessed the first access point.

26. The computer-program product of claim 24, wherein the determination of the mapping is made upon resolving confusion associated with use of the first identifier by the access terminal.

27. The computer-program product of claim 24, wherein the computer-readable medium further comprises code for causing the computer to:

receive a measurement report comprising the first identifier from the access terminal;

determine that there is access point confusion associated with the first identifier; and

use the stored information to resolve the confusion.

28. The computer-program product of claim 24, wherein:

the first access point comprises a femto access point;

the determination of the mapping is performed at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

29. A method of communication, comprising:

receiving an indication of an access point identifier acquired by an access terminal;

identifying at least one access point based on the access point identifier and stored information that indicates a mapping associated with the access terminal, wherein the mapping relates the access point identifier to the at least one other access point; and

sending at least one message to the at least one access point to prepare the at least one access point for handover of the access terminal.

30. The method of claim 29, wherein the stored information indicates that the access terminal has previously accessed the at least one access point

31. The method of claim 29, further comprising:

determining that there is access point confusion associated with the access point identifier; and

using the stored information to resolve the confusion.

32. The method of claim 29, wherein:

the at least one access point comprises at least one femto access point;

the access point identifier is received at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

33. The method of claim 29, wherein the indication of the access point identifier is received at the macro access point via a measurement report sent by the access terminal.

34. The method of claim 29, wherein the access point identifier comprises a pilot pseudonoise offset or a physical cell identifier.

35. The method of claim 29, wherein:

the access point identifier comprises a physical cell identifier; and

the stored information maps the access point identifier to at least one global cell identifier.

36. An apparatus for communication, comprising:

a communication controller configured to receive an indication of an access point identifier acquired by an access terminal; and

a handover controller configured to identify at least one access point based on the access point identifier and stored information that indicates a mapping associated with the access terminal, wherein the mapping relates the access point identifier to the at least one other access point, wherein the handover controller is further configured to send at least one message to the at least one access point to prepare the at least one access point for handover of the access terminal.

37. The apparatus of claim 36, wherein the stored information indicates that the access terminal has previously accessed the at least one access point

38. The apparatus of claim 36, wherein the handover controller is further configured to:

determine that there is access point confusion associated with the access point identifier; and

use the stored information to resolve the confusion.

39. The apparatus of claim 36, wherein:

the at least one access point comprises at least one femto access point;

the access point identifier is received at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

40. An apparatus for communication, comprising:

means for receiving an indication of an access point identifier acquired by an access terminal;

means for identifying at least one access point based on the access point identifier and stored information that indicates a mapping associated with the access terminal, wherein the mapping relates the access point identifier to the at least one other access point; and

means for sending at least one message to the at least one access point to prepare the at least one access point for handover of the access terminal.

41. The apparatus of claim 40, wherein the stored information indicates that the access terminal has previously accessed the at least one access point

42. The apparatus of claim 40, further comprising:

means for determining that there is access point confusion associated with the access point identifier; and

means for using the stored information to resolve the confusion.

43. The apparatus of claim 40, wherein:

the at least one access point comprises at least one femto access point;

the access point identifier is received at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

44. A computer-program product, comprising:

computer-readable medium comprising code for causing a computer to;

receive an indication of an access point identifier acquired by an access terminal;

identify at least one access point based on the access point identifier and stored information that indicates a mapping associated with the access terminal, wherein the mapping relates the access point identifier to the at least one other access point; and

send at least one message to the at least one access point to prepare the at least one access point for handover of the access terminal.

45. The computer-program product of claim 44, wherein the stored information indicates that the access terminal has previously accessed the at least one access point

46. The computer-program product of claim 44, wherein the computer-readable medium further comprises code for causing the computer to:

determine that there is access point confusion associated with the access point identifier; and

use the stored information to resolve the confusion.

47. The computer-program product of claim 44, wherein:

the at least one access point comprises at least one femto access point;

the access point identifier is received at a serving macro access point for the access terminal; and

the information is stored at the macro access point.

48. A method of communication, comprising:

receiving information that indicates that a common identifier is used to identify a plurality of access points during handovers from a first access point; and

providing statistical information indicative of a probability that a given one of the access points is identified by the node identifier during a handover from the first access point.

49. The method of claim 48, further comprising:

receiving the identifier from an access terminal; and

using the statistical information to identify, from the plurality of access points, at least one candidate target access point for handing-over the access terminal from the first access point.

50. The method of claim 49, further comprising sending at least one message to prepare the at least one candidate target access point for handover of the access terminal.

51. The method of claim 49, wherein the identification of the at least one candidate target access point comprises determining which of the access points is associated with a highest probability of being identified by the identifier during a handover.

52. The method of claim 49, further comprising:

determining whether a mapping is maintained for the access terminal, wherein the mapping maps the identifier to an access point to which the access terminal was handed-over during a prior handover from the first access point; and

determining whether to use the statistical information to identify the at least one candidate target access point based on the determination of whether the mapping is maintained.

53. The method of claim 48, wherein the information is received and the statistical information is stored at the first access point.

54. The method of claim 48, wherein:

the identifier comprises a physical cell identifier; and

the received information relates the physical cell identifier to global cell identifiers assigned to the plurality of access points.

55. An apparatus for communication, comprising:

a communication controller configured to receive information that indicates that a common identifier is used to identify a plurality of access points during handovers from a first access point; and

a statistics controller configured to provide statistical information indicative of a probability that a given one of the access points is identified by the node identifier during a handover from the first access point.

56. The apparatus of claim 55, wherein the communication controller is further configured to receive the identifier from an access terminal, the apparatus further comprising:

a handover controller configured to use the statistical information to identify, from the plurality of access points, at least one candidate target access point for handing-over the access terminal from the first access point.

57. The apparatus of claim 56, wherein the identification of the at least one candidate target access point comprises determining which of the access points is associated with a highest probability of being identified by the identifier during a handover.

58. The apparatus of claim 55, wherein the information is received and the statistical information is stored at the first access point.

59. An apparatus for communication, comprising:

means for receiving information that indicates that a common identifier is used to identify a plurality of access points during handovers from a first access point; and

means for providing statistical information indicative of a probability that a given one of the access points is identified by the node identifier during a handover from the first access point.

60. The apparatus of claim 59, further comprising:

means for receiving the identifier from an access terminal; and

means for using the statistical information to identify, from the plurality of access points, at least one candidate target access point for handing-over the access terminal from the first access point.

61. The apparatus of claim 60, wherein the identification of the at least one candidate target access point comprises determining which of the access points is associated with a highest probability of being identified by the identifier during a handover.

62. The apparatus of claim 59, wherein the information is received and the statistical information is stored at the first access point.

63. A computer-program product, comprising:

computer-readable medium comprising code for causing a computer to;

receive information that indicates that a common identifier is used to identify a plurality of access points during handovers from a first access point; and

provide statistical information indicative of a probability that a given one of the access points is identified by the node identifier during a handover from the first access point.

64. The computer-program product of claim 63, wherein the computer-readable medium further comprises code for causing the computer to:

receive the identifier from an access terminal; and

use the statistical information to identify, from the plurality of access points, at least one candidate target access point for handing-over the access terminal from the first access point.

65. The computer-program product of claim 64, wherein the identification of the at least one candidate target access point comprises determining which of the access points is associated with a highest probability of being identified by the identifier during a handover.

66. The computer-program product of claim 63, wherein the information is received and the statistical information is stored at the first access point.