CONTROLLING ACCESS POINT TRANSMIT POWER BASED ON EVENT-TRIGGERED ACCESS TERMINAL MESSAGING

• US 20120046026A1
• Filed: 02/18/2011
• Published: 02/23/2012
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chande, Vinay, Meshkati, Farhad, Patel, Chirag Sureshbhai, Yavuz, Mehmet, Nagaraja, Sumeeth
• Granted Patent: US 8,849,337 B2
• Time in Patent Office: Days
• US Class Current: 455/422.1
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/18 TPC being performed according to specific parameters
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading

Abstract

Transmit power for an access point is controlled based on measurement reports received by the access point from one or more access terminals that are not currently being served by the access point. In some aspects, transmit power is controlled based on the number of received messages that correspond to a particular event. In some aspects, transmit power is controlled based on the contents of the received messages. For example, the access point may use signal strength information included in the messages to determine a level of transmit power that mitigates interference at a defined subset of reporting access terminals.

Claims

1. A method of communication, comprising:

receiving messages at an access point, wherein the messages comprise measurement reports from at least one access terminal that is not currently being served by the access point;

identifying a quantity of the messages that indicate the occurrence of a specified type of event;

comparing the quantity to a threshold; and

controlling transmit power of the access point based on the comparison.

2. The method of claim 1, wherein the specified type of event comprises a UMTS Event 1A.

3. The method of claim 1, wherein the messages are received from the at least one access terminal via a network backhaul.

4. The method of claim 1, wherein:

the quantity comprises an observed event count; and

the threshold comprises a target event count.

5. The method of claim 4, wherein the controlling of the transmit power comprises:

determining a power adjustment based on a difference between the target event count and the observed event count; and

adjusting the transmit power based on determined power adjustment.

6. The method of claim 5, wherein the determination of the power adjustment comprises applying a monotonic non-decreasing function to the difference between the target event count and the observed event count.

7. The method of claim 1, wherein:

the access point comprises a femto cell; and

the at least one access terminal is currently being served by a macro cell.

8. The method of claim 1, further comprising receiving other messages from at least one access terminal that is currently being served by the access point, wherein:

the other messages are indicative of channel quality on a forward link of the access point; and

the controlling of the transmit power is further based on the other messages.

9. The method of claim 1, further comprising receiving registration messages at the access point, wherein:

the registration messages are indicative of a quantity of registration attempts by at least one access terminal that is not authorized to receive active mode service via the access point; and

the controlling of the transmit power is further based on the registration messages.

10. The method of claim 1, further comprising:

determining that another access terminal near the access point is actively receiving information from another access point; and

restricting transmission by the access point as a result of the determination.

11. The method of claim 1, further comprising:

receiving pilot signals at the access point, wherein the pilot signals are received from at least one other access point;

identifying channel conditions at the access point based on the received pilot signals; and

setting at least one limit for the transmit power based on the identified channel conditions.

12. An apparatus for communication, comprising:

a receiver operable to receive messages, wherein the messages comprise measurement reports from at least one access terminal that is not currently being served by the apparatus; and

a controller operable to identify a quantity of the messages that indicate the occurrence of a specified type of event, and further operable to compare the quantity to a threshold, and further operable to control transmit power of the apparatus based on the comparison.

13. The apparatus of claim 12, wherein the specified type of event comprises a UMTS Event 1A.

14. The apparatus of claim 12, wherein the messages are received from the at least one access terminal via a network backhaul.

15. The apparatus of claim 12, wherein:

the quantity comprises an observed event count; and

the threshold comprises a target event count.

16. The apparatus of claim 15, wherein the controlling of the transmit power comprises:

determining a power adjustment based on a difference between the target event count and the observed event count; and

adjusting the transmit power based on determined power adjustment.

17. The apparatus of claim 16, wherein the determination of the power adjustment comprises applying a monotonic non-decreasing function to the difference between the target event count and the observed event count.

18. The apparatus of claim 12, wherein:

the apparatus comprises a femto cell; and

the at least one access terminal is currently being served by a macro cell.

19. The apparatus of claim 12, wherein:

the receiver is further operable to receive other messages from at least one access terminal that is currently being served by the apparatus;

the other messages are indicative of channel quality on a forward link of the apparatus; and

the controlling of the transmit power is further based on the other messages.

20. The apparatus of claim 12, wherein:

the receiver is further operable to receive registration messages;

the registration messages are indicative of a quantity of registration attempts by at least one access terminal that is not authorized to receive active mode service via the apparatus; and

the controlling of the transmit power is further based on the registration messages.

21. The apparatus of claim 12, wherein the controller is further operable to:

determine that another access terminal near the apparatus is actively receiving information from an access point; and

restrict transmission by the apparatus as a result of the determination.

22. The apparatus of claim 12, wherein:

the receiver is further operable to receive pilot signals from at least one access point;

the controller is further operable to identify channel conditions at the apparatus based on the received pilot signals; and

the controller is further operable to set at least one limit for the transmit power based on the identified channel conditions.

23. An apparatus for communication, comprising:

means for receiving messages, wherein the messages comprise measurement reports from at least one access terminal that is not currently being served by the apparatus;

means for identifying a quantity of the messages that indicate the occurrence of a specified type of event;

means for comparing the quantity to a threshold; and

means for controlling transmit power of the apparatus based on the comparison.

24. The apparatus of claim 23, wherein:

the quantity comprises an observed event count; and

the threshold comprises a target event count.

25. The apparatus of claim 24, wherein the controlling of the transmit power comprises:

determining a power adjustment based on a difference between the target event count and the observed event count; and

adjusting the transmit power based on determined power adjustment.

26. The apparatus of claim 25, wherein the determination of the power adjustment comprises applying a monotonic non-decreasing function to the difference between the target event count and the observed event count.

27. The apparatus of claim 23, wherein:

the apparatus comprises a femto cell; and

the at least one access terminal is currently being served by a macro cell.

28. The apparatus of claim 23, further comprising:

means for determining that another access terminal near the apparatus is actively receiving information from an access point; and

means for restricting transmission by the apparatus as a result of the determination.

29. The apparatus of claim 23, further comprising:

means for receiving pilot signals from at least one access point;

means for identifying channel conditions at the apparatus based on the received pilot signals; and

means for setting at least one limit for the transmit power based on the identified channel conditions.

30. A computer-program product, comprising:

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

receive messages at an access point, wherein the messages comprise measurement reports from at least one access terminal that is not currently being served by the access point;

identify a quantity of the messages that indicate the occurrence of a specified type of event;

compare the quantity to a threshold; and

control transmit power of the access point based on the comparison.

31. The computer-program product of claim 30, wherein:

the quantity comprises an observed event count; and

the threshold comprises a target event count.

32. The computer-program product of claim 31, wherein the controlling of the transmit power comprises:

determining a power adjustment based on a difference between the target event count and the observed event count; and

adjusting the transmit power based on determined power adjustment.

33. The computer-program product of claim 32, wherein the determination of the power adjustment comprises applying a monotonic non-decreasing function to the difference between the target event count and the observed event count.

34. The computer-program product of claim 30, wherein:

the access point comprises a femto cell; and

the at least one access terminal is currently being served by a macro cell.

35. The computer-program product of claim 30, wherein the computer-readable medium further comprises code for causing the computer to:

determine that another access terminal near the access point is actively receiving information from another access point; and

restrict transmission by the access point as a result of the determination.

36. The computer-program product of claim 30, wherein the computer-readable medium further comprises code for causing the computer to:

receive pilot signals at the access point, wherein the pilot signals are received from at least one other access point;

identify channel conditions at the access point based on the received pilot signals; and

set at least one limit for the transmit power based on the identified channel conditions.

37. A method of communication, comprising:

receiving measurement reports at a network entity, wherein each of the measurement reports correspond to a specified access point;

determining that the specified access point controls transmit power based on measurement reports; and

sending the measurement reports to the specified access point as a result of the determination.

38. The method of claim 37, wherein:

the measurement reports are received from a plurality of access terminals;

the method further comprises aggregating the measurement reports based on which one of the access terminals sent a given one of the measurement reports; and

the sending of the measurement reports comprises sending the aggregated measurement reports along with indications that identify each subset of the measurement reports sent by each of the access terminals.

39. The method of claim 37, wherein the sending of the measurement reports is triggered by a request from the specified access point.

40. The method of claim 37, wherein the sending of the measurement reports is performed periodically.

41. The method of claim 37, wherein the specified access point comprises a femto cell.

42. The method of claim 37, wherein the network entity comprises a radio network controller, a Home NodeB management server, or a femto cell.

43. An apparatus for communication, comprising:

a receiver operable to receive measurement reports, wherein each of the measurement reports corresponds to a specified access point;

a controller operable to determine that the specified access point controls transmit power based on measurement reports; and

a transmitter operable to send the measurement reports to the specified access point as a result of the determination.

44. The apparatus of claim 43, wherein:

the measurement reports are received from a plurality of access terminals;

the controller is further operable to aggregate the measurement reports based on which one of the access terminals sent a given one of the measurement reports; and

the sending of the measurement reports comprises sending the aggregated measurement reports along with indications that identify each subset of the measurement reports sent by each of the access terminals.

45. The apparatus of claim 43, wherein the sending of the measurement reports is triggered by a request from the specified access point.

46. The apparatus of claim 43, wherein the sending of the measurement reports is performed periodically.

47. The apparatus of claim 43, wherein the specified access point comprises a femto cell.

48. The apparatus of claim 43, wherein the apparatus comprises a radio network controller, a Home NodeB management server, or a femto cell.

49. An apparatus for communication, comprising:

means for receiving measurement reports, wherein each of the measurement reports correspond to a specified access point;

means for determining that the specified access point controls transmit power based on measurement reports; and

means for sending the measurement reports to the specified access point as a result of the determination.

50. The apparatus of claim 49, wherein:

the measurement reports are received from a plurality of access terminals;

the apparatus further comprises means for aggregating the measurement reports based on which one of the access terminals sent a given one of the measurement reports; and

the sending of the measurement reports comprises sending the aggregated measurement reports along with indications that identify each subset of the measurement reports sent by each of the access terminals.

51. The apparatus of claim 49, wherein the sending of the measurement reports is triggered by a request from the specified access point.

52. The apparatus of claim 49, wherein the sending of the measurement reports is performed periodically.

53. A computer-program product, comprising:

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

receive measurement reports at a network entity, wherein each of the measurement reports corresponds to a specified access point;

determine that the specified access point controls transmit power based on measurement reports; and

send the measurement reports to the specified access point as a result of the determination.

54. The computer-program product of claim 53, wherein:

the measurement reports are received from a plurality of access terminals;

the computer-readable medium further comprises code for causing the computer to aggregate the measurement reports based on which one of the access terminals sent a given one of the measurement reports; and

the sending of the measurement reports comprises sending the aggregated measurement reports along with indications that identify each subset of the measurement reports sent by each of the access terminals.

55. The computer-program product of claim 53, wherein the sending of the measurement reports is triggered by a request from the specified access point.

56. The computer-program product of claim 53, wherein the sending of the measurement reports is performed periodically.