Interference mitigation in wireless networks

• US 8,165,528 B2
• Filed: 12/27/2007
• Issued: 04/24/2012
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: Airvana Corporation (CommScope Holding Company, Inc.)
• Inventors: Raghothaman, Balaji, Humblet, Pierre A.
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): MEHRA, INDER P
• Application Number:
  US11/965,070
• Publication Number:
  US 20090170547A1
• Time in Patent Office: 1,580 Days
• Field of Search: 455/423, 455/63.1, 455/452.2, 455/453, 455/522, 370/329, 370/503
• US Class Current: 455/63.1
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link

Abstract

An access terminal is enabled to communicate with a private access point while interference caused by the access terminal is mitigated. A maximum allowable transmit rate of the access terminal for communication with the private access point is determined. The access terminal is caused to communicate at a transmit rate at or below the maximum allowable transmit rate.

Claims

1. A method of enabling an access terminal in a set of access terminals in a network to communicate with a private access point in the network, the method comprising:

determining a first transmit rate of the access terminal for communication with the private access point; and

causing the access terminal to communicate at a second transmit rate at or below the first transmit rate;

wherein the first transmit rate is constrained in accordance with

2. The method of claim 1, wherein actions of determining and causing mitigate interference at the macro access point.

3. The method of claim 1, wherein the private access point comprises a first private access point;

and

wherein actions of determining and causing mitigate interference at a second private access point in the network.

4. The method of claim 1, wherein contributions to interference at the macro access point due to the set of access terminals are constrained by the interference limit for the macro access point.

5. The method of claim 1, wherein the first transmit rate comprises a maximum allowable transmit rate;

and

wherein the interference limit comprises a maximum interference limit.

6. The method of claim 1, wherein determining the first transmit rate comprises:

receiving a value PG_i;

wherein PG_i comprises an estimate of the interference limit divided by a number of access terminals of the set of access terminals.

7. The method of claim 1, wherein the transmit power comprises a first transmit power, and wherein determining the first transmit rate comprises:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

receiving a value indicative of a second transmit power;

wherein the second transmit power is based in part on the path gain G_i^M and the interference limit.

8. The method of claim 1, wherein determining the first transmit rate comprises:

determining a power value, the power value being a value indicative of an amount of power received from the access terminal at the macro access point; and

estimating the first transmit rate based in part on the power value and on the interference limit.

9. The method of claim 8, wherein the power values comprises a first power value, and wherein determining the first power value comprises:

receiving a macro access point signal strength value and a private access point signal strength value from the access terminal;

determining a second power value, the second power value being a value indicative of an amount of power received from the access terminal at the private access point; and

determining the first power value based on the macro access point signal strength value, the private access point signal strength value, a private access point transmit power value, a macro access point transmit power value, and the second power value.

10. The method of claim 1, wherein determining the first transmit rate comprises:

receiving an estimated transmit power of the access terminal; and

estimating the first transmit rate based on the estimated transmit power.

11. The method of claim 10, wherein estimating the first transmit rate based on the estimated transmit power comprises:

estimating the first transmit rate according to the following equation;

12. The method of claim 11, further comprising:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

sending the path gain G_i^M to a programmable server;

wherein the programmable server is configured to manage the private access point.

13. The method of claim 12, wherein the programmable server is configured to determine the estimated transmit power based in part on the path gain G_i^M and the interference limit for the macro access point.

14. The method of claim 12, wherein the path gain G_i^M comprises a first path gain G_i^M, and wherein the method further comprises:

estimating a second path gain G_i^F from the i^th access terminal to the private access point; and

estimating a total power value Î

_O^AT indicative of a total power measured by the access terminal;

wherein the first path gain G_i^M and the second path gain G_i^F are based in part on the total power value Î

_O^AT.

15. The method of claim 1, wherein causing the access terminal to communicate at the second transmit rate comprises:

setting an attribute on the access terminal to affect a packet size of packets transmitted by the access terminal.

16. The method of claim 1, wherein causing the access terminal to communicate at second transmit rate comprises:

sending a message to the access terminal instructing the access terminal to communicate at the second transmit rate.

17. One or more machine-readable storage media configured to store instructions that are executable by one or more processing devices to perform operations comprising:

determining a first transmit rate of an access terminal in a set of access terminals in a network for communication with a private access point in the network; and

causing the access terminal to communicate at a second transmit rate at or below the first transmit rate;

wherein the first transmit rate is constrained in accordance with

18. The one or more machine-readable storage media of claim 17, wherein the operations mitigate interference at the macro access point.

19. The one or more machine-readable storage media of claim 17, wherein the private access point comprises a first private access point;

and

wherein the operations mitigate interference at a second private access point in the network.

20. The one or more machine-readable storage media of claim 17, wherein contributions to interference at the macro access point due to the set of access terminals are constrained by the interference limit for the macro access point.

21. The one or more machine-readable storage media of claim 17, wherein the first transmit rate comprises a maximum allowable transmit rate;

and

wherein the interference limit comprises a maximum interference limit.

22. The one or more machine-readable storage media of claim 17, wherein determining the first transmit rate comprises:

receiving a value PG_i;

wherein PG_i comprises an estimate of the interference limit divided by a number of access terminals of the set of access terminals.

23. The one or more machine-readable storage media of claim 17, wherein the transmit power comprises a first transmit power, and wherein determining the first transmit rate comprises:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

receiving a value indicative of a second transmit power;

wherein the second transmit power is based in part on the path gain G_i^M and the interference limit.

24. The one or more machine-readable storage media of claim 17, wherein determining the first transmit rate comprises:

determining a power value, the power value being a value indicative of an amount of power received from the access terminal at the macro access point; and

estimating the first transmit rate based in part on the power value and on the interference limit.

25. The one or more machine-readable storage media of claim 24, wherein the power values comprises a first power value, and wherein determining the first power value comprises:

receiving a macro access point signal strength value and a private access point signal strength value from the access terminal;

determining a second power value, the second power value being a value indicative of an amount of power received from the access terminal at the private access point; and

determining the first power value based on the macro access point signal strength value, the private access point signal strength value, a private access point transmit power value, a macro access point transmit power value, and the second power value.

26. The one or more machine-readable storage media of claim 17, wherein determining the first transmit rate comprises:

receiving an estimated transmit power of the access terminal; and

estimating the first transmit rate based on the transmit power.

27. The one or more machine-readable storage media of claim 26, wherein estimating the first transmit rate based on the estimated transmit power comprises:

estimating the first transmit rate according to the following equation;

28. The one or more machine-readable storage media of claim 27, wherein the operations further comprise:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

sending the path gain G_i^M to a programmable server;

wherein the programmable server is configured to manage the private access point.

29. The one or more machine-readable storage media of claim 28, wherein the programmable server is configured to determine the estimated transmit power based in part on the path gain G_i^M and the interference limit for the macro access point.

30. The one or more machine-readable storage media of claim 28, wherein the path gain G_i^M comprises a first path gain G_i^M, and wherein the operations further comprise:

estimating a second path gain G_i^F from the i^th access terminal to the private access point; and

estimating a total power value Î

_O^AT indicative of a total power measured by the access terminal;

wherein the first path gain G_i^M and the second path gain G_i^F are based in part on the total power value Î

_O^AT.

31. The one or more machine-readable storage media of claim 17, wherein causing the access terminal to communicate at the second transmit rate comprises:

setting an attribute on the access terminal to affect a packet size of packets transmitted by the access terminal.

32. The one or more machine-readable storage media of claim 17, wherein causing the access terminal to communicate at the second transmit rate comprises:

sending a message to the access terminal instructing the access terminal to communicate at the second transmit rate.

33. A system comprising:

one or more processing devices; and

one or more machine-readable storage media configured to store instructions that are executable by the one or more processing devices to perform operations comprising;

determining a first transmit rate of an access terminal in a set of access terminals in a network for communication with a private access point in the network; and

causing the access terminal to communicate at a second transmit rate at or below the first transmit rate;

wherein the first transmit rate is constrained in accordance with

34. The system of claim 33, wherein the operations mitigate interference at the macro access point.

35. The system of claim 33, wherein the private access point comprises a first private access point;

and

wherein the operations mitigate interference at a second private access point in the network.

36. The system of claim 33, wherein contributions to interference at the macro access point due to the set of access terminals are constrained by the interference limit for the macro access point.

37. The system of claim 33, wherein the first transmit rate comprises a maximum allowable transmit rate;

and

wherein the interference limit comprises a maximum interference limit.

38. The system of claim 37, wherein determining the first transmit rate comprises:

receiving a value PG_i;

wherein PG_i comprises an estimate of the interference limit divided by a number of access terminals of the set of access terminals.

39. The system of claim 37, wherein the transmit power comprises a first transmit power, and wherein determining the first transmit rate comprises:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

receiving a value indicative of a second transmit power;

wherein the second transmit power is based in part on the path gain G_i^M and the interference limit.

40. The system of claim 33, wherein determining the first transmit rate comprises:

determining a power value, the power value being a value indicative of an amount of power received from the access terminal at the macro access point; and

estimating the first transmit rate based in part on the power value and on the interference limit.

41. The system of claim 40, wherein the power values comprises a first power value, and wherein determining the first power value comprises:

receiving a macro access point signal strength value and a private access point signal strength value from the access terminal;

determining a second power value, the second power value being a value indicative of an amount of power received from the access terminal at the private access point; and

determining the first power value based on the macro access point signal strength value, the private access point signal strength value, a private access point transmit power value, a macro access point transmit power value, and the second power value.

42. The system of claim 33, wherein determining the first transmit rate comprises:

receiving an estimated transmit power of the access terminal; and

estimating the first transmit rate based on the transmit power.

43. The system of claim 42, wherein estimating the first transmit rate based on the estimated transmit power comprises:

estimating the first transmit rate according to the following equation;

44. The system of claim 43, wherein the operations further comprise:

estimating the path gain G_i^M from the i^th access terminal to the macro access point; and

sending the path gain G_i^M to a programmable server.

45. The system of claim 44, wherein the a programmable server is configured to:

determine the estimated transmit power based in part on the path gain G_i^M and the interference limit for the macro access point.

46. The system of claim 44, wherein the path gain G_i^M comprises a first path gain G_i^M, and wherein the operations further comprise:

estimating a second path gain G_i^F from the i^th access terminal to the private access point; and

estimating a total power value Î

_O^AT indicative of a total power measured by the access terminal;

wherein the first path gain G_i^M and the second path gain G_i^F are based in part on the total power value Î

_O^AT.

47. The system of claim 33, wherein causing the access terminal to communicate at the second transmit rate comprises:

setting an attribute on the access terminal to affect a packet size of packets transmitted by the access terminal.

48. The system of claim 33, wherein causing the access terminal to communicate at the second transmit rate comprises:

sending a message to the access terminal instructing the access terminal to communicate at the second transmit rate.