Access point interference control and selection methods

• US 7,653,357 B2
• Filed: 05/22/2006
• Issued: 01/26/2010
• Est. Priority Date: 08/22/2005
• Status: Active Grant

• Current Assignee: Telcordia Legacy Inc.
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson), Toshiba America Research Inc (Toshiba Corporation)
• Inventors: Vakil, Faramak, Famolari, Dave, Matsuo, Ryoko, Obayashi, Shuichi, Gopalakrishnan, Praveen, Kodama, Toshikazu
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US11/419,625
• Publication Number:
  US 20070060057A1
• Time in Patent Office: 1,345 Days
• Field of Search: 342/159, 455/69
• US Class Current: 455/69
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• 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

In some embodiments, a system and method is disclosed for, among other things, reducing interference in a first wireless network from a second wireless network. In some embodiments, the method includes that an Interfered AP, which Interfered AP either itself receives interference or has a station in the Interfered AP'"'"'s network that receives interference from an Interfering AP or from a station within the Interfering AP'"'"'s network, selects how to reduce interference from a plurality of interference reduction methods—e.g., including transmit power control (TPC), channel switching (CS) and/or the like.

Claims

1. A method for reducing interference in a first wireless network from a second wireless network, comprising:

at an Interfered AP, which Interfered AP either itself receives interference or has a station in the Interfered AP'"'"'s network that receives interference from an Interfering AP or from a station within the Interfering AP'"'"'s network, said Interfered AP selecting a method to reduce interference from a plurality of interference reduction methods.

2. The method of claim 1, further including said Interfered AP selecting how to reduce interference on a respective occasion based at least in part on an elimination process.

3. The method of claim 2, further including said Interfered AP selecting how to reduce interference on a respective occasion based at least in part on a) a number of Interfering APs or b) a number of APs or stations receiving interference signals.

4. The method of claim 1, further including said Interfered AP selecting how to reduce interference on a respective occasion based at least in part on a selection policy.

5. The method of claim 4, further including said Interfered AP selecting how to reduce interference on a respective occasion based at least in part on a selection policy that uses load information for selection.

6. The method of claim 4, further including said Interfered AP selecting how to reduce interference on a respective occasion based at least in part on a selection policy that uses a received power of an interference signal for selection.

7. The method of claim 1, further including said Interfered AP initially checking neighborhood channels and if there are any sufficiently vacant channels, changing its channel thereto.

8. The method of claim 1, further including said Interfered AP selecting a channel with a minimum load as a candidate channel.

9. The method of claim 1, further including said Interfered AP evaluating whether or not Transmit Power Control works well in a current channel by using a heavy-load threshold.

10. The method of claim 8, further including said Interfered AP evaluating whether or not Transmit Power Control works well in a candidate channel.

11. The method of claim 1, further including performing the following steps in the case of Transmit Power Control selection:

1) the Interfering AP inquiring with its stations about their current transmit powers and checking whether a reduction of transmit power is appropriate; and

     2) the Interfering AP effecting a reduction of a transmit power and monitoring whether the reduction adversely affects stations in its network.

12. The method of claim 1, further including performing the following steps in the case of Transmit Power Control selection:

the Interfering AP checks the path loss condition of each station in its network and adjusts transmit power such that the station which has the maximum path loss can transmit with a certain appropriate transmission rate.

13. The method of claim 1, further including the Interfering AP checking the condition of each station in the Interfering APs network and raising a transmit power if it detects that reduction adversely effects a transmission rate of a station.

14. The method of claim 1, wherein to initiate Transmit Power Control, the Interfered AP sends a request for Transmit Power Control to the Interfering AP via another device capable of communicating with the Interfering AP.

15. The method of claim 1, wherein the Interfered AP communicates with the Interfering AP via a backbone network or via an intermediate wireless device.

16. The method of claim 1, wherein said Interfered AP collects capability information and current status information.

17. The method of claim 1, wherein said Interfered AP eliminates at least some interference reduction methods, selects candidate methods based on capability information, and, if plural alternative possible candidate methods are available, prioritizes them based on a predetermined policy.

18. A method for reducing interference in a first wireless local area network from a second wireless local area network, comprising:

a) at an Interfered AP, which AP itself receives interference or has a station in the Interfered AP'"'"'s network that receives interference from an Interfering AP or from a station within the Interfering AP'"'"'s network, selecting a reduction method from a plurality of interference reduction methods, wherein one of said interference reduction methods is transmit power control of the Interfering AP and/or of a station within the Interfering AP'"'"'s network;

b) transmitting a request from the Interfered AP to have the Interfering AP perform transmit power control in the case that the Interfered AP selects transmit power control.

19. The method of claim 18, wherein said plurality of interference reduction methods includes channel switching or antenna dispersion or direction control.

20. The method of claim 18, further including having said Interfering AP check whether it can reduce a transmit power.