Managing a radio environment without location information

• US 7,756,542 B1
• Filed: 07/22/2004
• Issued: 07/13/2010
• Est. Priority Date: 07/22/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Olson, Timothy S., Kaiser, Daryl A.
• Primary Examiner(s): Appiah; Charles N
• Assistant Examiner(s): Peaches; Randy
• Application Number:
  US10/898,105
• Time in Patent Office: 2,182 Days
• Field of Search: 370/252, 370/254, 370/901, 370/216, 370/338, 455/67.11, 455/115, 455/115.2, 455/115.3
• US Class Current: 455/522
• CPC Class Codes: H04L 41/0816 the condition being an adaptation, e.g. in response to network events
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 48/12 using downlink control channel

Abstract

In an access point operating in a wireless local area network, a method is disclosed for assisting a radio manager to manage a radio environment without location information. By performing radio discovery to receive beacon signals from neighboring access points, an initial configuration of a radio environment is generated based on said received beacon signals. Measurements are received from a client device that performs measurements by a user walking through a desired coverage area while operating the client device and the radio configuration is adjusted based on the received measurements.

Claims

1. In an access point operating in a wireless local area network, a method for assisting a radio manager to manage a radio environment without location information, the method comprising:

performing radio discovery to receive a beacon signal from a neighboring access point that is operative to repetitively transmit the beacon signal at different signal strengths;

determining a signal strength of the beacon signal received from the neighboring access point;

generating an initial radio configuration of a radio environment based on said received signal strength of the beacon signal;

receiving measurements from a client device that performs measurements by a user walking through a desired coverage area while operating the client device; and

adjusting the initial radio configuration based on the received measurements,

wherein performing radio discovery comprises initially receiving said beacon signal at a maximum power setting and iteratively receiving said beacon signal at reduced power level settings until the beacon signal is received at a lowest power level setting.

2. The method of claim 1, further comprising reporting the receipt of said beacon signals to a radio manager.

3. The method of claim 1, further comprising reporting the received measurements to a radio manager.

4. The method of claim 1, further comprising detecting background radio frequency levels and reporting them to a radio manager.

5. In a radio manager operating to control access points in a wireless local area network, a method for managing a radio environment without location information, the method comprising:

directing a plurality of access points to perform radio discovery;

receiving data from said plurality of access points, said received data describing signal strength of beacon signals received by an access point from neighboring access points;

calculating path loss information using the signal strength of the beacon signals;

identifying neighboring access points suffering from black holes using the calculated path loss information; and

iteratively adjusting the neighboring access points suffering from black holes in order to correct black holes without creating a new black hole with a different neighboring access point.

6. The method of claim 5, wherein said received data describes measurements performed by a client device as the client device moves through a desired coverage area.

7. The method of claim 5, wherein directing the access points to perform radio discovery comprises directing the access points to transmit beacon signals at various signal strengths and report received signal strengths to said radio manager.

8. The method of claim 5, wherein directing the access points to perform radio discovery comprises directing the access points to transmit beacon signals at a maximum signal strength and iteratively transmit beacon signals at successively lower signal strengths until a beacon signal is transmitted at a lowest power setting.

9. A computer-readable memory comprising instructions, which, when executed by a computer, assist a radio manager to manage a wireless local area network without location information, by:

performing radio discovery to receive beacon signals from neighboring access points that repetitively transmit said received beacon signals at varying signal strengths;

generating an initial radio configuration of a radio environment based on said received beacon signals;

receiving measurements from a client device that performs measurements by a user walking through a desired coverage area while operating the client device; and

adjusting the radio configuration based on the received measurements,

wherein performing radio discovery comprises initially receiving said beacon signals at a maximum power setting and iteratively receiving said beacon signals at reduced power level settings until the beacon signal is received at a lowest power level setting.

10. A computer-readable memory comprising instructions, which, when executed by a computer, manages a radio environment without location information, by:

directing a plurality of access points to perform radio discovery to receive beacon signals from neighboring access points that repetitively transmit said received beacon signals at varying signal strengths;

using data received from said plurality of access points to characterize a radio environment, characterization of the radio environment including identifying neighboring access points in a black hole; and

configuring the wireless local area network in response to said characterization, the wireless local area network being configured such that beacon signals are skewed with respect to neighboring access points in the black hole,

wherein configuring the wireless local area network includes iteratively adjusting the neighboring access points in the black hole in order to correct the black hole without creating a new black hole with a different neighboring access point.

11. The computer-readable medium of claim 10, wherein the beacon signals are skewed by an interval that is sufficient to prevent an extended period of time during which the black hole can occur.

12. The computer-readable medium of claim 11, wherein the interval is one or two milliseconds.

13. An access point device for use in a wireless local area network, the access point device serving wireless clients, the access point device comprising:

a transmitter for transmitting signals to a client device, and for transmitting beacon signals to inform other devices of the existence of said access point device, and for transmitting the existence of detected access points and received signal strength data related to said detected access points to a radio manager; and

a receiver for receiving signals from a client device, and for receiving beacon signals from other access point devices that repetitively transmit the beacon signals at different signal strengths and detecting background radio frequency energy, and for receiving instructions from said radio manager, said instructions related to configuring a wireless local area network without location information of access points,

wherein the receiver initially receives said beacon signals at a maximum power setting and iteratively receives said beacon signals at reduced power level settings until the beacon signal is received at a lowest power level setting.

14. An access point device for use in a wireless local area network, the access point device serving wireless clients, the access point device comprising:

means for transmitting signals to a client device;

means for transmitting beacon signals to inform other devices of the existence of said access point device;

means for transmitting the existence of detected access points and received signal strength data related to said detected access points to a radio manager;

means for receiving signals from a client device;

means for receiving beacon signals from other access point devices and detecting radio frequency energy, said beacon signals being initially received at a maximum power setting and iteratively received at reduced power level settings until the beacon signal is received at a lowest power level setting;

means for determining signal strengths of the beacon signals from the radio frequency energy;

means for generating an initial radio configuration of a radio environment based on the signal strengths of the beacon signals;

means for receiving instructions from said radio manager, said instructions related to configuring a wireless local area network without location information of access points; and

means for configuring the wireless local area network using the instructions.