Method and apparatus to intelligently perform scanning and assist scanning by profiling scanning history

• US 8,041,319 B2
• Filed: 12/23/2004
• Issued: 10/18/2011
• Est. Priority Date: 12/23/2004
• Status: Expired due to Fees

• Current Assignee: Avaya Incorporated
• Original Assignee: Avaya Incorporated
• Inventors: Engwer, Darwin A., He, Haixiang
• Primary Examiner(s): SHEDRICK, CHARLES TERRELL
• Application Number:
  US11/021,301
• Publication Number:
  US 20060142004A1
• Time in Patent Office: 2,490 Days
• Field of Search: 455/434, 455/435.2, 455/436, 455/452.2, 455/432, 370/329, 370/323, 370/332, 709/227
• US Class Current: 455/144
• CPC Class Codes: H04W 36/008375 based on historical data
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

According to one embodiment, a method involves determining whether a wireless connection between a first access point and a wireless station has failed. If so, a partial scanning process is conducted only on a subset of communication channels over which data is transmitted by access points neighboring the first access point. The subset of communication channels, inclusive of zero, is determined by analysis of a scanning history database.

Claims

1. A method for associating a wireless station with one of a plurality of access points of a wireless network, the method comprising:

scanning a plurality of communication channels by the wireless station, the plurality of communication channels being used to transmit data from the plurality of access points of the wireless network, the wireless station comprises a wireless electronic device comprising logic that processes information and a wireless transceiver that receives information from and transmits information to an access point or another wireless station, and wherein the access point comprises a wireless electronic device that provides bi-directional connection between one or more wireless stations and a wired network;

storing data obtained from each scan of the plurality of communication channels into a scanning history database that maps a plurality of neighboring access points for a first access point by creating a plurality of records, each record being associated with one of the plurality of access points, each record including access point selection results that indicate patterns of access point selection, the scanning history database also storing beacon timing information including beacon interval and beacon transmit time;

constructing a mathematical network map that indicates a plurality of neighboring access points for each of the access points from access point information stored in said scanning history database;

determining whether a wireless connection between the first access point and a wireless station has failed;

in response to the wireless connection between the first access point and the wireless station failing, identifying a second access point in the scanning history database, the access point selection results for the second access point indicating that the second access point is normally chosen when the first access point becomes unavailable, and associating the wireless station with the second access point selected from the plurality of neighboring access points without rescanning prior to association based on information within the scanning history database;

detecting a failure to associate the wireless station with the second access point;

in response to a wireless connection between the second access point and the wireless station failing, conducting a partial scanning process that identifies a third access point, the partial scanning process being conducted on only a subset of available communication channels over which data is transmitted by the plurality of neighboring access points, the subset of available communication channels being determined by analysis of a mathematical network map, wherein the subset of available communication channels being determined by analysis of the mathematical network map includes access points listed in the scanning history database as reachable and having previously provided signals with a measured signal strength above a predetermined threshold, wherein a time of conducting the partial scanning process is based on beacon timing information;

selecting the third access point based on a weighted analysis of the partial scanning results, the weighted analysis being based on at least signal strength, location, or up/down time; and

associating the wireless station with the third access point.

2. The method of claim 1 further comprising:

detecting a failure to associate the wireless station with the second access point;

identifying a third access point in the scanning history database, the access point selection results for the third access point indicating that the third access point is chosen when the first access point becomes unavailable; and

associating the wireless station with the third access point without rescanning prior to association.

3. The method of claim 2 further comprising recording the association of the third access point following the failure of the connection with the first access point in the scanning history database.

4. The method of claim 1 wherein determining whether a wireless connection between the first access point and a wireless station has failed further comprises detecting prolonged receipt of signals having a signal strength below a minimum threshold.

5. The method of claim 1 wherein said constructing a mathematical network map comprises utilizing geographical positions of APs to build said map.

6. The method of claim 1, further comprising:

determining prior usage history indicating chosen substitute access points by accessing the scanning history database;

directly scanning a channel of a given substitute candidate access point;

in response to identifying that the given substitute candidate access point satisfies certain threshold requirements for establishing communication with the wireless station, storing corresponding access point information and associating with the given substitute candidate access point; and

in response to identifying that the given substitute candidate access point fails satisfies certain threshold requirements for establishing communication with the wireless station, identifying other candidate access points listed in the scanning history database.

7. The method of claim 6, further comprising:

wherein storing data obtained from each scan of the plurality of communication channels into the scanning history database includes storing scanning results that include capabilities of a transmitting access point, security policies supported by a specific access point, channel number, signal strength, and global positioning satellite (GPS) data that identifies a geographical position of the specific access point;

the scanning history data base also storing access point selection results that identify a likelihood that given certain access points are selected over other access points based on prior selection histories; and

wherein detecting the failure includes detecting a dropout without the wireless station roaming to a different geographical position.

8. A wireless station comprising:

a non-volatile memory;

a wireless transceiver that receives messages from a plurality of access points of a wireless network and extracts data from the messages; and

logic coupled to the non-volatile memory and the wireless transceiver, the logic performing operations including;

scanning the data from a plurality of communication channels transmitted by the plurality of access points, storing data obtained from each scan of the plurality of communication channels into a scanning history database in the nonvolatile memory, the scanning history mapping a plurality of neighboring access points for a first access point by creating a plurality of records, each record being associated with one of the plurality of access points, each record including access point selection results that indicate patterns of access point selection, the scanning history database also storing beacon timing information including beacon interval and beacon transmit time;

constructing a mathematical network map that indicates a plurality of neighboring access points for each of the access points from access point information stored in said scanning history database, determining whether a wireless connection between the first access point and a wireless station has failed;

in response to the wireless connection between the first access point and the wireless station failing, identifying the second access point in the scanning history database, the access point selection results for the second access point indicating that the second access point is normally chosen when the first access point becomes unavailable, and associating the wireless station with the second access point selected from the plurality of neighboring access points without rescanning prior to association based on information within the scanning history database, detecting a failure to associate the wireless station with the second access point;

in response to a wireless connection between the second access point and the wireless station failing, conducting a partial scanning process that identifies a third access point, the partial scanning process being conducted on only a subset of available communication channels over which data is transmitted by the plurality of neighboring access points, the subset of available communication channels being determined by analysis of a mathematical network map, wherein the subset of available communication channels being determined by analysis of the mathematical network map includes access points listed in the scanning history database as reachable and having previously provided signals with a measured signal strength above a predetermined threshold, wherein a time of conducting the partial scanning process is based on beacon timing information;

selecting the third access point based on a weighted analysis of the partial scanning results, the weighted analysis being based on at least signal strength, location, or up/down time; and

associating the wireless station with the third access point.

9. The wireless station of claim 8 wherein the logic further performs operations including detecting a failure to associate the wireless station with the second access point, identifying a third access point in the scanning history database, the access point selection results for the third access point indicating that the third

access point is chosen when the first access point becomes unavailable;

associating the wireless station with the third access point without rescanning prior to association; and

wherein the logic further performs operations including recording the association of the third access point following the failure of the connection with the first access point in the scanning history database.

10. The wireless station of claim 8 wherein determining whether a wireless connection between the first access point and a wireless station has failed further comprises detecting prolonged receipt of signals having a signal strength below a minimum threshold.

11. The wireless station of claim 8 wherein said constructing a mathematical network map comprises utilizing geographical positions of APs to build said map.

14. The method of claim 10 wherein determining whether a wireless connection between the first access point and a wireless station has failed further comprises detecting prolonged receipt of signals having a signal strength below a minimum threshold.

12. A method for associating a wireless station with one of a plurality of access points of a wireless network, the method comprising:

acquiring a scanning history database that maps a plurality of neighboring access points for a first access point by creating a plurality of records, each record being associated with one of the plurality of access points, each record including access point selection results that indicate patterns of access point selection, the scanning history database also storing beacon timing information including beacon interval and beacon transmit time;

determining whether a wireless connection between the first access point and a wireless station has failed;

in response to the wireless connection between the first access point and the wireless station failing, identifying the second access point in the scanning history database, the access point selection results for the second access point indicating that the second access point is normally chosen when the first access point becomes unavailable, and associating the wireless station with the second access point selected from the plurality of neighboring access points without rescanning prior to association, wherein a wireless station comprises a wireless electronic device comprising logic for processing information and a wireless transceiver for receiving information from and transmitting information to an access point or another wireless station, and wherein an access point comprises a wireless electronic device that provides bi-directional connection between one or more wireless stations and a wired network;

detecting a failure to associate the wireless station with the second access point;

in response to a wireless connection between the second access point and the wireless station failing, conducting a partial scanning process that identifies a third access point, the partial scanning process being conducted on only a subset of available communication channels over which data is transmitted by the plurality of neighboring access points, the subset of available communication channels being determined by analysis of a mathematical network map, wherein the subset of available communication channels being determined by analysis of the mathematical network map includes access points listed in the scanning history database as reachable and having previously provided signals with a measured signal strength above a predetermined threshold, wherein a time of conducting the partial scanning process is based on beacon timing information;

selecting the third access point based on a weighted analysis of the partial scanning results, the weighted analysis being based on at least signal strength, location, or up/down time; and

associating the wireless station with the third access point.

13. The method of claim 12 further comprising:

detecting a failure to associate the wireless station with the second access point;

identifying a third access point in the scanning history database, the access point selection results for the third access point indicating that the third access point is chosen when the first access point becomes unavailable;

associating the wireless station with the third access point without rescanning prior to association; and

recording the association of the third access point following the failure of the connection with the first access point in the scanning history database.

15. The method of claim 12 wherein said patterns of access point selection include patterns where one AP is selected after a previous AP becomes unavailable.

16. A wireless station comprising:

a non-volatile memory;

a wireless transceiver that receives messages from a plurality of access points of a wireless network and extracts data from the messages; and

logic coupled to the non-volatile memory and the wireless transceiver, the logic performing operations including;

acquiring a scanning history database that maps a plurality of neighboring access points for a first access point by creating a plurality of records, each record being associated with one of the plurality of access points, each record including access point selection results that indicate patterns of access point selection, the scanning history database also storing beacon timing information including beacon interval and beacon transmit time;

storing the scanning history database in the non-volatile memory;

determining whether a wireless connection between the first access point and the wireless station has failed;

in response to the wireless connection between the first access point and the wireless station has failed failing, identifying the second access point in the scanning history database, the access point selection results for the second access point indicating that the second access point is normally chosen when the first access point becomes unavailable, and associating the wireless station with the second access point selected from the plurality of neighboring access points without rescanning prior to association;

detecting a failure to associate the wireless station with the second access point;

in response to a wireless connection between the second access point and the wireless station failing, conducting a partial scanning process that identifies a third access point, the partial scanning process being conducted on only a subset of available communication channels over which data is transmitted by the plurality of neighboring access points, the subset of available communication channels being determined by analysis of a mathematical network map, wherein the subset of available communication channels being determined by analysis of the mathematical network map includes access points listed in the scanning history database as reachable and having previously provided signals with a measured signal strength above a predetermined threshold, wherein a time of conducting the partial scanning process is based on beacon timing information;

selecting the third access point based on a weighted analysis of the partial scanning results, the weighted analysis being based on at least signal strength, location, or up/down time; and

associating the wireless station with the third access point.

17. The wireless station of claim 16 wherein the logic further performs operations including detecting a failure to associate the wireless station with the second access point, identifying a third access point in the scanning history database, the access point selection results for the third access point indicating that the third access point is chosen when the first access point becomes unavailable;

associating the wireless station with the third access point without rescanning prior to association; and

wherein the logic further performs operations including recording the association of the third access point following the failure of the connection with the first access point in the scanning history database.

18. The wireless station of claim 16 wherein determining whether a wireless connection between the first access point and a wireless station has failed further comprises detecting prolonged receipt of signals having a signal strength below a minimum threshold.

19. The wireless station of claim 16 wherein said patterns of access point selection include patterns where one AP is selected after a previous AP becomes unavailable.