Method and system for positioning wireless device

Abstract

Aspects of the disclosure provide a method. The method includes storing a database of positioning data. Each positioning data can associate position information of a location with an identifier of a wireless station for providing wireless connection at the location and a characteristic of a wireless signal received at the location. Further, the method includes receiving a position request from a wireless device that receives an identifier and a specific characteristic of a wireless signal from a specific wireless station, identifying the specific wireless station using the identifier to retrieve a group of positioning data from a database, selecting a subset in the group of positioning data using the specific characteristic, and determining position information of the wireless device using the selected subset of positioning data.

What is claimed is: 
     
       1. A method, comprising:
 providing a database of positioning data, each positioning data associating position information of a location with an identifier of a wireless station for providing wireless connection at the location and a strength of a signal received at the location; 
 receiving a position request from a wireless device that receives an identifier and a signal strength from a specific wireless station; 
 identifying the specific wireless station using the identifier to retrieve a group of positioning data from the database; 
 selecting a subset in the group of positioning data using the received signal strength; 
 determining position information of the wireless device using the selected subset of positioning data; and 
 calculating an estimated uncertainty value associated with the determined position information of the wireless device using circular error probable (CEP) theory to calculate a threshold percentage of radius of the determined position information of the wireless device. 
 
     
     
       2. The method of  claim 1 , wherein the selecting the subset in the group of positioning data further comprises:
 selecting, when the received signal strength is inside the boundaries of a group of positioning data, the subset when the received signal strength is inside the boundaries of the subset. 
 
     
     
       3. The method of  claim 2 , further comprising:
 determining the subset when the received signal strength is outside the boundaries of a group of positioning data. 
 
     
     
       4. The method of  claim 3 , wherein the determining the subset is based on calculating a closeness between the received signal strength and each signal strength in the group of positioning data. 
     
     
       5. The method of  claim 4 , wherein the calculating the closeness is based on exponential decay model. 
     
     
       6. The method of  claim 1 , wherein the determining position information of the wireless device further comprises:
 weigh-averaging position information in the selected subset of positioning data when the received signal strength is inside the boundaries of a group of positioning data. 
 
     
     
       7. The method of  claim 6 , further comprising:
 averaging position information in the selected subset of positioning data when the received signal strength is outside the boundaries of a group of positioning data. 
 
     
     
       8. The method of  claim 6 , wherein the calculated threshold percentage of radius is 95% radius of the determined position information of the wireless device. 
     
     
       9. The method of  claim 6 , wherein a weight of a position is determined based on the received signal strength to each signal strength in the selected subset of positioning data. 
     
     
       10. An apparatus, comprising:
 a storage medium configured to provide a database of positioning data, each positioning data associating position information of a location with an identification of a wireless station device for providing wireless connection at the location and the strength of a signal received at the location; and 
 a processor configured to: 
 receive a position request from a wireless device that receives an identifiers identifier and the strength of a signal from a specific wireless station; 
 identify the specific wireless station using the identifier to retrieve a group of positioning data from a database; 
 select a subset in the group of positioning data using the received signal strength; 
 determine position information of the wireless device using the selected subset of positioning data; and 
 calculate an estimated uncertainty value associated with the determined position information of the wireless device using circular error probable (CEP) theory to calculate a threshold percentage of radius of the determined position information of the wireless device. 
 
     
     
       11. The apparatus of  claim 10 , wherein the processor selects the subset in the group of positioning data further comprises:
 select when the received signal strength is inside the boundaries of a group of positioning data, the subset when the received signal strength is inside the boundaries of the subset. 
 
     
     
       12. The apparatus of  claim 11 , wherein the processor configured to select the subset in the group of positioning data further comprising comprising: determine the subset when the received signal strength is outside the boundaries of a the group of positioning data. 
     
     
       13. The apparatus of  claim 12 , wherein the processor determines the subset is based on calculating the a closeness between the received signal strength and each signal strength in the group of positioning data. 
     
     
       14. The apparatus of claim  12  13, wherein the processor calculates the a closeness is based on exponential decay model. 
     
     
       15. The apparatus of  claim 10 , wherein the processor determines position information of the wireless device further comprises:
 weigh-average position information in the selected subset of positioning data when the received signal strength is inside the boundaries of a group of positioning data. 
 
     
     
       16. The apparatus of  claim 15 , wherein the processor configured to determine position information of the wireless device further comprising comprises:
 average position information in the selected subset of positioning data when the received signal strength is outside the boundaries of a the group of positioning data. 
 
     
     
       17. The apparatus of  claim 15 , wherein the calculated threshold percentage of radius is 95% radius of the determined position information of the wireless device. 
     
     
       18. The apparatus of  claim 15 , wherein the processor determines a weight of a position based on the received signal strength to each signal strength in the selected subset of positioning data. 
     
     
       19. An apparatus, comprising:
 a data retriever that comprises a reception module configured to receive the identifiers and the strength of signals from wireless stations, and a mapping module configured to identify the wireless stations using the identifiers; 
 a data processor that comprises a retrieval module configured to extract the groups of positioning data from a database, and a clustering module configured to select the subsets in the groups of positioning data using the strength of the received signals; 
 a location estimator that comprises a position module configured to determine position information of the a wireless device using the selected subsets of in the groups of positioning data, calculate an estimated uncertainty value associated with the determined position information of the wireless device using a circular error probable (CEP) theory to calculate a threshold percentage of a radius of the determined position information of the wireless device, and a position filtering module configured to exclude outliers when outliers whose distances of the outliers exceed a threshold; and 
 a data manager that comprises a cluster allocation module configured to reset clustering boundaries of a subset when a requirement is satisfied.