×

Calculation of quality of wlan access point characterization for use in a wlan positioning system

  • US 7,551,579 B2
  • Filed: 05/08/2006
  • Issued: 06/23/2009
  • Est. Priority Date: 05/08/2006
  • Status: Active Grant
First Claim
Patent Images

1. In a positioning system having a plurality of Wi-Fi access points in a target area, a method for determining a quality of estimation of characteristics of a Wi-Fi access point, the method comprising:

  • a Wi-Fi enabled scanning device receiving and measuring a number of received signal strength (RSS) samples of a Wi-Fi signal transmitted by the Wi-Fi access point;

    estimating a total distance traveled by the Wi-Fi enabled scanning device while measuring the number of RSS samples;

    using the estimated total distance traveled to calculate the quality of estimation of characteristics of the Wi-Fi access point;

    associating a corresponding speed of travel of the Wi-Fi enabled scanning device with each RSS sample;

    associating a corresponding period of time of scanning with each RSS sample;

    determining a confidence factor, CFn, using the sum of each of the speeds of travel of the Wi-Fi enabled scanning device weighted by the corresponding period of time of scanning for each RSS sample; and

    determining the quality of estimation, R, according to the equation;

    R = ( R max - R min )

    [ log

    ( CF n )
    - log

    ( CF min )
    ]
    [ log

    ( CF max )
    - log

    ( CF min )
    ]
    + R min
    wherein;

    Rmax is a maximum quality of estimation;

    Rmin is a minimum quality of estimation;

    CFmax is a maximum confidence factor; and

    CFmin is a minimum confidence factor.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×