United States Patent
US Patent 7515578: Estimation of position using WLAN access point…
US 7515578 · granted 2009-04-07
Abstract
A method for estimating position using WLAN access point radio propagation characteristics in a WLAN location based service is provided. A location-based services system has a plurality of Wi-Fi access points in a target area. The Wi-Fi access points are positioned at geographic locations and have signal coverage areas. A method of characterizing at least one of the Wi-Fi access points comprises determining the geographic location of the Wi-Fi access point, dividing the signal coverage area of the Wi-Fi access point into at least one section, and determining radio propagation characteristics for each section. The radio propagation characteristics of each section characterize a radio channel of the Wi-Fi access point, and the characterization can be used in a location algorithm.
| Patent Number | 7515578 |
|---|---|
| Title | Estimation of position using WLAN access point radio propagation characteristics in a WLAN positioning system |
| Filed | 2006-05-08 |
| Granted | 2009-04-07 |
| Inventor(s) | Shabdiz; Farshid, Pahlavan; Kaveh |
| Assignee | Skyhook Wireless, Inc. |
| CPC Classification | H04W 4/00 |
| Number of Claims | 24 |
Abstract
A method for estimating position using WLAN access point radio propagation characteristics in a WLAN location based service is provided. A location-based services system has a plurality of Wi-Fi access points in a target area. The Wi-Fi access points are positioned at geographic locations and have signal coverage areas. A method of characterizing at least one of the Wi-Fi access points comprises determining the geographic location of the Wi-Fi access point, dividing the signal coverage area of the Wi-Fi access point into at least one section, and determining radio propagation characteristics for each section. The radio propagation characteristics of each section characterize a radio channel of the Wi-Fi access point, and the characterization can be used in a location algorithm.
Claim 1
A method of characterizing at least one of Wi-Fi access points, using the coverage area of the Wi-Fi access point, so that the characterization may be used later toeffectively weigh signals transmitted by said Wi-Fi access point when performing a location estimation, the method of characterization comprising: determining the geographic location of the Wi-Fi access points; for each Wi-Fi access point, measuring aplurality of power values for signals transmitted by a corresponding Wi-Fi access point, each power value being measured at position relative to each corresponding Wi-Fi access point; determining a signal coverage area of each Wi-Fi access point basedon said measured plurality of power values; dividing the signal coverage area of the Wi-Fi access point into at least two sections, Wherein the coverage area is divided according to at least two radials and at least one distance from the Wi-Fi accesspoint; determining radio propagation characteristics for each section; and assigning a weight to each section based on the coverage areas of the Wi-Fi access points, where sections having relatively small coverage areas are assigned a higher effectiveweight than sections having relat
Claims
24 totalA method of characterizing at least one of Wi-Fi access points, using the coverage area of the Wi-Fi access point, so that the characterization may be used later toeffectively weigh signals transmitted by said Wi-Fi access point when performing a location estimation, the method of characterization comprising: determining the geographic location of the Wi-Fi access points; for each Wi-Fi access point, measuring aplurality of power values for signals transmitted by a corresponding Wi-Fi access point, each power value being measured at position relative to each corresponding Wi-Fi access point; determining a signal coverage area of each Wi-Fi access point basedon said measured plurality of power values; dividing the signal coverage area of the Wi-Fi access point into at least two sections, Wherein the coverage area is divided according to at least two radials and at least one distance from the Wi-Fi accesspoint; determining radio propagation characteristics for each section; and assigning a weight to each section based on the coverage areas of the Wi-Fi access points, where sections having relatively small coverage areas are assigned a higher effectiveweight than sections having relat