Server for updating location beacon database
A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to reduce arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, Wi-Fi identity information and GPS location information is detected. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database.
1. A Wi-Fi location server system, comprising:
a collection of information in a non-transitory computer-readable medium describing Wi-Fi access points for at least one target area, the collection including information for a plurality of Wi-Fi access points in the target area, the information including identification information for a corresponding Wi-Fi access point and calculated position information for the corresponding Wi-Fi access point, wherein the calculated position information is obtained from recording multiple readings of the Wi-Fi access point at different locations around the Wi-Fi access point so that the calculation of the position of the Wi-Fi access point reduces arterial bias in the calculated position information;
computer-implemented logic for receiving sets of newly-discovered readings for Wi-Fi access points in the target area and location information representing one or more locations at which any of the newly-discovered readings were detected;
computer-implemented logic for identifying potential error in the location information including grouping readings into subsets, assigning one or more attributes to each subset, comparing attributes of at least two subsets, and identifying the potential error in the location information based on results of the comparing; and
computer-implemented logic to determine position information for Wi-Fi access points based on the multiple readings of the Wi-Fi access point at different locations around the Wi-Fi access point and the location information representing one or more locations at which any of the multiple readings were detected, wherein the location information with potential error is excluded.
2. The system of claim 1 , wherein the target area has a radius on the order of tens of miles.
3. The system of claim 1 , wherein the plurality of Wi-Fi access points in the target area includes substantially all of the Wi-Fi access points in the target area.
4. The system of claim 1 , wherein the collection of information provides reference symmetry within substantially the entire target area.
5. The system of claim 1 , wherein the logic for identifying the potential error in the location information includes signal clustering techniques.
6. The system of claim 5 , wherein the signal clustering techniques include:
determining a plurality of the multiple readings that share one or more similar signal characteristics; and
designating as potentially erroneous those readings lacking in the determined similarity.
7. The system of claim 5 , wherein the signal clustering techniques include:
determining a first centroid for a corresponding Wi-Fi access point based on all newly-discovered readings and location information; and
designating as potentially erroneous at least one reading and location information set in which the distance between the first centroid and location information of the set exceeds a predetermined threshold.
8. The system of claim 5 , wherein the signal clustering techniques include:
determining weighted centroids based on the age of the location information; and
designating as potentially erroneous at least one reading and location information set in which the distance between one or more of the centroids and location information of the set exceeds a predetermined threshold.
9. The system of claim 1 , further comprising logic to identify at least one portion of the target area in which potential error in the location information was encountered during the recording of the multiple readings of the Wi-Fi access points.
10. The system of claim 1 , further comprising logic to identify at least one portion of the target area for which the collection of information lacks calculated position information for Wi-Fi access points.