×

System and method of passive and active scanning of WLAN-enabled access points to estimate position of a WLAN positioning device

  • US 8,185,129 B2
  • Filed: 07/06/2007
  • Issued: 05/22/2012
  • Est. Priority Date: 07/07/2006
  • Status: Active Grant
First Claim
Patent Images

1. A device for estimating the position of itself in response to gathering wireless signal information from WLAN access points (APs), said device comprising:

  • a WLAN radio module for receiving WLAN signals transmitted by WLAN APs in range of said device, wherein the WLAN APs are capable of transmitting on a set of WLAN channels;

    logic to cause the WLAN radio module to perform a scanning sequence in which the WLAN radio module receives WLAN signals transmitted by WLAN APs in range of said device, wherein the scanning sequence includes an active scanning phase and a passive scanning phase, each of the active and passive scanning phases ending after detecting a sufficient numbers of APs to locate the device;

    extraction logic for extracting information from said received WLAN signals to identify the WLAN APs; and

    logic to cooperate with a WLAN-based positioning system to estimate the position of the device based at least in part on the extracted information identifying the WLAN APs in the range of said device;

    wherein said WLAN radio module is configured to receive signals transmitted by WLAN APs on only a subset of said set of WLAN channels upon a start of the scanning sequence, wherein the subset consists only of WLAN channels that are most commonly used in at least one selected geographic region.

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