Patent ID: 8576818
Filing Date: 2013-11-05
Classification: G01S

Abstract:
1. A method of determining the physical position of a movable node in a network, comprising: sending a first sent WiFi signal from one of an unknown node and a first reference node having a known location, and repeating the sent WiFi signal in the other of the unknown node and first reference node with a first reply WiFi signal; deriving a distance between the unknown node and the first reference node from the time of flight of the first sent and first reply WiFi signals; sending a second sent WiFi signal from one of the unknown node and a second fixed node having a known location, and repeating the sent second WiFi signal in the other of the unknown node and second reference node with a second reply WiFi signal; deriving a distance between the unknown node and the second reference node from the time of flight of the second sent and second reply WiFi signals; and determining a physical location of the unknown node based on the derived distances between the unknown node and the first and second reference nodes; wherein repeating at least one of the first and second sent WiFi signals comprises repeating the respective sent WiFi signal with the respective first or second reply WiFi signal on a different frequency or channel than the respective sent WiFi signal without processing the respective sent WiFi signal.