Patent ID: 9684058
Date: 2017-06-20
CPC Classifications: G01S,H04W,Y02D

Claim:
1. A method of estimating the position of a user device comprising a Bluetooth receiver, the method comprising: the user device detecting one or more Bluetooth beacons configured to transmit signals at any of a plurality of discrete transmit power levels, and a computer processing system comprising a processor calculating an estimate of the position of the user device taking into account transmit power data concerning the transmit power level of the one or more said Bluetooth beacons at the time when the respective Bluetooth beacon is detected and beacon position data concerning the position of the one or more said Bluetooth beacons, wherein for some or all of the Bluetooth beacons, the respective Bluetooth beacon automatically switches between at least some of the plurality of discrete transmit power levels in a cycle in which the transmit power level decreases monotonically from a highest level through at least one intermediate level to a lowest level before returning to the said highest level.