False alarm avoidance system

Abstract

The invention refers to a method of using a tag in a localisation system, the method comprising at said tag operating a magnetic induction signal detection circuit to detect signals, and upon detection of a magnetic induction signal comprising a first identification code: correlating the magnetic induction signal comprising said first identification code to an ultrasound signal comprising a second identification code, received via an ultrasound signal detection circuit. If said correlation reveals an association between said first identification code and said second identification code: a radio frequency announcement signal is transmitted via a radio frequency signal transmitter circuit to signify said association. The invention also refers to a method of using a beacon in said localisation system, as well as the localisation system comprising one or more tags and one or more beacons.

Dependencies are inferred from the claim text.