Patent attributes
A system and methods for estimating the location of a mobile device are disclosed. In accordance with one embodiment, a mobile device receives a wireless electromagnetic signal and an ultrasound signal from a first beacon during a first occurrence of a time slot. The mobile device further receives a wireless electromagnetic signal and an ultrasound signal from a second beacon during a second occurrence of the time slot, where the ultrasound signals from the first and second beacons have non-overlapping areas of coverage. The electromagnetic and ultrasound signals from the first beacon are used to estimate a first location of the mobile device, and the electromagnetic and ultrasound signals from the second beacon are used to estimate a second location of the mobile device.