The document discusses indoor positioning systems (IPS) as an alternative to GPS for locating objects and people inside buildings. It defines IPS as using lights, radio waves, magnetic fields or other sensors to determine position. It explains that IPS works by using small beacon devices that emit signals at regular intervals, allowing a receiver like a phone to calculate distance based on signal strength. Finally, it lists common uses of IPS in places like hospitals, offices, malls and more where GPS location is not possible or accurate indoors.