US Patent 11882503 Method and system of two-tier location tracking

A low-power tracking device transmitting periodic beacons for nearby hotspots using wide-area wireless network, such as LoRaWAN hotspots. The hotspots estimate the tracking device's coarse location, relying solely on the hotspots' received signal strength and hotspots' geolocation information, in order to reduce the tracking device's power consumption. When the tracking device is considered as lost, one or a plural of finder units are deployed within tracking device's vicinity to provide high precision location tracking. Using finder's instruction, the tracking device can reduce the beacon transmission intervals, transmit additional sensor information and perform other operations, to assist higher precision location tracking.