Multi-layer statistical wireless terminal location determination

Abstract

Disclosed are embodiments for determining a location of a wireless terminal. The wireless terminal measures signal strength of a plurality of wireless transmitters. Based on this information, a plurality of location probability surfaces are generated. Each location probability surface indicates a plurality of probabilities that the wireless terminal is in each of a corresponding plurality of geographic regions. These probability surfaces are then averaged to determine a composite location probability surface. A motion probability surface is also determined, which stores a plurality of probabilities indicating variations of motion of the wireless terminal. The composite location probability surface is then updated based on the motion probability surface. A location estimate of the wireless terminal is then determined based on the updated composite location probability surface.

1 . A system, comprising:
 hardware processing circuitry;   one or more hardware memories storing instructions that when executed configure the hardware processing circuitry to perform operations comprising:
 receiving, from a wireless terminal, a signal strength measurement of a signal received by the wireless terminal, the signal generated by a first wireless transmitter; 
 determining, for each of a plurality of regions, an expected signal strength of the signal from the wireless transmitter in the respective region; 
 determining, for each of the plurality of regions, a corresponding first difference between the expected signal strength in the respective region and the signal strength measurement; 
 determining, for each of the plurality of regions, a corresponding first probability that the wireless terminal is located in the respective region based on one of the first differences that corresponds to the respective region; 
 estimating a first location of the wireless terminal at a first time based on the determined first probabilities.