US 11,856,545 B1
High precision distance computations for FTM estimates
Sandeep Shetty, San Jose, CA (US)
Assigned to ESPAN SYSTEMS, Las Vegas, NV (US)
Filed by Sandeep Shetty, San Jose, CA (US)
Filed on Feb. 3, 2022, as Appl. No. 17/592,263.
Claims priority of provisional application 63/145,141, filed on Feb. 3, 2021.
Int. Cl. H04W 56/00 (2009.01); H04L 43/0864 (2022.01); H04W 64/00 (2009.01)
CPC H04W 56/005 (2013.01) [H04L 43/0864 (2013.01); H04W 56/009 (2013.01); H04W 64/003 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of determining wireless radio locations, comprising:
identifying a group of location fixed radios in a network;
identifying one or more fixed radios in the network with known location coordinates;
associating the radios with known location coordinates into a group;
constructing one or more sets of three radios from the group of radios with known location coordinates;
performing a round trip time (RTT) measurement for each radio in the sets of three radios;
calculating timing bias error values for radios in the sets of three radios;
moving radios with calculated timing bias error values into the group of radios with known location coordinates and known timing bias error values;
determining RTT values between each radio in the group of radios with known location coordinates and known timing bias error values and radios outside the group of radios with known location coordinates and known timing bias error values;
determining timing bias error values for each radio outside the group of radios with known location coordinates and known timing bias error values, wherein the timing bias error value for each radio outside the group of radios with known location coordinates and known timing bias error values is based on the determined RTT values; and
estimating location coordinates for each radio outside the group of radios with known location coordinates and known timing bias error values.