Patent ID: 7627333
Filing Date: 2009-12-01
Classification: H04W

Abstract:
1. A method of locating a mobile appliance in a network overlay geolocation system having a plurality of base stations and a second plurality of wireless location sensors comprising: measuring the time of arrival (TOA) of a reverse signal from the mobile appliance at one or more of the second plurality of wireless location sensors (WLS) to create time difference of arrival (TDOA) measurements; synchronizing the TDOA measurements of the reverse signal to a common time base; measuring the TOA of a forward channel from one or more of the plurality of base stations at the mobile appliance to create enhanced observed time difference (E-OTD) measurements; and determining a location estimate based on the TDOA measurements of the reverse signal and the E-OTD measurements, wherein the E-OTD measurements are provided to a geo-location control system by an Abis monitoring unit.