Abstract: A method and devices are disclosed that locate a target station moving at a constant velocity. A method and devices are disclosed for producing an RTT vector that is based upon the changes in position of the airborne measuring station position and the relative change in position of the target station. In one embodiment, the target station is an access point or station conforming to the IEEE 802.11 Standard and the airborne measuring station may also be a device that conforms to the IEEE 802.11 Standard.

Abstract: A method and devices are disclosed that locate a target station moving at a constant velocity. A method and devices are disclosed for producing an RTT vector that is based upon the changes in position of the airborne measuring station position and the relative change in position of the target station. In one embodiment, the target station is an access point or station conforming to the IEEE 802.11 Standard and the airborne measuring station may also be a device that conforms to the IEEE 802.11 Standard.

Abstract: A method in a wireless device (WD) for determining a best-fit geo-location of a target station is described. The best-fit geo-location is determined using a plurality of round-trip times (RTTs). The target station is movable. The method includes assigning values to current target station parameters. The current target station parameters include a current location for the target station and movement parameters. A plurality of square residuals is determined based at least in part on the current target station parameters. Each square residual of the plurality of square residuals corresponds to one RTT. A minimum of a sum of squared residuals (SSR) is determined based at least on the plurality of square residuals. best-fit parameters are determined based at least in part on the determined minimum of the SSR. In addition, the best-fit geo-location of the target station is determined based at least on the best-fit parameters.

Abstract: A method and wireless devices (WDs) for geo-location of wireless devices are disclosed. According to one aspect, a method in a first WD includes: transmitting a sequence of ranging signals and receiving a plurality of ranging response signals from a second WD, the ranging response signals being responsive to the ranging signals. For each of the plurality of ranging response signals, a received sequence of bits is determined. A correlation between the received sequence of bits and an expected sequence of bits is determined. The method also includes determining a subset of the plurality of received sequences of bits deemed not to arise from noise, and determining the subset being based at least in part on the correlations. The method also includes determining a distance between the first WD and the second WD based at least in part on a plurality of received sequences in the subset.

Abstract: A method, wireless device and measuring station are disclosed that determine the best fit geo-location of a target station. According to one aspect, a method includes, using a “Pass Filter” for minimization of the summation of squared miss probabilities SSMP that improves the fitting process of the measured data over the method of minimization of the summation of the squared residuals (SSR) in the presence of spurious measurements. A “Pass Filter” approach is disclosed that reduces the corruption of the fitting process by outlier data and still yields the same result in the limit of clean data as the classic summation of the squared residuals (SSR) method.

Abstract: A method for determining a geo-location of a target station is provided. The method includes receiving a plurality of RTTs over a plurality of successive time intervals. Each successive time interval is equal to a predetermined amount of time. The plurality of RTTs is placed into a plurality of bins. Each bin has a predetermined time width and a count of RTTs placed in the bin. A bin with a highest count of RTTs (maxCb) and another bin with a next highest count of RTTs are selected and a maximum count ratio determined. The bin with maxCb to a maximum bin value is set based at least on a predetermined threshold of the maximum count ratio. During a next successive time interval, the RTTs that are placed in the bin that is set to the maximum bin value are selected to determine the geo-location of the target station.

Abstract: A method in a measuring station is described. The method includes determining a plurality of Time of Flights (TOFs) corresponding to plurality of beacons and determining an overall circular error probability ellipse (CEP) based at least in part upon a plurality of times of departure and a corresponding plurality of measuring station positions for each TOF. The method further includes determining at least one individual CEP of a plurality of individual CEPs if at least one of a predetermined time has elapsed and the measuring station has travelled a predetermined distance and determining a merged CEP, where the merged CEP includes the plurality of individual CEPs. Further, the merged CEP is determined to be a better CEP if the merged CEP is more consistent with the plurality of individual CEPs than with the overall CEP. The better CEP is usable to determine a location of a wireless device.

Abstract: A method, wireless device and measuring station are disclosed that determine the best fit geo-location of a target station. According to one aspect, a method includes, using a “Pass Filter” for minimization of the summation of squared miss probabilities SSMP that improves the fitting process of the measured data over the method of minimization of the summation of the squared residuals (SSR) in the presence of spurious measurements. A “Pass Filter” approach is disclosed that reduces the corruption of the fitting process by outlier data and still yields the same result in the limit of clean data as the classic summation of the squared residuals (SSR) method.

Abstract: A method implemented in a first wireless device is described. The method includes transmitting a plurality of paging requests, receiving a first plurality of bit streams, and performing a first correlation, during a reception window, of each bit stream. When a correlation threshold is exceeded, a synchronization packet is transmitted, a bit stream received, and a second correlation performed. When a third time difference between a first time difference and a second time difference is within a predetermined time difference range, a plurality of poll packets is transmitted, a second plurality of bit streams received, and a third correlation is performed of each bit stream of the second plurality of bit streams with a second expected bit stream. The method further includes determining a correlation time of a maximum correlation value of each poll packet and determining the plurality of RTTs corresponding to the plurality of poll pockets.

Abstract: A method and measuring station to determine the geo-location of a wanted target station in the presence of rogue responder stations are disclosed. One method includes: transmitting a packet with a fictitious address not corresponding to the wanted target station address; transmitting a packet with the wanted target station address; determining at least one of: a first difference between a round trip time (RTT) associated with a response packet from a responder station and an RTT associated with a response packet from the wanted target station; and a second difference between a time of arrival (TOA) associated with the responder station's response packet and a TOA associated with the wanted target station's response packet; and distinguishing between the response from the responder station and the response from the wanted target station based on at least at least one of the first difference and the second difference.

Abstract: A method and wireless devices (WDs) for geo-location of wireless devices are disclosed. According to one aspect, a method in a first WD includes: transmitting a sequence of ranging signals and receiving a plurality of ranging response signals from a second WD, the ranging response signals being responsive to the ranging signals. For each of the plurality of ranging response signals, a received sequence of bits is determined. A correlation between the received sequence of bits and an expected sequence of bits is determined. The method also includes determining a subset of the plurality of received sequences of bits deemed not to arise from noise, and determining the subset being based at least in part on the correlations. The method also includes determining a distance between the first WD and the second WD based at least in part on a plurality of received sequences in the subset.

Abstract: A method in a measuring station is described. The method includes determining a plurality of Time of Flights (TOFs) corresponding to plurality of beacons and determining an overall circular error probability ellipse (CEP) based at least in part upon a plurality of times of departure and a corresponding plurality of measuring station positions for each TOF. The method further includes determining at least one individual CEP of a plurality of individual CEPs if at least one of a predetermined time has elapsed and the measuring station has travelled a predetermined distance and determining a merged CEP, where the merged CEP includes the plurality of individual CEPs. Further, the merged CEP is determined to be a better CEP if the merged CEP is more consistent with the plurality of individual CEPs than with the overall CEP. The better CEP is usable to determine a location of a wireless device.

Abstract: A method, wireless device and measuring station are disclosed that determine the best fit geo-location of a target station. According to one aspect, a method includes, using a “Pass Filter” for minimization of the summation of squared miss probabilities SSMP that improves the fitting process of the measured data over the method of minimization of the summation of the squared residuals (SSR) in the presence of spurious measurements. A “Pass Filter” approach is disclosed that reduces the corruption of the fitting process by outlier data and still yields the same result in the limit of clean data as the classic summation of the squared residuals (SSR) method.

Abstract: A method and wireless devices (WDs) for geo-location of wireless devices are disclosed. According to one aspect, a method in a first WD includes: transmitting a sequence of ranging signals and receiving a plurality of ranging response signals from a second WD, the ranging response signals being responsive to the ranging signals. For each of the plurality of ranging response signals, a received sequence of bits is determined. A correlation between the received sequence of bits and an expected sequence of bits is determined. The method also includes determining a subset of the plurality of received sequences of bits deemed not to arise from noise, and determining the subset being based at least in part on the correlations. The method also includes determining a distance between the first WD and the second WD based at least in part on a plurality of received sequences in the subset.

Abstract: A method for determining a geo-location of a target station is provided. The method includes receiving a plurality of RTTs over a plurality of successive time intervals. Each successive time interval is equal to a predetermined amount of time. The plurality of RTTs is placed into a plurality of bins. Each bin has a predetermined time width and a count of RTTs placed in the bin. A bin with a highest count of RTTs (maxCb) and another bin with a next highest count of RTTs are selected and a maximum count ratio determined. The bin with maxCb to a maximum bin value is set based at least on a predetermined threshold of the maximum count ratio. During a next successive time interval, the RTTs that are placed in the bin that is set to the maximum bin value are selected to determine the geo-location of the target station.

Abstract: A method implemented in a first wireless device is described. The method includes transmitting a plurality of paging requests, receiving a first plurality of bit streams, and performing a first correlation, during a reception window, of each bit stream. When a correlation threshold is exceeded, a synchronization packet is transmitted, a bit stream received, and a second correlation performed. When a third time difference between a first time difference and a second time difference is within a predetermined time difference range, a plurality of poll packets is transmitted, a second plurality of bit streams received, and a third correlation is performed of each bit stream of the second plurality of bit streams with a second expected bit stream. The method further includes determining a correlation time of a maximum correlation value of each poll packet and determining the plurality of RTTs corresponding to the plurality of poll pockets.

Abstract: A method for determining a geo-location of a target station is provided. The method includes receiving a plurality of RTTs over a plurality of successive time intervals. Each successive time interval is equal to a predetermined amount of time. The plurality of RTTs is placed into a plurality of bins. Each bin has a predetermined time width and a count of RTTs placed in the bin. A bin with a highest count of RTTs (maxCb) and another bin with a next highest count of RTTs are selected and a maximum count ratio determined. The bin with maxCb to a maximum bin value is set based at least on a predetermined threshold of the maximum count ratio. During a next successive time interval, the RTTs that are placed in the bin that is set to the maximum bin value are selected to determine the geo-location of the target station.

Abstract: A method and measuring station to determine the geo-location of a wanted target station in the presence of rogue responder stations are disclosed. One method includes: transmitting a packet with a fictitious address not corresponding to the wanted target station address; transmitting a packet with the wanted target station address; determining at least one of: a first difference between a round trip time (RTT) associated with a response packet from a responder station and an RTT associated with a response packet from the wanted target station; and a second difference between a time of arrival (TOA) associated with the responder station's response packet and a TOA associated with the wanted target station's response packet; and distinguishing between the response from the responder station and the response from the wanted target station based on at least at least one of the first difference and the second difference.

Abstract: A method and devices are disclosed for producing a differential RTT vector (RTV) that is based upon the relative change in an airborne measuring station velocity relative to the target wireless device based upon RTT measurements, the RTT measurements being taken at known time intervals to a ground based target station, and the velocity and heading of the airborne measuring station. In one embodiment, the target device is an access point or station conforming to the IEEE 802.11 standard and the airborne measuring station 110 may also be a device that conforms to the IEEE 802.11 standard. The disclosed method enables the quick determination of the location of a target station to an accuracy of, for example, in the order of one half degree of bearing within, for example, a period in the order of 5 seconds.

Abstract: A method and devices are disclosed for producing a RTT vector (RTV) that is based upon the change in an airborne measuring station position and the corresponding RTT results taken at known time intervals to a ground based target station. In one embodiment, the target station is an access point or station conforming to the IEEE 802.11 standard and the airborne measuring station 110 may also be a device that conforms to the IEEE 802.11 standard. The disclosed method enables the location of a target station to an accuracy in the order of, for example, less than one half degree of bearing within, for example, a period in the order of 5 seconds.