| Patent application number | Description | Published |
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| 20080248741 | TIME DIFFERENCE OF ARRIVAL BASED ESTIMATION OF DIRECTION OF TRAVEL IN A WLAN POSITIONING SYSTEM - Methods of estimating the bearing of a WLAN-enabled device are provided. A method of estimating a bearing of a WLAN-enabled device includes estimating a speed and geographic location of the device and receiving signals transmitted by an access point, including a first message and a second message. The method further includes accessing a database to determine the geographic location of the access point, determining an actual time of arrival value of the second message, and determining a time difference of arrival value for the second message based on the actual time of arrival of the second message and an expected time of arrival of the second message, which is based on an actual arrival time of the first message. Estimating the bearing of the device is based on the estimated speed and location of the device, the time difference of arrival value, and the location of the access point. | 10-09-2008 |
| 20080248808 | ESTIMATION OF POSITION, SPEED AND BEARING USING TIME DIFFERENCE OF ARRIVAL AND RECEIVED SIGNAL STRENGTH IN A WLAN POSITIONING SYSTEM - A method of estimating the speed of a WLAN-enabled device in a WLAN positioning system is provided. A method of estimating a speed of travel of a WLAN-enabled device includes the WLAN-enabled device receiving signals transmitted by a WLAN access point in range of the WLAN-enabled device. The signals include a first message and a second message. The method also includes estimating an expected time of arrival of the second message based on an actual arrival time of the first message and determining an actual time of arrival value of the second message. The method further includes determining a time difference of arrival value for the second message based on the actual time of arrival of the second message and the expected time of arrival of the second message and estimating the speed of travel of the WLAN-enabled device based on the time difference of arrival value. | 10-09-2008 |
| 20090075672 | SERVER FOR UPDATING LOCATION BEACON DATABASE - A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to reduce arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, Wi-Fi identity information and GPS location information is detected. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database. | 03-19-2009 |
| 20090149197 | CONTINUOUS DATA OPTIMIZATION OF NEW ACCESS POINTS IN POSITIONING SYSTEMS - Methods and systems of continuously optimizing data in WiFi positioning systems. A location-based services system uses WiFi-enabled devices to monitor WiFi access points in a target area to indicate whether a WiFi access point is newly-observed. A WiFi-enabled device communicates with WiFi access points within range of the WiFi-enabled device so that observed WiFi access points identify themselves. A reference database is accessed to obtain information specifying a recorded location for each observed WiFi access point in the target area. Observed WiFi access points for which the reference database has no information specifying a corresponding recorded location are identified. The recorded location information for each of the observed WiFi access points is used to calculate the position of the WiFi-enabled device. The reference database is informed of the WiFi access points (for which there was no information in the database) and is provided the calculated position in conjunction therewith. | 06-11-2009 |
| 20090154371 | ESTIMATION OF POSITION USING WLAN ACCESS POINT RADIO PROPAGATION CHARACTERISTICS IN A WLAN POSITIONING SYSTEM - A method for estimating position using WLAN access point radio propagation characteristics in a WLAN location based service is provided. A location-based services system has a plurality of Wi-Fi access points in a target area. The Wi-Fi access points are positioned at geographic locations and have signal coverage areas. A method of characterizing at least one of the Wi-Fi access points comprises determining the geographic location of the Wi-Fi access point, dividing the signal coverage area of the Wi-Fi access point into at least one section, and determining radio propagation characteristics for each section. The radio propagation characteristics of each section characterize a radio channel of the Wi-Fi access point, and the characterization can be used in a location algorithm. | 06-18-2009 |
| 20090175189 | CALCULATION OF QUALITY OF WLAN ACCESS POINT CHARACTERIZATION FOR USE IN A WLAN POSITIONING SYSTEM - Methods and systems for classifying WLAN access points according to the quality of estimation of characteristics of the WLAN access points are provided. The classifications may be used to scale a reference database and quantify an expected error of estimation of the characteristics of the access points. WLAN access points may be classified based on their impact on a user's position, speed of travel, and direction of travel estimation accuracy in a WLAN positioning system. A method for determining a quality of estimation of characteristics of a Wi-Fi access point comprises a Wi-Fi enabled scanning device measuring a number of received signal strength (RSS) samples of the Wi-Fi signal transmitted by the Wi-Fi access point. A total distance traveled by the Wi-Fi enabled scanning device while measuring the number of RSS samples is estimated and used to estimate the quality of estimation of characteristics of the Wi-Fi access point. | 07-09-2009 |
| 20090252138 | ESTIMATION OF SPEED AND DIRECTION OF TRAVEL IN A WLAN POSITIONING SYSTEM USING MULTIPLE POSITION ESTIMATIONS - A method for estimating the speed and bearing of a Wi-Fi enabled device using WLAN radio signals in a WLAN based location service is provided. A method used to estimate a speed of travel of a Wi-Fi enabled device comprises the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device, and using the signals to estimate the speed of and/or direction of travel of the Wi-Fi enabled device. | 10-08-2009 |
| 20090303112 | SYSTEM AND METHOD FOR REFINING A WLAN-PS ESTIMATED LOCATION USING SATELLITE MEASUREMENTS IN A HYBRID POSITIONING SYSTEM - This disclosure describes a system and method for refining a WLAN-PS estimated location using satellite measurements. In some embodiments, the disclosure relates to a method of determining the location of a WLAN and satellite enabled device by using two or more satellite measurements to refine an initial WLAN based location determination. The method can include estimating a position of the WLAN and satellite enabled device using a WLAN positioning system, gathering satellite location measurements from at least two satellites, determining an uncertainty area around the WLAN location estimate based on the expected error of the WLAN location estimate, wherein the uncertainty area has a plurality of possible location solutions, and determining the device location estimate inside the WLAN location uncertainty that best satisfies the satellite measurements. | 12-10-2009 |
| 20090303113 | METHODS AND SYSTEMS FOR IMPROVING THE ACCURACY OF EXPECTED ERROR ESTIMATION IN A HYBRID POSITIONING SYSTEM - This disclosure describes methods and systems for improving the accuracy of expected error estimation in a hybrid positioning system. In some embodiments, the method of determining an expected error in a location determination of a WLAN and satellite enabled device can include determining a WLAN location estimate and an expected error estimate for the WLAN location estimate, obtaining measurements from at least two satellites, and determining the expected error of the location determination by evaluating the consistency of the satellite positioning system measurements to the WLAN positioning system location estimation. | 12-10-2009 |
| 20090303114 | METHOD AND SYSTEM FOR DETERMINING LOCATION USING A HYBRID SATELLITE AND WLAN POSITIONING SYSTEM BY SELECTING THE BEST WLAN-PS SOLUTION - This disclosure describes a method and system for determining location using a hybrid satellite and WLAN positioning system by selecting the best WLAN-PS solution. In some embodiments, the method of increasing the accuracy of a WLAN based position estimate using satellite positioning information can include determining a set of possible WLAN location solutions for a WLAN and satellite enabled device based on one or more WLAN access points, obtaining satellite information for the WLAN and satellite enabled device from at least two different satellites, and using the satellite information from the at least two different satellites to determine the best WLAN location solution from the set of possible WLAN location solutions. | 12-10-2009 |
| 20090303115 | METHODS AND SYSTEMS FOR STATIONARY USER DETECTION IN A HYBRID POSITIONING SYSTEM - This disclosure describes methods and systems for stationary user detection in a hybrid location system. In some embodiments, the method for determining whether a satellite enabled device is stationary by measuring the Doppler frequency of received satellite signals can include acquiring satellite measurements from at least two satellites, wherein the satellite measurements include Doppler frequency measurements, acquiring a rough estimate of location of the satellite enabled device and calculating an internal frequency offset of satellite enabled device. | 12-10-2009 |
| 20090303119 | SYSTEMS AND METHODS FOR USING ENVIRONMENTAL INFORMATION IN A HYBRID POSITIONING SYSTEM - This disclosure describes systems and methods for using environmental information in a hybrid positioning system. Some embodiments relate to a method for determining the position of a WLAN and satellite positioning system enabled device using characteristics of the environment in which the device is located, the method can include detecting WLAN APs in range of the device, obtaining environmental characteristics from a reference database based on the WLAN APs detected by the device, and determining whether to use the WLAN or satellite positioning system based on the environmental characteristics. | 12-10-2009 |
| 20090303120 | SYSTEMS AND METHODS FOR DETERMINING POSITION USING A WLAN-PS ESTIMATED POSITION AS AN INITIAL POSITION IN A HYBRID POSITIONING SYSTEM - This disclosure describes a method and system for determining position using a WLAN-PS estimated position as an initial position. In some embodiments, the method can include calculating a WLAN position estimate of the WLAN and satellite enabled device and using the WLAN position estimate as an initial position in satellite position system to determine the location of the WLAN and satellite enabled device. | 12-10-2009 |
| 20090303121 | SYSTEM AND METHOD FOR USING A SATELLITE POSITIONING SYSTEM TO FILTER WLAN ACCESS POINTS IN A HYBRID POSITIONING SYSTEM - This disclosure describes a system and method for using a satellite positioning system to filter WLAN access points in a hybrid positioning system. In some embodiments, the method can include detecting WLAN APs in range of the WLAN and satellite enabled device, obtaining satellite measurements from at least two satellites to provide a plurality of possible satellite locations of the device, and providing a weight for each AP based on the distance from the WLAN APs to the possible satellite locations of the device. | 12-10-2009 |
| 20090310585 | METHODS AND SYSTEMS FOR DETERMINING LOCATION USING A CELLULAR AND WLAN POSITIONING SYSTEM BY SELECTING THE BEST WLAN PS SOLUTION - The disclosed subject matter relates to a method and system for increasing the accuracy of a WLAN based position estimate using cellular positioning information. In some embodiments, the method can include determining a set of possible WLAN location solutions for a WLAN and cellular enabled device based on one or more WLAN access points, obtaining cellular measurements from at least one cell tower, and determining the best WLAN location solution from the set of possible WLAN location solutions using the cellular measurements. In one embodiment, the method can include using the cellular measurements from the at least one cell tower to provide a cellular based location estimate for the WLAN and cellular enabled device. | 12-17-2009 |
| 20090312035 | METHODS AND SYSTEMS FOR DETERMINING LOCATION USING A CELLULAR AND WLAN POSITIONING SYSTEM BY SELECTING THE BEST CELLULAR POSITIONING SYSTEM SOLUTION - The present disclosure relates to systems and methods for determining the location of a WLAN and cellular position system enabled device using a WLAN position estimate to select the best cellular positioning system location. The method can include estimating a position of the WLAN and cellular enabled device using a WLAN positioning system and an expected error estimate for the WLAN based position estimate, determining a set of possible cellular based position estimates for the WLAN and cellular enabled device using cellular measurements obtained from at least one cell tower, determining an uncertainty area around the WLAN location estimate based on the expected error of the WLAN location estimate, and determining the device location by selecting cellular based location estimates located within the uncertainty area. | 12-17-2009 |
| 20090312036 | METHODS AND SYSTEMS FOR IMPROVING THE ACCURACY OF EXPECTED ERROR ESTIMATION IN LOCATION DETERMINATIONS USING A HYBRID CELLULAR AND WLAN POSITIONING SYSTEM - The present disclosure relates to systems and methods for improving the accuracy of expected error estimations in hybrid cellular and WLAN location determination. In some embodiments, the method can include providing a WLAN based location estimate and an expected error estimate for the WLAN based location estimate, providing a cellular based location estimate and an expected error estimate for the cellular based location estimate, and determining the expected error of the location determination by evaluating the consistency of the cellular based location estimate to the WLAN based location estimate. In some embodiments, the location estimate with the lower expected error can be selected as the location determination of the WLAN and cellular enabled device. In some embodiments, the consistency of the estimates can include the distance between the cellular based location estimate and the WLAN based location estimate. | 12-17-2009 |
| 20100052983 | SYSTEMS AND METHODS FOR MAINTAINING CLOCK BIAS ACCURACY IN A HYBRID POSITIONING SYSTEM - This disclosure describes systems and methods for maintaining clock bias accuracy in a hybrid positioning system. In some embodiments, the method to maintain the stability of an internal clock of an satellite positioning system receiver by using WLAN access points (APs) can include maintaining the internal clock accuracy of a satellite positioning system receiver by using one or more WLAN APs as a reference. | 03-04-2010 |
| 20110012780 | SYSTEMS AND METHODS FOR USING A SATELLITE POSITIONING SYSTEM TO DETECT MOVED WLAN ACCESS POINTS - The disclosed subject matter generally relates to hybrid positioning systems and methods and, more specifically, systems and methods of detecting moved WLAN assess points using a wireless local area network based positioning system (WLAN-PS) and a satellite-based positioning system (SPS) with at least two satellites measurement. | 01-20-2011 |
| 20110012784 | METHODS AND SYSTEMS FOR DETERMINING LOCATION USING A HYBRID SATELLITE AND WLAN POSITIONING SYSTEM BY SELECTING THE BEST SPS MEASUREMENTS - The disclosed subject matter generally relates to hybrid positioning systems and methods, more specifically, systems and methods of integrating a wireless local area network (WLAN) based positioning system (WLAN-PS) and a satellite positioning system (SPS) to improve accuracy of location estimates by selecting the best set of measurements from both systems. | 01-20-2011 |
| 20110021207 | System and Method for Estimating Positioning Error Within a WLAN-Based Positioning System - The invention features a method of estimating an expected error of a position estimate for use in a WLAN positioning system that estimates the position of a WLAN-enabled device. The WLAN-enabled device receives signals transmitted by at least one WLAN access point in range of the WLAN-enabled device, and a position of the WLAN-enabled device is estimated based on the received signals from the at least one WLAN access point in range. A signal strength value is measured for the signals transmitted by the at least one WLAN access point, and a maximum signal strength value is determined. The method also estimates an expected error of the position estimate based on the maximum signal strength value of the signals transmitted by the at least one WLAN access point in range of the WLAN enabled device. The expected error predicts a relative accuracy of the position estimate. | 01-27-2011 |
| 20110035420 | Location Beacon Database - A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device. While traversing the target area, detecting Wi-Fi signals from Wi-Fi access points in range of the Wi-Fi device and recording identity information of the detected Wi-Fi access point in conjunction with GPS location information of the vehicle when the detection of the Wi-Fi access point was made. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database. | 02-10-2011 |
| 20110045840 | METHOD AND SYSTEM FOR ESTIMATING RANGE OF MOBILE DEVICE TO WIRELESS INSTALLATION - A method of and system for estimating the range of a mobile device to a wireless installation is disclosed. A method of estimating the position of a mobile device includes receiving signals transmitted by fixed-position wireless communication stations in range of a mobile device. One of the wireless communication stations from which signals are received by the mobile device is designated as a serving station and location information is retrieved for said serving station and at least one other neighboring station from which signals are received. For each of the at least one other neighboring stations, a corresponding distance between the serving station and said neighboring station is determined based on the location information. A position of the mobile device is estimated based on the location information for the serving station and said neighboring stations and further based on the distances between the serving station and said neighboring stations. | 02-24-2011 |
| 20110058495 | Estimation of Speed and Direction of Travel in a WLAN Positioning System - A method for estimating the speed and bearing of a Wi-Fi enabled device using WLAN radio signals in a WLAN based location service is provided. A method used to estimate a speed of travel of a Wi-Fi enabled device comprises the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device, and using the signals to estimate the speed of and/or direction of travel of the Wi-Fi enabled device. | 03-10-2011 |
| 20110074626 | IMPROVEMENT OF THE ACCURACY AND PERFORMANCE OF A HYBRID POSITIONING SYSTEM - The present disclosure relates to a method for determining the position of a WLAN positioning system (WPS) and satellite positioning system (SPS) enabled device. The method can include determining an initial WPS position of the device using WPS, calculating an error region around the initial WPS position of the device, dividing the error region into a plurality of points, obtaining satellite measurements from at least two satellites in view of the device, determining a variation in a receiver clock bias for each point within the error region based on the satellite measurements from at least two satellites, selecting the point with the lowest variation in the receiver clock bias, and determining whether or not to use the point with the lowest variation in receiver clock bias to refine the initial WPS position of the device. | 03-31-2011 |
| 20110080317 | METHOD OF DETERMINING POSITION IN A HYBRID POSITIONING SYSTEM USING A DILUTION OF PRECISION METRIC - The disclosed subject matter relates to a method for determining the position of a device in a hybrid positioning system. The method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, determining a dilution of precision (DOP) based on the satellite measurements, if the DOP is small, refining the initial position estimate using the satellite measurements, and if the DOP is large, providing the initial estimate as a final position estimate for the device. In some embodiments, the non-satellite positioning system is a WLAN positioning system. In some embodiments, the method includes obtaining satellite measurements from two satellites or three satellites. | 04-07-2011 |
| 20110080318 | Determining A Dilution of Precision Metric Using Two or Three GPS Satellites - The disclosed subject matter relates to a method for determining a Dilution of Precision Metric (DOP) with less than four satellites in a hybrid positioning system. In some embodiments, the method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, constructing a geometry matrix corresponding to the measurements from the less than four satellites using each satellite's position and the initial position estimate, multiplying the geometry matrix by its transpose to construct an H matrix, determining an inverse of the H matrix, and determining the DOP based on a sum of the diagonal elements of the inverse H matrix. In some embodiments, the non-satellite positioning system is a WLAN positioning system. | 04-07-2011 |
| 20110080841 | System and Method for Estimating Positioning Error within a WLAN-Based Positioning System - The invention features a method of estimating an expected error of a position estimate for use in a WLAN positioning system that estimates the position of a WLAN-enabled device. The WLAN-enabled device receives signals transmitted by a WLAN access point in range of the WLAN-enabled device. The method estimates the position of the WLAN-enabled device based on the received signals from the WLAN access point in range of the WLAN enabled device. The method also estimates an expected error of the position estimate based on characteristics of the WLAN access point in range of the WLAN enabled device, wherein the expected error predicts a relative accuracy of the position estimate. | 04-07-2011 |
| 20110093443 | Access Point Database - A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device. While traversing the target area, detecting Wi-Fi signals from Wi-Fi access points in range of the Wi-Fi device and recording identity information of the detected Wi-Fi access point in conjunction with GPS location information of the vehicle when the detection of the Wi-Fi access point was made. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database. | 04-21-2011 |
| 20110164522 | Estimation of Position Using WLAN Access Point Radio Propagation Characteristics in a WLAN Positioning System - A method for estimating position using WLAN access point radio propagation characteristics in a WLAN location based service is provided. A location-based services system has a plurality of Wi-Fi access points in a target area. The Wi-Fi access points are positioned at geographic locations and have signal coverage areas. A method of characterizing at least one of the Wi-Fi access points comprises determining the geographic location of the Wi-Fi access point, dividing the signal coverage area of the Wi-Fi access point into at least one section, and determining radio propagation characteristics for each section. The radio propagation characteristics of each section characterize a radio channel of the Wi-Fi access point, and the characterization can be used in a location algorithm. | 07-07-2011 |
