Abstract: Techniques and systems for unlocking a first device based on signals transmitted between the first device and a second device are disclosed. A disclosed technique includes receiving, by a first device, at least one wireless signal from a second device; transmitting, by the first device, at least one wireless signal to the second device; determining, by the first device, transit times of the at least one received wireless signal and the at least one transmitted wireless signal; determining, by the first device, one or more range measurements between the first device and the second device based at least in part on the transit times; determining, by the first device, an unlock decision based at least in part on the one or more range measurements; and causing, by at least the first device, the first device to unlock if the unlock decision is positive.

Abstract: Techniques and systems for unlocking a first device based on signals transmitted between the first device and a second device are disclosed. A disclosed technique includes receiving, by a first device, at least one wireless signal from a second device; transmitting, by the first device, at least one wireless signal to the second device; determining, by the first device, transit times of the at least one received wireless signal and the at least one transmitted wireless signal; determining, by the first device, one or more range measurements between the first device and the second device based at least in part on the transit times; determining, by the first device, an unlock decision based at least in part on the one or more range measurements; and causing, by at least the first device, the first device to unlock if the unlock decision is positive.

Abstract: Techniques for location source control for paired devices are described. Location source control selects a location source for a mobile device. The mobile device can receive, from an application program, a request for determining a location of the mobile device. The mobile device can determine a first location estimate using a location subsystem of the mobile device. The mobile device can determine whether to provide the first location estimate as input to the application program, or to provide a second location estimate as input to the application program. The second location estimate can be an estimated location of the companion device and determined by the companion device.

Abstract: A method comprising: receiving a radio map of an indoor venue using survey data collected by a survey device positioned throughout the venue, the radio map including a boundary; obtaining harvest data that correspond to locations that are outside of the boundary; filtering the harvest data; and extending the radio map using the survey data and the filtered harvest data, wherein the extended radio map is defined at least in part by an extension of the boundary.

Abstract: Techniques for location source control for paired devices are described. Location source control selects a location source for a mobile device. The mobile device can receive, from an application program, a request for determining a location of the mobile device. The mobile device can determine a first location estimate using a location subsystem of the mobile device. The mobile device can determine whether to provide the first location estimate as input to the application program, or to provide a second location estimate as input to the application program. The second location estimate can be an estimated location of the companion device and determined by the companion device.

Abstract: Among other things, we describe a method that includes, on an electronic device, determining that a current quality metric of signals received by a location system of the electronic device does not meet a threshold quality metric, and based on the determination, selecting a recommendation for changing a position of the device in a manner that would alter the current quality metric. This aspect can also include corresponding systems, apparatus, and computer program products stored on a storage device.

Abstract: Methods, program products, and systems of using a mobile WAP for location and context purposes are disclosed. In general, in one aspect, a server can estimate an effective location of a wireless access gateway using harvested data. The server can harvest location data from multiple mobile devices. The harvested data can include a location of each mobile device and an identifier of a wireless access gateway that is located within a communication range of the mobile device. In some implementations, the server can identify a mobile wireless access gateway based on a distance comparison. Data indicating the mobility of a wireless access gateway can be used by a mobile device to initiate one or more actions, including managing power of the mobile device, modifying entrance and exit conditions of virtual fences and determining a context of the mobile device.

Abstract: The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtaining structural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

Abstract: Systems, methods and computer-readable mediums are disclosed for rapid reconfiguration of device location systems. In some implementations, a method comprises: determining, by a server computer, a fault in global location data, the server computer configured to periodically communicate with client devices over a network, the global location data being applicable to multiple client devices and independent of any particular location of any particular client device; determining, by the server computer, a potential impact of the faulty global location data on location systems implemented on the client devices; generating, by the server computer, a reconfiguration file including reconfiguration data for reconfiguring the location systems on the client devices to adapt to the faulty global location data; and automatically sending, by the server computer, the reconfiguration file to the client devices.

Abstract: Methods, program products, and systems for using multiple sensors to determine a location fingerprint are described. A sampling device can measure RF signals detected at a train station of a transit system or a route of the transit system. The sampling device, or a location server receiving the measurements, can filter RF signal measurements using one or more readings from sensors coupled to the sampling device and that are different from RF receivers. The readings can be taken concurrently with the RF signal measurements. These readings, designated as motion cues, can include motion sensor readings, barometer readings, or magnetometer readings. Using the motion cues, the sampling device or location server can distinguish different platforms of a station of the transit system and different levels of the station, or filter out RF signal measurements that may have been inaccurate, e.g., as caused by disturbances from a train entering or leaving a station.

Abstract: Reduced resolution location determination for improved anonymity of a user location is disclosed. In some implementations, a first location of a computing device operating in a geographic area is determined. A population density of the geographic area is estimated. A grid overlay is generated, including a number of cells based on the estimated population density. Using the grid overlay, a second location is generated for the computing device that is less precise than the first location. The less precise second location can be used in a local search or other application to improve the anonymity of the user location.

Abstract: Collocated access point (AP) harvest data is combined with accurate location-tagged harvest data to improve access point location estimates and to estimate the location of access points that could not be previously estimated.

Abstract: Coarse location estimation for mobile devices is disclosed for detecting mobile device presence at general locations of interest and switching operating modes and services for one or more location context aware applications. In some implementations, sensor data is received from a plurality of data sources at a location. For each data source, a first probability is estimated that the mobile device is at the location based on sensor data from the data sources. A second probability is estimated that the mobile device is not at the location based on sensor data from the data sources. The first and second estimated probabilities are statistically combined to generate a third estimated probability that the mobile device is at the location.

Abstract: Techniques and systems for unlocking a first device based on signals transmitted between the first device and a second device are disclosed. A disclosed technique includes receiving, by a first device, at least one wireless signal from a second device; transmitting, by the first device, at least one wireless signal to the second device; determining, by the first device, transit times of the at least one received wireless signal and the at least one transmitted wireless signal; determining, by the first device, one or more range measurements between the first device and the second device based at least in part on the transit times; determining, by the first device, an unlock decision based at least in part on the one or more range measurements; and causing, by at least the first device, the first device to unlock if the unlock decision is positive.

Abstract: In general, in one aspect, a method includes receiving, on a mobile device, an indication that an application executing on the mobile device has entered a background state, determining, based on data received from a location system of the mobile device, that the mobile device has remained within a geographic area during a time interval, the geographic area being defined by a radius determined according to an application type of the application, and disabling at least a portion of the location system of the mobile device.

Abstract: Techniques and systems for unlocking a first device based on signals transmitted between the first device and a second device are disclosed. A disclosed technique includes receiving, by a first device, at least one wireless signal from a second device; transmitting, by the first device, at least one wireless signal to the second device; determining, by the first device, transit times of the at least one received wireless signal and the at least one transmitted wireless signal; determining, by the first device, one or more range measurements between the first device and the second device based at least in part on the transit times; determining, by the first device, an unlock decision based at least in part on the one or more range measurements; and causing, by at least the first device, the first device to unlock if the unlock decision is positive.

Abstract: Reduced resolution location determination for improved anonymity of a user location is disclosed. In some implementations, a first location of a computing device operating in a geographic area is determined. A population density of the geographic area is estimated. A grid overlay is generated, including a number of cells based on the estimated population density. Using the grid overlay, a second location is generated for the computing device that is less precise than the first location. The less precise second location can be used in a local search or other application to improve the anonymity of the user location.

Abstract: In some implementations, a method includes receiving, from a server, location data identifying locations of access points and mobile access points. A mobile device may determine an identifier of an access point within a communication range. The identifier is compared with the location data to identify parameters for the access point. The access point is determined to be a mobile access point based on the identified parameters included in the location data. In response to identifying the mobile access point, operating parameters executed by the mobile device are updated.

Abstract: Among other things, we describe a method that includes, on an electronic device, determining that a current quality metric of signals received by a location system of the electronic device does not meet a threshold quality metric, and based on the determination, selecting a recommendation for changing a position of the device in a manner that would alter the current quality metric. This aspect can also include corresponding systems, apparatus, and computer program products stored on a storage device.

Abstract: The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtaining structural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.