Abstract: Methods, systems, and computer program product for prefetching location data based on predicted user behavior. A mobile device can request, from a user routine subsystem of the mobile device, a list of locations that a user of the mobile device routinely visits while the user carries the mobile device. The mobile device can determine a cluster of these locations that are within a specified distance between one another. The mobile device can request location data for these locations from a location server, even if the user is not at one of these locations. The location data can include a venue map and a venue location fingerprint. Upon detecting that the user entered a venue at one of these locations, the mobile device can determine a location of the user inside of the venue using the venue location fingerprint. The mobile device can then display the location on a venue map.

Abstract: Methods, systems, and computer program products for a mobile device determining its location based on a location of a companion device are described. A mobile device can receive a request for determining a location of the mobile device from an application. The request can include an accuracy specification providing a lower limit on accuracy of the determined location. The mobile device can determine that the mobile device is incapable of achieving that accuracy. The mobile device can then submit a location request to a companion device that has paired with the mobile device. The companion device, upon receiving the location request, can determine a location of the companion device and provide the location of the companion device to the mobile device. The mobile device can then designate the location of the companion device as the location of the mobile device, and provide the location to the application.

Abstract: Systems, methods and computer-readable mediums are disclosed for GNSS velocity estimation for pedestrians. In some implementations, a method includes receiving a periodic sensor signal; determining a fundamental motion frequency of the periodic sensor signal; extracting a periodicity feature from the periodic sensor signal based on the fundamental motion frequency; and responsive to the extracting, initiating pedestrian velocity estimation.

Abstract: Methods, systems, and computer program products for correcting in-venue location estimation using structural information are described. A mobile device can use wireless location technologies and dead reckoning to determine an estimated location of the mobile device in a venue. The mobile device can compare the estimated location with a map of the venue. Upon determining that the estimated location conflicts with a structural constraint, the mobile device can adjust the location estimation using the structural information. Adjusting the location estimation can include adjusting a statistical filter that provides estimation of the location and changing a heading of the mobile device used in the dead reckoning.

Abstract: A parameter related to the Earth's magnetic field can be used to determine accuracy of a magnetometer of a mobile device. In one aspect, a first instance of a parameter related to Earth's magnetic field is determined using data generated by the magnetometer. The magnetometer data can be based in part on a position of the mobile device with respect to the Earth. A second instance of the parameter can be determined using data generated by a model of Earth's magnetic field. The model data can also be based in part on the position of the mobile device with respect to the Earth. The first instance of the parameter can be compared with the second instance of the parameter. An accuracy metric for the magnetometer can be determined based on a result of the comparison. An indication of the accuracy metric can be presented by the mobile device.

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: 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: Methods, program products, and systems of location estimation using a probability density function are disclosed. In general, in one aspect, a server can estimate an effective altitude 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. The server can calculate an effective altitude of the wireless access gateway using a probability density function of the harvested data. The probability density function can be a sufficient statistic of the received set of location coordinates for calculating an effective altitude of the wireless access gateway. The server can send the effective altitude of the wireless access gateway to other mobile devices for estimating altitudes of the other mobile devices.

Abstract: Methods, systems, and computer program product for location determination using dual statistical filters are described. A mobile device can determine a location of the mobile device using a particle filter and a Kalman filter. The particle filter can filter candidate locations of the mobile device using measurements of environment variables in the venue. The Kalman filter can filter inputs from a sensor of the mobile device for measuring angular movement of the mobile device. The particle filter and the Kalman filter can be linked by heading of the mobile device. Output of the Kalman filter can be used to determine where to place particles, or candidate locations, in a next iteration of the particle filter. Output from the particle filter can be used to determine a center mode of the Kalman filter and to determine a bias of the sensor for measuring angular movement.

Abstract: Power management techniques for crowd-sourced lost-and-found service are described. A mobile device participating in the crowd-sourced lost-and-found service can monitor signals from an electronic tag using a first subsystem that has low power consumption. The mobile device can monitor wireless signals from wireless access points (APs) using a second subsystem that has low power consumption. Identifiers of detected tags and APs are stored locally in the respective subsystems. At pre-specified intervals, the subsystems can submit the stored identifiers to an application processor of the mobile device. The application processor can be activated to determine the location of the tags using known location of the APs. The application processor can be deactivated after the location of the tags are determined. The mobile device can then submit the location to a remote server. The remote server can provide the location to an owner of an item attached to the tag.

Abstract: A proximity fence can be a location-agnostic fence defined by signal sources having no geographic location information. The proximity fence can correspond to a group of signal sources instead of a point location fixed to latitude and longitude coordinates. A signal source can be a radio frequency (RF) transmitter broadcasting a beacon signal. The beacon signal can include a payload that includes an identifier indicating a category to which the signal source belongs, and one or more labels indicating one or more subcategories to which the signal source belongs. The proximity fence defined by the group of signal sources can trigger different functions of application programs associated with the proximity fence on a mobile device, when the mobile device moves within the proximity fence and enters and exits different parts of the proximity fence corresponding to the different subcategories.

Abstract: Systems, methods, and computer program products for determining the location and direction of travel of a mobile device using map vector constraints is disclosed.

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: System and method for submitting a location of a mobile device to a public service for providing emergency assistance are described. A mobile device can determine that a user is making an emergency call from the mobile device. The mobile device can then enable a location determination function of the mobile device and determine a location of the mobile device. The mobile device can determine the location in multiple attempts, including, in a first time window, attempting to determine a location with low uncertainty and, if the attempt fails, determining a location with high uncertainty in a second time window. The mobile device can then submit the location to a dispatcher through a mobile network operator.

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: In some implementations, a tightly-coupled elevation-assisted location estimate can be calculated based on digital elevation model (DEM) elevation measurements and global navigation satellite system (GNSS) data. The DEM elevation measurements and GNSS data can be provided as input to an estimator (e.g., a Kalman filter) to calculate an estimated geographic location of a mobile device. In some implementations, DEM elevation data can be filtered before being provided to the Kalman filter for estimating the geographic location of the mobile device. The DEM elevation data can be filtered in response to detecting bridge and/or tunnel events that indicate that the DEM elevation data does not accurately represent the actual elevation of the mobile device.

Abstract: Methods, program products, and systems for using a location fingerprint database to determine a location of a mobile device are described. A mobile device can use location fingerprint data received from a server to determine a location of the mobile device at the venue. The mobile device can obtain, from a sensor of the mobile device, a vector of sensor readings, each sensor reading can measure an environment variable, e.g., a signal received by the sensor from a signal source. The mobile device can perform a statistical match between the vector and the location fingerprint data. The mobile device can then estimate a current location of the mobile device based on the statistical match.

Abstract: System and method for submitting a location of a mobile device to a public service for providing emergency assistance are described. A mobile device can determine that a user is making an emergency call from the mobile device. The mobile device can then enable a location determination function of the mobile device and determine a location of the mobile device. The mobile device can determine the location in multiple attempts, including, in a first time window, attempting to determine a location with low uncertainty and, if the attempt fails, determining a location with high uncertainty in a second time window. The mobile device can then submit the location to a dispatcher through a mobile network operator.

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 of non-intrusive region notification are described. A mobile device can be programmed to trigger an application program when the mobile device enters or exits a region. The region can be defined by various virtual fencing technologies. If, at the time of entry or exit of a region, the mobile device is in a power-saving operating mode, the mobile device can transition to an active operating mode temporarily, register a fence-crossing event (entry or exit of the region) with the application program, and then transition back to the power-saving operating mode. The mobile device can launch the registered application program in response to the mobile device receiving a user input to enter the active operating mode. The application program can provide a user interface associated with the region on a display surface of the mobile device in place of a home screen or other user interface.