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, devices and computer-readable storage mediums are disclosed for assisted GNSS velocity estimation. In an implementation, a method comprises: obtaining, by a mobile device, a step-based speed measurement based on sensor data; obtaining, by the mobile device, a step-based speed uncertainty associated with the step-based speed measurement; determining, by the mobile device, that one or more assistance conditions are met; responsive to the determining, assisting a state estimator using the step-based speed measurement and the associated step-based speed uncertainty; and estimating at least one of the position, velocity or speed of the mobile device using the assisted state estimator.

Abstract: Systems and techniques are described that can be used to determine a number of levels of a multilevel building crossed by a mobile device, that is carried by a user during an elevator trip, based on characteristics of a periodic magnetometer signal. The periodic magnetometer signal is formed, by a magnetometer of the mobile device, in response to the magnetometer traversing a portion of an iron-based periodic structure corresponding to the number of levels of the multilevel building during the elevator trip.

Abstract: In some implementations, a beaconing protocol can be used to broadcast beacon information to mobile devices. The beaconing protocol can be used by a Bluetooth Low Energy (LE) (e.g., Bluetooth 4.0) beacon to transmit a package of information that identifies the beacon and indicates the calibrated transmission power (e.g., measured power) of the beacon. The package of information can be configured by beacon providers and/or beacon installers at the locations where the beacons are installed. When a mobile device receives the beacon package, the mobile device can use the beacon identification information and/or the measured power of the beacon to determine a location (e.g., precise location, geofence location) of the mobile device. In some implementations, the mobile device can transmit the beacon information to a server and the server can determine the location of the mobile device and send location and/or content information back to the mobile device.

Abstract: Crowd-sourced location data from client devices is processed using enhanced filtering techniques in non-realtime by a centralized server process to improve the accuracy and reliability of georeferenced geodata. At a server computer, enhanced filtering techniques make use of future information to improve georeferencing of the geodata. In some implementations, the server computer can be configured to implement batch processing of raw GNSS data and other crowd-sourced location data (e.g., wireless scan data, inertial sensor data) using, for example, a smoothing filter or batch estimator. Augmentation data (e.g., satellite ephemeris data, clock offset and ionospheric delay) and sensor data independent of client devices can also be used by the server computer to augment the crowd-sourced location data to further improve georeferencing of geodata.

Abstract: Methods, systems, and computer program product for generating location fingerprint data for a venue are described. A sampling device surveying a venue can move inside the venue. While the sampling device moves, the sampling device can record environmental readings including, for example, strengths of signals from multiple radio signal sources. The sampling device can take the recording at fixed or various time intervals. Meanwhile, the sampling device can determine, based on a starting point and motion sensor readings, an estimated location of the mobile device for each time the sampling device takes the recordings. The sampling device can display a motion path of the estimated locations and a user interface item for receiving a user input for correcting the estimated locations. The sample device can tag the recorded environmental readings with the corrected locations, and submit the tagged readings to a server for determining a location fingerprint for the venue.

Abstract: Methods, program products, and systems for building a location fingerprint database for a transit system are described. The transit system can be a subway system including underground train stations and routes where location determination using GPS signals is difficult or impossible. A sampling device can measure signals, e.g., radio frequency (RF) signals detected at the stations or on the routes. A location server can construct a location fingerprint for each of the stations and the routes. Each location fingerprint can represent expected signal measurements by a user device if the user device is located at the respective station or route. The location server can provide the location fingerprint to a user device for the user device to determine a location of the user device within the station or on the route.

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: 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, systems, and computer program product for deduplicating location fingerprint data for a venue are described. A system including a location server, or a mobile device, or both, can deduplicate the location fingerprint data. Deduplicating the location fingerprint data can include identifying correlated signal sources the signals of which are mutually dependent such that measurements of one signal source can be used to predict measurements of another. The system can determine a mutual information entropy value for each pair of signal sources, and identify the correlated signal sources based on high mutual information entropy value. The system can adjust weights of the correlated signal sources in location determination.

Abstract: Methods, program products, and systems for baseband location monitoring and related functions are disclosed. A mobile device can monitor its own current location using its baseband subsystem and decide whether to selectively activate its application subsystem based on whether particular conditions are satisfied by the current location. The mobile device can also correlate location and cellular signal information using its baseband subsystem and provide the correlated location and cellular signal information to a server. The server can receive the correlated location and cellular signal information from the baseband subsystems of a large number of widely distributed mobile devices and generate respective profiles of cellular network base stations that transmitted the cellular signals to the mobile devices.

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: Among other things, we describe a method that includes, on an electronic device, receiving, from a first location system of the electronic device, first data indicative of a first location of the device at a first time, comparing the first data to second data indicative of a second location of the device at a second time, the second data having been received from a second location system of the electronic device, and based on the comparison, determining whether the first data meets a threshold of location data integrity.

Abstract: Methods, program products, and systems for reducing a location search space are described. A mobile device, when arriving at a venue, can determine a location of the mobile device using signals from one or more signal sources associated with the venue. The mobile device can use a coarse location estimator to estimate a coarse location of the mobile device at the venue. The mobile device can request, from a server, detailed location data associated with the coarse location. The detailed location data can include location fingerprint data associated with a portion of the venue that includes the coarse location. The mobile device can determine an estimated location that has finer granularity than the coarse location using the location fingerprint data.

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: 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 some implementations, radio access technology (RAT) signals can be monitored and used to synchronize an internal clock of a mobile device to a network system clock without registering the mobile device to the network. In some implementations, a RAT processor can be configured to receive RAT signals and to prevent transmission of RAT signals. In some implementations, the internal clock can be associated with a GNSS processor and can be used to calculate a location of the mobile device. In some implementations, a RAT processor that is configured for a particular radio access technology can be configured to monitor signals associated with another radio access technology when synchronizing the internal clock. In some implementations, the RAT processor can monitor signals in response to a power event. The power event can be associated with powering a display of the mobile device.

Abstract: Surveying techniques for generating location fingerprint data are described. A mobile device can survey a venue by measuring, at multiple locations at the venue, signals from one or more signal sources. At each location, the mobile device can take multiple measurements of signals. The mobile device can take each measurement at a distinct orientation. The measurements can be used to determine expected measurements of the signals at the venue. Differences between the multiple measurements of signals can be used to determine a variance of the expected measurements. The expected measurements and variance can be designated as location fingerprint data for the venue. The location fingerprint data can be used by mobile devices for determining a location at the venue.

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.