Abstract: Methods, program products, and systems for selective location determination are described. A mobile device can determine a location of the mobile device using various techniques. When there is a conflict between the locations determined using different techniques, the mobile device can select a most trustworthy location from the locations, and designate the most trustworthy location as a current location of the mobile device. The mobile device can determine a first location of the mobile device (e.g., a coarse location) using a cell identifier (cell ID) of a cellular network. The mobile device can determine a second location of the mobile device (e.g., a fine location) using one or more media access control (MAC) addresses of a WLAN. The first location and second location can be associated with confidence values that can indicate trustworthiness of the first location and second location.

Abstract: Methods, program products, and systems for multi-tier geofence detection are disclosed. In general, in one aspect, a mobile device can be configured to perform a task when the mobile device enters a geographic region. The mobile device can monitor a current location using a multi-tier approach. A baseband subsystem can monitor a coarse location of the mobile device using various course location parameters, such as a mobile country code (MCC), a location area code (LAC), or a cell identifier (cell ID), as the mobile device moves closer to the geographic region. Upon determining that the mobile device is in a cell that intersects the geographic region, the baseband subsystem can transfer the monitoring to the application subsystem. The task can be performed when the application subsystem determines that the mobile device is currently located in the geographic region.

Abstract: Methods, program products, and systems of determining a time zone based on location is disclosed. In general, in one aspect, a mobile device can store one or more geometric shapes using latitude and longitude coordinates. The geometric shapes can be associated with time zones. The mobile device can determine a current location. The mobile device can identify a geometric shape in which the mobile device is currently is located. The mobile device can determine the time zone associated with the identified geometric shape.

Abstract: Methods, program products, and systems for task management based on travel distance are disclosed. In general, in one aspect, a method executed on a mobile device can include receiving a request to perform a task in a first subsystem (e.g., an application subsystem) of the mobile device. The request can indicate that the task is to be performed when the mobile device travels at least a threshold distance. The mobile device can determine a duration of silence. The mobile device can configure a second subsystem (e.g., a baseband operating system) of the mobile device to send a notification to the first subsystem notifying that the mobile device has traveled after at least the duration of silence. The first subsystem can receive the notification and determine that the threshold distance has been satisfied based on the received notification. The first subsystem can perform the task upon the determining.

Abstract: Methods, program products, and systems for location-based application program management are described. A mobile device can receive a first application program to be executed in an application subsystem. The first application program can be configured to be invoked or notified when the mobile device is located at a defined location. The mobile device can register the first application program to a second application program that executes in a baseband subsystem. The mobile device can set the application subsystem to a power-saving operating mode. The second application program can monitor a current location of the mobile device. When the mobile device is currently located at the defined location, the second application program can set the application subsystem to an active operating mode, and invoke the first application program.

Abstract: Methods, program products, and systems for location determination using cached location area codes are described. A mobile device can store a set of location area codes (LACs) of a cellular communications network on the mobile device. Each LAC can represent a location area of the cellular communications network that encompasses at least a predetermined number of cells. Each LAC can be further associated with an estimated geographic area. The estimated geographic area can be defined as a circle centered at a location and having a radius representing an uncertainty of the location. The mobile device can determine a current LAC of the mobile device based on a wirelessly received signal. The mobile device can determine a current location of the mobile device by performing a lookup in the stored set of LACs using the current LAC.

Abstract: Methods, program products, and systems for managing a location database are described. A server computer can receive location information from location-aware mobile devices (e.g., GPS-enabled devices) located within a communication range of access points of a wireless communications network. The server computer can calculate average geographic locations using the received locations for each access point. Based on the average geographic locations, the server computer can assign the access points to cells of a geographic grid. The server computer can filter the access points in each cell based on popularity, stability, longevity, and freshness of the access point and the received data. When a second mobile device connects to an access point in a cell, the server computer can transmit locations of the access points in the cell and in neighboring cells to the second mobile device such that a location of the second mobile device can be estimated.

Abstract: Methods, program products, and systems for location determination using cached location area codes are described. A server computer can receive location information from location-aware mobile devices (e.g., GPS-enabled devices) located in a location area of a cellular communications network. The server computer can also receive from the mobile device the location area code associated with the location area in which the mobile devices are located. The server computer can estimate a coarse geographic location of the location area, as well as a number of cells encompassed by the location area using the received information. The server computer can store the estimated geographic locations associated with sufficiently large location areas (e.g., location areas having more than a certain number of cells). The server computer can provide the stored geographic locations to second mobile devices that are not GPS-enabled for estimating current locations of the second mobile devices.

Abstract: Methods, program products, and systems for location filtering using mobile country code (MCC) is described. A mobile device can determine its geographic location using locations of access points of a wireless communications network to which the mobile device is connected. The mobile device can wirelessly receive identifiers of one or more access points of the wireless communications network and a current MCC through a cellular network. The mobile device can identify a polygon that is a bounding box of a geographic area that corresponds to the current MCC. The mobile device can select a set of access point locations from a location database using the received identifiers, where the access point locations are inside the identified polygon. The mobile device can determine a current location of the mobile device based on an average location of the selected set of access point locations.

Abstract: Methods, program products, and systems for adaptive location determination are described. A server computer can receive location information from location-aware mobile devices (e.g., GPS-enabled devices) located in a cell of a cellular communications network. The server computer can calculate an average geographic location using the received locations and distance between each location and the calculated average. The server computer can exclude locations that are sufficiently far away from the average. The server computer can repeat the calculation and exclusion until a level of precision is achieved for the average geographic location. The average geographic location and an error margin can be associated with the cell. The server computer can provide the average geographic location and the error margin to a mobile device (e.g., a non-GPS-enabled device) that is in the cell. The mobile device can display the information on a map display of the mobile device.

Abstract: Methods, program products, and systems for determining a location of a mobile device using a location database are described. The mobile device can host the location database, which can store locations associated with access points. The locations can be distributed in a group of cells of a geographic grid. When the mobile device moves and connects to an access point associated with a location that is outside the group of cells, the mobile device can request an update of the location database. The mobile device can calculate a current location of the mobile device using current access points that are within a communication range of the mobile device by performing a lookup in the location database using identifiers of the current access points. The mobile device can calculate the current location using the locations corresponding to the current access points in the location database.

Abstract: A compass output in a first portable electronic device is monitored as the first device and a second electronic device come closer to each other. It is determined, by a process running in the first device, whether a magnetic field signature that is based on the monitored compass output is associated with a previously defined type of electronic device with which a network device discovery process is to be conducted. Other embodiments are also described and claimed.

Abstract: Multiple instances of a geomagnetic field are calculated. Multiple instances of an average magnitude of a subset of the instances of the geomagnetic field are also calculated. When the average magnitude changes by more than a first predetermined threshold, the user is informed that compass accuracy has degraded. Other embodiments are also described and claimed.

Abstract: Multiple instances of a geomagnetic field are calculated. Multiple instances of an average magnitude of a subset of the instances of the geomagnetic field are also calculated. When the average magnitude changes by more than a first predetermined threshold, the user is informed that compass accuracy has degraded. Other embodiments are also described and claimed.

Abstract: The magnitude of a sensed, raw magnetic field in a portable device is monitored over a given time interval. The monitored magnitude is compared with predetermined criteria. Based on the comparison, recalibration of a compass function is signed. Other embodiments are also described and claimed.

Abstract: Measurement data is collected from a magnetic sensor in a portable device, while the device is being carried by its end user and without requiring the end user to deliberately rotate or position the device while the output data is being collected. For example, the device may be held in the user's hand while walking or standing, or it may be fixed to the dashboard of an automobile or boat. Measurement data may also be collected from one or more positing, orientation or movement sensors. The collected measurement data from one or both of the magnetic sensor and the position, orientation or movement sensor is processed. In response, either a 2D compass calibration process or a 3D process is signaled to be performed. Other embodiments are also described and claimed.