Abstract: Methods, program products, and systems for monitoring geofence exits using wireless access points are disclosed. In general, in one aspect, the mobile device can select, from multiple wireless access points, one or more wireless access points for monitoring a geofence. Selecting the one or more wireless access points can include determining multiple geographic regions corresponding to the geofence. The mobile device can select the one or more wireless access points based on a maximum total number of wireless access points to be selected and an access point allowance for each of the geographic regions. The access point allowance can indicate a maximum number of wireless access points to be selected for the geographic region. The mobile device can detect a potential entry or exit of the geofence by monitoring the selected one or more wireless access points using a wireless processor.

Abstract: Methods, program products, and systems for monitoring geofence exits using wireless access points are disclosed. In general, in one aspect, a mobile device can detect one or more entry gateways that are wireless access points selected for monitoring a geofence. The mobile device can determine that the mobile device is located in the geofence based on the detection. The mobile device can monitor the entry gateways and one or more exit gateways, which can be wireless access points observable by the mobile device when the mobile device is in the geofence. When the mobile device determines, after a number of scans using a wireless processor, that the entry gateways and exit gateways are unobservable, the mobile device can use an application processor to determine whether the mobile device has exited from the geofence.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a motion state of a mobile device. Accelerometer data is received from accelerometer sensors onboard the mobile device, wherein the accelerometer data represents acceleration of the mobile device in three-dimensional space. An accelerometer signal vector representing at least a force due to gravity on the mobile device is determined. Two-dimensional accelerometer data orthogonal to the accelerometer signal vector is calculated. A motion state of the mobile device is determined based on the two-dimensional accelerometer data.

Abstract: In some implementations, a location of a mobile device can be determined by calculating an average of the locations of wireless signal transmitters that have transmitted signals received by the mobile device. In some implementations, locations are weighted with coefficients and the average is a weighted average. In some implementations, the locations of the wireless signal transmitters are determined based on identification information encoded in the wireless signals received by the mobile device. The identification information can include an identifier for a wireless signal transmitter. The identification information can include characteristics of the received wireless signal that can be used to identify wireless signal transmitters. In some implementations, identification information from one signal can be combined with identification information from another signal to determine a location of a wireless transmitter.

Abstract: Methods, program products, and systems of motion-based device operations are described. A mobile device can coordinate operations of a motion sensor and a proximity sensor. The mobile device can determine a gesture event using the motion sensor. The mobile device can determine a proximity event using the proximity sensor. The mobile device can use the gesture event and proximity event to confirm one another, and determine that the mobile device has moved in proximity to a target object following a specified gesture. Upon confirmation, the mobile device can perform a specified task.

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 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. The server can calculate an effective location 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 location of the wireless access gateway. The server can send the effective location of the wireless access gateway to other mobile devices for estimating locations of the other mobile devices.

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, program products, and systems for monitoring a geofence using wireless access points are disclosed. In general, in one aspect, a mobile device receives data defining a geofence. The mobile device can select, from multiple wireless access points, one or more wireless access points for monitoring the geofence. The selected wireless access points can be monitored by a wireless processor of the mobile device. The wireless processor can detect a potential entry of the geofence when at least one of the selected one or more wireless access points is detected. Upon a detection of the potential entry of the geofence by the wireless processor, the mobile device can use an application processor of the mobile device to determine whether the mobile device entered the geofence.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a presumed activity associated with a mobile device. A plurality of sensor values detected by one or more sensors onboard the mobile device is received over a period of time. A plurality of derived values is calculated from the plurality of sensor values. The derived values are selectively combined to generate one or more abstract values. A presumed activity is identified from a plurality of possible activities based on a level of similarity between the one or more abstract values and expected values of each of the plurality of possible activities that correspond to the one or more abstract values.

Abstract: A journaling subsystem on a mobile device stores event data related to applications or other subsystems running on the mobile device. The event data can be stored and indexed in a journal database so that a timeline of past events can be reconstructed in response to search queries. In some implementations, a timeline can be reconstructed with markers on a map display based on search results. When the user interacts with a marker on the map display, the event data collected by the mobile device is made available to the user.

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: 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: 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: A mobile device can store a set of first CDMA identifiers including, for example, system identifiers, network identifiers, or zone identifiers. Each first CDMA identifier can be associated with a first geographic location. The mobile device can determine a current location by matching a current first CDMA identifier with a stored first CDMA identifier. If a user desires a current location that has finer granularity, the mobile device can retrieve a set of second CDMA identifiers including, for example, base station identifiers. Each second CDMA identifiers can be associated with a second geographic location that has a finer granularity than that of the first geographic location. The mobile device can match a current second CDMA identifier from the retrieved second CDMA identifiers and designate the second geographic location associated with the matching second CDMA identifier as the current location that has the finer granularity.

Abstract: Methods, program products, and systems for multi-tier detection of a geofence 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-tiered approach. A baseband subsystem can monitor a coarse location of the mobile device using a CDMA system identifier, a CDMA network identifier, a CDMA zone identifier, or a CDMA base station identifier, in that order, as the mobile device moves closer to the geographic region. The baseband subsystem can notify an application subsystem when the mobile device is in a cell that intersects the geographic region. The application subsystem can perform the task upon notification.

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: Data provided by an access point of a wireless local area network (“WLAN”) is used to assist a mobile device in cell reselection. If a serving cell of a cellular communications network is unsuitable for providing cellular service, a candidate cell co-located with the serving cell can be selected as the serving cell based on quality of service metrics associated with the serving cell and the candidate cell. The mobile device can be proactively commanded to switch to the candidate cell for receiving cellular service. In some implementations, the quality of service metrics are calculated from call logs collected from mobile devices operating in the cellular communications network. In some implementations, network information regarding serving cell performance can be used with the call logs to generate the quality of service metrics.

Abstract: A 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. A beacon network can provide more accurate estimates of mobile device location and advertise location based services available to the mobile device.

Abstract: In general, in one aspect, a mobile device can perform reverse geocoding based on context, in addition to latitude and longitude coordinates. The reverse geocoding can be used to determine in which geofence among multiple geofences the mobile device is located. Thus, the mobile device can be associated with a street address, a postal code, a named land feature, or a commercial, cultural, or political entity associated with the geofence. The context can include a pattern of movement, as well as an accuracy of the latitude and longitude coordinates. Information in the context can be compared to selection criteria of the geofence. A geofence having selection criteria that match the context the best can be selected.

Abstract: A journaling subsystem on a mobile device stores event data related to applications or other subsystems running on the mobile device. The event data can be stored and indexed in a journal database so that a timeline of past events can be reconstructed in response to search queries. In some implementations, a timeline can be reconstructed with markers on a map display based on search results. When the user interacts with a marker on the map display, the event data collected by the mobile device is made available to the user.