Abstract: In one embodiment, a technique is provided for estimating and using an expected error of a position estimate of a WLAN-enabled mobile device produced by a WLAN positioning system. The WLAN-enabled mobile device receives signals transmitted by a plurality of WLAN access points in range of the WLAN-enabled device. The position of the WLAN-enabled device is estimated based on the received signals from the WLAN access points in range of the WLAN-enabled device. An expected error of the position estimate is based on at least one of a spatial spread associated with geographic positions of the WLAN access points, signal coverage areas of the WLAN access points, or a number of the WLAN access points. The expected error is used in providing one or more location-based services to a user of the WLAN-enabled mobile device.

Abstract: In one embodiment, techniques are provided for estimating demographic information. A current device demographic profile for a mobile device is retrieved. An estimated geographic location of the mobile device and a time at which the mobile device visited the estimated geographic location is determined. Based on this, a location demographic profile for a geographic area that includes the estimated geographic location and for a time frame that includes the determined time is retrieved. The current device demographic profile for the mobile device is updated based on the location demographic profile. Further, the location demographic profile is updated based on a plurality of device demographic profiles of a plurality of mobile devices that visit geographic locations within the geographic area, the plurality of mobile devices including the mobile device.

Abstract: In one embodiment, techniques are provided for setting a quality attribute of a WiFi access point that is suspected to have moved. The WiFi access point is identified when within range of a mobile WiFi-enabled device based on received signals received by a Wi-Fi radio of a mobile WiFi-enabled device. A recorded location associated with the identified WiFi access point is received from a local copy of a reference database or a remote store of the reference database on a server system. A location estimate is determined for the mobile WiFi-enabled device and compared to the recorded location associated with the identified WiFi access point to evaluate whether the identified WiFi access point has moved from its recorded location. Feedback is then generated that is sent to the server system in response to determining that the identified WiFi access point has moved, where the feedback is usable to set the quality attribute.

Abstract: In one embodiment, Wi-Fi access point data is cached on a mobile client device in response to distances to WPS tile boundaries. The mobile client device identifies one or more Wi-Fi access points in range based on signals received by a Wi-Fi radio, and estimates its location utilizing the identified one or more Wi-Fi access points and Wi-Fi access point data of one or more Wi-Fi positioning system (WPS) tiles in a WPS tile store on the mobile client device. Based on the estimated location, the mobile client device determines it is within a threshold distance of a boundary of the one or more WPS tiles present in the WPS tile store and requests one or more new WPS tiles from a reference database of a remote server. Upon receipt, the one or more new WPS tiles are cached in the WPS tile store on the mobile client device.

Abstract: In one embodiment, demographics associated with a selected geographic area may be estimated using visitor demographics. For each mobile device of a plurality of mobile devices, a more recent location estimate of the mobile device determined by a positioning system that is within the selected geographic area may be associated with a previous location estimate of the mobile device determined by the positioning system. Origin geographic areas that include the previous location estimates are determined. Demographics associated with the selected geographic area may be estimated based at least in part on demographics associated with the origin geographic areas of the plurality of mobile devices.

Abstract: In one embodiment, a technique is provided for detecting that a wireless beacon is pathological. Data points captured by mobile devices or specialized scanning devices are received at software executing on an electronic device, each data point containing information about beacon attributes. A set of disjoint regions are defined in one or more dimensions and each data point is associated with a corresponding region based on at least one element of the information of the data point lying within the boundaries of the corresponding region. An aggregate attribute is determined for each region based on the information of data points associated with the corresponding region. Then the aggregate attribute of one or more regions is used to determined whether the wireless beacon is pathological, and if determined to be pathological, the wireless beacon is excluded from use by a beacon-based positioning system.

Abstract: In one embodiment, scanning data is received for wireless access points whose wireless signals were observed by the one or more scanning devices in a target area. For each group of scanning data that shares a common identifier of a Wi-Fi access point, a centroid of the scanning data is determined, a set of scanning data of the group that exceeds a threshold distance from the centroid is designated as having potential error, and a location of the Wi-Fi access point is calculated. The calculated location of the Wi-Fi access point for each group of scanning data is stored in a reference database. Upon receiving a request for a location of a mobile device, an identity of one or more Wi-Fi access points in range of the mobile device is determined, and the location of the mobile device is computed using calculated locations from the reference database.

Abstract: In one embodiment, a technique is provided for building a reference database used to estimate a position of a wireless local area network (WLAN) enabled device. Samples are obtained for WLAN access points, the samples for each WLAN access point being based on WLAN signals transmitted by the WLAN access point and received by one or more scanning devices. Software of a WLAN positioning system executing on one or more computing devices estimates a position of each WLAN access point based on the samples of the WLAN access point. The software also estimates a geographical area covered by the samples of each WLAN access point and determines a quality metric of each WLAN access point based on the estimated geographical area covered by the samples of the WLAN access point. The software then builds the reference database based on the estimated position and quality metric of each WLAN access point.

Abstract: In one embodiment, a technique is provided for estimating and using an expected error of a position estimate of a wireless local area network (WLAN)-enabled mobile device. The WLAN-enabled mobile device received signals transmitted by a plurality of WLAN access points that are in range. A position of the WLAN-enabled mobile device is estimated based on the signals from one or more of the plurality of WLAN access points. An expected error of the position estimate is estimated based on a combination of correlated parameters, such as a spatial spread of geographic positions of the one or more WLAN access points, the signal coverage areas of the one or more WLAN access points, and a number of the one or more WLAN access points. Based on the expected error, the position estimate may be weighted or excluded from use in deriving a position, speed, or direction of travel.

Abstract: In one embodiment, techniques are provided for efficiently selecting and distributing wireless local area network (WLAN) access point (AP) data to a mobile client device. A reference database is maintained on a network server. An expected future location of the mobile client device is determined. The expected future location represents a location different than a present location of the mobile client device, which the mobile client device is expected to visit in the future. One or more tiles are transferred from the reference database to the mobile client device for a bounded geographic region that includes the expected future location. The one or more tiles are stored on the mobile client device to be available for use in satisfying one or more subsequently received requests for estimation of location of the mobile device.

Abstract: In one embodiment, techniques approximate use of geo-fences of shapes and/or sizes other than those natively support by a mobile device. Upon receiving an initial geo-fence (e.g., a non-supported geo-fence), the mobile device may generate a group of geo-fences (e.g., a group of supported geo-fences) whose union approximates the initial geo-fence, where the group includes one or more geo-fences. The mobile device may treat the group of supported geo-fence as an equivalent to the non-supported geo-fence. When the mobile device crosses one of the supported geo-fences of the group of supported geo-fences, and does not enter into another supported geo-fence of the group of supported geo-fences, a notification may be sent to an application that utilizes the non-supported geo-fence that the non-supported geo-fence has been triggered.

Abstract: Methods and systems of continuously optimizing data in WiFi positioning systems. A location-based services system uses WiFi-enabled devices to monitor WiFi access points in a target area to indicate whether a WiFi access point has moved relative to its previously recorded location. A WiFi-enabled device communicates with WiFi access points within range of the WiFi-enabled device so that observed WiFi access points identify themselves; A reference database is accessed to obtain information specifying a recorded location for each observed WiFi access point in the target area. The recorded location information is used for each of the observed WiFi access points in conjunction with predefined rules to infer whether an observed WiFi access point has moved relative to its recorded location. The reference database is informed of the identity of any observed WiFi access point that is inferred to have moved.

Abstract: In one embodiment, when it is determined that one or more Wi-Fi positioning system (WPS) tiles that are necessary to estimate a location of a mobile client device are not present in a WPS tile store on the mobile client device, or are present in the WPS tile store on the mobile client device but out of date, one or more new WPS tiles are requested from a remote server. Each WPS tile is a set of Wi-Fi access point data for Wi-Fi access points within a bounded geographical region. The one or more new WPS tiles are received from the remote server, and are cached in the WPS tile store on the mobile client device. Subsequent to the caching, one or more further locations of the mobile client device are estimated autonomously from the remote server, utilizing Wi-Fi access point data in the WPS tile store.

Abstract: In various embodiments, a WPS dedicated device is used to estimate the position of a user device. The WPS dedicated device is configured to be receive-only and lacks WLAN packet transmission capabilities, or is configured to provide limited-transmission and is capable of transmitting only a predefined subset of WLAN packets supported by a WLAN protocol. The WPS dedicated device may be used with optimized scanning procedures that include a plurality of phases that are progressed through until WLAN information sufficient to identify at least a threshold number of more WLAN APs is obtained, that simultaneously scan on multiple WLAN channels, or that provide other types of optimization.

Abstract: In one embodiment, characteristics of signals received from Wi-Fi access points during a traversal of a number of drivable streets within a geographic area having a radius of one or more miles are determined, the characteristics of a given signal including a unique identifier of a Wi-Fi access point that transmitted the signal, a location where the signal was observed, and an observed signal strength at the location where the signal was observed. Using the characteristics, a reference database is built including records descriptive of Wi-Fi access points in the geographic area. To determine a current location of a mobile device, an observed signal strength of one or more Wi-Fi access points observed by the mobile device from the current location is determined and a current location of the mobile device is computed using at least the observed signal strength of the one or more Wi-Fi access points observed by the mobile device in comparison to information in the reference database.

Abstract: Method of and systems for assigning estimated positions and attributes to wireless access points in a positioning system are disclosed. A method of estimating a characteristic of a wireless beacon includes receiving a set of data points. Each data point contains information about characteristics of a wireless beacon. The method also includes dividing at least one dimension into a set of regions in which each region of the set has region boundaries that do not overlap with other regions. The method further includes associating each data point with one corresponding region based on at least one element of the information of the data point lying within the boundaries of the corresponding region and determining an aggregate characteristic for each region based on the information of the data points associated with the corresponding region. The method estimates a characteristic of the wireless beacon based on at least one aggregate characteristic.

Abstract: Methods and systems for classifying WLAN access points according to the quality of estimation of characteristics of the WLAN access points are provided. The classifications may be used to scale a reference database and quantify an expected error of estimation of the characteristics of the access points. WLAN access points may be classified based on their impact on a user's position, speed of travel, and direction of travel estimation accuracy in a WLAN positioning system. A method for determining a quality of estimation of characteristics of a Wi-Fi access point comprises a Wi-Fi enabled scanning device measuring a number of received signal strength (RSS) samples of the Wi-Fi signal transmitted by the Wi-Fi access point. A total distance traveled by the Wi-Fi enabled scanning device while measuring the number of RSS samples is estimated and used to estimate the quality of estimation of characteristics of the Wi-Fi access point.

Abstract: Disclosed are techniques for privacy preserving mobile demographic measurement of individuals, groups, and locations over time and space. A method of estimating demographic information associated with a user of a mobile device and/or a location while preserving the privacy of the user based at least in part on a location estimate of the mobile device of the user includes receiving an estimated geographical location of the mobile device of the user and receiving a time at which the mobile device was at the estimated geographical location. The method includes assigning substitute identifiers for the geographical location and the time at which the mobile device was at the estimated geographical location. The method includes associating the geographical areas substitute identifiers with demographic information and estimating demographic information associated with the user of the mobile device based on the substitute identifiers and based on the demographic information associated with substitute identifiers.

Abstract: In one embodiment, techniques are employed to estimate a position of a wireless local area network (WLAN) enabled mobile device. The mobile device receives one or more wireless local area network (WLAN) packets transmitted within a range of the mobile device. The mobile device extracts information from the one or more WLAN packets to identify one or more WLAN access points (APs), and caches information indicating an identity of the one or more WLAN APs and a time of detection of the one or more WLAN APs. Subsequent to the caching, a request may be received for a position estimate of the mobile device. In response to the subsequently-received request for the position estimate, the cached information is provided to a WLAN positioning system (WPS) to obtain an estimate of a position of the mobile device.

Abstract: Methods of and systems for resolving multiple location estimate conflicts in a WLAN-positioning system are provided. Disclosed are methods to quantify the probability that a particular location estimate of a mobile device made by a Wi-Fi based positioning system is correct to within an arbitrary accuracy. Implementations use observed access point cluster size, age information for access point location determination, and/or cumulative distribution functions that characterize the conditional probability that one or more access points detected by the mobile device have relocated within a specified time interval to make the probability determinations.