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.

Abstract: A method of and system for estimating the range of a mobile device to a wireless installation is disclosed. A method of estimating the position of a mobile device includes receiving signals transmitted by fixed-position wireless communication stations in range of a mobile device. One of the wireless communication stations from which signals are received by the mobile device is designated as a serving station and location information is retrieved for said serving station and at least one other neighboring station from which signals are received. For each of the at least one other neighboring stations, a corresponding distance between the serving station and said neighboring station is determined based on the location information. A position of the mobile device is estimated based on the location information for the serving station and said neighboring stations and further based on the distances between the serving station and said neighboring stations.

Abstract: In one embodiment, techniques are employed to estimate a position of a wireless local area network (WLAN) enabled mobile device. The mobile device sniffs one or more WLAN packets destined for one or more WLAN devices other than the mobile device. Information identifying one or more WLAN APs is extracted from the one or more WLAN packets destined for the one or more WLAN devices other than the mobile device. A record of the one or more WLAN APs is generated that includes at least some of the extracted information. A WLAN positioning system (WPS) is cooperated with, to use the generated record of the one or more WLAN APs to obtain an estimate of a position of the mobile device.

Abstract: A method for estimating position using WLAN access point radio propagation characteristics in a WLAN location based service is provided. A location-based services system has a plurality of Wi-Fi access points in a target area. The Wi-Fi access points are positioned at geographic locations and have signal coverage areas. A method of characterizing at least one of the Wi-Fi access points comprises determining the geographic location of the Wi-Fi access point, dividing the signal coverage area of the Wi-Fi access point into at least one section, and determining radio propagation characteristics for each section. The radio propagation characteristics of each section characterize a radio channel of the Wi-Fi access point, and the characterization can be used in a location algorithm.

Abstract: Systems and methods for providing contextual information about a place within a range of a wireless signal beacon are provided. A reference database of wireless beacons stores attributes associated with wireless beacons. Wireless-enabled devices and/or server systems receive information identifying wireless beacons in range of the wireless-enabled devices and determine a received signal strength indication of the wireless beacons. The wireless-enabled devices and/or server systems then retrieve from the reference database extended attributes that are associated with the wireless beacons and determine at least one associated contextual attribute about the place within range of the wireless beacons.

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 is newly-observed. 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. Observed WiFi access points for which the reference database has no information specifying a corresponding recorded location are identified. The recorded location information for each of the observed WiFi access points is used to calculate the position of the WiFi-enabled device. The reference database is informed of the WiFi access points (for which there was no information in the database) and is provided the calculated position in conjunction therewith.

Abstract: A method of and system for estimating temporal demographics of mobile users is disclosed. A method of estimating demographic information associated with a selected geographical area includes, for at least one individual, determining a selected geographical area along a portion of a track of travel of the individual and determining demographic information associated with the at least one individual. The method also includes estimating a ratio of individuals transiting into the area versus individuals that are residents of the area and estimating demographic information associated with the area based on the estimated ratio and based on demographic information associated with the at least one individual.

Abstract: In one embodiment, an area in which a mobile device may be located is determined using a satellite-based positioning system (SPS). An area in which the mobile device may be located is determined using a wireless local area network based positioning system (WLAN-PS). The area determined using the SPS is compared to the area determined using the WLAN-PS. In response to the area determined using the SPS being remote from the area determined using the WLAN-PS, it is concluded that the one or more WLAN APs have been moved to be about the area determined using the SPS. One or more locations of the one or more WLAN APs are updated in the reference database.

Abstract: Systems for and methods of determining likelihood of atypical transmission characteristics of reference points in a positioning system are disclosed. A method of determining a measure of likelihood that a designated wireless device exhibits signal transmission characteristics atypical of a wireless device of a type matching the designated device includes determining reference points associated with the designated device, which are a geographic position at which signals from the designated device were detected and/or another wireless device from which signals were also detected by a receiver within a selected period of time during which the signals from the designated device were detected.

Abstract: A method for estimating the speed and bearing of a Wi-Fi enabled device using WLAN radio signals in a WLAN based location service is provided. A method used to estimate a speed of travel of a Wi-Fi enabled device comprises the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device, and using the signals to estimate the speed of and/or direction of travel of the Wi-Fi enabled device.

Abstract: The disclosed subject matter relates to a method and system for increasing the accuracy of a WLAN based position estimate using cellular positioning information. In some embodiments, the method can include determining a set of possible WLAN location solutions for a WLAN and cellular enabled device based on one or more WLAN access points, obtaining cellular measurements from at least one cell tower, and determining the best WLAN location solution from the set of possible WLAN location solutions using the cellular measurements. In one embodiment, the method can include using the cellular measurements from the at least one cell tower to provide a cellular based location estimate for the WLAN and cellular enabled device.

Abstract: Systems for and methods of determining likelihood of reference point identity duplication in a positioning system are disclosed. A method of determining a measure of likelihood that a designated identifier is shared by wireless devices includes determining reference points associated with any wireless device having a designated identifier. The reference points are a geographic position at which signals from any of the wireless devices were detected and/or wireless devices from which signals were also detected within a selected period of time during which the signals from any of the wireless devices having the designated identifier were detected. The method also includes determining statistical information about a temporal distribution of detection of signals of reference points, a spatial distribution of the reference points, and/or a cardinality of the reference points and determining a measure of likelihood that the designated identifier is shared by wireless devices is based on the statistical information.

Abstract: Systems for and methods of determining likelihood of relocation of reference points in a positioning system are disclosed. A method of determining a measure of likelihood that an estimated geographic location of a designated wireless device is not its accurate present location includes determining a set of reference points associated with the device, which are a geographic position at which signals from the device were detected and/or other devices having a relationship with the designated device. The existence of the relationship is based on the devices being within signal reception range of a same position within a selected period of time. The method includes retrieving attributes of the reference points and/or of the relationships and determining a measure of likelihood that an estimated geographic location associated with the designated device is not its present location based on the attributes of the reference points of the set and/or of the relationships.

Abstract: A method of providing a relevant subset of information to a client device is based in part on scanning for Wi-Fi access points within range of the client device, using a Wi-Fi database that covers a large target region to retrieve information about these access points, using this information to estimate the position of the mobile client device, selecting a limited region in the vicinity of the estimated location of the client device, and providing information about Wi-Fi access points within this limited region to the client. For efficient transfer and maintenance of data, the target region may be divided into a hierarchy of fixed geographical tiles.

Abstract: Systems for and methods of determining likelihood of mobility of reference points in a positioning system are disclosed. A method of determining a measure of likelihood that a designated wireless device is a mobile device includes determining a set of reference points associated with a designated wireless device. The reference points are a geographic position at which signals from the device were detected and/or another wireless device from which signals were also detected by a receiver within a selected period of time during which the signals from the designated device were detected. The method also includes retrieving statistical information about a temporal distribution of detection of signals of reference points, a spatial distribution of the reference points, and/or a cardinality of the reference points. The method includes determining a measure of likelihood that the designated wireless device is a mobile wireless device based on the statistical information.