Patent•
Positioning With Wireless Local Area Networks And WLAN-Aided Global Positioning Systems
01 Nov 2013-
TL;DR: In this paper, a wireless device can quickly determine its relative and/or coordinate position based on information provided by an access point in the wireless local area network (WLAN), which can reduce the time to acquire the necessary GPS satellite data.
Abstract: Accurate position capability can be quickly provided using a Wireless Local Area Network (WLAN). When associated with a WLAN, a wireless device can quickly determine its relative and/or coordinate position based on information provided by an access point in the WLAN. Before a wireless device disassociates with the access point, the WLAN can periodically provide time, location, and decoded GPS data to the wireless device. In this manner, the wireless device can significantly reduce the time to acquire the necessary GPS satellite data (i.e. on the order of seconds instead of minutes) to determine its coordinate position.
Citations
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Patent•
28 Jun 2004TL;DR: In this paper, a mobile station uses wireless signals from a plurality of wireless networks for position determination (e.g., for data communication, for obtaining time and/or frequency information, for range measurement, for sector or altitude estimation).
Abstract: Methods and apparatuses for position determination and other operations. In one embodiment of the present invention, a mobile station uses wireless signals from a plurality of wireless networks (e.g., with different air interfaces and/or operated by different service providers) for position determination (e.g., for data communication, for obtaining time and/or frequency information, for range measurement, for sector or altitude estimation). In one embodiment of the present invention, mobile stations are used to harvest statistical data about wireless access points (e.g., the locations of mobile stations that have received signals from the wireless access points, such as from cellular base stations, wireless local area network access points, repeaters for positioning signals, or other wireless communication transmitters) and to derive location information (e.g., position and coverage area of the wireless access points) for the wireless networks from the collected statistical data.
375 citations
Patent•
23 Oct 2012
TL;DR: In this paper, 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.
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.
367 citations
Patent•
04 Feb 2013
TL;DR: In this article, the authors propose a solution to estimate the location of a mobile device from a remote server by caching one or more WPS tiles in the WPS tile store on the mobile client device.
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.
317 citations
Patent•
08 Mar 2013
TL;DR: In this paper, Wi-Fi access points are located in a target geographical area to build a reference database of locations of WiFi access points, and the location information is used to reverse triangulate the position of the detected WAP.
Abstract: A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device. While traversing the target area, detecting Wi-Fi signals from Wi-Fi access points in range of the Wi-Fi device and recording identity information of the detected Wi-Fi access point in conjunction with GPS location information of the vehicle when the detection of the Wi-Fi access point was made. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database.
317 citations
Patent•
20 Nov 2009TL;DR: In this paper, the authors proposed a method for wirelessly determining a position of a mobile station by measuring a round trip time (RTT) to a plurality of wireless access points, estimating a first distance to each wireless access point based upon the RTT delay and an initial processing time associated with each access point, and combining the first and second distance estimates, and calculating the position based on the combined distance estimates.
Abstract: One method for wirelessly determining a position of a mobile station includes measuring a round trip time (RTT) to a plurality of wireless access points, estimating a first distance to each wireless access point based upon the round trip time delay and an initial processing time associated with each wireless access point, estimating a second distance to each wireless access point based upon supplemental information, combining the first and second distance estimates to each wireless access point, and calculating the position based upon the combined distance estimates. Another method includes measuring a distance to each wireless access point based upon a wireless signal model, calculating a position of the mobile station based upon the measured distance, determining a computed distance to each wireless access point based upon the calculated position of the mobile station, updating the wireless signal model, and determining whether the wireless signal model has converged.
256 citations
References
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Patent•
04 Dec 1996
TL;DR: In this paper, a precision carrier frequency signal for calibrating a local oscillator of a GPS receiver which is used to acquire GPS signals was used to determine approximate Doppler data for satellites in view of the remote GPS receiver.
Abstract: A precision carrier frequency signal for calibrating a local oscillator of a GPS receiver which is used to acquire GPS signals. The precision carrier frequency signal is used to calibrate the local oscillator such that the output of the local oscillator, which is used to acquire GPS signals, is modified by a reference signal generated from the precision carrier frequency signal. The GPS receiver locks to this precision carrier frequency signal and generates the reference signal. In another aspect of the invention, satellite almanac data is transmitted to a remote GPS receiver unit from a basestation via a communication link. The remote GPS receiver unit uses this satellite almanac data to determine approximate Doppler data for satellites in view of the remote GPS receiver unit.
679 citations
Patent•
23 Apr 1999
TL;DR: In this article, a location system for commercial wireless telecommunication infrastructures is described, which is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, e.g., CDMA, AMPS, NAMPS or TDMA communication standards.
Abstract: A location system is disclosed for commercial wireless telecommunication infrastructures. The system is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, e.g., CDMA, AMPS, NAMPS or TDMA communication standards, for processing both local MS location requests and more global MS location requests via, e.g., Internet communication between a distributed network of location centers. The system uses a plurality of MS locating technologies including those based on: (1) two-way TOA and TDOA; (2) pattern recognition; (3) distributed antenna provisioning; (5) GPS signals, (6) angle of arrival, (7) super resolution enhancements, and (8) supplemental information from various types of very low cost non-infrastructure base stations for communicating via a typical commercial wireless base station infrastructure or a public telephone switching network. Accordingly, the traditional MS location difficulties, such as multipath, poor location accuracy and poor coverage are alleviated via such technologies in combination with strategies for: (a) automatically adapting and calibrating system performance according to environmental and geographical changes; (b) automatically capturing location signal data for continual enhancement of a self-maintaining historical data base retaining predictive location signal data; (c) evaluating MS locations according to both heuristics and constraints related to, e.g., terrain, MS velocity and MS path extrapolation from tracking and (d) adjusting likely MS locations adaptively and statistically so that the system becomes progressively more comprehensive and accurate. Further, the system can be modularly configured for use in location signing environments ranging from urban, dense urban, suburban, rural, mountain to low traffic or isolated roadways. Accordingly, the system is useful for 911 emergency calls, tracking, routing, people and animal location including applications for confinement to and exclusion from certain areas.
657 citations
Patent•
10 Aug 1992
TL;DR: In this article, a multilaterating two-way message delivery system for mobile resource management provides efficient twoway radio data communication for multitudes of portable transponders (22) using a single frequency in half-duplex communication.
Abstract: A multilaterating two-way message delivery system for mobile resource management provides efficient two-way radio data communication for multitudes of portable transponders (22) using a single frequency in half-duplex communication. The system includes at least one transponder device (22) which transmits and receives data using a radio frequency communication link, and an array of at least three bases (12a-f) which communicate with the transponder device (22) using the radio frequency communication link. The radio frequency communication link employed by each base station (12a-f) and the transponder device (22) is designed to provide multilateration information and to deliver message data simultaneously. Further, a control arrangement (10) is coupled to the array of base stations to coordinate the communication between the base stations (12a-f) and the transponder devices (22). Time division multiplex and spread spectrum technology is employed by the system for communication efficiency and minimizing the effect of multipath interference.
618 citations
Patent•
09 Mar 2015
TL;DR: In this article, the location of the mobile phones using the network is identified, and load adjustments for the system are easily accomplished so that the wireless network is not subject to an overload situation.
Abstract: For a wireless network, a tuning system in which mobile phones using the network are routinely located. With the location of the mobile phones identified, load adjustments for the system are easily accomplished so that the wireless network is not subject to an overload situation. Ideally the location of the mobile phones is accomplished whether the mobile phones are transmitting voice data or not.
498 citations
Patent•
05 Sep 2002TL;DR: In this article, a system and method for performing real-time position detection and motion tracking of mobile communications devices (120) moving about in a defined space comprised of a plurality of locales is provided.
Abstract: A system and method for performing real-time position detection and motion tracking of mobile communications devices (120) moving about in a defined space comprised of a plurality of locales is provided. A plurality of access points (110) are disposed about the space to provide an interface between mobile devices and a network having functionality and data available or accessible therefrom. Knowledge of adjacency of locales may be used to better determine the location of the mobile device as it transitions between locales and feedback may be proceed to monitor the status and configuration of the access points.
485 citations