Abstract: A system and method for estimating the position of a mobile device using information from a constellation of satellites. A first set of satellites of the constellation may be selected and then a second set of satellites of the constellation may be selected as a function of signals received from the first set of satellites. Data may be transmitted to the mobile device based on signals received from the second set of satellites, and a location of the device estimated based on the data. One embodiment may select the second set as a function of an intersection of coverage areas of ones of the first set of satellites. Another embodiment may select the second set as a function of one or more satellites that are not occluded by the Earth from one or more of the first set of satellites.

Abstract: An object is to enhance certainty of a positioning process in a mobile communication terminal even with a large error of approximate location information. A mobile communication terminal 1 is a mobile communication terminal for performing GPS positioning using GPS positioning assist data and signals received from GPS satellites. The mobile communication terminal 1 has an assist data requesting unit 13 which receives as the GPS positioning assist data, approximate location information of the mobile communication terminal 1 and error information indicative of an error of the approximate location information, a GPS positioning unit 11 which performs the GPS positioning, a positioning result determining unit 14 which determines whether the error information used in the GPS positioning is not less than a threshold THM, with a failure in the GPS positioning, and an input accepting unit 15 which accepts input of approximate location information when the error information is not less than the threshold THM.

Abstract: A GNSS capable LBS client device sends a device RF environment report to a location server and subsequently receives a capture profile from the location server. A new RF environment report is generated according to the received capture profile. The device RF environment report comprises various encountered RF information, for example, state of radios, state of power and/or memory resource, and/or positioning variables. The received capture profile comprises information of a desired RF environment report expected from the GNSS capable LBS client device. The capture profile is determined according to the received RF environment report and a reference database. Desired RF environment data are captured according to the received capture profile, and time and location stamped to generate the new device RF environment report, which is sent to the location server to update the reference database to enhance locating the GNSS capable LBS client device when need.

Abstract: A mobile communication terminal 10A, in a process of acquiring assistance information in advance for using for a GPS position measuring at step S10, makes a judgment of whether or not the assistance information is to be acquired, prior to the GPS position measuring command by a user. When a result of this judgment is affirmative, the terminal 10A transmits an assistance information request to a position measuring assistance server 50. When the assistance information is returned from the position measuring assistance server 50 in response to this the assistance information request, in the cellular phone 10A, the assistance information is received and stored, and then prepared for a command for position measuring by the user, for which possibility of being made is higher in a short period. As a result, it is possible to perform quickly the position measuring of a current location of the mobile communication terminal.

Abstract: A system and method for determining the location of a wireless device. A boundary for an approximate area in which the wireless device is located is determined and a plurality of satellites may be determined as a function of the boundary. Assistance data is transmitted to the device which includes information from the plurality of satellites, and the location of the wireless device may be determined from the information. In one embodiment, if the number of the plurality of satellites is greater than a predetermined threshold then the number of satellites may be reduced as a function of one or more of the elevation of each satellite above the horizon, a distance between each satellite to one or more other satellites, and an altitude of each satellite.

Abstract: The invention provides a method of processing signals from a satellite positioning system in which a user inputs an approximate indication of current position, and this is used when processing satellite samples to reduce the processing required or increase the reliability. This approach avoids the need for an automated approximate location system (for example using cellular telephony). This represents a change in the way GPS (or other satellite systems) is used. Instead of relying on a GPS system to provide a location in entirely automated manner, the approach is for the user to give an approximate location (which will generally be known), and for the GPS system then to correct this and provide an accurate location. This approach can enable the GPS system to function in areas where it would normally be unreliable.

Abstract: Locating satellites (e.g., GPS) are culled into a sub-plurality based largely on dwell time within an inverted cone above a relevant site in communication with a wireless device. A first inverted cone having a first base angle is defined above a first site, a second inverted cone having a second base angle is defined above a second site. If the second site is farther from an equator of Earth than the first site, then the second inverted cone is made to have a base angle larger than a base angle of the first inverted cone. If the first site is farther from the equator of Earth than the second site, then the first inverted cone is made to have a base angle larger than a base angle of the second inverted cone. The span of the inverted cone over the site closest to the equator may be limited.

Abstract: The present invention provides a global navigation satellite system (GNSS) based positioning system and tracking method using a data communication network. When a GNSS-based positioning device is connected to a data communication network, the positioning device transfers the GNSS digital data and supplementary information used for additional performance improvement to a location tracking server through the data communication network, the location tracking server calculates a position of the positioning device with improved receiver sensitivity based on plentiful computational resources available at the location tracking server. Thus, the positioning device may find its location of even in very poor signal condition. Further, the present invention provides a positioning system and method using a data communication network, which may achieve time synchronization when there is a need to extract not only position information but also absolute timing information.

Abstract: A wireless GNSS receiver, for example a Bluetooth® receiver, including a bidirectional link to the host, and an update client, for downloading extended ephemeris data from the host, by the Bluetooth® link. The invention reuses the protocol used for NMEA data transfer, in order to send the extended ephemeris data up to the receiver. Hence, the extended ephemeris data can be sent without having to instantiate any other type of connection to the receiver. The invention reduces the cost and complexity of BT-GPS receivers that want to make use of extended ephemeris technology in order to reduce the time to first fix of GPS receivers left off for more than four hours.