Abstract: A data packet transmission monitor (15) monitors the transmission of data packets in a given wireless communication system to determine (20) a predetermined condition. In response to determining the predetermined condition, the transceiver (14) for the base station (13) automatically sends (21) a signal to one or more wireless communication units (10) to cause the units (10) to make neighbor cell measurements. Optionally, the base station (13) sends such a signal when no data packets are to be sent by the base station (13). In another embodiment, the data packet transmission monitor (15) tracks (50) the transmission of data packets and determines (51) whether the transmissions allow for a certain number of neighbor cell measurements. If a certain number of neighbor cell measurements are not allowed, a signal is automatically sent (21) to the wireless communication unit (10) to make one or more neighbor cell measurements.

Abstract: The invention provides a cellular telephone or other communications device with improved satellite positioning capability. A location reference point and a selective uncertainty range may be used as aiding information to seed a global positioning calculation. In embodiments, the location reference point may represent the location of the cellular service site or other network service site serving the communications device. In embodiments, the selective uncertainty may be selected from a plurality of possible uncertainties and may represent an approximate distance from the communications device to the location reference point. In other embodiments, the selective uncertainty may represent a range of possible locations within a network service area.

Abstract: A method and system for managing calls in a communication network (100) is provided. The method includes establishing a voice path between the mobile station (102) and a called entity (110) through a switching center (104). The method also includes receiving a first request from the switching center at the serving node (106). The substitution information of a cell is then determined, followed by a measure-position request being sent from the serving node to the mobile station, and receiving a message at the serving node in response to the measure-position request. The message comprises either an error or location information of the mobile station. The substitution information is then sent from the serving node to the mobile station and the switching center, when the error is received. The location information is sent to the switching center, when the location information is received.

Abstract: To address the need for faster location determination by GPS-equipped units, this application describes embodiments of the present invention that provide GPS-assist data to a remote unit (110) that is determining its location. This GPS assist data is relative to a central point of a grid element that contains the particular remote unit. The grid element is a geographical area within which a predetermined number of GPS satellites are viewable from anywhere within the grid element. By providing GPS-assist data for a grid element, the remote unit receives GPS-assist data sufficiently local in nature to help it determine its location more quickly. Also, because there are significantly fewer grid elements than cell sites over a region such as the US, the maintenance of current GPS-assist data on a grid element basis requires less network bandwidth than it would on a cell site basis.

Abstract: To address the need for an apparatus and method of economically synchronizing base sites (110–113) in wireless communication systems, the present invention provides a GPS-based solution for synchronizing slave sites (111–113) to a regional master site (110). In general, the master site reports to the slave sites information indicating the timing variance of GPS satellites (101–105). The slave sites then use this information in combination with information they collect from the same satellites to periodically resynchronize their clocks to the master clock.

Abstract: The invention provides a cellular telephone or other communications device with improved satellite positioning capability. A location reference point and a selective uncertainty range may be used as aiding information to seed a global positioning calculation. In embodiments, the location reference point may represent the location of the cellular service site or other network service site serving the communications device. In embodiments, the selective uncertainty may be selected from a plurality of possible uncertainties and may represent an approximate distance from the communications device to the location reference point. In other embodiments, the selective uncertainty may represent a range of possible locations within a network service area.

Abstract: To address the need for faster location determination by GPS-equipped units, this application describes embodiments of the present invention that provide GPS-assist data to a remote unit (110) that is determining its location. This GPS assist data is relative to a central point of a grid element that contains the particular remote unit. The grid element is a geographical area within which the same 12 or more GPS satellites are viewable from anywhere within the grid element. By providing GPS-assist data for a grid element, the remote unit receives GPS-assist data sufficiently local in nature to help it determine its location more quickly. Also, because there are significantly fewer grid elements than cell sites over a region such as the US, the maintenance of current GPS-assist data on a grid element basis requires less network bandwidth than it would on a cell site basis.

Abstract: To address the need for an apparatus and method of economically synchronizing base sites (110-113) in wireless communication systems, the present invention provides a GPS-based solution for synchronizing slave sites (111-113) to a regional master site (110). In general, the master site reports to the slave sites information indicating the timing variance of GPS satellites (101-105). The slave sites then use this information in combination with information they collect from the same satellites to periodically resynchronize their clocks to the master clock.

Abstract: A method and apparatus to calibrate and correct magnetic and geometrical distortions in an imaging system, specifically a computed tomography (CT) system, includes a distortion measuring object which is placed on the surface of an image intensifier. An image frame of the distortion measuring object is generated, and a correction table is generated to correct the image frame. Once the correction table has been generated using the distortion measuring object, subsequent image frames are corrected using the correction values in the correction tables. A method and apparatus to calibrate and correct offsets, veiling glare and scatter in an imaging system, specifically a computed tomography system. An image frame is generated and areas not directly impinged by direct radiation are used to correct areas of the detector that are directly impinged. A method and apparatus for correcting and calibrating an imaging system, specifically a computed tomography system.

Abstract: A flexible video selector for use in various imaging systems including computed tomography (CT) imaging systems. A system operator inserts a number of video parameters identifying frames, lines and pixels of video information to be collected. A plurality of registers and counting devices are employed to control the video data selection. An A/D converter may be driven at intervals corresponding to the selected video information. In this manner, only video information corresponding to the selected pixels of the selected lines of the selected frame of video information are digitized for further processing. When implemented in a CT imaging system, the invention provides for x-ray dose control corresponding to the selected video parameters.