2397 results about "Time of arrival" patented technology

A computer-implemented method provides location-sensitive and time-sensitive calendaring to a wireless device, such as a cellphone, pager, PDA, etc. A user's calendar is maintained with a number of appointments, start times and end times for the appointments, meeting place and a list of attendees for the appointments. When the present time reading is within a predetermined minimum of a meeting start time of an appointment of a calendar of a user, the location of the user is determined based on the location of the wireless device. The location of the meeting place is also determined. Using historical data (of the user or others), the estimated time of arrival of the user at the meeting place is determined. If the estimated time of arrival is after the meeting start time, then a late message may be sent to the user and/or to the other meeting attendees.

A wireless terminal receives signaling information, pertaining to a reference signal transmission in at least one specifically designated sub frame, the signaling information including a list, the list including base station identities. The terminal determines, from at least one of the base station identities in the list, the time-frequency resources associated with a reference signal transmission intended for observed time difference of arrival (OTDOA) measurements from a transmitting base station associated with said one base station identity. The time of arrival of a transmission from the transmitting base station, relative to reference timing, is measured. The wireless terminal can receive a command from a serving cell to start performing inter-frequency OTDOA measurement on a frequency layer containing reference signals, the frequency layer distinct from the serving frequency layer, the serving frequency layer not containing positioning reference signals. The wireless terminal can perform OTDOA measurements subsequent to the reception of the command on a carrier frequency different from the serving cell carrier frequency. A base station transmitter can jointly schedule a reference signal transmission from a plurality of base station transmitters for the purpose of OTD estimation enhancement, and transmit identical reference signals from the plurality of base station transmitters, the reference signals being identical both in the signal sequence and time-frequency resources used for transmission.

Techniques to more accurately measure the arrival times of transmissions received at a remote terminal from a number of base stations. In one aspect, unassigned finger processors are used to process and measure the arrival times of transmissions from base stations not in the active set. In another aspect, if no finger processors are available for assignment, the arrival times can be measured in the time period between updates of a reference oscillator used for the measurements. In accordance with a method for determining a position of a remote terminal, a first set of one or more base stations in active communication with the remote terminal is identified and each base station in the first set is assigned at least one finger processor. A second set of one or more base stations not in active communication with the remote terminal is also identified and an available finger processor is assigned to each of at least one base station in the second set. A (signal arrival) time measurement is then performed for each base station, and outputs indicative of the measurements are provided for further processing. To improve accuracy, the measurements can be performed within a narrow time window.

The present invention is related to a method and a system for automatically allocating a particle beam to one of a plurality of treatment rooms. Upon receiving a request from one of the beam users, the system checks whether the beam is available and may automatically allocate the beam to the requesting room. Otherwise, the request may be put on a waiting list of pending requests, in a position which depends on the priority level (and arrival lime) coupled to said request.

An RF object locating system and method that uses or includes a set of N (N>2) receivers (monitoring stations) located at fixed positions in and/or about a region to be monitored, one or more reference transmitters that transmit a timing reference, a location processor that determines object location based on time-of-arrival measurements, and at least one object having an untethered tag transmitter that transmits RF pulses, which may additionally include object ID or other information. Free-running counters in the monitoring stations, whose phase offsets are determined relative to a reference transmitter, are frequency-locked with a centralized reference clock. Time-of-arrival measurements made at the monitoring stations may be stored and held in a local memory until polled by the location processor. The invention permits rapid acquisition of tag transmissions thereby enabling the monitoring of large numbers of objects, and also provides a unique approach to data correlation in severe multipath environments.

A system and method locates a wireless local area network (WLAN) signal source. A wireless LAN signal as an RF signal is propagated from a WLAN signal source at a fixed, known location to a plurality of receivers having unsynchronized clocks. The time-of-arrival is measured at each receiver and the timing relationship from the fixed, known location of the signal source is used to relate time-of-arrival measurements from a signal arriving from an unknown location.

A wireless local area network includes a plurality of access point stations that receive and transmit communications signals within the wireless local area network. A first set of access point stations are WiFi compliant and measure signal strength and determine the received signal strength indication (RSSI). A second set of access point stations are operable in accordance with the time of arrival (TOA) real time location standard (RTLS). A dual mode mobile station is operative for multimode communication with both the WiFi and RTLS compliant access point stations. A location processor is operatively connected with each of the access point stations and processes the RSSI and creates a RSSI locate map and processes communication signals from the second set of access point stations and determines which signals are first-to-arrive signals to locate the mobile station and update the RSSI locate map and locate any non-dual mode WiFi devices.

A method and apparatus of determining a lower bound of an excess delay in a time of arrival measurement of a received signal. Determining the lower bound of an excess delay in a time of arrival measurements includes receiving signals from at least two base stations and determining the time difference of arrival between the received signals from their respective base stations. Then estimating a lower bound of excess delay introduced into the signals received from the base stations based on the time of arrival of the signals from the respective base stations and a known distance between the base stations. The lower bound of excess delay may be used to adjust the estimate of a mobile unit's location based on the time of arrival measurements of the received signals.

A system of cell phone positioning in real time is provided with specialized location device installations on multiplicity of base stations BSs in CDMA and TDMA cellular communication networks. The purpose of the positioning system is to enable tracking and locating large quantities of anonymous mobile cell phones MS in any number of network cells to be used for real time traffic-forecasting systems, emergency services E911, and other client-initiated position requests. Location data thus obtained can be continuously updated from vehicular-based cellular phones, collected, processed and used as a basis for input to intelligent transportation systems, such as real time urban traffic guidance for vehicular congestion and intelligent traffic control systems. The system is capable of covering large urban geographical areas and number of independent cell structures serving thousands of mobile cell phone clients. It is an independent plug-in solution with specialized synchronized location device installations in each cell BS. Centrally located specialized location software based on Time of Arrival (TOA) and Time Difference of Arrival (TDOA) methods for high speed location processing in central Location Database Server (LDS). The inventive system consists of number of component functions: Operator-initiated functions, location device functions and software enabled positioning functions.

A device for identifying interference source in wireless communications is provided, including a correlation compound module, a matching and screening module, a statistical analysis module, and a match identification module. The correlation compound module uses the time of arrival (TOA) of the burst as the synchronization basis to compound the correlated frequency word, time difference of arrival (TDOA) word, amplitude word and angle of arrival (AOA) word to form a burst descriptor word (BDW). The matching and screening module uses the BWD to match the burst library to screen out the non-interference sources. The statistic analysis module uses the screened outcome for statistical analysis, and obtains a source discriminator file (SDF). The matching and identification module uses the SDF to search the interference source library for matching and obtains an identification result.

A RF signal repeater system is added to a wireless communications network which increases user data rates at the periphery of the cellular coverage area by boosting the downlink (base station to mobile user) signal and uplink (mobile user to base station) signal. The RF signal repeater system includes a signal tagging means that adds a unique electronic signature to the repeated signal such that position determination errors due to a non-line of sight propagation path can be corrected. The repeated signal is received and processed with a location measurement unit to determine the time of arrival and to extract the signal tag of the repeated signal. The time of arrival measurement and recovered signal tag are then processed at a mobile location center to determine the true position of the transmitter.

A cable modem communicates the timing of the arrival of certain packets (such as TCP ACK packets) to a cable modem termination system. This timing feature is useful in methods for increasing the throughput in the downstream direction by eliminating TCP ACKs backing up at a cable modem. In particular, a cable modem termination system implementing an unsolicited bandwidth grant service in which unsolicited grants of bandwidth are sent by the cable modem termination system to the cable modem. The grants of bandwidth are timed to arrive at the cable modem simultaneous with or shortly after the arrival of the TCP ACK from an end station connected to the cable modem. Several methods of calculating or predicting when the unsolicited grants should be sent to the cable modem are described. The method is also applicable to other types of packets, such as voice packets from a end station implementing a Voice over Internet Protocol (VoIP) application.

A satellite system employing time diversity and a single frequency network of terrestrial re-radiation stations is provided wherein each terrestrial re-radiation station inserts a delay into a terrestrial signal. The delay allows the time of arrival of the early time diversity signal at the center of terrestrial coverage to coincide with the arrival of the corresponding late time diversity signal, thereby improving hand-off between terrestrial and satellite signals at a receiver. The delay also adjusts for distance differences between each terrestrial re-radiation station and the satellite and between each station and the center of the terrestrial coverage region. This adjustment optimizes the TDM-MCM reception by synchronizing at the center of the SFN the phase of the MCM signals re-radiated from the re-radiating stations of the SFN. The delay also compensates for the processing delay encountered when converting a satellite LOS TDM stream into a multicarrier modulated stream for transporting the satellite LOS TDM stream to user receivers and for the diversity delay between the early and late signals.

A high accuracy search and tracking system that uses a round-trip messaging scheme in which the time of arrive (TOA) of ranging signals is accurately determined to yield the range estimates between a target communications device and one or more search communications devices. Successive ranging estimates are used by a search device to home in upon the target device. The physical location pinpoint communications system can be used alone, or in combination with other location estimation systems that can be used initially, or throughout the search and tracking process to pinpoint the physical location of the target device. The search radio(s) transmits ranging signals to the target radio which responds by transmitting reply ranging signals. Upon reception of the reply ranging signal, the search radio determines the range to the reference radio from the signal propagation time. Errors in TOA estimates can be minimized using advanced processing techniques, if required.

A wireless location system has at least one wireless tag to be located by the wireless location system, wherein the at least one wireless tag transmits two wireless signals having a known time relationship and having different bandwidths. A plurality of receivers is provided wherein a first receiver receives and processes a first of the two wireless signals and estimates a time to arrive (TOA) of the first wireless signal, and a second receiver receives and processes a second of the two wireless signals and estimates a TOA of the second wireless signal at the second transceiver. The plurality of receivers is time synchronized based on a common timing signal. A location server is coupled to each of the plurality of receivers. The location server receives the TOA of the first wireless signal from the first receiver and the TOA of the second wireless signal from the second receiver. The location server calculating a TDOA of the two wireless signals and estimates a position of the at least one wireless tag based on the TDOA

This invention is a system and method of locating a target using distributed antenna. The antenna consists of several receiving elements in known locations. At least one of the receiving elements is also a transmitter and transmits an interrogation signal to a target. The return signal from the target is received by a plurality of receiving elements and the target's position is calculated using the time of arrivals of the reply signal and the round trip delay between the transmission of the interrogation signal and the reception of the subsequent reply signal.

A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

Systems and methods for accurately calculating the latency of a data-network, by providing an electronic device that receives data packets moving across a network data point and compares their time of arrival with a timestamp stored within a data packet. The electronic device may calculate the average latency by comparing N number of data packets. Further systems and methods for comparing the latencies at N number of electronic devices placed at unique network data points and calculating latencies between each device.

An asynchronous network system includes a transmitting apparatus which transmits time-synchronization-information data through an asynchronous network, and information processing apparatuses which share identical time information by receiving the time-synchronization-information data. At least one data item whose transmission and reception within a predetermined reaching time are requested to be guaranteed is transmitted by one information processing apparatus among the information processing apparatuses to at least one of the other information processing apparatuses in a state in which the one information processing apparatus occupies a first interval on a communication schedule based on time-synchronization information represented by the time-synchronization-information data.

A method for calibrating an impulse radio distance measuring system comprising an impulse radio transceiver by conducting a pulse through a transmit receive switch to an antenna, receiving return energy which has been discharged across the transmit receive switch, determining a time of arrival of the return energy. The return energy is comprised of two distinct pulses, one of which represents discharge of the transmit switch as the original pulse travels to the antenna, the second represents energy reflected from the antenna and again discharged across the transmit receive switch while the switch is in the transmit position. The timing of the un-reflected energy is determined then the timing of the reflected energy relative to the un-reflected energy is determined through auto-correlation of the time domain scan of the received composite waveforms.

An improved system and method for determining a position of a mobile station in a mobile telecommunications network is disclosed. The system includes a database having geographical information pertaining to the service area of the telecommunications network, including whether service areas therein are characterized as urban areas, suburban areas or "badurban" areas in which radio communication is especially limited. The system further includes a mobile location center (MLC) which, among other things, calculates the number of access signal bursts which are required for transmission by the mobile station to be located. The access burst number is calculated based upon the geographical information pertaining to the service areas stored in the database and upon a requested position determination accuracy. By measuring the time of arrival delay of the burst signal transmission received by two or more base transceiver stations, the MLC computes the position of the mobile station.

A system is disclosed for synchronizing a clock in a well containing a drill string with a clock located near the surface of the well. The system includes devices for transmitting and receiving a pair of acoustic signals between locations associated with each clock and processing those signals. The system determines the time of arrival of each acoustic signal by analyzing the shape of a function of the acoustic signal chosen from a group of functions suitable to determine a clock offset with millisecond accuracy.

Standard mobile cellular telephones use shortened burst signal transmissions to synchronize the transmission of a call over a cellular telephone network. These shortened bursts as well as other traffic channel bursts can be used to locate the position of the cell phone. In operation, a primary base station sends a traffic channel designation message to a selected mobile phone which then initiates selected traffic channel burst transmissions, such as shortened bursts, over an interval of five seconds or less. The primary station and at least two other neighboring base stations receive these burst transmissions and determine their respective distances from the cell phone based upon the time of arrival of the bursts or some other suitable distance related measurement. A command center determines the location of the cell phone by triangulating the distance measurements of the base stations.

An ultra-wideband (UWB) antenna array is provided. One embodiment of the present invention employs a multi-element antenna for UWB beam forming and also for time-of-arrival vector processing to resolve multi-path problems in an UWB communication system. Another embodiment of the present invention recovers the energy contained in the multi-path reflections to increase signal-to-noise ratios of received UWB pulses.