7053 results about "Time synchronization" patented technology

A transmitter transmits time synchronized data via a pager / WiMax / 802.x access to a receiver system, wherein the receiver system is programmed to receive data for specific geographic locations. The geographic locations may be specified by the user or by the receiver system, and includes state, zip codes, towns, counties, towns, or cardinal regions. The receiver is able to find its location when outside its cell region and is able to synchronize to the data transmitted in the new cell region. Further, the receiver system is able to remotely monitor weather data and other information at a different location via wireless Internet or voice over IP. A transceiver may also be used to receive weather or alert data. In response to receiving data, the transceiver transmits the data to low powered devices in a house using a different frequency band than the frequency band it received the data.

Timing synchronization between base stations of uncoordinated communication networks includes obtaining timing synchronization information from one base station, and adjusting a clock of the other station in response to the synchronization information. The timing synchronization information can be identified from a strongest synchronization signal from nearby uncoordinated base stations. The timing synchronization can accommodate clock offsets and frequency offsets.

Systems and methods are disclosed for time synchronization of operations in a control system. Synchronization networks and devices are provided for transferring synchronization information between controllers in a distributed or localized control system, which is employed in order to allow operation of such controllers to be synchronized with respect to time. Also disclosed are synchronization protocols and hardware apparatus employed in synchronizing control operations in a control system.

Methods and apparatuses for synchronizing basestations in a cellular network. One exemplary method performs time synchronization between at least two basestations, a first basestation and a second basestation, of a cellular communication system. In this exemplary method, a first time-of-day and a first geographical location of a first mobile cellular receiver station (MS) are determined from a first satellite positioning system (SPS) receiver which is co-located with the first MS, and the first time-of-day and first location are transmitted by the first MS to a first basestation which determines a time-of-day of the first basestation from the first time-of-day and first location and from a known location of the first basestation. Also in this exemplary method, a second time-of-day and a second geographical location of a second MS are determined from a second SPS receiver which is co-located with the second MS, and the second time-of-day and the second location are transmitted to a second basestation which determines a time-of-day of the second basestation from the second time-of-day and the second location and a known location of the second basestation. Other methods and apparatuses are also described for synchronizing basestations in a cellular network.

An energy efficient MAC protocol for a sensor network that extends the battery life of remotely located wireless nodes by employing MAC operations involving transmission of a wake-up signal with more processing gain, dynamic adjustment of a transmission rate of synchronization messages for fast time synchronization and an energy efficient neighboring node discovery technique.

A vehicle fleet management information system identifies location and direction of movement of each vehicle in a fleet in real-time, and automatically reports such information, as well as status of predetermined events in which the vehicle is engaged, directly to the fleet manager. Each fleet vehicle has an assigned time slot to transmit its reporting information over a communications network without interfering with transmissions from other vehicles in their own respective time slots. A timing control phase lock loop (PLL) provides precise time synchronization for timing corrections from a global positioning system (GPS) based time reference. A dual band full-duplex interface of the network has TDMA on one-half and broadcast on the other half. Microprocessor time processing units in components of the network perform precise clock synchronization. Space diversity performed on received vehicle transmitted messages avoids data corruption. Different vehicles have different periodic transmission intervals, by dynamically allocating the slots for various update rates. Auxiliary reporting slots enable prompt reporting of important data by the respective vehicle transmitters independent of the slower periodic transmission intervals.

A novel and useful synchronization mechanism that functions to provide a uniform time base for mesh points in a WLAN mesh based network. The invention enables timing synchronization to a common reference clock base by advertising the common TSF within beacon transmissions. All MPs in a mesh share a common DTIM interval. The synchronization mechanism enables the mesh points to avoid collisions in the generation and transmission of beacons. The TBTT offsets of the current MP and its neighbors are advertised in beacons so that neighboring MPs that hear the beacons can select non-overlapping TBTT offsets. Each MP receives one or more beacons from its neighbors and compares the timing of its neighbors to that of itself and adopts the highest TSF (i.e. the fastest) in the mesh. Eventually, all MPs in the mesh will adjust their timing to that of the MP with the fastest clock. The reception of beacons by MPs from its neighbors is also advertised. This allows for MPs to verify that the beacons they send are actually heard and are not in collision with beacon transmissions of other MPs.

In an OFDM-based receiver, means for achieving time synchronization comprising: A. means for extracting pilot signals contained in the OFDM received signal; B. means for analyzing the pilot signals in the frequency domain and for issuing a signal indicative of a synchronization error in the received signal; C. means for correcting the synchronization error responsive to the signal indicative of the synchronization error. In an OFDM-based receiver, automatic frequency correction means in a subscriber unit comprising: A. an inner frequency correction loop for generating a LO frequency related to a frequency of a received signal; B. an outer frequency correction loop for correcting the LO frequency according to instructions received from a base station. In an OFDM-based receiver, a channel sounder comprising: A. means for extracting pilot signals contained in the OFDM received signal; B. means for analyzing the pilot signals in the frequency domain and for issuing signals indicative of a distortion in each pilot signal, wherein each of said pilot distortion signals comprises both an amplitude and a phase component; C. means for analyzing the signals indicative of a distortion in each pilot signal and for computing therefrom corrective signals for correcting distortions in the received signal.

A method and apparatus for time synchronization in a communications system such as a system including cable modems is provided. The synchronization method comprises the steps of receiving a first timestamp from a headend unit with the cable modem, and generating a first cable modem time reference with the cable modem in response to the receipt of the first timestamp. The cable modem then receives a second timestamp from the headend unit and generates a second cable modem time reference in response to the receipt of the second timestamp. A headend difference time comprising the difference of the first and second timestamps is then generated as is a cable modem difference time comprising the difference of the first and second cable modem time references. A clock error time that comprises the difference of the headend difference time and the cable modem difference time is then generated as well as a correction factor in response to the clock error time. The local clock of the cable modem is then synchronized with the master clock of the headend unit through the adjusting of the output of the local clock output in response to the correction factor. The correction factor in one instance comprises an offset value representative of the amount of clock error per local clock pulse. This offset value is added to an accumulator on each local clock pulse, and the local clock output is adjusted when the accumulator rolls over. The synchronized clock signal can then be utilized to determine a time slot in which the cable modem can transmit an upstream signal to the headend without colliding the upstream signal with upstream signals from other modems in the system.

The position of a non-cooperating emitter is determined by detecting a signal from the emitter at three or more receiver communication devices positioned at different locations. The receiver communication devices determine respective detection times of the emitted signal in respective local time reference frames. To establish a common time reference frame for the emitted signal detections, each receiver communication device exchanges time synchronization signals with a reference communication device. Since any of the receiver communication devices and the reference communication device may be mobile, the signal exchange allows each receiver communication device to accurately determine the signal propagation time between itself and the reference communication device and factor the signal propagation time into an accurate adjustment of the local time reference frame. Using trilateration, the position of the emitter is determined from known positions of the receiver communication devices and the emitted signal detection times from the receiver communication devices.

A display unit for binocular representation of a multicolor image including a control unit triggering an imaging element such that the imaging element generates in a temporal successive manner the image to be displayed for a first beam path and a second beam path as a first image and second image, respectively. The images are generated in a pre-distorted manner, opposite of the chromatic aberration of the respective beam path, such that the chromatic aberration generated in the respective beam path is compensated when the first and second image is displayed. The display unit includes a switching module which operates in temporal synchrony with the first and second image being generated, such that a user can see the first image only via the first beam path and the second image only via the second beam path.

A collaboration program operates on a computer system for storing, sharing and synchronizing data between different users. Centrally stored content data items are organized by associations into one or more folders, with the folders arranged by associations in a multi-level hierarchical structure. Users have access to all folders and content data items falling within at least one top level folder or “file cabinet” viewable by that user. When a user makes a change / addition to the hierarchical structure, that change / addition is transmitted to a server, which makes the change / addition to the necessary associations and sends messages through a TCP / IP format advising other signed-on users of the change / addition. With each content data item having the capability of being associated into multiple folders and each folder having the capability of being associated into multiple other folders or file cabinets, the computer system operating the collaboration program gives different users simultaneous, synchronized access to the folders and content data items in the hierarchical structure.

A timing system for time synchronization between a time server and a time client over a packet network. The timing system includes a time server for generating current timestamp information and a time client having a phase-locked loop driven client clock counter. The time client periodically exchanges time transfer protocol messages with the time server over the packet network, and calculates an estimated client time based on the timestamp information. The phase-locked loop in the time client receives periodic signals representing the estimated server time as its input and calculates a signal which represents the error difference between the estimated server time and the time indicated by the time client clock counter. The error difference eventually converges to zero or a given error range indicating the time presented by the client clock counter, which is driven by the phase-locked loop having locked onto the time of the time server.

A system matches frame counter values between a timing master and one or more slave devices in a synchronous network. To detect synchronization losses, a timing master counts transmitted frames of a continuous data stream. When a synchronization loss occurs, the timing master transmits a message to the slave devices that includes a synchronization frame counter value. The message synchronizes the frame counter value of the timing master to the frame counter value of the slave devices.

In an OFDM-based receiver, a time synchronization unit comprising: A. a device for extracting pilot signals contained in the OFDM received signal; B. a device for analyzing pilot signals in the frequency domain and for issuing a signal indicative of a synchronization error in the received signal; C. a device for correcting the synchronization error, responsive to the signal indicative of the synchronization error. In an OFDM-based receiver, an automatic frequency correction device in a subscriber unit comprising: A. an inner frequency correction loop for generating a LO frequency related to a frequency of a received signal; B. an outer frequency correction loop for correcting the LO frequency according to instructions received from a base station.

An interface system including a manipulandum adapted to be moveable according to a manual gesture imparted by the user; a sensor adapted to detect a characteristic of the manual gesture imparted to the manipulandum and to generate a sensor signal representing the detected characteristic of the manual gesture; a microphone adapted to detect a characteristic of an utterance spoken by the user and to generate an audio signal representing the detected characteristic of the spoken utterance; and a control system adapted receive the generated sensor and audio signals and to transmit a command signal to an electronic device via a communication link, the command signal being based on the generated sensor and audio signals and the time synchronization between them.

One or more embodiments provide Common Industrial Protocol (CIP) based time synchronization systems and methods. The CIP Sync solution can be part of Ethernet / IP and can be based on standard UDP (User Datagram Protocol) and / or IEEE 1588 (Time Synchronization) Ethernet technology. According to an embodiment is a system that compensates for step changes in a master clock.

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

A radio-over-fiber (RoF) system and method for controlling a transmission time is provided. In a Time Division Duplex (TDD) wireless communication system comprising a Base Station (BS) having a donor and a remote connected thereto via am optical fiber, upstream and downstream Radio Frequency (RF) signals are transmitted and received, and by reliably transmitting a switch control signal to the remote and simultaneously compensating for a transmission time delay occurring in the optical cable, time synchronization of the upstream and downstream RF signals transmitted and received via antennas of the BS and the remote is controlled, thereby efficiently increasing the performance of a TDD wireless service system.

An optical system tracks the motion of objects, including the human body or portions thereof using a plurality of three-dimensional active markers based upon triangulation from data read via multiple linear CCDs through cylindrical lenses. Each marker is lit in sequence so that it is in sync with a frame capture using the imaging system positioned and oriented so as to provide a basis for computing three-dimensional location. In the preferred embodiment, the imaging system detects an infrared signal which is sent out by the tag controller as part of the tag / marker illumination sequence at the beginning of the first tag position capture time. The controller then traverses through the tags in time sync with each imaging system frame capture cycle. Thus, only one unique tag will be lit during each image capture of the cameras, thereby simplifying identification. Using linear CCD sensors, the frame time (i.e. point acquisition time) is very short, allowing very many markers to be sampled and located sequentially in real time.

FIG. 7 shows a camera system (700) that operates to time-stamp video content captured from multiple cameras (740) relative to a recorded and time-synchronized location of a portable tracking unit (722). The position of the cameras (740) is known to the system. Based on the time and position data for each uniquely identifiable tracking unit, an editing suite (770) automatically compiles a composite video made up from time-spliced video segments from the various cameras. Video or still images captured by the cameras (740)are cross-referenced against the client address stored in database (760) and related to the assigned, uniquely identifiable tracking unit (722). A server (750) is arranged to use the client address to send reminder messages, which reminder messages may include selected images taken by the composite video. Alternatively, a client (720) can use the client address to access the database and view the composite video. In the event that the client (720) wants to receive a fair copy of the composite video, the server (750) is arranged to process the request and send the composite video to the client. Streaming of multiple video feeds from different cameras that each encode synchronized time allows cross-referencing of stored client-specific data and, ultimately, the assembly of the resultant composite video that reflects a timely succession of events having direct relevant to the client (720).

A deposition system and process for the formation of thin film materials. In one embodiment, the process includes forming an initial plasma from a first material stream and allowing the plasma to evolve in space and / or time to extinguish species that are detrimental to the quality of the thin film material. After the initial plasma evolves to an optimum state, a second material stream is injected into the deposition chamber to form a composite plasma that contains a distribution of species more conducive to formation of a high quality thin film material. The deposition system includes a deposition chamber having a plurality of delivery points for injecting two or more streams (source materials or carrier gases) into a plasma region. The delivery points are staggered in space to permit an upstream plasma formed from a first material stream deposition source material to evolve before combining a downstream material stream with the plasma. Injection of different material streams is also synchronized in time. The net effect of spatial coordination and time synchronization of material streams is a plasma whose distribution of species is optimized for the deposition of a thin film photovoltaic material at high deposition rates. Delivery devices include nozzles and remote plasma sources.

Disclosed is a method and system by which a base station without a Global Positioning System (GPS) receiver acquires time synchronization in a Broadband Wireless Access (BWA) communication system. The method includes scanning neighbor base stations around a first base station and requesting time synchronization information from the scanned neighbor base stations by the first base station; receiving responses from predetermined neighbor base stations having already acquired time synchronization from among the neighbor base stations, the responses including time synchronization information of the predetermined neighbor base stations; and selecting a second base station from among the predetermined neighbor base stations and acquiring time synchronization based on the time synchronization information of the second base station.

Embodiments of an integrated node, such as a programmable logic controller, are provided for process automation and seamless, flexible subsystem communications, allowing a remote host to interface with a plurality of remote and in-plant subsystems and services using a wired or wireless network interface and having a database server and a protocol translator or translation server to convert and manipulate various industrial interfaces and protocols. Embodiments of the integrated node time-synchronize the plurality of remote subsystems, acquire and archive time-stamped process data, report exceptions therein to the remote host, and extract and transmit time-stamped process data to the remote host. Embodiments of computer program products and computer implemented methods also are provided to detect a time of communication failure and a time of a corresponding recovery between a node and either a remote subsystem or a remote host.

Half duplex, Frequency Hopped-Spread Spectrum wireless transceivers (102), operating without a central controller, maintain time synchronization with the frequency hopping sequence for a period after transmission of a half duplex signal ceases. The wireless transceiver (102) operates their receivers (308) according to the RF frequency hopping sequence and schedule (200). The wireless transceiver (102) is then able to send a short transmission request to signal that it will start transmitting on the Frequency Hopping schedule (200) of the previously ceased transmission. A wireless transceiver (102) that was either the original transmitter or the original receiver is able to transmit this transmission request. A subset of time slots within the hopping schedule (200) can be optionally assigned to the original transmitter and original receiver to obviate collisions of the transmit request transmissions from both device at the same time.

The invention discloses an IEEE 1588 time synchronization system. By adding a time-stamp processing module, a time-stamp message transceiving sub module, a time-stamp message resolving sub module, a time-stamp message generating sub module, a local time recording register, and an RTC correction / time read-write module in the module are used for combining peripheral components such as a switch module, a PHY and a real-time clock (RTC) module to form a hardware system. When in use, the high precision time synchronization requested by an IEEE 1588v2 protocol can be implemented by using the modes of one-to-one or one-to-many of master-slave synchronization. The invention also discloses a method for implementing the IEEE 1588 time synchronization, which can implement the function of the time synchronization system by processing the time information of master-slave devices in real time. The invention plays an active role in promoting Ethernet construction.

An apparatus, system and method for multimedia capturing, logging and retrieval are disclosed. The apparatus provides time synchronized voice and data interactions capturing and logging, secured playback and retrieval functionality for dispute resolution, for detecting negative and positive conduct, for business analysis and performance, and for quality management. The apparatus provides for synchronization and association of multi-media interactions for financial transactions in order to provide for the retrieval, playback, and review of the transaction-specific events in their temporally correct and integrated sequence.

A kind of fault detection oscilloscope device and method for the quality of power and the electrical system are disclosed, which belongs to the field of detection technique of electric system, and it includes three subsystems: detection oscilloscope subsystem, remote-control monitor subsystem, and time setting subsystem; the oscilloscope subsystem can do multi-point diagnosis for electric system, and detects and records the quality parameters of power; the remote-control monitor subsystem consists of precedence sever and Internet client, and it can realize the double action that transmitting fault information and monitoring the daily running of protective and safe device; the time setting subsystem provides the system time and insures the time synchronization with system; the realizing method includes dynamic parameter measurement, fault time division; starting criterion, fault oscilloscope, uploading record, and remote-control command procession. The invention realizes the digitalization, network, intelligent, and integration of detection oscilloscope device, and it can improve the quality of power, ensure the equipment running safely and steadily.