170 results about "Synchronization networks" patented technology

The invention relates to a method for synchronizing a communications cycle and a communications node in a network. Said node comprises: devices for receiving a desired value for a time base of a communications cycle of the communications node in a communications link to an additional communications node of the network; devices for determining a system deviation between the desired value and an actual value of the time base; and a device for generating a manipulated variable for correcting the time base in accordance with the system deviation.

A wireless communications network and method of synchronizing network base stations. Wireless mobile units, e.g., cell phones, periodically measure transmission timing differences between pairs of adjacent base stations and each provide the measurements to a server base station. An absolute transmission timing difference (ATD) is determined for each difference measurement. ATDs are collected and combined for each pair of base stations. A timing relationship is developed for all base stations from the combined ATDs. A timing correction is extracted for each base station from the timing relationship. Application of the timing corrections synchronizes the base stations.

A method and system for enabling peer to peer synchronization between members of a synchronized network. A predefined synchronization reference area on each member of the network is provided. A common identifier associated with the synchronization network is provided to each member. Changes are detected on a member regarding a data item. A network identifier associated is obtained. A unique identifier of a synchronization module is obtained. A relative path to the data item within the predefined synchronization reference area is obtained. A unique value is calculated based upon a content of a version of the data item that is associated with the change. A log number counter is incremented. A log representing the data item and the chance is created. The log includes data regarding the type of change, the network identifier, the unique identifier of the synchronization module, the relative path, the unique value, and the log number.

The invention discloses a high-precision Ethernet timing device which is characterized in that hardware comprises a time processing module CPU (central processing unit), the time processing module CPU is connected with a time processing field programmable gate array (FPGA) through a BUS and is connected with a GPS (global position system) receiving module through a serial port as well as connected with an IEEE1588 (Institute of Electrical and Electronic Engineers 1588) ground synchronization network module through a timing signal; the IEEE1588 ground synchronization network module comprises an IXP425 processor and an IEEE1588 FPGA port, a low-temperature drift crystal oscillator is used as a crystal oscillator source to be accessed into an FPGA phase-locked loop, and a time clock port FPGA, the IEEE1588 ground synchronization network module and the time processing module CPU are provided with timing signal output ports. The invention can be used for building an IEEE1588 ground time synchronization network and supporting clock mutual automatic switching, and can achieve timing precision of 100us in an electric system II region Ethernet under the condition of not supporting IEEE1588 by a router switch and the like.

The invention discloses an intelligent power grid distributed self-supporting photovoltaic power supply system. The system comprises a central controller, a DC/DC (direct current to direct current) direct chopper circuit, a power dispensable circuit, a DC/AC (direct current to alternating current) bidirectional inverter circuit, an island detection circuit and an energy accumulator, wherein the central controller is used for collecting data in real time, and controlling the DC/DC direct current chopper circuit, the power dispensable circuit, the DC/AC bidirectional inverter circuit, the island detection circuit and the energy accumulator through analytic calculation, so that the seamless switching between synchronization network and off network can be realized, the synchronization mode operation when a public utility grid is normal can be guaranteed, the system can quickly perform the automatic off-line and off-network mode operation when power is down, the remote dispatching acceptability to a public power grid, the power interaction between the system and the power grid, the off-peak power consumption of load and economical operation of the system can be realized, the power supply quality can be improved, the safety and the reliability of loaded power consumption can be guaranteed, the spontaneous self-supply rate of the system can be improved, and the impact of intermittency and fluctuation of photovoltaic power output to the power grid can be reduced.

A method and apparatus for synchronizing applications of network terminals are provided. Time information, which is synchronized and managed with other terminals for controlling use of media in the network in a media access control (MAC) layer, is transmitted to an application layer so as to directly execute the application using a synchronization interface. Accordingly, it is possible to synchronize applications without exchanging packets for obtaining synchronization information of terminals using a TCP/IP protocol.

A system and method are disclosed for synchronizing edge devices on a network, wherein the network has limited bandwidth and does not support a practical carrier sense mechanism. The edge devices transmit, using a slotted protocol, to a server located at a central data aggregation point. The server also controls a Central Transmitter, which sends messages to the edge devices to assign transmission slots and provide timing information to the edge devices to ensure that transmissions sent by devices sharing the same communication channel do not collide.

The invention provides a method for the hot standby of dual database servers in the technical field of database systems. A system comprises an active database server and a standby database server. The two servers perform regular handshake, master-slave negotiation, data access and data synchronization through a synchronization network port. A server network port of the active database server employs a virtual Internet protocol (IP) address to externally provide server service, and a service network port of the standby database server does not externally provide database service. A database client accesses the active database server through the virtual IP address by adopting a transmission control protocol (TCP). A flexibly selectable real-time/quasi-real-time database synchronization mechanism, a comprehensive data consistency detection method for the active and standby database servers and a selectable data consistency recovery means are provided by the invention.

Providing a frequency reference to a mobile telecommunications base station is disclosed. A radio frequency signal that includes a periodic component having a known frequency is received. A frequency reference is derived from the received radio signal, based at least in part on the periodic component. The frequency reference is used to transmit from the base station at an assigned frequency.

A method and system of synchronizing two nodes of a network uses a demodulated output signal of a time division multiplex (TDM) demodulator to perform frequency and timing synchronization independently. Frequency synchronization is performed without using a program clock reference, by detecting a symbol timing loop error of the TDM demodulator. The error is filtered by an oscillator control loop filter if the error is within a predetermined range. Thus, an output voltage of a digital to analog converter that receives the filtered output controls an oscillator. In the timing synchronizer, an error between a program clock reference (PCR) and a value of a counter in the terminal is computed if the PCR is a not a first PCR, and the error is filtered with a timing loop control filter. A processor then adjusts a value of the counter in the terminal based on the filtered output.

A method of precisely synchronizing clocks held in separate nodes on a communication network is provided that adjusts clock frequency based on a measure of relative clock rates and absolute clock offsets. In one embodiment, clock convergence is obtained with one synchronization session.

The inventive embodiment discloses a method, a device and a system for synchronizing time on a main clock side and a slave clock side in a synchronization network, which belong to the communication field and are designed to solve the technical problem in achieving time synchronization of the synchronization network. The method synchronizing time on the slave clock side in the synchronization network comprises the following steps: receiving a synchronous message supported on a first downlink frame; generating an entrance indication pulse according to the received first downlink frame, the entrance indication pulse being fixed with the time delay of fixed-frame bytes in the first downlink frame; collecting a first time on the slave clock side according to the entrance indication pulse; receiving a following message supported on a second downlink frame, the following message carrying a first time for transmitting the synchronous message on the main clock side; and adjusting the local time according to the difference between the first time on the main clock side and the first time on the slave clock side.

A method of and a system for synchronising a plurality of spaced apart nodes of a network to a reference time of a control centre, the method comprising receiving measurement data from each of the plurality of nodes; ranking the plurality of nodes with respect to one another according to the measurement data; selecting one or more master nodes from the plurality of nodes according to the ranking; assigning each of the plurality of nodes to a corresponding master node; determining a first time offset between the local time measured at each node and the local time measured at its corresponding master node and determining a second time offset between each of the master nodes and the reference time such that the time offset between the local time measured at each node and the reference time can be determined.

The invention discloses a verifiable and adjustable full synchronous communication network, and an implementation method thereof. The implementation method of the verifiable and adjustable full synchronous communication network comprises the steps: setting a time frequency standard system and a performance monitoring and evaluation system; comparing all the PRCs (Primary Reference Clock), LPRs (Local Primary Reference) and the like of the whole network respectively with the time frequency standard system in a common view satellite mode; according to the obtained clock error through common view comparison between the PRCs and LPRs and the time frequency standard system, calculating, processing and evaluating the technical performance in the performance monitoring and evaluation system; and adjusting the clock of each PRC and each LPR through the clock error so as to realize full synchronization of the communication synchronization network. The implementation method of the verifiable and adjustable full synchronous communication network belongs to a communication synchronization network full synchronizing method based on satellite common view, can establish a high accuracy time frequency measuring system, a synchronization performance evaluation system and a synchronous calibration system, can realize trusted verification and calibration of the synchronization performance quality, and can realize full synchronous operation of the full synchronous communication network based on the above capabilities.

The invention relates to a digital synchronization network, and provides a DPLL circuit having a holdover function that generates a high-precision reference clock with a temperature correction to perform a free-running frequency control at a holdover time. In a holdover mode of the DPLL circuit using a DDS, the DPLL circuit having a holdover function adds a correction value calculated from a temperature characteristic of a slave oscillator to a fixed DDS control value during a detection of a holdover, thereby changing the DDS control value according to the temperature characteristic.

The present invention provides methods, apparatuses and a program relating to fast recovering for network listening schemes in synchronization over air for small cells. The present invention includes tracking, at a first base station, a reference signal of a second base station, determining, whether the reference signal can be tracked, if it is determined that the reference signal can be tracked, adjusting, at the first base station, a system clock of the first base station based on the reference signal of the second base station, and estimating and storing parameters relating to a frequency difference between the system clock of the first base station and a system clock of the second base station, and if it is determined that the reference signal cannot be reliably tracked, adjusting the system clock of the first base station based on the stored parameters.

The invention discloses a high-speed optical fiber ring network communication network control topology of a large-capacity power electronic system. The control topology comprises a main node, multiple slave nodes, an on-off machine network, a fault protective network, a synchronization network and a high-speed data communication network. The control topology is high in communication speed, simple in structure, good in synchronization effect, high in distributed modularization and high in reliability.

The invention discloses a cloud synchronization method of a high-precision timing system of an optical network. Compared with time synchronization technologies in the prior art, the cloud synchronization method achieves transmitting of ultraprecise time frequency through bidirectional comparison in a one-fiber transmitting mode; besides, the cloud synchronization method is provided, a four-level cloud synchronization network on the standard of the ultraprecise time frequency is transmitted through one fiber can be built for supporting ground-based timing, the high-precision ground-based timing system based on the ground optical network is formed, and therefore the high-precision timing system is formed, the high-precision timing system and a space-based timing system are standbys for each other and support each other, a ultraprecise timing service is provided for a national defense and military network of China anyplace and anytime, and an extremely accurate regenerated UTC atomic time ultraprecise time frequency standard is provided for a civil communication network and various special communication networks.