55 results about "Network time synchronization" patented technology

The invention provides a wireless ad hoc network time synchronization method, device and system and communication equipment, and relates to the technical field of communication. The wireless ad hoc network time synchronization method comprises the following steps: generating a reference clock signal based on a GNSS (Global Navigation Satellite System) signal of a global navigation satellite system; generating a local clock signal synchronized with the reference clock signal; determining a sending window of the wireless frame according to preset sending time slot configuration; wherein the starting moment of the sending window is set to be deviated from a specified edge of the reference clock signal by a preset time delay; generating and sending the wireless frame in the sending window; wherein the wireless frame at least comprises equipment identification information and time synchronization identification information, and the initial sending time of the wireless frame is consistent with the initial time of the sending window.

The invention provides a method and a system for time synchronization between network devices. The method comprises the following steps: a first network device sends a request message carrying a first timestamp recorded when a port is out to a second network device; receiving a response message carrying the first timestamp, the second timestamp and the third timestamp from the second network equipment, and recording a fourth timestamp when the response message enters the port; and obtaining a mapping relationship between the first network equipment timestamp and the second network equipment timestamp according to the multiple groups of timestamps. According to the method and the device, the mapping relationship between the timestamps of different devices is obtained by using the least square algorithm according to the multiple groups of timestamps obtained according to the interaction message, and the first network device time corresponding to the timestamp of the second network device is obtained by using the mapping relationship, so that time synchronization can be realized without modifying the timestamps of the devices; the problem that when the network equipment has no absolute timestamp and the timestamp does not support modification, the existing time synchronization protocol cannot be used for time synchronization is solved.

This application discloses a network time synchronization verification method, apparatus, electronic device, and computer-readable storage medium. The method includes: sending probe packets to a time synchronization server at a first preset time interval to obtain a round-trip delay sequence within a preset time window; extracting statistical features from the round-trip delay sequence and constructing a network path fingerprint based on the statistical features; obtaining a time offset change when a time synchronization jump or time synchronization request is detected; calculating the fingerprint deviation of the current network path fingerprint relative to the fingerprint baseline; performing consistency matching between the time offset change and the fingerprint deviation, and determining the reliability of the time offset change based on the consistency matching result. This application can distinguish between interpretable offsets caused by normal network fluctuations and uninterpretable offsets caused by link manipulation when a time synchronization jump occurs in the network time synchronization.

This invention relates to a time synchronization method for 5G and TSN converged networks based on a timestamp compensation algorithm, belonging to the field of cross-network time synchronization. It includes: introducing a 5G network as a TSN virtual bridge into the TSN network to form a cross-network, which includes a TSN1 network, a 5G network, and a TSN2 network. The cross-network uses the TSN switches in the TSN1 network as the master clock and the TSN devices in the TSN2 network as slave clocks. Synchronization is achieved by transmitting time synchronization information step-by-step across the NW-TT module, the 5G network clock domain, and the DS-TT module. The cross-network time synchronization includes TSN2 network time synchronization, 5G network time synchronization, and TSN2 network time synchronization. This invention improves the accuracy of time synchronization by calculating the frequency offset and dwell time between NW-TT and DS-TT within the 5G system and performing time compensation in the DS-TT.

Method (300) for providing fault-tolerant network time synchronization in a motor vehicle communication network (100), wherein the motor vehicle communication network (100) comprises: a video controller (115) coupled with a first camera (110) and a second camera (175), a lidar controller (125) coupled with a first lidar transceiver (130) and a second lidar transceiver (120), a radar controller (145) coupled with a first radar transceiver (140) and a second radar (150), a processor (160), a user interface (165), a vehicle controller (155) and a trailer interface (170) the procedure includes the following: Generation of a time synchronization signal; Transmission of the time synchronization signal from a first switch (415) to a second switch (425) via a first connection and from the first switch (415) to a third switch (435) via a second connection; Detecting a connection error on the second connection; and Transmitting the time synchronization signal from the second switch to the third switch (435) via a third connection in response to the connection fault, wherein the time synchronization signal is generated by a radar controller coupled to the first switch, and wherein a first radar sensor is coupled to the second switch and a second radar sensor is coupled to the third switch, wherein the lidar controller (125), the video controller (115) and the radar controller (145) are each configured to receive and process data from their respective sensors, and the video controller (115) is set up to receive images from the first camera (110) and the second camera (175) and to process the images to generate image data for use in creating an object map around the vehicle (105).

The invention belongs to the technical field of avionics, and particularly relates to an architecture design method of a TSN network end system with dual-processor collaboration. The system architecture comprises a main processor and a network card; a buffer A, a register A, a buffer B, a register B, a coprocessor and a protocol conversion module are arranged in the network card; the main processor performs data interaction with a buffer A and a register A in the network card; the coprocessor performs data interaction with a buffer B and a register B in the network card; the protocol conversion module performs data interaction with the buffer A, the register A, the buffer B, the register B and an external network; the main processor is used for receiving an airborne light thunder signal, a sensor signal, an avionics / electromechanical control signal and a graphic video signal, and outputting light thunder sensor data, an avionics / electromechanical control instruction and a graphic video signal; the coprocessor is used for receiving avionics network management data, network time synchronization data and built-in self-inspection data and outputting corresponding data packets.

The invention discloses a method and a system for testing synchronous digital quantity injection of a regional stability control system based on network time synchronization, and the method is characterized in that the method comprises the following steps: S1, determining a test case needed by each control strategy function test of the stability control system according to the architecture and functions of the regional stability control system; s2, based on the test state sequence and the test input quantity determined by the test case, automatically generating a stability control system digital quantity injection test script matched with the test state sequence and the test input quantity; s3, through a network time synchronization mechanism, it is ensured that clock references of the test computer systems of all the sites are consistent, triggering time marks of test cases are set in a unified mode, and generated test case scripts are distributed to stability control devices of all the sites; and S4, analyzing the received test case script by the stability control device of each station, and extracting a test state sequence and characteristic parameters related to the station device.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device (WCD) may perform a clock tracking procedure that comprises: transmitting, to an access point (AP), an extended personal area network (XPAN) synchronization message pair that is addressed to a peripheral device associated with the WCD, and receiving, from the AP, an XPAN synchronization response message pair that is associated with the XPAN synchronization message pair. The WCD may transmit, to the AP, user data that is addressed to the peripheral device at a time that is based at least in part on an estimated awake window, the estimated awake window being based at least in part on the XPAN synchronization response message pair. Numerous other aspects are described.

This application discloses a clock synchronization method, apparatus, board, and computer-readable storage medium, relating to the field of network time synchronization technology. The service card encapsulates a device sending timestamp in a first NTP request message sent by the main control card based on the first current service system time to obtain a second NTP request message, which is then sent to the NTP server. Based on the second current service system time, the service card encapsulates a device receiving timestamp in a second NTP response message sent by the NTP server to obtain a first NTP response message. The first NTP response message is then sent to the main control card, allowing the main control card to calculate the network clock deviation between itself and the NTP server based on the first NTP response message, and adjust the main control system time accordingly. This method avoids the problem of large errors between the device sending timestamp and the device receiving timestamp, thus ensuring that the network clock deviation calculated by the main control card will not have significant errors.

The application provides a network time synchronization system and method, and belongs to the technical field of network security. The system comprises a sending end and a plurality of receiving ends. Each receiving end is provided with a physical link between the sending end. The sending end is connected with a secure coding modulator. Each receiving end is connected with a secure demodulation decoder. The secure coding modulator and each secure demodulation decoder are provided with a secure transmission auxiliary device. The secure transmission auxiliary device comprises a first end channel simulation subsystem connected with the secure coding modulator, a second end channel simulation subsystem connected with the secure demodulation decoder, a plurality of channel simulation subsystems and a plurality of secure exchange devices located between the first end channel simulation subsystem and the second end channel simulation subsystem. A special communication link is arranged between the secure transmission auxiliary devices. The application realizes the secure transmission of secret information bits in the network time synchronization message, physical layer identity authentication, physical layer routing control and other functions.

The application provides a physical layer identity authentication method and device of a network time synchronization system, and belongs to the technical field of network security, and specifically comprises the following steps: encoding and modulating a sending end original time synchronization message, and inserting an identity authentication pilot sequence; performing pre-distortion of the message signal related to the sending end identity; performing step-by-step equalization of the message signal by each device based on a pre-measured and stored frequency domain channel matrix of a physical channel; a security demodulator extracts a current sub-block identity authentication pilot sequence, estimates, interpolates and stores the pre-distorted sequence, and then performs frequency domain equalization, demodulation and decoding on the current sub-block data sub-carrier by using the pre-distorted sequence to recover the original time synchronization message and a message security indication vector; identity authentication is judged based on the error code rate of the message security indication vector, and the original time synchronization message is sent to a receiving end or discarded according to the judgment. The scheme of the application effectively overcomes external and internal attackers, and realizes time source identity authentication.

The application provides a time synchronization method and device, electronic equipment, storage medium and computer program product, relates to the technical field of network time synchronization, and the method comprises the following steps: receiving a synchronization message sent by a time server; wherein the synchronization message comprises time data; the time data is used for representing the time delay in a communication path; and time synchronization is performed based on the time data and a receiving timestamp of the synchronization message. The scheme in the embodiment of the application can improve network performance.

The invention relates to a fuzzy multi-layer network time synchronization method with an output coupling characteristic, which comprises the following steps of: constructing a fuzzy multi-layer output network with the output coupling characteristic, and establishing a predefined time stability lemma of a switching type; a controller is triggered based on a fixed time intermittent dynamic event, a synchronization error is defined, a fixed time output synchronization problem of a fuzzy multilayer network with an output coupling characteristic is solved, a fixed time output synchronization criterion is established, and fixed time output synchronization of the multilayer network is realized; and based on the predefined time stability lemma of the switching type, solving the predefined time output synchronization problem of the fuzzy multilayer network with the output coupling characteristic, and establishing a predefined time output synchronization criterion to realize the predefined time output synchronization of the multilayer network. According to the invention, under the condition that the initial value of the node is unknown, the fixed / predefined time is synchronized by using the node output information.

The invention discloses a wireless network time synchronization method and system, and a storage medium, and the method comprises the steps: collecting network node time data, forming an original sampling sequence, and generating a whole network clock observation matrix; based on the connection strength between each pair of network nodes, constructing a Laplacian matrix; on the basis of an objective function of a graph regularization robust low-rank decomposition model, carrying out joint optimization solution on the whole-network clock observation matrix, and alternately updating a low-rank matrix and a sparse matrix; after convergence conditions are met, drift and offset correction values are calculated, and correction parameters are generated; and performing wireless network time synchronization according to the correction parameter. The problem that an existing synchronization algorithm is unstable in precision under the conditions of strong interference, packet loss and dynamic topology is solved, and unification of high precision and high robustness of clocks of the whole network is achieved.

This invention relates to the field of network time synchronization technology, and discloses a network time synchronization method, system, storage medium, and electronic device for bypassing UDP port blocking. The method includes: sending a time synchronization request to a Network Time Protocol (NTP) server through a User Datagram Protocol (UDP) port to detect the reachability of the NTP primary channel; when the NTP primary channel is determined to be unreachable, generating a query domain name containing a first time parameter to form a Domain Name System (DNS) query message encapsulating the time synchronization request; constructing a DNS secure transmission backup channel and sending the DNS query message to the target server; receiving the DNS response message returned by the target server and extracting a second time parameter from it; calculating the clock offset between the client and the target server based on the first and second time parameters, and adjusting the local system clock accordingly; the above method achieves secure and reliable network time synchronization under UDP port blocking.

The invention provides a cross-network time synchronization method, device and equipment in a smart power grid, and relates to the technical field of time synchronization. The method comprises the following steps: acquiring electrical operation data in a transformer substation in a target smart power grid, link characteristic data in a cross-network transmission link system, a Beidou time service signal and a power grid time signal of the target smart power grid; unifying the initial time of each link according to the Beidou time service signal, the power grid time signal and the link characteristic data, and obtaining an initial deviation calibration table; according to the initial deviation calibration table, the electrical operation data and the link characteristic data, constructing a multi-link cooperative time delay model; according to the link feature data, the electrical operation data and a multi-link collaborative delay model, obtaining delay prediction data of each link; and each link is calibrated based on the time delay prediction data, so that the cross-network time in the target smart power grid is synchronized. According to the invention, integrated time synchronization management of multiple types of transmission networks can be realized.

The invention discloses a low-voltage carrier multi-configuration network time synchronization collaboration method, which is characterized in that network nodes are divided into a plurality of logic communication groups, and a periodic synchronization reference frame and a time slot distribution mechanism are adopted, so that intra-group high-precision synchronization and cross-group seamless forwarding are realized; by adopting the method, the synchronization precision is remarkably improved, and the reference node periodically broadcasts the synchronization frame and compensates the transmission delay, so that the clock skew of each node is reduced to be below millisecond level; flexible configuration and rapid reconstruction capability are realized, dynamic increase and decrease of nodes and real-time update of configuration are supported, manual intervention is not needed, and configuration switching time delay is less than 20 milliseconds; communication is high in reliability, time slot isolation reduces inter-group conflicts, and a cross-group forwarding mechanism ensures that the data transmission success rate is high; the compatibility is strong, the deployment is easy, only a synchronization frame and time slot mapping need to be added in an existing PLC link layer protocol, and primary equipment of a power grid does not need to be changed; the operation and maintenance cost is reduced, and the operation efficiency and stability of the power distribution network communication system are improved.

The invention belongs to the technical field of wireless communication, and discloses a LoRa network synchronization method based on hardware time compensation modeling and a least square method, and the method comprises the following steps: S1, obtaining a bidirectional timestamp data set during message interaction between a gateway and a node; s2, performing data preprocessing on the obtained bidirectional timestamp data set; s3, in combination with hardware processing time delay, establishing a dynamic affine clock model to realize logic time synchronization; and S4, estimating the parameters by using a least square parameter estimation method, and verifying the prediction precision by using the estimated parameters obtained based on OLS in the step S5 and adopting a cross validation form. According to the LoRa network synchronization method based on hardware time compensation modeling and the least square method, node power consumption and hardware processing delay fluctuation are effectively reduced, and high-precision LoRa network time synchronization is achieved.

The invention relates to a multimedia sound source box and method supporting time synchronization and intelligent time zone acquisition. The multimedia sound source box comprises a main control chip unit, a power management unit, a clock unit, a storage unit, a network interface unit, an external communication unit, an audio output unit and a time synchronization unit. The main control chip unit is respectively connected with the power supply management unit, the clock unit, the storage unit, the network interface unit, the audio output unit and the time synchronization unit; according to the invention, high-precision network time synchronization can be realized, and time errors caused by network delay are reduced; time zone information can be automatically acquired and switched, and manual intervention of a user is not needed; meanwhile, a time synchronization mechanism among multiple devices is provided, synchronous playing of multiple audio devices in a local area network is ensured, power consumption and cost of time synchronization are reduced, and the method is suitable for consumer-level multimedia devices.

This invention discloses a fault injection and fault tolerance testing device based on a network time synchronization protocol, comprising: a first data interface, a traffic splitting module, a test configuration module, a fault injection module, a time synchronization module, a synchronization status monitoring module, and a second data interface. The fault injection module injects faults into synchronization frames according to fault injection configuration information to obtain fault-injected synchronization frames. The time synchronization module implements the network time synchronization protocol function based on the fault-injected synchronization frames and outputs response synchronization frames. The fault injection module injects faults into the received response synchronization frames to obtain fault-injected response synchronization frames. The synchronization status monitoring module monitors the working status of the time synchronization module, obtains status monitoring information, and evaluates the fault tolerance of the time synchronization function based on the status monitoring information. This invention implements fault tolerance testing of devices with time synchronization functions through hardware logic, making the fault tolerance testing results more reliable.

The invention belongs to the technical field of network communication, and particularly relates to an SNTP message sending method and device, a storage medium and a program product. According to the method, the field of the sending time in the SNTP message is filled with 0 in the application packaging link of SNTP message sending, the FPGA system sending time is obtained by adding the current FPGA system time to a set time interval threshold value in the driving processing link, and the set time interval threshold value is larger than or equal to the time needed by a driver to send the SNTP message to an FPGA module; the method comprises the following steps of: calculating UTC time corresponding to FPGA system sending time according to a corresponding relation between the UTC time and FPGA system time, further updating the sending time in a received SNTP message to the corresponding UTC time, and then sending the SNTP message by an FPGA module according to the calculated FPGA system sending time. According to the SNTP message sending method, the time synchronization precision of the SNTP message is ensured, the implementation cost and difficulty are reduced, and the problems that an existing network time synchronization method is complex in operation and high in implementation cost are solved.

The application relates to the technical field of network time synchronization, in particular to a cross-clock-domain high-precision PTP time engine synchronization system and method, which comprises a master clock domain, a master time engine module is established in the master clock domain, the master time engine module comprises a master time engine counter, the master clock domain is used for driving the master time engine counter, the bit width of the master time engine counter is 80 bits, the master time engine counter is used for generating master time information and a second pulse signal 1PPS_OUT_M, a port Rx clock domain is further included, a port Rx time engine module is independently arranged in the port Rx clock domain, the port Rx time engine module comprises a port Rx time engine counter, the port Rx clock domain is used for driving the port Rx time engine counter, the bit width of the port Rx time engine counter is 80+N bits, wherein the high 48 bits Counter_Rx[79+N:32+N] represent the second bit, the low 32+N bits Counter_Rx[31+N:0] represent the part within the second, and one LSB represents 2^‑N nanoseconds, so that the precision of the device is improved.

The invention relates to the technical field of ship communication, in particular to a time synchronization method of AIS (Automatic Identification System) forwarding equipment based on GNSS (Global Navigation Satellite System) and AIS message fusion. The AIS forwarding equipment comprises an AIS receiving module, a time synchronization module, an AIS data storage module and a communication module; the time synchronization method comprises the following working conditions: I, if a mobile network can be accessed, performing time calibration by adopting an NTP protocol, and synchronizing a local clock and a second counting module; and working condition II, if the mobile network cannot be accessed, starting a network-free time synchronization mode, maintaining a second counting rhythm through a GNSS second pulse, marking a periodic calibration second counting module and a local clock in combination with a UTC second mark in the AIS message data, and marking a timestamp for the AIS message data. The method ensures that the forwarding equipment can still mark the accurate time of which the error is less than 1 second for the stored AIS message in a long-time off-line state, and provides a key technical support for realizing dynamic seamless supervision of a full-voyage ship.

Disclosed are systems and methods for configuring time synchronization in a network. The system includes a time signal source to provide a common time signal to multiple configurable communication devices and a network controller in a control plane, in communication with the multiple configurable communication devices. The network controller is configured to receive time signal source information and to receive device configuration information for a first configurable communication device. The network controller is also configured to determine settings for time signal distribution and to transmit the settings to the multiple configurable communication devices to cause the first configurable communication device to transmit the time signal from the time signal source in a data plane for consumption by the multiple configurable communication devices.

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a wireless communication device (WCD) may perform a clock tracking procedure that includes transmitting an extended personal area network (XPAN) synchronization message pair addressed to a peripheral device associated with the WCD to an access point (AP); and receiving an XPAN synchronization response message pair associated with the XPAN synchronization message pair from the AP. The WCD may send user data addressed to the peripheral device to the AP at a time based at least in part on an estimated wake-up window, the estimated wake-up window based at least in part on the XPAN synchronization response message pair. Numerous other aspects are described.

The invention discloses a time-frequency synchronization system and method based on HPLC and HRF dual-mode communication, and relates to the technical field of communication network time synchronization, and the method comprises the steps: collecting a power grid voltage zero-crossing moment, and determining a phase bucket index at a current moment; executing dual-mode interaction in a corresponding time period to obtain a timestamp; calculating an HRF offset estimation value and an HPLC bidirectional quantity; determining an HPLC asymmetric item by using the HRF offset estimation value and updating an asymmetric compensation table; when the HRF is unavailable, calculating time synchronization offset after phase compensation by using the compensation table and adjusting a local clock; and determining a frequency correction factor for frequency taming based on the time synchronization offset. According to the invention, the time-frequency synchronization precision and stability of dual-mode communication in a complex power grid environment can be improved.

Embodiments of synchronizing the device clock in wound monitoring and / or therapy systems are disclosed. In some cases, a wound monitoring and / or therapy device can maintain a device clock, which can be set to a network time obtained from a network or internal time associated with a time set during configuration of the device. The device can selectively set the device clock to the network time in response to obtaining the network time and determining that the device clock is set to the internal time. In some cases, a remote computing device can receive a record transmitted by a wound monitoring and / or treatment device. The record can include a first set of operational parameters associated with monitoring and / or provision of treatment by the device and a first timestamp indicating a time of obtaining at least some operational parameters. The remote computing device can synchronize the first timestamp with network time.

The invention discloses a time-sensitive network time synchronization method based on frequency overcompensation, and belongs to the technical field of deterministic communication. Comprising five steps of message receiving and analysis, synchronization frequency judgment, first phase synchronization, second phase synchronization and frequency ratio calculation, and frequency overcompensation. The slave clock completes initial alignment in a phase adjustment mode when receiving the time synchronization message for the first time and the second time and calculates the frequency ratio of the master clock to the slave clock, the phase is kept unchanged from the third time of synchronization, and the frequency of the local clock is adjusted by calculating an overcompensation coefficient; and the slave clock and the master clock have the same display time when the next synchronization period arrives. According to the invention, a traditional phase adjustment mode is replaced by a frequency overcompensation mechanism, so that the local time of the slave clock continuously changes and does not jump, the clock striding phenomenon is fundamentally eliminated, the problem that the gating scheduling period is skipped or repeatedly executed due to clock striding is avoided, and the deterministic transmission characteristic of the time-sensitive network is ensured.