12 results about "Network time synchronization" patented technology

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.

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).

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 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.

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 application discloses a kind of perception decision integration target detection and tracking method based on high-low view angle cooperation, comprising: high-low video stream access and timing multimodal alignment based on network time synchronization protocol;Based on the backbone layer network target detection and depth feature extraction of CSPDarknet;Based on homography correction and geographic coordinate registration, cross-view space mapping;Based on the track association integration of unified geographic spatial distance measurement and bipartite graph matching;Based on the perception decision integration generation of multi-branch spatio-temporal graph convolution network ST-GCN.The application can solve the problem of feature collapse and matching recognition error rate soaring caused by the dependence of existing technology on re-identification depth appearance features in response to high-low pitch angle sharp crossing, realize the effect of uninterrupted and high-precision entity re-anchor in the target appearance distortion state across the scale deformation barrier.

This invention discloses a method and system for video evidence collection based on the shared usage time of instruments. By acquiring instrument identifiers and binding them to the evidence collection device, the Region of Interest (ROI) of the screen display area, status indication area, and operation area is calibrated, and a unified evidence collection timeline is established based on network time synchronization and a local secure clock. Video streams covering the ROI and auxiliary evidence streams are acquired synchronously. Multi-source data is input into a recognition model containing a multi-branch visual encoder for the ROI, an auxiliary evidence encoder, a cross-modal alignment gating module, a hierarchical temporal transformer, and an event query header. The model outputs a state probability sequence and regresses the start and end event boundaries and confidence intervals. The net usage time is calculated under state transition constraints and verified for consistency with auxiliary evidence. When the difference exceeds a threshold, frames are added to the event window for re-inference to update boundaries or mark disputes. Key segments and keyframes are extracted to generate evidence packages, a frame-level hash chain is constructed, and signatures are completed within a TEE. Combined with a timestamp service encapsulation, verifiable and tamper-proof evidence results are achieved.

The application provides a kind of intelligent three-dimensional positioning method and system based on Bluetooth beacon and LoRa ad hoc network, belongs to the field of building construction safety.The technical scheme is: S1, establish the three-dimensional positioning constraint model of tunnel construction area and complete node system configuration;S2, positioning terminal collects and pre-processes multi-source observation data to generate unified observation package;S3, based on LoRa ad hoc network, unified observation package is cooperated, converged and reliably transmitted;S4, execute semantic constraint multi-source fusion three-dimensional positioning solution;S5, execute three-dimensional ambiguity resolution and output positioning result and closed loop update.The beneficial effects of the application are: the application improves alignment accuracy through ad hoc network time synchronization and windowed fusion, and guarantees data continuity through multi-hop reliable transmission and confidence retransmission;three-dimensional reachable domain and connectivity rules are used to resolve ambiguity and reduce cross-zone and cross-height misjudgment;confidence is output, and constraints are calibrated and dynamically updated online, so that positioning is long-term stable and reliable.

This invention discloses a time synchronization method and related apparatus for an industrial smart tablet. The method includes: firstly, acquiring the historical moment when the industrial smart tablet, which does not rely on any form of network time synchronization, was last synchronized via a time synchronization device; then, determining the independent runtime and average operating temperature of the real-time clock chip of the industrial smart tablet during the operating period after the historical moment; next, determining a target time deviation based on the independent runtime and average operating temperature; if the target time deviation is less than or equal to a time deviation threshold, performing a second time synchronization operation on the industrial smart tablet; if it is greater than the time deviation threshold, sending a time synchronization prompt message to the time synchronization device, causing the time synchronization device to perform a first time synchronization operation on the industrial smart tablet based on the time synchronization prompt message. The implementation method of this application improves the accuracy of time synchronization for industrial smart tablets.

The present application relates to the technical field of ship communication, in particular to a time synchronization method of AIS forwarding equipment based on GNSS 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: working condition I. If mobile network can be accessed, NTP protocol is used for time calibration, and local clock and second counting module are synchronized; working condition II. If mobile network cannot be accessed, network-free time synchronization mode is started, second counting beat is maintained through GNSS second pulse, and second counting module and local clock are periodically calibrated in combination with UTC second mark in AIS message data, and time stamp is marked for AIS message data. The present application ensures that the forwarding equipment can still mark accurate time with error less than 1 second for stored AIS message under long-time offline state, and provides key technical support for realizing dynamic seamless supervision of ships in whole voyage.