A time synchronization system includes a master and slave devices connected to each other via a data bus and a signal line dedicated to transmission of a fixed-period signal. The master device transmits the fixed-period signal through the signal line regularly at a transmission period, and transmits start time information indicating a transmission start time at which transmission of the fixed-period signal is started and transmission period information indicating the transmission period for the fixed-period signal through the data bus. The slave device counts a number of times the fixed-period signal is received and calculates, as a current time in the master device, a transmission time at which the master device transmits the fixed-period signal based on the number of times the fixed-period signal is received. The slave device corrects the time to the calculated current time in the master device.

The present disclosure provides systems and methods for proving an event. The system comprises a network of one or more beacon nodes and each beacon node is configured to: receive a request over the network for proving a time and location for an event, and the request comprises event data generated by a requesting entity; create a timestamp for the event using a clock of the beacon node, wherein the clock is synchronized to a trusted time source; generate a hash code for the timestamp and the event data and record the hash code to a ledger at the beacon node.

A system (100) comprising: a first unit (104) and one or more second units (104). The first unit (102) comprises: a timing reference (114) configured to provide a master-timing-reference-signal; a master time block configured to provide a master-time-signal (117) for the first unit (102) based on the master-timing-reference-signal; and a first interface (122) configured to: receive timestamped-processed-second-RF-signals from the one or more second units (104); and provide a first-unit-timing-signal (262) to the one or more second units (104) based on the master-time-signal. The one or more second units (104) each comprise: a slave time block (141) configured to: determine a slave-time-signal (142) for the second unit (104) based on the master-timing-reference-signal; determine one or more second-timing-values based on the slave-time-signal; determine an adjustment-time based on the first-unit-timing-signal received from the first unit (102) and the second-timing-values; and adjust the slave-time-signal based on the adjustment-time.

A time synchronization method includes receiving, by a receive-end device, a first timestamp and a first header signal sent by a transmit-end device, where the first timestamp indicates a first moment at which a first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal. The method further includes sending a second header signal to the transmit-end device, where a third moment at which the receive-end device sends the second header signal. The method further includes receiving a fourth timestamp sent by the transmit-end device, where the fourth timestamp indicates a fourth moment at which the transmit-end device receives the second header signal. The method further includes synchronizing time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment.

The present disclosure provides systems and methods for timestamping events on edge devices. A trusted source measures the latency to the edge device and the edge device's clock offset, and stores the information at the trusted source for later use. The trusted source sends the latency and the device's clock offset to the edge device for later use. The trusted source or the edge device adjusts a timestamp generated at the edge device using an estimated clock offset. The estimated clock offset is determined by extrapolation or interpolation from measured clock offsets.

Described herein are systems and methods for implementing a look up table by a network node, and performing or supporting time synchronization based on the look up table. In one aspect, a network node may receive a packet. The network node can identify a few number of bits in the packet, and determine one or more actions or functions corresponding to the few number of bits via the look up table. In addition, the network node can execute or perform the determined one or more actions to support time synchronization.

A method for time synchronization in a vehicle may include transmitting, by a satellite navigation device to a controller and at least one LiDAR device, a UTC and a PPS signal. The satellite navigation device may have a first clock. The method may include synchronizing, by the controller, a second clock of the controller with the first clock of the satellite navigation device based on the PPS signal and the UTC. The method may include synchronizing, by the at least one LiDAR device, a third clock of the at least one LiDAR device with the first clock of the satellite navigation device based on the PPS signal and the UTC. The method may include synchronizing, by at least one camera, a fourth clock of the at least one camera with the second clock of the controller.

An audio system, method, and computer program product for synchronizing device clocks. The systems, methods and computer program product can establish a first isochronous data stream between a peripheral device and a first device and establish a second isochronous data stream between the first device and a second device to send data between the first and second device. As the two data streams may rely on two different device clocks, e.g., one clock which defines the timing for the first isochronous data stream and a second clock which defines the timing for the second isochronous data stream, the systems, methods, and computer program disclosed herein are configured to maintain synchronization and/or synchronize the first clock with the second clock to prevent data loss due to clock drift.

A method for exchanging a clock synchronization packet performed by a network apparatus, including: exchanging a clock synchronization packet with a first clock source, where the network apparatus includes a boundary clock; determining a first time deviation of the boundary clock relative to the first clock source according to the clock synchronization packet exchanged with the first clock source, where the boundary clock avoids performing an operation of calibrating a time of a local clock of the boundary clock according to the first time deviation; and sending a clock synchronization packet to a first slave clock of the boundary clock, where the clock synchronization packet includes a first timestamp, a value of the first timestamp is equal to a first corrected value, and the first corrected value is a value obtained by the boundary clock by correcting the time of the local clock by using the first time deviation.

A bus system, a method for operating a bus system and a participant of a bus system are provided. The participant includes a timer and a transceiver circuit. The transceiver circuit is configured to receive a data packet having a time stamp value via a bus. The timer is configured for synchronization, based on the time stamp value. The timer is configured to change the time stamp value. The transceiver circuit is configured to transmit the data packet with the changed time stamp value via the bus.