Timestamp circuitry of a network device modifies a packet by embedding a future timestamp in the packet to generate a timestamped packet. The future timestamp corresponds to a transmit time that occurs after the timestamp circuitry embeds the future timestamp in the packet. The timing information is added to the packet and the packet is then transferred to transmitter circuitry of the network device via a communication link, internal to the network device, that operates according to a media independent communication interface. Time gating circuitry of the transmitter circuitry i) holds the timestamped packet from proceeding to a network link coupled to the network device prior to a current time reaching the transmit time, and ii) releases the timestamped packet for transmission via the network link in response to the current time reaching the transmit time.

A first timing error of a network device is determined based at least in part on a first received network message from a timing synchronization source. At a first instance, it is determined whether the first timing error exceeds a threshold. In response to a determination at the first instance that the first timing error exceeds the threshold, a clock of the network device is corrected based at least in part on the first received network message. A second timing error of the network device is determined based at least in part on a second received network message from the timing synchronization source. At a second instance, it is determined whether the second timing error exceeds the threshold. In response to a determination at the second instance that the second timing error does not exceed the threshold, the clock of the network device is allowed to function without correction.

Provided are a method for time synchronization between a head-mounted device and a peripheral device. The method includes: obtaining sample data of an inertial measurement unit of the peripheral device, and determining a first timestamp representing a time at which the sample data is sampled; transmitting an interrupt request and the sample data to the head-mounted device, and determining a second timestamp representing a time at which the interrupt request is transmitted; determining a third timestamp representing a time at which the interrupt request is received by the head-mounted device; and determining a time difference based on the third timestamp and the second timestamp, and performing time compensation for the first timestamp based on the time difference to enable the peripheral device and the head-mounted device to complete the time synchronization with a unified time standard.

Apparatuses, methods, and systems for dynamically estimating a propagation time between a first node and a second node of a wireless network are disclosed. One method includes receiving, by the second node, from the first node a packet containing a first timestamp representing the transmit time of the packet, receiving, by the second node, from a local time source, a second timestamp corresponding with a time of reception of the first timestamp received from the first node, calculating a time difference between the first timestamp and the second timestamp, storing the time difference between the first timestamp and the second timestamp, calculating a predictive model for predicting the propagation time based the time difference between the first timestamp and the second timestamp, and estimating the propagation time between the first node and the second node at a time by querying the predictive model with the time.

Embodiments of the present disclosure relate to systems and methods for monitoring and verifying latency on TSN-configured networks. The disclosure describes a novel and inventive time capture location protocol that supplements existing TSN protocols. This supplemental TSN protocol details a way to capture the time at which a message arrives at various points in a TSN-configured network. The captured times allow for monitoring and verification of TSN based features and their underlying systems, including run-time diagnostics to detect problems and delays.

A transmitting method stores data making up a coded stream into a predetermined data unit and transmits the stored data in the predetermined data unit. The transmitting method further generates presentation time information indicating a presentation time of the predetermined data unit, based on reference time information received from an external source; and transmits the predetermined data unit, first control information which includes the generated presentation time information, and second control information which includes leap second information indicating whether or not the presentation time information is a time that is before a leap second adjustment. A receiving method receives the predetermined data unit, first control information, and second control information; and reproduces the received predetermined data unit based on the first and second control information that are received.

The present application generally relates to network timing synchronization in the presence of link faults including apparatus and methods In various embodiments, a method includes generating a time synchronization signal, transmitting the time synchronization signal from a first switch to a second switch via a first link and from the first switch to a third switch via a second link, detecting a link failure of the first link, and transmitting the time synchronization signal from the second switch to the third switch via a third link in response to the link failure.

A method includes computing electrical phase of electrical metering devices including obtaining data indicating zero-crossing times at first and second metering devices. A time difference between the zero-crossing times may be determined. In a first example, the time difference may be based at least in part on calculations involving a first value of a first free-run timer on a first metering device, a second value of a second free-run timer on a second metering device, the time of reception of a packet, and a latency defined by a time taken for the packet to propagate through at least one layer of at least one of the first metering device and the second metering device. A phase difference between the first zero-crossing and the second zero-crossing may be determined, based at least in part on the determined time difference.

High-frequency communications in 5G and especially 6G will require precise synchronization of user devices with the base station, including setting the user device clock time and clock rate. The base station can assist user devices by periodically providing a guard-space timestamp point, at which a phase or amplitude of the timing signal abruptly changes in the middle of the guard-space of a particular resource element or a particular OFDM symbol. A receiver can determine precisely the time of arrival of the timestamp point, and correct its clock setting to agree with the time of the timestamp point. The receiver can then provide uplink messages aligned with the base station's clock, by adding a previously determined timing advance to each uplink transmission. In addition, the user device can measure two guard-space timing signals with a predetermined separation, thereby adjusting the clock rate.

This disclosure describes methods to process timing information of flows in a network. One or more processors determine a latency associated with each of one or more packets of a flow passing through a device. The one or more processors determine that the latency is greater than a baseline latency, and the one or more processors provide a message indicating at least the flow and that the latency is greater than the baseline latency.