H04J3/0682

SYSTEM AND METHOD OF CLOCK RECOVERY IN A PACKET-COMPATIBLE NETWORK
20230076889 · 2023-03-09 ·

There is provided a method of clock recovery and a system thereof. The method comprises: by master clock node or by client clock node, generating a first flow of time-stamped packets bearing indication of high priority of delivery and, in parallel, generating a second flow of time-stamped packets bearing indication of lower priority of delivery. By client clock node, processing the packets from the first flow separately from the packets from the second flow to define, separately for each flow, a function informative of changes of packets' delays in the respective flow over time; using the defined functions informative of changes of packets' delays in the first and the second flows over the same time intervals to assess a cause of the packets' delays changes; and applying a clock recovery algorithm in a manner differentiated in accordance with the assessed cause.

DYNAMIC DELAY EQUALIZATION FOR MEDIA TRANSPORT

Systems and methods of the present disclosure provide for dynamic delay equalization of related media signals in a media transport system. Methods include receiving a plurality of related media signals, transporting the related media signals along different media paths, calculating uncorrected propagation delays for the media paths, and delaying each of the related media signals by an amount related to the difference between the longest propagation delay (of the uncorrected propagation delays) and the uncorrected propagation delay of the related media signal/media path. Calculating the uncorrected propagation delays and delaying the related media signals may be performed in response to a change to the propagation delay of at least one of the related media signals/media paths. Additionally or alternatively, calculating the uncorrected propagation delays and delaying the related media signals may be performed while transporting the related media signals.

Clock synchronisation between devices using message timestamps

A method at a first device for synchronising a first clock of the first device to a second clock of a second device, includes receiving a first message comprising an identifier from a third device; generating a first timestamp in dependence on the time at which the first message is received at the first device according to the first clock; receiving a second message from the second device comprising the identifier and a second timestamp, the second timestamp having been generated in dependence on the time at which the second device received the first message from the third device according to the second clock; and adjusting the first clock in dependence on a time difference between a time indicated by the first timestamp and a time indicated by the second timestamp.

Detecting time delay between circuits to achieve time synchronization
20220329339 · 2022-10-13 ·

Systems, circuits, and methods for synchronizing devices in the time-domain are provided. A method, according to one implementation, includes determining a round-trip number based on a width of one cycle of a timestamping clock signal. The round-trip number is equal to a plurality of times that a clock signal is to be transmitted in a loop from a timing-leader component to a timing-follower component and back to the timing-leader component. The method also includes utilizing the timestamping clock signal to detect a cumulative time delay that results when the clock signal is transmitted in the loop a number of times equal to the round-trip number. The cumulative time delay is configured to enable synchronization of the timing-follower component with the timing-leader component.

Protection against Man-in-the-Middle Attacks in Virtualization Environments
20230073668 · 2023-03-09 · ·

A man-in-the-middle protection module can monitor data traffic exchanged between a source and destination nodes over a source-destination link via a network. The module can utilize a traffic probe packet to determine a packet delay associated with the data traffic. The module can store the packet delay and can determine that the packet delay is greater than a normal packet delay. If so, the module can determine that an attacker has compromised the source-destination link. The module can command a virtual machine associated with the source node to be decommissioned. The module can instruct a virtualization orchestrator to create a new source node. The data traffic can be rerouted to be exchanged between the new source node and the destination node over a new source-destination link via the network. The module can create and send fake data traffic towards the MitM attacker over the source-destination link via the network.

SYNCHRONIZING SYSTEMS ON A CHIP USING TIME SYNCHRONIZATION MESSAGES
20230109476 · 2023-04-06 ·

An electronic eyewear device includes first and second systems on a chip (SoCs) having independent time bases and an inter-SoC interface that connects the first and second SoCs. The operations of the first and second SoCs are synchronized by aligning the time bases for the SoCs using a modified PTP technique. The technique includes the second SoC receiving a time synchronization message from the first SoC over the inter-SoC interface, recording a local timestamp of receipt of the time synchronization message, receiving a master timestamp corresponding to a timestamp recorded by the first SoC corresponding to the time of sending the time synchronization message by the first SoC, and calculating a time offset between the local timestamp and the master timestamp. The time bases of the first SoC and second SoC are then aligned using the calculated time offset. To account for transmission delays, multiple time offsets may be averaged.

Time coherent network
11619719 · 2023-04-04 · ·

A sensor network, which includes a sensor controller serially coupled to a plurality of sensor modules, is configured to program the sensor modules so as to transfer measurement data to the sensor controller and to synchronize the sensor modules to picosecond accuracy via on-chip or on-module custom circuits and a physical layer protocol. The sensor network has applications for use in PET, LiDAR or FLIM applications. Synchronization, within picosecond accuracy, is achieved through use of a picosecond time digitization circuit. Specifically, the picosecond time digitization circuit is used to measure on-chip delays with high accuracy and precision. The delay measurements are directly comparable between separate chips even with voltage and temperature variations between chips.

Method and apparatus for low power channel access
11653302 · 2023-05-16 · ·

Systems, methods and devices for low power channel access using a wake up radio are disclosed herein. In accordance with one exemplary embodiment, a method performed by a communication device includes: receiving a wake up signal at a wake up radio from a communication node at a receipt time, wherein the wake up signal indicates a node active time for a main radio to begin communicating with the communication node; determining a transition time between an initiation time for the main radio and a device active time, wherein the device active time is during the node active time; determining a delay time from the receipt time to the initiation time; initiating the main radio at the initiation time; and communicating with the communication node using the main radio during the device active time.

OLT, ONU, PON system, and information transmission method in PON system

The present disclosure relates to information transmission methods in a passive optical network (PON) system. One example method includes sending, by an optical line terminal (OLT), a first power range and time indication to an unregistered optical network unit (ONU), where the first power range and the time indication indicate the ONU to send a serial number of the ONU to the OLT at a time indicated by the time indication in case a downlink receive power of the ONU is within the first power range, and receiving, by the OLT, the serial number of the ONU.

TIME SYNCHRONIZATION ERROR COMPENSATION METHOD FOR MULTI-HOP WIRELESS BACKHAUL NETWORK BASED ON PTP

The present invention relates to a wireless network communication technology, and in particular to a time synchronization error compensation method for multi-hop wireless backhaul network based on PTP. Based on PTP, the present invention uses an intermediate node to count the timestamps of transceiving the PTP synchronization message Sync and the delay request message Delay_Req, detect and compensate the local forwarding time of synchronization message Sync and the delay request message Delay_Req and the link delay of transmitting the two between nodes based on the linear regression technology, thereby finally implementing asymmetric delay correction of wireless links between the master and slave nodes and completing time synchronization error compensation. The present invention uses the header of the PTP message to transmit the additional time information about the compensation time, the sending time and arrived time of the message and time correction value without modifying the existing PTP, thereby reducing the message overhead, meeting requirements of real-time and high precision of synchronization error compensation, improving the existing time synchronization precision and having strong practicality.