A system, method and computer product for performing a time synchronization between first and second nodes includes the first node performing: generating a synchronization message, transmitting the synchronization message to the second node at a first time, taking a first timestamp in response to the synchronization message being transmitted and transmitting a timestamp message including the first timestamp to the second node at a second time; and the second node performing: receiving the synchronization message and the timestamp message from the first node, taking a second timestamp in response to the synchronization message being received, receiving the timestamp message from the first node, obtaining the first timestamp based on the received timestamp message, obtaining a timing offset between the first timestamp and the second timestamp and performing a time synchronization to the first node based on the timing offset.

A method for operating a data network, wherein the data network contains network devices that use data connections to interchange data packets, wherein a mechanism is operated in order to determine at least one end-to-end latency between network devices, characterized in that as a mechanism a network device transmits a trigger packet to at least one further network device and a timestamp is used to establish when the trigger packet has reached this at least one further network device.

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.

A method for determining a correctness of an actually received timestamp is provided. A communication network includes a master clock, a first ECU having a first slave clock, a validator having a second slave clock, and a first communication bus. The first ECU uses a first communication standard having a deterministic scheme. The method includes synchronizing, at the first ECU, a time of the first slave clock to a global time of the master clock, synchronizing, at the validator, a time of the second slave clock to the global time of the master clock, predicting, at the validator, a timestamp to be received in an actual communication cycle from the first ECU based on the deterministic scheme of the communication standard used by the first ECU, and comparing, at the validator, the predicted timestamp with the actually received timestamp from the first ECU.

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 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 method and apparatus for controlling delay over a data path in a device for transporting Ethernet packets over an optical transport network. The device is configured to receive an incoming clock signal having a first frequency and an incoming data signal and to output an outgoing clock signal having a second frequency and an outgoing data signal. One or more delays over the data path in the device are measured in a predetermined measurement period. A phase adjustment amount is determined based on the one or more measured delays over the data path in the predetermined measurement period, and based on the determining phase adjustment amount, a phase of the outgoing clock signal is adjusted by a phase locked loop in such a way that the delay over the data path in the device is substantially equal to a fixed delay value.

A network of nodes communicating with a central node using a Time Division Multiple Access (TDMA) communications network is disclosed. Each node can synchronize an internal clock with an internal clock of the central node when entering the TDMA communications network using a packet received from the central node. Furthermore, each node can maintain synchronization using subsequent packets communicated in the TDMA communications network and a time slot assigned for the subsequent packet.

An apparatus and a method for converting an upstream radio frequency (RF) signal to a digital signal and transmitting the digital signal via an Internet protocol (IP) packet based on an optical network in a cable broadcasting network is provided. The apparatus for transmitting an upstream RF signal includes a detector configured to detect an upstream RF signal, and a transmitter configured to digitize the detected upstream RF signal and transmit the digitized RF signal to a headend via an IP packet.

A transport network (20) is connected to a first wireless base station (3, 4) and to a second wireless base station (6). The first wireless base station comprises a remote radio unit (3) and a baseband processing unit (4) which are connected by the transport network (20). A node (16) of the transport network (20) receives a synchronous time division multiplexed communication signal which carries at least a first communication signal between the baseband processing unit (4) and the remote radio unit (3). The node (16) determines a frequency synchronisation signal from the synchronous time division multiplexed communication signal. The node (16) transmits the synchronous time division multiplexed communication signal to the remote radio unit (3) of the first wireless base station. The node (16) transmits the frequency synchronisation signal to the second wireless base station (6). The node (16) also assists with providing phase/time synchronisation to the second wireless base station (6).