The disclosure provides methods, apparatus and computer-readable media for synchronization over an optical network. A method comprises: receiving, from a client, a request to initiate a synchronization service for a client node coupled to the optical communication network; and, in response to the request, establishing a synchronization service to the client node via a virtual synchronization network utilizing the optical communication network. The synchronization service utilizes a bidirectional optical channel established via the optical communication network for the transmission of synchronization data for the client.

A network system includes a synchronous master device to output a cooperative-operation timing signal in a cooperative-operation cycle, a time master station connected to a network, and a time slave station connected to the network. The time master station includes a master clock to count a time, and a master generation unit to generate master cooperative-operation-time information on the basis of the cooperative-operation timing signal and the time counted by the master clock. The time slave station includes a slave clock to count a time, and a slave generation unit to generate slave cooperative-operation-time information on the basis of the master cooperative-operation-time information and the time counted by the slave clock.

This document discloses a solution for synchronizing two apparatuses of the same or different wireless network. A synchronization control apparatus may receive measurement reports from a first apparatus and a second apparatus, wherein at least one of the measurement reports comprises at least one information element indicating an offset between clocks of the first apparatus and the second apparatus. The synchronization control apparatus may synchronize the first apparatus and the second apparatus with each other on the basis of the measurement reports.

A communication device includes: a plurality of sensors, each of which includes at least one sensor element that detects information relating to a single detection target and an output circuit that generates an output signal based on a detection signal of the sensor element and transmits the output signal; and a controller that acquires the output signal. One of the sensors transmits the output signal to the controller at an output timing that is shifted, by a predetermined period shorter than a length of one period of the output signal, from another output timing when another one of the sensors transmits the output signal.

A first synchronization signal for synchronization with a synchronization signal source is acquired from a first signal source. A first signal synchronized with the synchronization signal source is generated based on the first synchronization signal. A second synchronization signal for synchronization with the synchronization signal source is acquired from a second signal source different from the first signal source. A second signal synchronized with the synchronization signal source is generated based on the second synchronization signal. A timing signal synchronized with the synchronization signal source is generated based on the first signal of a synchronization device. A phase difference between the timing signal and the second signal is output. An offset is set so that there is no phase difference between the timing signal and the second signal based on the phase difference.

A method for synchronizing data collected by one or more sensors of an aerial vehicle includes: generating, by a controller of the aerial vehicle, one or more time stamps each representing a clock time of the controller; sending instruction information to one or more sensors external to the aerial vehicle; receiving a plurality of data packets returned from the one or more external sensors corresponding to a number of first clock times; obtaining data collected by a built-in sensor at a number of second clock times; and analyzing, according to the data packets returned by the external sensors and the data collected by the built-in sensor, a flight state of the aerial vehicle. The instruction information carries the one or more time stamps and directs the one or more external sensors to perform data collection. Each second clock time is the same as a corresponding first clock time.

A communication system comprises a clock generator configured to generate a plurality of system clock signals used to synchronize components included in each of communication nodes in the communication system based on an external clock signal provided by an external clock source located outside the communication system and a physical layer configured to transmit any one of the generated system clock signals to a small cell communicatively connected to an end communication node of the communication system.

A multi-node, quantum communication network for providing quantum-secure time transfer with Damon attack detection is described. The network includes three or more nodes connected via authenticated communication channels forming a closed loop. By determining differences between the local times at as well as the time durations required for photons to travel between the three or more nodes, the network detects a Damon attack, if present. For example, the network imposes a closed loop condition to detect the Damon attack. The network can also use the local time differences and time durations for photon travel between nodes to synchronize the local clocks at the three or more nodes of the network.

In some examples, a controller includes an interface to receive presence indicators associated with computer nodes, and a processor to determine, based on the presence indicators, a quantity of a set of computer nodes that are present in a system, and adjust, based on the determined quantity, phases of activity control indications provided to the computer nodes of the set of computer nodes, wherein the adjusting is to vary a first phase of a first activity control indication of the activity control indications relative to a second phase of a second activity control indication of the activity control indications.

A time synchronization method and apparatus includes determining a time difference between reference time and system time of an artificial intelligence device, where the reference time is timed by an internal clock of the artificial intelligence device and is aligned based on a satellite timing signal, or the reference time is timed by an internal clock of the artificial intelligence device; and adjusting the system time based on a preset step value if the time difference is greater than a preset value.