Techniques are disclosed relating to maintaining a first reference clock for a first local area network (LAN). The first reference clock is usable by a first set of computing devices coupled to the first LAN to participate in a shared experience with a second set of computing devices coupled to a second LAN. A computing system synchronizes, via a first time synchronization protocol, the first reference clock with a global reference clock accessible to the computing system over a wide area network (WAN). The computing system provides, via a second time synchronization protocol, a time value of the first reference clock to one of the first set of computing devices to coordinate an event in the shared experience with one of the second set of computing devices, where the second time synchronization protocol has a precision that is greater than a precision of the first time synchronization protocol.

Systems, methods, apparatuses, and computer program products for working clock determination for a mobile user equipment. A method may include receiving time domain information at a session management function during a protocol data unit (PDU) session procedure. The method may also include forwarding the time domain information to a user plane function for the PDU session procedure. The method may further include configuring the user plane function according to the time domain information to enable determination of a correct mapping between the time domain information and a user equipment or a PDU session.

A method and apparatus for synchronizing the oscillators onboard satellites of a same network, while minimizing relativistic effects. The method consists of identifying a reference signal having minimal Doppler frequency shifting; adjusting the frequency of an ovenized oscillator to the minimally shifted reference signal, and repeating the process for all satellites of a satellite train having a similar orbital path. Subsequently, the clocks on board the satellites of a same train can be set to a same time, by relaying a clock synchronization protocol between the satellites. The method includes a number of error measurement techniques allowing to further compensate for relativistic effects and make further corrections over time.

Embodiments describe monitoring network activity and behavior of authorized clocks to identify suspicious activity, and in response, removing a clock for an authorized clock list. In one embodiment, a network monitor detects changes in profiles corresponding to the authorized clocks such as a disconnecting from a port, changing a network location, unexpected changes in the clock signal, changes to the clock ID or MAC address, and the like. If the network monitor deems these changes suspicious, it removes the clock from the authorized clock list. When the current master clock fails, the PTP endpoints select a new master clock only if that clock is included in the authorized clock list. In this manner, the network monitor can constantly update the authorized clock list to ensure it contains only clocks that have not been tampered with or replaced with rogue clocks.

Systems and methods are disclosed herein for syntonizing machines in a network. A coordinator accesses probe records for probes transmitted at different times between pairs of machines in the mesh network. For different pairs of machines, the coordinator estimates the drift between the pair of machines based on the transit times of probes transmitted between the pair of machines as indicated by the probe records. For different loops of at least three machines in the mesh network, the coordinator calculates a loop drift error based on a sum of the estimated drifts between pairs of machines around the loop and adjusts the estimated absolute drifts of the machines based on the loop drift errors. Here, the absolute drift is defined relative to a drift of a reference machine.

This application discloses a time synchronization fault processing method, apparatus, and system, and belongs to the communication field. The method includes: When time of a first translator in a first network is not synchronized with a clock source in the first network, the first translator stops communicating time information with at least one other translator in the first network than the first translator, where the time information is used for obtaining time synchronized with a clock source in a second network.

Coordinated timing networks are dynamically merged into a single coordinated timing network. This merge occurs without taking down any of the servers. Each server of the merged coordinated timing network has the same coordinated timing network identifier (CTN ID), and the merged coordinated timing network has one selected primary time server. Optionally, the merged coordinated timing network may include a backup time server and an arbiter.

A method for communications is proposed. The method may comprise receiving, by a first network node, a report of clock quality of a second network node from a third network node. A clock of the first network node is selected as a master clock for synchronization in a first timing domain, a clock of the second network node is selected as a is selected as a master clock for synchronization in a second timing domain, and the third network node is attached to at least the first timing domain and the second timing domain. Based at least in part on the received report, it may be determined whether to synchronize the first timing domain to the second timing domain. In response to the determination of synchronizing the first timing domain to the second timing domain, the first network node can obtain timing information of the second network node from the third network node. The method may further comprise tuning the clock of the first network node to synchronize the first timing domain to the second timing domain, based at least in part on the timing information of the second network node.

Disclosed are methods and systems to improve the time synchronization of power distribution systems and/or other distributed device networks. The disclosure relates to nesting selection algorithms to elect a grand master clock from among groups of devices in a network.

A method corrects the time defined by an internal clock of an entity capable of receiving signals from a satellite positioning system and of communicating with at least one other entity. When the signals do not allow the satellite positioning of the entity, the method includes: receiving, by the entity, a message originating from the other entity, the message including a first piece of time data associated with the instant the message was transmitted; determining, by the entity, a second piece of time data associated with the instant the message was received by the entity; calculating a time difference between the second piece of time data and the first piece of time data; and then, when the time difference is negative, determining a time correction to be made to the internal clock of the entity.