A synchronization method includes obtaining a first timestamp difference of a packet on a target link. The first timestamp difference is a difference between a sending timestamp and a receiving timestamp of the packet at a first moment. The synchronization method further includes performing packet selection based on the first timestamp difference to obtain a second timestamp difference; obtaining a delay prediction value of the target link at the first moment, compensating for the second timestamp difference based on the delay prediction value to obtain a compensated timestamp difference; and performing time and/or clock synchronization based on the compensated timestamp difference. The second timestamp difference is compensated for based on the delay prediction value, that is, PDV noise introduced to the target link is compensated for. In this way, the PDV noise is reduced.

A communication apparatus requests, to a network, allocation of a first network slice for executing predetermined processing required when executing a communication service executed by the communication apparatus and allocation of a second network slice for the communication service, supplies a result of the predetermined processing executed in the first network slice for communication in the second network slice, and performs communication by using the result of the predetermined processing in the second network slice.

A system includes a plurality of line cards and a timing card. A clock generation circuit on the timing card generates a clock signal which is pulse width modulated according to information to be transmitted. A clock line supplies the pulse width modulated clock signal to the line cards. The timing card sends a first control word to the plurality of line cards over the clock line after sending a beacon. The first control word includes a size field specifying a first length of first data following the first control word. The timing card sends time of day information over the clock line to the line cards following the first control word. The time of day information may be encrypted. A second control word follows the time of day information. One or more additional control words can follow the second control word before the next beacon.

The Digital Time Processing using Rational Number Filters (DTP RNF) disclosed herein is contributing methods, systems and circuits for using a Precision Time Protocol (PTP) such as IEEE 1588 for distributing a master time secured by a master unit to slave units by utilizing slave clocks, synchronous to referencing frames communicated with PTP messages or compatible with them data receiver clocks, for maintaining a local slave time which is increased to a local master time by adding to it an estimate of a transmission delay derived by processing PTP messages or by other means, wherein such distribution of the master time includes filtering out phase noise of the timing referencing signals with the Rational Number Filters in order to produce accurate and stable timing implementing signals such as the slave clock, local slave time and local master time.

In one embodiment, a method receives a first time from a network device. The first time is derived from a first timing source in a first domain. The method receives a second time in a second domain from a second timing source. A difference time value is calculated between the first time and the second time. The method then sends the difference time value to the network device where the network device uses the difference time value to send a delay value to other computing devices to synchronize timing of the other computing devices in the second domain. The other computing devices are configured to synchronize the respective time using the delay value with mobile network devices to allow timing synchronization between the mobile network devices.

A method for synchronizing a timing end application (TEA) in an edge communication network includes (a) receiving, at a first access device, a time stamp from a first TEA communicatively coupled to the first access device, (b) transmitting the time stamp from the first access device to a second access device via communication media of the edge communication network, (c) adjusting the time stamp to account for transit time of the time stamp from the first access device to the second access device, and (d) after adjusting the time stamp, transmitting the time stamp from the second access device to a second TEA communicatively coupled to the second access device.

A frequency deviation change rate computation unit (204) computes a frequency deviation change rate being a change rate per unit time of a frequency deviation between a clock frequency of a synchronization reference device serving as a reference of time synchronization and a clock frequency of a time synchronization device which performs time synchronization with the synchronization reference device. A time correction amount computation unit (205) computes a first correction amount corresponding to a static frequency deviation between the clock frequency of the synchronization reference device and the clock frequency of the time synchronization device, performs time integration of the frequency deviation change rate to compute a second correction amount corresponding to temporal transition of the frequency deviation between the clock frequency of the synchronization reference device and the clock frequency of the time synchronization device, and computes a time correction amount for correcting a time of the time synchronization device with using the first correction amount and the second correction amount. A time correction unit (206) corrects the time of the time synchronization device with using the time correction amount.

A communication method implemented by a terminal device includes detecting whether a clock source declaration from a user plane network element is received within a first duration, and when the terminal device does not receive the clock source declaration from the user plane network element within the first duration, sending a clock source declaration from a remote device to the user plane network element. According to the method, when the terminal device does not receive the clock source declaration from the user plane network element within the first duration, this indicates that the user plane network element cannot receive a clock source declaration from another terminal device. Accordingly, the clock source declaration of the remote device is sent to the user plane network element.

This application discloses a clock synchronization method and a related apparatus in a distributed system. The distributed system includes a plurality of nodes, and the plurality of nodes include a master node and a plurality of slave nodes. The master node obtains a plurality of local clock offsets, where each of the plurality of local clock offsets indicates a clock offset between two nodes in the distributed system. The master node determines a global clock offset of a target slave node relative to the master node based on the plurality of local clock offsets, and sends the global clock offset to the target slave node. The target slave node obtains a clock reference value of a local clock, and then performs clock synchronization based on the clock reference value and the global clock offset.

In one embodiment, a network device, includes a network interface port configured to receive data symbols from a network node over a packet data network, at least some of the symbols being included in data packets, and controller circuitry including physical layer (PHY) circuitry, which includes receive PHY pipeline circuitry configured to process the received data symbols, and a counter configured to maintain a counter value indicative of a number of the data symbols in the receive PHY pipeline circuitry.