Systems and methods for implementing a software emulation of a clock calibrated by the software based on sampling a hardware clock.

A method for processing a time synchronization packet is provided. In an embodiment a terminal device receives a time synchronization packet of a first clock source from an external device; receives first indication information from a network device, where the first indication information instructs the terminal device to enter a time synchronization activated state of the first clock source, or the first indication information instructs the terminal device to enter a time synchronization deactivated state of the first clock source; and processes the time synchronization packet of the first clock source based on the first indication information. When a clock source is activated and deactivated, the terminal device processes a time synchronization packet of the clock source in different manners, and signaling indicates whether the clock source is activated or deactivated.

The present invention provides a method for time synchronizing one or more devices in a control network using a first device. The method comprises selecting a first device from information of the topology of the control network. The method further comprises sending a first set of packets to the second device, receiving a first set of delay requests in response to the first set of packets, and sending a first set of delay responses in response to the first set of delay requests. The method further comprises, determining a first set of forward times and first set of backward times. The method further comprises, determining a first minimum forward time and a first minimum backward time. Further the method comprises determining a first correction factor. The method also comprises, applying the first correction factor to a clock provided at the second device and storing the first correction factor.

A clock calibration method and apparatus is provided, where the method includes a terminal device uses first timing information, adjusts second timing information of the terminal device based on reference timing information, and when determining that a first condition is met, switches from using the first timing information to using the second timing information. The first timing information is primary timing information, the second timing information is standby timing information, and the first condition includes that: the first timing information is different from the reference timing information, and the second timing information is the same as the reference timing information; or the first timing information is different from the second timing information; or the first timing information is different from the reference timing information.

A method for securing time synchronization in a server ECU, including: initializing time synchronization of the components; storing a unique clock identification of a grandmaster clock; identifying a shadow controller; transmitting the synchronization messages; querying the sending time with the shadow controller; inserting the time in the follow-up message via the controller that forms the grandmaster clock, and retransmitting the time; sending additional messages relating to time synchronization via selected network devices that do not provide the previously determined grandmaster clock. The time information sent in the additional messages relating to time synchronization and also the clock parameters relevant for determining the best clock by means of BMCA and the domain number match those of the previously determined grandmaster clock, or are comparable with them. The additional messages relating to time synchronization contain a unique clock identification corresponding to the identification of the respective selected network device.

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.

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.

A method for synchronizing a network device includes: receiving, by the network device, a first SSM and a second SSM, where the first SSM carries a first SSM code for indicating a quality level of a first clock source and a first eSSM code for indicating the quality level of the first clock source, and the second SSM carries a second SSM code for indicating a quality level of a second clock source and a second eSSM code for indicating the quality level of the second clock source. When a value of the first SSM code is less than a value of the second SSM code, the network device calibrates a frequency of the network device based on a timing signal of the first clock source.

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.

Systems and methods for retaining synchronization between a CMTS core and an RPD when the RPD loses synchronization to a timing grandmaster, where both the core and the RPD are configured for individual synchronization in a slave configuration to the timing grandmaster, by operating the core as a boundary clock that sends timing information to the RPD.