Telefonaktiebolaget Lm Ericsson (publ)

Yao Peng

Ming Wang

Guoliang Gao

Jianhui Wu

Daiying Liu

The present disclosure provides a method and time synchronization node for enabling extended holdover time. The method comprises: detecting whether the TS node loses time synchronization with its master TS node or not; and transmitting a first announce message comprising a first indicator to one or more slave TS nodes in response to detecting that the TS node loses the time synchronization with its master TS node, wherein the first indicator indicates a holdover time budget for enabling extended holdover time at the one or more slave TS nodes.

Method and time synchronization (TS) node for enabling extended holdover time

The present disclosure relates to a clock distribution method and apparatus in a network. The method performed at a first clock distribution apparatus comprises: determining (S) whether the first clock distribution apparatus is in a lock state; and transmitting (S), to a second clock distribution apparatus, a first announce message when the clock distribution apparatus is not in the lock state; wherein the first announce message is generated based on a default configuration about a local clock state of the first clock distribution apparatus. According to embodiments of the present disclosure, the clock distribution apparatus may generate first announce messages based on a local clock state of the clock distribution apparatus. Thus, a downstream apparatus which receives the first announce messages may avoid selecting an unstable/unlocked clock distribution apparatus as the best master, based on the local clock state of the clock distribution apparatus.

Clock distribution method and apparatus in network

The present disclosure relates to a clock distribution method and apparatus in a network. A method performed at a clock distribution apparatus comprises: receiving a first clock signal; receiving a second clock signal; calculating an offset difference between the first clock signal and the second clock signal; compensating the second clock signal, based on the offset difference; and outputting a clock signal, based on the compensated second clock signal. The offset difference between the first clock signal and the second clock signal is calculated and used to compensate the second clock signal. The switching of the clock signal will be smoother for the downstream.

A method for switching clock sources is provided. In the method, Precision Time Protocol, PTP, packets are monitored using each of PTP ports which connect to a new grandmaster (). A frequency and a phase for the PTP port are calculated based on the PTP packets (). In response to a successful check for the frequency and the phase, the PTP port is added to a candidate list (). A phase calibration and a phase stability check may be introduced prior to the alternate BMCA.

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Beijing, China

Yao Peng