Abstract: A clock determining method includes: when both a second network device and a first network device are synchronous with a reference clock, simulating, by using delay information between the second network device and the first network device and clock frequency information of the second network device, a second virtual clock synchronized with a first virtual clock, where the first virtual clock is used to simulate a clock of the first network device. A clock of the second network device can thus be simulated to perform a subsequent operation by using the simulated clock. For example, the simulated clock may be used to estimate precision time protocol (PTP) message synchronization performance of the second network device. Therefore, the PTP message synchronization performance of the second network device may be pre-determined before a global navigation satellite system (GNSS) fails, to guide network operation and maintenance activities.

Abstract: 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.

Abstract: A clock oscillator includes a first resonator, a second resonator, and a frequency synthesis module, where an output frequency of the first resonator is higher than an output frequency of the second resonator, the frequency synthesis module is configured to generate a synthesis frequency based on the output frequency of the first resonator and the output frequency of the second resonator, and the synthesis frequency is used as a clock frequency output by the clock oscillator. The clock oscillator uses both of the two resonators with the different output frequencies as clock signal sources, and generates a synthesized clock signal by using the frequency synthesis module.

Abstract: A search request sent by a user is received to obtain one or more query words included in the search request. Historical operating information relating to a data object in a search result corresponding to the query words is conducted statistics. An attribute of the data object is selected as a specified attribute to generate a probability distribution model of the attribute value on the specified attribute of the data object. A respective probability corresponding to the attribute value of each data object on the specific attribute in the research result corresponding to the search request sent by the current user is calculated by using the probability distribution model. The output rank of the data objects in the search result is adjusted by using the probability. The present techniques improve reasonability of displaying the data objects in the search result and provide more accurate result.