Synchronous correction method based on IEEE1588 clock model

Abstract

The invention discloses a synchronous correction method based on an IEEE1588 clock model, and belongs to the technical field of communication. The method comprises the following steps: (1) acquiring the moment point of the IEEE1588 clock model to obtain each timestamp; (2) acquiring the relation between the time of a server and the time of a client through the IEEE1588 clock model, and acquiring the relation among the timestamps in Sync message sending and receiving processes in combination with a PTP (Picture Transfer Protocol); (3) performing difference operation based on the relation among the timestamps; and (4) acquiring the asymmetrical offset of an nth exchange process according to a first-order difference value given in the step (3), moving an average filter through exponential weighting in order that value theta is close to zero, and finishing correction between the server and the client. According to the method, a conventional thought is jumped out, and compensation is performed once again on the basis of the IEEE1588 clock model, so that the problem of end-to-end time non-synchronization is solved, and end-to-end interaction time becomes symmetrical.

Description

technical field [0001] The invention relates to a clock synchronization correction method, which belongs to the technical field of communication. Background technique [0002] Using IEEE1588v2 and a specially designed clock recovery mechanism can provide clock synchronization accuracy up to microsecond or even submicrosecond level. And this is based on a very important assumption that the transmission delay of the data packet from the master clock to the slave clock and the transmission delay from the clock to the master clock are equal. In reality, however, the communication paths are not perfectly symmetrical, mainly due to different forward and reverse link delays and queuing delays. The difference in packet delay is mainly due to the different queuing engineering of packets of elements in the communication network, such as switches and routers. This is especially true when timing transfers are done end-to-end and there is no form of timing assistance from the network t...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to propose a synchronous correction method with a secondary calibration process based on the IEEE1588 clock model to solve the problem of time asymmetry between master and slave clocks.

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