A method and device for synchronizing time at an onu end of an xg-pon1 system

A technology of XG-PON1 and time synchronization, which is applied in the direction of time division multiplexing system, electrical components, multiplexing communication, etc. It can solve the problems that the ONU terminal cannot accurately output 1PPS and TOD signals, and the system cannot work normally.
CN105450324BActive Publication Date: 2018-01-02FENGHUO COMM SCI & TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
FENGHUO COMM SCI & TECH CO LTD
Publication Date
2018-01-02

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Abstract

The invention discloses an ONU-end time synchronization method and apparatus of an XG-PON1 system. The method comprises the following steps: determining whether downlink data frames received by an ONU are synchronous, and if not, outputting corresponding 1PPS and TOD signals through a local crystal oscillator clock; if so, extracting OMCI frames including the TOD information from the downlink data frames and obtaining SFC values of the OMCI frames through an analysis, comparing the SFC values with multiframe counting values SFC of the downlink data frames, and if they are equal, after time-delay compensation, outputting the corresponding 1PPS and TOD signals by use of frame header indication signals and corresponding time information; and if the SFC values are not equal, outputting the corresponding 1PPS and TOD signals through a line recovery clock. According to the invention, no matter whether an ONU-end clock synchronizes or not, an ONU end can accurately output accurate 1PPS and TOD signals, and the system works normally even without signal output.
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Description

Technical field

[0001] The invention relates to the field of communication passive optical networks, in particular to an ONU end time synchronization method and device of an XG-PON1 system. Background technique

[0002] XG-PON1, as an access network technology, has a higher rate and splitting ratio than GPON, smooth evolution from Gigabit Passive Optical Network (GPON) technology, and support for full-service operation capabilities, achieving low cost , Long-distance high-speed access.

[0003] The XG-PON1 access system is composed of the central office optical line terminal equipment OLT and the remote optical network unit ONU equipment. Its physical layer rate is asymmetric, that is, the downstream rate is 10Gbit / s and the upstream rate is 2.5Gbit / s. The time synchronization function is defined in the XG-PON1 protocol G.987.3 formulated by the International Telecommunications Union Telecommunications Standardization Organization ITU-T. When the XG-PON1 equipment is used in the t...

Claims

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