Frequency and time synchronization method for passive optical network

A passive optical network and time synchronization technology, which is applied in the field of communication systems and can solve the problem that the precise synchronization of ONU cannot be guaranteed.
CN101431385AActive Publication Date: 2009-05-13ZTE CORP
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Patent Information

Authority / Receiving Office
CN ยท China
Current Assignee / Owner
ZTE CORP
Publication Date
2009-05-13

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Abstract

The invention discloses a method for synchronizing frequency and time of a passive optical network. The method comprises the following steps: an optical line terminal periodically transmits a protocol message with a time stamp to an optical network unit, dynamically measures range information used for maintaining the passive optical network, and acquires time deviation between the optical line terminal and the optical network unit in real time; real-time and dynamic compensation for the time deviation is carried out on the optical network unit, so that the frequency and the time of the optical network unit is synchronized to the optical line terminal. As the range information of the passive optical network is utilized, IEEE1588 protocol is combined, synchronous transfer of time and frequency between devices on the passive optical network can be realized so as to ensure that the optical network unit is accurately synchronized to the optical light terminal on frequency and time, and each optical network unit has the same frequency and time.
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Description

technical field

[0001] The invention relates to a passive optical network synchronization method in the field of communication systems, in particular to a frequency and time synchronization method in the passive optical network. Background technique

[0002] Passive Optical Network PON (Passive Optical Network) technology is a point-to-multipoint optical fiber access technology, which consists of the optical line terminal OLT (Optical Line Terminal, optical line terminal) ONU (Optical Network Unit, optical network unit) and an optical distribution network ODN (Optical Distribution Network, optical distribution network).

[0003] There are many types of passive optical networks, which can be roughly divided into wavelength division PON, power PON and hybrid PON combining these two types. Among them, power PON is divided into APON, GPON and EPON due to different link layer protocols.

[0004] Taking power PON as an example, its downlink generally adopts time division multiple...

Claims

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