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Method for calculating synchronous time of passive optical network, system and optical network equipment

A technology of passive optical network and optical network equipment, applied in the direction of time division multiplexing system, transmission system, synchronization device, etc., can solve the problems of performance degradation, failure to work normally, IEEE1588 protocol is not suitable for PON network bearing, etc. High reliability, low cost effect

Active Publication Date: 2012-05-23
HUAWEI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0021] The network delay and offset between the master and slave devices are symmetrical. Once the fluctuation of the above delay changes, the performance will be deteriorated, and even it will not work properly.
[0022] Due to the characteristics of the protocol itself, IEEE1588 requires the transmission delay of IEEE1588 frames to be fixed, otherwise its performance indicators will be reduced, but because of the implementation of PON transmission of Ethernet frames, it is determined that IEEE1588 frames cannot be transmitted between ONU and OLT. The delay is fixed, so the IEEE1588 protocol is not suitable for PON network bearer

Method used

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  • Method for calculating synchronous time of passive optical network, system and optical network equipment
  • Method for calculating synchronous time of passive optical network, system and optical network equipment
  • Method for calculating synchronous time of passive optical network, system and optical network equipment

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Embodiment 1

[0068] Such as image 3 shown, combined with Figure 4 , which is Embodiment 1 of the present invention, a schematic flowchart of a method for calculating synchronization time of a passive optical network, including the following steps:

[0069] In step S301, the OLT obtains the synchronization time source data T0, the OLT processes the fixed delay data T1, the distance delay information from the OLT to the ONU, and sends them to the time synchronization device.

[0070] The OLT selects one of the two synchronous time sources, extracts the synchronous time information and performs corresponding format conversion to obtain the synchronous time source data T0. Synchronized time source data T0 can be from GPS (Global Positioning System, Global Positioning System) or GLONASS (GLObal NAvigation Satellite System, Global Navigation Satellite System) or Beidou satellite or NTP (Network Time Protocol, Network Time Protocol) or IEEE1588 interface or time synchronization Get it online....

Embodiment 2

[0081] Embodiment 2 of the present invention, an optical network device, combined with Figure 5 As shown, including receiving module, time synchronization processing module and sending module:

[0082] The receiving module is used to receive the synchronous time source data T0, the optical line terminal OLT processes the fixed delay data T1, the optical network unit ONU processes the fixed delay data T3, and the distance delay information from the optical line terminal OLT to the optical network unit ONU; and Send the above information to the time synchronization processing module;

[0083] The time synchronization processing module is used to obtain the optical fiber transmission delay data T2 according to the received distance delay information from the optical line terminal OLT to the optical network unit ONU; according to the synchronization time source data T0, the optical line terminal OLT processes The fixed delay data T1, the optical network unit ONU processes the fi...

Embodiment 6

[0105] Embodiment 6 of the present invention, a network system, including an optical line terminal OLT and at least one optical network unit ONU:

[0106] The optical line terminal OLT is used to receive the synchronization time source data T0; according to the distance delay information from the optical line terminal OLT to the optical network unit ONU, the optical fiber transmission delay data T2 is obtained; the optical line terminal OLT processes the fixed delay data T1, the optical line terminal OLT processes the fixed delay data T1 specifically, in the optical line terminal OLT, the processing delay time between the signal from the synchronization time input port to the passive optical network PON port output; sending the synchronization time source Data T0, the optical fiber transmission delay data T2 and the optical line terminal OLT processing fixed delay data T1;

[0107] The optical network unit ONU is used to obtain the fixed delay data T3 processed by the optical ...

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Abstract

The embodiment of the invention discloses a method for calculating the synchronous time of a passive optical network, which comprises the following steps: receiving synchronous time source data, optical line terminal OLT processing fixed time delay data, optical network unit ONU processing fixed time delay data and information on distance delay from an optical line terminal OLT to an optical network unit ONU; acquiring optical fiber transmission delay data according to information on the distance delay from the optical line terminal OLT to the optical network unit ONU; acquiring synchronous time data according to the synchronous time source data, the optical line terminal OLT processing fixed time delay data, the optical network unit ONU processing fixed time delay data and the optical fiber transmission delay data; and transmitting the synchronous time data. The embodiment of the invention also discloses optical network equipment and a system for the time synchronization of passive optical network. The method realizes the synchronization of the input time of the OLT and the output time of the ONU in the system and provides a low-cost and high-reliability solution.

Description

technical field [0001] The embodiments of the present invention relate to the field of optical communication, and in particular to a time synchronization method for a passive optical network, an optical network device, and a system for time synchronization of a passive optical network. Background technique [0002] PON (Passive Optical Network, Passive Optical Network), as a broadband optical access technology, is characterized by a point-to-multipoint physical topology structure, which consists of an optical line terminal OLT, a passive optical distribution network ODN, and multiple optical network units. ONU composition; multiple ONUs share fiber resources and OLT ports; optical branch points in ODN do not require active node devices, only passive optical splitters, so PON has bandwidth resource sharing, saving equipment room investment, and equipment security High, fast network construction, low comprehensive network construction costs and low operation and maintenance co...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L7/00H04Q11/00H04J3/06
CPCH04J3/0682H04J3/1694
Inventor 李昆邹世敏周建林
Owner HUAWEI TECH CO LTD