WO2010000190A1

WO2010000190A1 - Calculating method, system and optical network apparatus for synchronous time of passitive optical network

Info

Publication number: WO2010000190A1
Application number: PCT/CN2009/072492
Authority: WO
Inventors: 李昆; 邹世敏; 周建林
Original assignee: 华为技术有限公司
Priority date: 2008-06-30
Filing date: 2009-06-26
Publication date: 2010-01-07
Also published as: CN101621713B; CN101621713A

Abstract

A calculating method for synchronous time of passive optical network is provided, which includes the following steps: receiving synchronization time source data, optical line terminal OLT-dealing invariable delay data, optical network unit ONU-dealing invariable delay data,and message of delay due to the distance between optical line terminal OLT and optical network unit ONU (S201); obtaining the optical fiber transmission delay data according to the message of delay due to distance between optical line terminal OLT and optical network unit ONU (S202); obtaining synchronous time data according to the synchronization time source data, the optical line terminal OLT-dealing invariable delay data, the optical network unit ONU-dealing invariable delay data and the optical fiber transmitting delay data(S203); sending the synchronous time data(S204). An optical network apparatus and a time synchronization system for passive optical network are also provided in the embodiments of the application. Application of the present invention can synchronize the input time of OLT and output time of ONU in the system, deduce cost and improve reliability.

Description

Description Method, system and optical network device for calculating synchronization time of passive optical network

[I] This application is required to be submitted to the Chinese Patent Office on June 30, 2008, application number 200810068191.X, and the invention titled "Calculation Method, System and Optical Network Equipment for Passive Optical Network Synchronization" Priority is hereby incorporated by reference in its entirety.

[2] Technical field

[3] The embodiments of the present invention relate to the field of optical communications, and in particular, to a method for inter-day synchronization of a passive optical network, an optical network device, and a system for time synchronization of a passive optical network.

[4] Background of the invention

[5] PON (Passive Optical

Network, Passive Optical Network) As a broadband optical access technology, it is characterized by a point-to-multipoint physical topology, by OLT (Optical Line Terminal), ODN (Optical)

Distribution

Network, passive optical distribution network), multiple ONUs (optical network units); multiple ONUs share optical resources and OLT ports; optical branch points in ODN do not require active node devices, only passive optical branches Therefore, the PON has the advantages of sharing bandwidth resources, saving investment in the equipment room, high equipment security, fast network construction, low comprehensive network construction cost, and low operation and maintenance costs. A variety of PON technologies are available, such as EPO N, GPON, and the like.

[6] At present, the important way to transmit synchronization is to use the IEEE1588 protocol. The IEEE1588 protocol is suitable for working in a packet transmission network. The PON network implements transmission synchronization by carrying IEEE1588 frames. The specific implementation is as follows:

[7] The synchronization process is divided into two phases: the offset measurement phase and the delay measurement phase.

[8] As shown in Figure 1A, the first phase is the offset measurement phase: The primary clock broadcasts two messages to all nodes on the network:

[9] 1. Sync message: The time when the message is expected to be sent;

[10] 2. Follow up message: The time when the message was actually sent.

[II] Synchronous messages are automatically sent at a given inter-turn interval. Follow-up message is used to calculate the send message 吋 local association The transmission delay caused by the discussion. The main clock periodically sends out a certain synchronization message (for example, every two seconds), which contains a time stamp (time)

Stamp) , which accurately describes the expected time of the packet. Assume that the time between the main clocks before synchronization is Tm=l 28s, and the time from the time of the cesium clock is Ts=l l ls. The main clock measures the exact time Tml sent, and the accurate time Tsl received is measured from the cesium clock. Since the synchronization message contains the expected issue time instead of the actual issue time, the master clock then sends a follow-up message, which adds a time stamp to accurately record the true timeout of the sync message. In this way, from the real time of the cuckoo clock using the follow-up message and the real reception time of the receiver, the offset between the cuckoo clock and the main cuckoo clock can be calculated:

[12] Offset = Tsl -Tml -Delay =111.75 - 128.5 -0 = 16.75s

[13] The Delay in the above equation refers to the propagation delay between the main clock and the slave clock, which will be measured during the measurement phase below, so it is unknown here, tentatively 0.

[14] The offset measurement phase can obtain an Adjust Time, which will be corrected from the 吋 clock to:

[15] Adjust Time = Ts - Offset

[16] The transmission delay is 0吋, and the inter-turn correction value from the 吋 clock is called Stave adjusts.

[17] The second phase is the delayed measurement phase, as shown in Figure 1B.

[18] Delayed measurement (delay

The measurement phase is used to measure the delay caused by network transmissions. It is achieved by the main message and the following message from the 吋 clock:

[19] 1. From Cuckoo Clock: Send Delay Request Message (DELAY REQUEST

Message), explain to the main clock "I am here to send delayed request information".

[20] 2. Main clock: Send delayed response message (Delay Response

Message), telling from the bell "I am here to receive your delayed request information".

[21] Delayed request message from Ts3 engraved 130.75s after receiving the synchronization message from the Cuckoo Clock Delay_

REQUEST, after receiving the Delay_REQUEST, the main clock sends a delay response message (Delay_Response), marking the accurate reception time Tm3---131.25s, and sending it to the slave clock. Therefore, the network delay can be calculated very accurately from the cesium clock:

[22] Delay = (Tm3-Ts3)/2=( 131.25 -130.75)72 = 0.25 [23] After obtaining the above offset value and Delay value, synchronization is achieved by adjusting the master and slave devices.

[24] In carrying out the invention, the inventors of the present invention found that the above technical solutions have the following main problems:

[25] The network delay and offset between the master and slave devices are symmetrical, and once the above-mentioned delay fluctuations will degrade performance, it may not even work properly.

[26] IEEE1588 requires the transmission delay of IEEE1588 frame to be fixed because of the characteristics of the protocol itself, otherwise it will reduce its performance index. However, because the implementation of PON transmission Ethernet frame determines the transmission of IEEE1588 frame between ONU and OLT.吋 can not be delayed, making the IEEE1588 protocol not suitable for PO

N network bearer.

[27] Summary of the invention

[28] The embodiment of the invention provides a method for calculating the synchronization time of the passive optical network, so as to achieve synchronization between the OLT input time and the ONU output time in the system.

[29] An embodiment of the present invention provides a method for calculating a synchronization time of a passive optical network, which includes the following steps.

[30] receiving synchronous inter-turn source data, optical line terminal OLT processing fixed delay data, optical network unit ONU processing fixed delay data, and optical line terminal OLT to optical network unit ONU distance delay information; according to the optical line The distance between the terminal OLT and the optical network unit ONU is delayed, and the fiber transmission delay data is obtained;

[31] obtaining synchronous synchronization data according to the synchronous inter-channel source data, the optical line terminal OLT processing fixed delay data, the optical network unit ONU processing fixed delay data, and the optical fiber transmission delay data; [32] Send the synchronized daytime data.

On the other hand, an embodiment of the present invention further provides an optical network device, including a receiving module, a day synchronization processing module, and a sending module:

[34] receiving module, configured to receive synchronous inter-turn source data, optical line terminal OLT processing fixed delay data, optical network unit ONU processing fixed delay data, and optical line terminal OLT to optical network unit ONU distance delay information; And sending the above information to the inter-time synchronization processing module;

[35] The inter-time synchronization processing module is configured to obtain the optical fiber transmission delay data according to the distance delay information of the received optical line terminal OLT to the optical network unit ONU; according to the synchronous inter-turn source data, the optical line The terminal OLT processes the fixed delay data, the optical network unit ONU processes the fixed delay data, and the optical fiber transmission delay data, and obtains synchronization time data, and sends the data to the sending module;

[36] The sending module is configured to send the received synchronization data.

On the other hand, an embodiment of the present invention further provides a network system, including an optical line terminal OLT, at least one optical network device, and at least one optical network unit ONU:

[38] the optical line terminal OLT is configured to receive the synchronous inter-turn source data, and obtain the fixed delay data of the optical line terminal OLT, and obtain the distance delay information of the optical line terminal OLT to each optical network unit ONU; The synchronous inter-turn source data, the optical line terminal OLT processes the fixed delay data, and the distance delay information is sent to the optical network device; the optical line terminal OLT processes the fixed delay data as: In the terminal OLT, the signal is processed from the synchronous inter-turn input port to the PON port output of the passive optical network;

[39] The optical network unit ONU is configured to send the optical network unit ONU to process the fixed delay data to the optical network device; and the optical network unit ONU processes the fixed delay data, specifically: in the optical network unit In the NU, the signal is extended from the PON input port of the passive optical network to the processing interval between the synchronous inter-turn output ports;

[40] the optical network device, configured to obtain, according to the distance delay information, fiber transmission delay data; according to the received synchronization inter-source data, the optical line terminal OLT processes fixed delay data, and light The network unit ONU processes the fixed delay data and the obtained fiber transmission delay data to obtain synchronous daytime data

[41] The optical network unit ONU is further configured to send the synchronization time data calculated by the optical network device.

[42] In another aspect, an embodiment of the present invention further provides an optical line terminal OLT, including

[43] a receiving module, configured to receive synchronous inter-turn source data;

[44] The ranging delay module is configured to obtain the fiber transmission delay data according to the distance delay information of the optical line terminal OLT to the optical network unit ONU;

[45] a fixed delay module for obtaining an optical line terminal OLT for processing fixed delay data, the optical line terminal

The OLT processes the fixed delay data specifically in the optical line terminal OLT, where the signal is processed between the synchronous inter-turn input port and the output of the PON port of the passive optical network;

[46] a sending module, configured to send the synchronous inter-turn source data, the optical fiber transmission delay data, and the optical line terminal OLT to process fixed delay data. [47] In another aspect, an embodiment of the present invention further provides an optical network unit ONU, including

[48] a receiving module, configured to receive synchronous inter-turn source data externally sent to the optical network unit 0NU, optical fiber transmission delay data, and an optical line terminal OLT to process fixed delay data;

[49] a fixed delay module for obtaining an optical network unit, the ONU processing fixed delay data, the optical network unit

The ONU processes the fixed delay data specifically in the ONU of the optical network unit, and the processing delay between the signal from the passive optical network PON input port to the synchronous inter-turn output port;

[50] a synchronization inter-turn calculation module, configured to receive data according to the receiving module and the optical network unit

The NU processes the fixed delay data to obtain synchronized data.

[51] A sending module, configured to send the synchronous data.

[52] In another aspect, an embodiment of the present invention further provides a network device, including an optical line terminal OLT and at least one optical network unit ONU:

[53] The optical line terminal OLT is configured to receive the synchronous inter-turn source data; obtain the optical fiber transmission delay data according to the distance delay information of the optical line terminal OLT to the optical network unit ONU; and obtain the optical line terminal OLT processing fixed delay吋 data, the optical line terminal OLT processing the fixed delay data is specifically in the optical line terminal 0 LT, the signal is processed from the synchronous inter-turn input port to the passive optical network PON port output between the processing delays; Synchronizing the inter-turn source data, the optical fiber transmission delay data, and the optical line terminal OLT processing the fixed delay data;

[54] The optical network unit ONU is configured to obtain the fixed delay data of the optical network unit ONU, and the optical network unit ONU processes the fixed delay data, specifically in the optical network unit ONU, and the signal is input from the passive optical network PO N Processing delay between the port and the synchronous output port; processing the fixed delay data according to the received synchronous inter-turn source data, the optical fiber transmission delay data, the optical line terminal OLT, and the The optical network unit ONU processes the fixed delay data to obtain synchronous daytime data.

[55] The technical solution of the embodiment of the present invention, because the transmission delay between the OLT and each ONU is compensated, and the internal processing delay of the OLT and the ONU is compensated, thereby achieving the OLT input time between the system and the OLT. 0 NU output synchronization between the turns, and a low cost and high reliability solution.

[56] BRIEF DESCRIPTION OF THE DRAWINGS

[57] FIG. 1A is a schematic diagram of a first stage principle of the IEEE 1588 protocol in the prior art;

FIG. 1B is a schematic diagram of a second stage principle of the IEEE 1588 protocol in the prior art; FIG. 2 is a schematic flowchart of a method for calculating a synchronization time between passive optical networks according to an embodiment of the present invention;

FIG. 3 is a schematic flowchart of a method for calculating a synchronization time between passive optical networks according to Embodiment 1 of the present invention; FIG.

4 is a schematic structural diagram of a day-to-day synchronization of a passive optical network according to Embodiment 1 of the present invention;

FIG. 5 is a schematic structural diagram of an optical network device according to Embodiment 2 of the present invention; FIG.

6 is a schematic structural diagram of a system for time synchronization of a passive optical network according to a third embodiment of the present invention;

7 is a schematic structural diagram of an OLT according to Embodiment 4 of the present invention;

8 is a schematic diagram of a 0NU structure according to Embodiment 5 of the present invention.

[66] Mode for carrying out the invention

[67] The specific method flow of the embodiment of the present invention is as shown in FIG. 2, and includes the following steps:

[68] Step S201: receiving synchronous inter-turn source data T0, OLT processing fixed delay data Tl, ONU processing fixed delay data Τ3, and 0LT to 0NU distance delay information;

Step S202: Obtaining the fiber transmission delay data according to the distance delay information from 0LT to 0NU.

[70] Step S203: processing the fixed delay data T1 according to the synchronous inter-turn source data Τ0, the OLT,

0NU processes the fixed delay data Τ3 and the optical fiber transmits the delay data Τ2, and obtains the synchronization time data Τ4;

[71] Step S204: Send the synchronization time data Τ4.

[72] There is no specific sequence between the foregoing steps S201 and S202. For example, the distance delay information from the OLT to the ONU may be received first, and then the information is extended according to the distance between the OLT and the ONU to obtain the fiber transmission delay. Data Τ 2, and then receive other data (such as TO or T1 or Τ 3).

[73] In order to more clearly describe the embodiments of the present invention, the specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings and embodiments.

[74] Embodiment 1

As shown in FIG. 3, and in conjunction with FIG. 4, it is a schematic flowchart of a method for calculating a synchronization time of a passive optical network according to Embodiment 1 of the present invention, which includes the following steps:

[76] Step S301: The OLT obtains the synchronous inter-turn source data T0, and the OLT processes the fixed delay data Tl,

The distance from the OLT to the ONU is delayed and sent to the inter-day synchronization device.

[77] The OLT selects one of the two synchronous inter-turn sources (here as an example and not a limitation, in the actual processing, one of the multi-channel synchronous inter-sources can be selected), and the synchronization time is extracted. Information and corresponding The format conversion is obtained, and the synchronous inter-time source data T0 is obtained. Synchronous daytime source data TO can be from GPS (Global Positioning System, Global Positioning System) or GLONASS (Global Navigation Satellite System) or Beidou Satellite or NTP (Network Time)

Protocol, Network Inter-Protocol Protocol) or IEEE1588 interface or inter-time synchronization network. The OLT determines the synchronization delay information from the synchronous inter-turn input port to the PON port output according to its own design scheme to process the fixed delay data Tl for the OLT. When the OLT design is determined, the T1 value is a determined value. The OLT obtains the distance delay information of the OLT to the ONU according to the ranging unit of the OLT. The distance delay information may be the delay time of the test signal from the OLT to the ONU, or may be the distance information of the OLT to the ONU. Then, 0 LT processes the fixed inter-turn source data T0 and the OLT to process the fixed delay data T1 and

The distance delay information from the OLT to the ONU is sent to the inter-day synchronization device.

[78] Step S302: The ONU receives the ONU processing fixed delay data T3 and sends it to the inter-time synchronization device.

[79] Based on its own design scheme, the ONU determines the processing delay between the synchronous inter-turn information from the ΡΟΝ input port to the synchronous inter-turn output port for the ONU to process the fixed delay data Τ3. When the ONU design is determined, the T3 value is the determined value. And send T3 to the day synchronization device.

[80] Step S303: The inter-time synchronization device obtains the fiber transmission delay data T2 according to the received delay information of the OLT to the ONU.

[81] In the art, the distance information and the transmission delay value have a certain correspondence relationship,

The transmission delay of lkm fiber is about 5 nanoseconds.

[82] There is no specific order between the above steps.

[83] Step S304: The inter-time synchronization device obtains the synchronization time data Τ4 according to the received T0, Tl, Τ3, and the calculated Τ2, and sends the data to the ONU.

In the present embodiment, T4 = T0 + T1 + T2 + T3.

[85] Step S305: The ONU will synchronize the daytime data Τ4 output.

[86] The ONU will synchronize the daytime data T4 output to synchronize the output of the ONU with the input of the OLT.

[87] It should be noted that the inter-time synchronization device may be an actual device or a virtual device, and the device may be included in an OLT or an ONU, or part of the functions of the device are performed by the OLT, and another part of the function is performed by The ONU is executed, as long as the sum of the two functions can implement the technical solution of the first embodiment. For example, step S303 is completed by the OLT, and step S304 is completed by the ONU. [88] All or part of the steps of implementing the foregoing method embodiments may be completed by using hardware related to the program instructions. The foregoing program may be stored in a computer readable storage medium, and after the program is executed, the method includes the above method embodiment. The foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

[89] The second embodiment of the present invention provides an optical network device, which has the structure shown in FIG. 5, and includes a receiving module, a synchronization processing module, and a sending module:

[90] The receiving module is configured to receive the synchronous inter-turn 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 optical line terminal OLT to the optical network unit ONU吋 information; and send the above information to the inter-time synchronization processing module;

[91] The inter-time synchronization processing module is configured to obtain the fiber transmission delay data T2 according to the distance delay information of the received optical line terminal OLT to the optical network unit ONU; according to the synchronous inter-turn source data T0, The optical line terminal OLT processes the fixed delay data T1, the optical network unit ONU processes the fixed delay data Τ3, and the optical fiber transmission delay data T2, and obtains the synchronization time data Τ4, and sends the data to the sending module;

[92] Send module, used to send the received synchronization data.

[93] wherein, the optical line terminal OLT processes the fixed delay data T1, specifically:

[94] In the optical line termination OLT, the signal is processed between the synchronous inter-turn input port and the passive optical network port output.

[95] The optical network unit ONU processes the fixed delay data Τ3 specifically:

[96] In the optical network unit ONU, the signal is delayed from the passive optical network ΡΟΝ input port to the synchronous inter-turn output port.

A third embodiment of the present invention provides a system for synchronizing a passive optical network, which has a structure as shown in FIG. 6, and includes an optical line terminal OLT, at least one optical network device, and at least one optical network unit ONU:

[98] The optical line terminal OLT is configured to receive the synchronous inter-turn source data T0, obtain the fixed delay data T1 of the optical line terminal OLT, and obtain the distance delay information of the optical line terminal OLT to each optical network unit ONU. Transmitting the synchronous inter-turn source data T0, the optical line terminal OLT processing fixed delay data T1, and the distance delay information to the optical network device; the optical line terminal OLT processing the fixed delay data T1 For: in the optical line terminal OLT, the signal is processed between the synchronous inter-turn input port and the passive optical network port output; [99] The optical network unit ONU is configured to send the optical network unit ONU to process the fixed delay data T3 to the optical network device; and the optical network unit ONU processes the fixed delay data Τ3 specifically: in the optical network unit ONU The delay between the processing of the signal from the passive optical network input port to the synchronous inter-turn output port

[100] an optical network device, configured to obtain, according to the distance delay information, fiber transmission delay data Τ2; according to the received synchronization inter-source data Τ0, the optical line terminal OLT processes the fixed delay data Tl, The optical network unit ONU processes the fixed delay data Τ3 and the obtained optical fiber transmission delay data Τ2 to obtain synchronous inter-day data Τ4;

[101] The optical network unit ONU is further configured to send the synchronization inter-day data 计算4 calculated by the optical network device.

The optical network unit ONU is configured to send the optical network unit ONU to process the fixed delay data T3 to the optical network unit; and receive the synchronous inter-day data T4.

[102] The specific signal processing, the execution process, and the like between the above-mentioned system modules are based on the same concept as the method embodiment of the present invention, and can be referred to in the first embodiment of the present invention, and will not be described here.

The optical network terminal OLT of the fourth embodiment of the present invention has a structure as shown in FIG. 7 and includes:

[104] receiving module, configured to receive synchronous inter-turn source data TO;

[105] a ranging delay module, configured to obtain a fiber transmission delay data T2 according to the distance delay information of the optical line terminal OLT to the optical network unit ONU;

[106] a fixed delay module, configured to obtain an optical line terminal OLT processing fixed delay data T1, and the optical line terminal OLT processing fixed delay data T1, specifically in the optical line terminal OLT, the signal from the synchronous inter-turn input port Processing delay between the output of the passive optical network;

[107] The sending module is configured to send the synchronous inter-turn source data Τ0, the optical fiber transmission delay data T2, and the optical line terminal OLT process the fixed delay data T1.

[008] Embodiment 5 of the present invention provides an optical network unit ONU, which has the structure shown in FIG. 8, and includes:

[109] a receiving module, configured to receive synchronous inter-turn source data externally sent to the optical network unit ONU, optical fiber transmission delay data, and an optical line terminal OLT to process fixed delay data;

[110] The fixed delay module is used to obtain the optical network unit. The ONU processes the fixed delay data T3, and the optical network unit ONU processes the fixed delay data. Τ3 is specifically in the optical network unit ONU, and the signal is from the passive optical network.

处理 The processing delay between the input port and the synchronous inter-turn output port; [111] a synchronization inter-turn calculation module, configured to receive data according to the receiving module and the optical network unit

NU processes the fixed delay data T3, and obtains the synchronization time data Τ4;

[112] A sending module, configured to send the synchronous data Τ4.

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

[114] The optical line terminal OLT is configured to receive the synchronous inter-turn source data TO; obtain the optical fiber transmission delay data T2 according to the distance delay information of the optical line terminal OLT to the optical network unit ONU; and obtain the optical line terminal OL T Processing the fixed delay data T1, the optical line terminal OLT processing the fixed delay data T1, specifically in the optical line terminal OLT, the signal is processed from the synchronous inter-turn input port to the passive optical network PON port output between the processing delays Transmitting the synchronous inter-turn source data T0, the optical fiber transmission delay data Τ2, and the optical line terminal OLT processing the fixed delay data T1;

[115] The optical network unit ONU is configured to obtain an optical network unit ONU to process the fixed delay data Τ3, and the optical network unit ONU processes the fixed delay data Τ3, specifically in the optical network unit ONU, the signal is from the passive optical network. Processing delay between the input port and the synchronous inter-turn output port; processing the fixed delay data according to the received synchronous inter-turn source data Τ0, the optical fiber transmission delay data Τ2, and the optical line terminal OLT T1 and the optical network unit ONU process the fixed delay data T3 to obtain the synchronization data Τ4.

[116] The specific signal processing, the execution process, and the like between the above-mentioned system modules are the same as the embodiment of the method of the present invention. For the description of the first embodiment of the present invention, reference is made to the description in the first embodiment of the present invention.

[117] The technical solution of the embodiment of the present invention has the following advantages, because the transmission delay between the OLT and each ONU is compensated, and the internal processing delay of the OLT and the ONU is compensated to achieve the OL 系统 in the system. The input is synchronized with the ONU output, and a low cost and high reliability solution is obtained.

The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present invention. And retouching should also be considered in the scope of protection of the present invention.

Claims

Claim

[1] A method for calculating a synchronization time between passive optical networks, characterized in that the method comprises:

Receiving the synchronous inter-turn source data, the optical line terminal OLT processing the fixed delay data, the optical network unit ON U processing the fixed delay data, and the distance delay information of the optical line terminal OLT to the optical network unit ONU;

Obtaining the fiber transmission delay data according to the distance delay information of the optical line terminal OLT to the optical network unit ONU;

And synchronizing the inter-turn source data, the optical line terminal OLT processing the fixed delay data, the optical network unit ONU processing the fixed delay data, and the optical fiber transmission delay data to obtain the synchronization data;

Sending the synchronization data.

[2] The method for calculating the synchronization time of the passive optical network according to claim 1, wherein the processing of the fixed delay data by the optical line terminal OLT is specifically:

In the optical line terminal OLT, the signal is processed between the synchronous inter-turn input port and the passive optical network PON port output;

The optical network unit ONU processes the fixed delay data as follows:

In the optical network unit ONU, the signal is delayed from the PON input port of the passive optical network to the processing output between the synchronous inter-turn outputs.

[3] A method for calculating a synchronization time of a passive optical network according to claim 1 or 2, wherein said synchronous inter-turn source data is available from Global Positioning System GPS or Global Navigation Satellite System GLONA SS or Beidou Obtained by satellite or network inter-day protocol NTP or IEEE1588 interface or inter-time synchronization network.

[4] An optical network device, comprising: a receiving module, a day synchronization processing module, and a transmitting module:

a receiving module, configured to receive synchronous inter-turn source data, optical line terminal OLT processing fixed delay data, optical network unit ONU processing fixed delay data, and optical line terminal OLT to optical network unit ON U distance delay information; The information is sent to the inter-time synchronization processing module; the inter-time synchronization processing module is configured to obtain the fiber transmission delay data according to the received distance delay information of the optical line terminal OLT to the optical network unit ONU; Source data The optical line terminal OLT processes the fixed delay data, the optical network unit ONU processes the fixed delay data and the optical fiber transmission delay data, obtains synchronization time data, and sends the data to the sending module; and the sending module is used to send the station Synchronized data received.

[5] The optical network device according to claim 4, wherein the optical line terminal OLT processes the fixed delay data as follows:

The optical network unit ONU processes the fixed delay data as follows:

[6] A network system, comprising: an optical line terminal OLT, at least one optical network device, and at least one optical network unit ONU:

The optical line terminal OLT is configured to receive the synchronization data of the inter-turn time, obtain the fixed delay data of the optical line terminal OLT, and obtain the distance delay information of the optical line terminal OLT to each optical network unit ONU; The inter-source data, the optical line terminal OLT processing the fixed delay data, and the distance delay information are sent to the optical network device; the optical line terminal OLT processing the fixed delay data is specifically: in the optical line terminal OLT , the signal is processed from the synchronous inter-turn input port to the PON port output of the passive optical network;

The optical network unit ONU is configured to send the optical network unit ONU to process the fixed delay data to the optical network device; and the optical network unit ONU processes the fixed delay data, specifically: in the optical network unit ONU, the signal The processing delay between the PON input port of the passive optical network and the synchronous inter-turn output port;

The optical network device is configured to obtain, according to the distance delay information, fiber transmission delay data; according to the received synchronization inter-source data, the optical line terminal OLT processes fixed delay data, and the optical network unit ONU Processing the fixed delay data and the obtained fiber transmission delay data to obtain synchronous daytime data;

The optical network unit ONU is further configured to send the synchronization data obtained by the optical network device.

[7] An optical line terminal OLT, comprising: a receiving module, configured to receive synchronous inter-turn source data;

a ranging delay module, configured to obtain the fiber transmission delay data according to the distance delay information of the optical line terminal OLT to the optical network unit ONU;

a fixed delay module for obtaining fixed delay data by the optical line terminal OLT, wherein the optical line terminal OLT processes the fixed delay data, specifically in the optical line terminal OLT, the signal from the synchronous inter-turn input port to the passive optical network Processing delay between PON port outputs;

And a sending module, configured to send the synchronous inter-turn source data, the optical fiber transmission delay data, and the optical line terminal OLT to process the fixed delay data.

[8] An optical network unit ONU, comprising:

a receiving module, configured to receive synchronous inter-turn source data, optical fiber transmission delay data, and optical line terminal OLT processing fixed delay data sent by the optical network unit ONU; and a fixed delay module for obtaining an optical network unit ONU Processing the fixed delay data, wherein the optical network unit ONU processes the fixed delay data, specifically in the optical network unit ONU, the signal delays from the passive optical network PON input port to the synchronous inter-turn output port;

a synchronization inter-time calculation module, configured to process the fixed delay data according to the data received by the receiving module and the optical network unit ONU to obtain synchronous inter-day data;

a sending module, configured to send the synchronous data.

[9] A network system, comprising: an optical line terminal OLT and at least one optical network unit

ONU:

The optical line terminal OLT is configured to receive the synchronous inter-turn source data; obtain the optical fiber transmission delay data according to the distance delay information of the optical line terminal OLT to the optical network unit ONU; and obtain the optical line terminal OLT to process the fixed delay data, The optical line terminal OLT processes the fixed delay data, specifically, in the optical line terminal OLT, between the synchronous inter-turn input port and the passive optical network PON port output processing delay; sending the synchronous inter-turn source Data, the fiber transmission delay data, and the optical line terminal OLT processing fixed delay data;

The optical network unit ONU is configured to obtain the fixed delay data of the optical network unit ONU, and the optical network unit ONU processes the fixed delay data, specifically in the optical network unit ONU, and the signal is from the passive optical network PON input port to the synchronization port. The processing between the output ports is delayed; according to the received Synchronizing the inter-turn source data, the optical fiber transmission delay data, the optical line terminal OLT processing the fixed delay data, and the optical network unit ONU processing the fixed delay data to obtain the synchronization inter-day data