KR20230167565A - Distance extension method and apparatus in passive optical network - Google Patents

Abstract

A method and apparatus for extending distance in a passive optical network are disclosed. The distance extension method performed by the distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONU) is to extend the distance to the OLT via the repeater. receiving registration information for each of a plurality of ONUs that have requested registration; synchronizing the timer of the first ONU and the timer of the repeater using registration information for the first ONU among the received registration information; and delaying the timer of the repeater synchronized with the timer of the first ONU by a compensation delay time according to the transmission distance from the OLT determined for each of the plurality of ONUs.

Description

Distance extension method and device in passive optical network {DISTANCE EXTENSION METHOD AND APPARATUS IN PASSIVE OPTICAL NETWORK}

The present invention relates to a passive optical network (PON), and more specifically, to a method of implementing a repeater for extending distance and increasing the number of branches in an optical network using Time Division Multiplexing (TDM). It's about.

PON is an optical network in which at least one optical network unit (ONU) is connected to one optical line terminal (OLT) in a 1:N structure, and can refer to the section between the telephone company and the subscribers. there is.

Due to the structure of this PON, the same data is transmitted in a broadcasting manner from the OLT to a plurality of ONUs in the downstream direction, and individual data is transmitted in a burst mode method in the upstream direction at the time allocated to each of the plurality of ONUs. You can.

In the case of a typical PON, the light intensity is reduced due to the use of a passive optical splitter, so the maximum distance between the OLT and ONU is limited to about 20km, and depending on the power budget, the number of ONUs that can be connected to one OLT is limited. There is a limit where the number is limited to a maximum of 128.

PON, which has high economic efficiency, is widely used in wired FTTH networks, and as the need for regionalization of telephone office offices increases to improve operation management efficiency and reduce costs, an appropriate method to expand the coverage of PON is required.

The present invention seeks to provide a structure and implementation method of a repeater capable of receiving burst mode data transmitted from an ONU without changing the structure of the OLT or adding additional additional functions.

In addition, the present invention seeks to provide a repeater that can expand the transmission distance and increase the number of branches of a PON without a registration process through distance measurement.

A distance extension method performed by a distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONUs) according to an embodiment of the present invention. Receiving registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater; synchronizing the timer of the first ONU and the timer of the repeater using registration information for the first ONU among the received registration information; and delaying the timer of the repeater synchronized with the timer of the first ONU by a compensation delay time according to the transmission distance from the OLT determined for each of the plurality of ONUs.

The synchronization step is performed by setting the transmission time of the registration message transmitted from the first ONU to the reception time of the corresponding registration message of the repeater based on the transmission time constituting the registration information for the first ONU. The ONU's timer and the repeater's timer can be synchronized.

identifying a boundary of burst mode data for each of the plurality of ONUs to be received by the repeater using registration information for each of the plurality of ONUs; and generating a control signal for controlling the operation of a limiting amplifier included in the OLT optical transceiver of the repeater based on a boundary of burst mode data to be received from each of the plurality of ONUs.

The method further includes comparing a predicted reception time of burst mode data and an actual measured reception time of burst mode data based on registration information for each of the plurality of ONUs, wherein the generating step generates the predicted burst mode data. The control signal for controlling the operation of the limiting amplifier can be modified according to the comparison result between the reception time of and the actual reception time of the burst mode data.

The generating step may generate a control signal for resetting the limiting amplifier in a time period in which there is no burst mode data based on the boundaries of burst mode data for each of the identified plurality of ONUs.

A distance extension method performed by a distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONUs) according to an embodiment of the present invention. Receiving registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater; Based on the registration information for the first ONU among the received registration information, the transmission time of the registration message to be transmitted from the first ONU is set to the reception time of the corresponding registration message of the repeater, thereby setting the timer of the first ONU and synchronizing the repeater's timer; identifying a boundary of burst mode data for each of the plurality of ONUs to be received by the repeater based on registration information for each of the plurality of ONUs; and generating a control signal for controlling the operation of a limiting amplifier included in the OLT optical transceiver of the repeater based on a boundary of burst mode data to be received from each of the plurality of ONUs.

The method may further include comparing the predicted burst mode data reception time and the actual burst mode data reception time based on registration information for each of the plurality of ONUs.

The generating step may modify a control signal for controlling the operation of the limiting amplifier according to a comparison result between the predicted reception time of the burst mode data and the actually measured reception time of the burst mode data.

The generating step may generate a control signal for resetting the limiting amplifier in a time period in which there is no burst mode data based on the boundaries of burst mode data for each of the identified plurality of ONUs.

The distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONUs) according to an embodiment of the present invention includes a processor, The processor receives registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater, and uses the registration information for the first ONU among the received registration information to register the first ONU. The timer and the repeater's timer can be synchronized, and the repeater's timer synchronized with the timer of the first ONU can be delayed by a compensation delay time according to the transmission distance from the OLT determined for each of the plurality of ONUs.

The processor sets the transmission time of the registration message transmitted from the first ONU to the reception time of the corresponding registration message of the repeater based on the transmission time constituting the registration information for the first ONU, thereby Timers and repeater timers can be synchronized.

The processor uses registration information for each of the plurality of ONUs to identify a boundary of burst mode data for each of the plurality of ONUs to be received by the repeater, and determines the burst mode data to be received from each of the plurality of ONUs. Based on the boundary of , a control signal for controlling the operation of the limiting amplifier included in the OLT optical transceiver of the repeater can be generated.

The processor compares the predicted burst mode data reception time and the actual burst mode data reception time based on registration information for each of the plurality of ONUs, and compares the predicted burst mode data reception time with the actual burst mode data reception time. The control signal for controlling the operation of the limiting amplifier can be modified according to the result of comparing the reception time of the mode data.

The processor may generate a control signal to reset the limiting amplifier in a time period without burst mode data based on the boundaries of burst mode data for each of the identified plurality of ONUs.

According to one embodiment of the present invention, it is possible to provide a structure and implementation method of a repeater capable of receiving burst mode data transmitted from an ONU without changing the structure of the OLT or adding additional additional functions.

In addition, according to an embodiment of the present invention, it is possible to provide a repeater that can expand the transmission distance and increase the number of branches of a PON without a registration process through distance measurement.

Figure 1 is a diagram showing the configuration of a PON including a repeater according to an embodiment of the present invention.
Figure 2 is a diagram showing an example of receiving burst mode data in an OLT according to an embodiment of the present invention.
Figure 3 is a diagram showing the internal structure of a repeater according to an embodiment of the present invention.
Figure 4 is a diagram showing a repeater time synchronization method according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a diagram showing the configuration of a PON including a repeater according to an embodiment of the present invention.

Referring to FIG. 1, the present invention can use a repeater 110 to expand the transmission distance and increase the number of branches of the PON 100. More specifically, the repeater 110 is placed between the OLT 120 and the optical splitter 130 to expand the transmission distance of the optical signal transmitted between the OLT 120 and the ONU 140 and to increase the number of branches. Through this, the number of ONUs 140 that can be connected to one OLT 120 can be increased.

This repeater 110 may be implemented using an optical amplification method or an optical-electrical-optical (OEO) method. First, the optical amplification method can be implemented with a circuit structure that re-amplifies the optical signal attenuated according to the transmission distance using an optical amplifier. This optical amplification method has the advantage of having a simple circuit structure, but has the disadvantage that the elements that make up the circuit are expensive and signal quality may deteriorate.

In contrast, the OEO method amplifies (re-amplifies) the optical signal transmitted between the OLT (120) and the ONU (140), compensates (re-shapes) the distortion of the amplified optical signal, and produces a distortion-compensated optical signal. It can be implemented with a circuit structure that re-tims the timing. This OEO method can expand the transmission distance of optical signals or increase the number of branches more efficiently than the optical amplification method.

Therefore, the present invention can provide a repeater 110 implemented with an OEO type circuit structure, and a more detailed operation method of the repeater 110 will be described in detail with reference to the following drawings.

Figure 2 is a diagram showing an example of receiving burst mode data in an OLT according to an embodiment of the present invention.

The PON 100 can transmit and receive data according to the TDM method using the optical splitter 130, which is a passive element. At this time, each ONU (140) connected to the OLT (120) transmits data to the OLT (120) in burst mode only during the time allocated by the OLT (120), and the OLT (120) also transmits data to each ONU (140). Data transmitted from can be received in burst mode.

Since the OLT (120) receives data from the ONU (140) located at various distances, the burst mode data received from each ONU (140) has different signal strengths as shown in FIG. 2, and the signal level difference between the burst mode data is very large. It has structural characteristics. Therefore, in order to stably restore a signal by removing the signal level difference between burst mode data, the OLT 120 may use a limit amplifier in the receiving unit.

At this time, the interval between burst mode data operated in the PON 100 is tens to hundreds of nanoseconds. Therefore, whenever burst mode data is received, the OLT 120 must reset the limiting amplifier before reception so that gain control of the input burst mode data can be performed at high speed.

In order to control ONUs 140 located at various distances using the TDM method, the OLT 120 measures the distance to the ONUs 140 during the registration process and compensates for the distance based on the distance measured for each ONU 140. You can set the logical time by performing . That is, by performing time synchronization through distance compensation for all ONUs 140, the OLT 120 can receive burst mode data from all ONUs 140 at a desired time. Accordingly, the OLT 120 can reset the limiting amplifier according to the reception time of burst mode data for all ONUs 140.

The OEO type repeater 110 provided by the present invention may also include the same limiting amplifier as the OLT 120. Accordingly, in order for the repeater 110 to reset the limiting amplifier, it must know the reception time of burst mode data transmitted from the ONU 140, so a distance measurement function is required.

However, if the OLT 120 performs distance measurement for the repeater 110 through a registration process in the same way as other ONUs 140, problems affecting the existing network may occur. Therefore, the repeater 110 provided in the present invention can predict the reception time of burst mode data transmitted from the ONU 140 without a registration process through distance measurement, and the limiting amplifier is based on the predicted reception time of the burst mode data. By resetting , it is possible to provide a method of performing gain control of input burst mode data at high speed.

Figure 3 is a diagram showing the internal structure of a repeater according to an embodiment of the present invention.

The repeater 110 provided in the present invention may be composed of a first optical transceiver 310, a second optical transceiver 320, and a distance extension device 330. At this time, the first optical transceiver 310 converts the downward optical signal received from the OLT 120 into an electrical signal, or converts the electrical signal received from the distance extender 330 into an upward optical signal to the OLT 120. It can perform the sending function.

Since the wavelengths of the uplink and downlink optical signals are different from each other, the repeater 110 and the OLT 120 may be connected through a single optical cable to enable transmission of the optical signal. At this time, the downward optical signal may be a continuous signal, while the upward signal may be a signal transmitted only in the burst mode data section. Accordingly, the repeater 110 can control the laser of the first optical transceiver 310 to be turned off for a section without burst mode data so that an upward signal is not generated.

The second optical transceiver 320 converts the upward optical signal received from the ONU 140 into an electrical signal, or converts the electrical signal received from the distance extender 330 into a downward optical signal and transmits it to the ONU 140. It can perform its function.

Likewise, the downstream optical signal may be a continuous signal, while the upstream signal may be a signal transmitted only in the burst mode data section. Accordingly, the repeater 110 predicts the reception time of the burst mode data received from the ONU 140 and resets the limiting amplifier of the second optical transceiver 320 based on the predicted reception time of the burst mode data, thereby receiving the input Gain control of burst mode data can be performed at high speed.

The distance extension device 330 is disposed between the first optical transceiver 310 and the second optical transceiver 320 and can control the overall operation of the repeater 110. At this time, the distance extension device 330 may include at least one unit of a burst reception unit, an uplink packet processing unit, a downstream packet processing unit, a state management unit, a time management unit, and a BW map processing unit. However, the structure of the distance extension device 330 is only an example and is not limited thereto, and the units constituting the distance extension device 330 may be controlled by at least one processor.

First, the burst receiver may extract a clock from the burst mode data received from the ONU 140 and identify the boundary of the received burst mode data. Since the clock used in the ONU 140 uses a recovered clock extracted from data transmitted from the OLT 120, a closed loop can be formed between the OLT 120 and the ONU 140.

In other words, the ONU 140 can use a clock synchronized to the clock used in the OLT 120, and the burst receiver transmits the clock synchronized between the OLT 120 and the ONU 140 to the clock of the repeater 110. It can be used as Through this, the burst receiver can match the clock of the repeater 110 to the phase of the input data.

Meanwhile, the BW map processing unit, which will be described below, provides the transmission time and frame length of the burst mode data, so the burst receiving unit provides the transmission time and frame length of the burst mode data that can be obtained through the BW map processing unit. The transmission start time and transmission end time can be known, and through this, the boundaries of burst mode data can be identified.

The upstream packet processing unit can determine the error status of the burst mode data received through the burst receiver and reinsert the preamble and delimiter when necessary. The OLT 120 transmits the burst profile to all ONUs at regular intervals, and the transmitted burst profile may include the preamble and delimiter pattern and length information that the ONU 140 will use for uplink transmission. Since this burst profile is transmitted to the ONU 140 via the repeater 110, the upstream packet processing unit of the repeater 110 can also identify the information included in the burst profile.

Burst mode data received from the ONU 140 is protected by FEC (Forward Error Correction,) and BIP (Bit Interleaved Parity) logic, and the upstream packet processing unit performs burst mode data through FEC decoding and BIP check. The presence or absence of data errors and the bit error rate (BER) can be calculated. Since the preamble and delimiter provide important information for identifying the boundaries of burst mode data, the upstream packet processing unit can insert a new packet, if necessary, by referring to the burst profile.

Additionally, the upstream packet processing unit may perform a function of comparing the predicted reception time and the actually measured reception time of burst mode data received from each ONU 140 and compensating for this. Normally, the burst mode data transmitted by the ONU 140 should arrive at the predicted reception time, but due to various errors, the actual burst mode data may arrive slightly earlier or slightly later based on the upward timer time. The upstream packet processing unit can perform a function to correct this. For example, if burst mode data arrives 1 clock early from the ONU (140), the upstream packet processing unit delays the arrived burst mode data by 1 clock and transmits it to the OLT (120). Can be transmitted.

The downstream packet processing unit can recover the synchronization of the data input from the first optical transceiver 310, extract control messages and uplink transmission information necessary for the repeater 110, and transmit them to the status management unit, time management unit, and BW map processing unit. .

The state management unit may manage the operating state of the repeater 110. Since the repeater 110 is not registered with the OLT 120 like a general ONU 140, a method is required to know the exact reception time of burst mode data received from the ONU 140 without its own distance measurement function.

To this end, the state management unit of the present invention changes the operating state of the repeater 110 using the registration information of the first ONU 140 registered in the OLT 120 via the repeater 110, thereby Time synchronization between (120) can be performed. A more detailed time synchronization method of the repeater 110 will be described in detail later with reference to FIG. 4.

The time management unit may operate a timer synchronized with the timer of the OLT 120 to determine the reception time of burst mode data received from the ONU 140. At this time, the timer of the time management unit may increase in time at the same period and at the same time interval as the timer of the OLT 120. At this time, the time management unit may separate timers to manage the downward time and the upstream time, of which the upstream timer operates from the time a registration message with the ONU ID of the first ONU 140 determined by the state management unit is received. , can be adjusted according to the compensation delay time.

The BW map processing unit can calculate the transmission time of burst mode data and the frame length of burst mode data for each ONU (140) using the BW map received from the OLT (120) and the use of FEC (Forward Error Correction). Using the information, the packet boundary for burst mode data input from the upstream packet processing unit to the burst receiving unit can be identified.

At this time, the BW map processing unit determines a time section without burst mode data based on the packet boundary for the burst mode data identified in the upstream packet processing unit and generates a control signal for resetting the limiting amplifier of the second optical transceiver 320. can be created. The control signal generated in this way is transmitted to the second optical transceiver 320 to reset the limiting amplifier, thereby controlling the repeater 110 to receive upward data.

Figure 4 is a diagram showing a repeater time synchronization method according to an embodiment of the present invention.

As mentioned above, the state management unit constituting the distance extension device 330 of the repeater 110 uses the registration information of the first ONU 140 registered in the OLT 120 via the repeater 110 to connect the repeater ( Time synchronization between the repeater 110 and the OLT 120 can be performed by changing the operating state of 110).

First, the repeater 110 can obtain frame synchronization through a downstream packet transmitted from the OLT 120.

Thereafter, when the repeater 110 receives a burst profile from the OLT 120, its operating state may transition to the serial number state. At this time, the burst profile may include the pattern and length information of the preamble and delimiter that the ONU 140 will use for uplink transmission, and may be broadcast at regular intervals by the OLT 120.

The operation state of the first ONU 140 that receives the burst profile may transition to the serial number state (SN state). Afterwards, when the first BW (Band Width) map is received from the OLT 120, the first ONU 140 sends a serial number ONU (SN_Number_ONU) message including its serial number to the OLT (120) to request registration. 120).

When the OLT 120 receives a serial number ONU (SN_Number_ONU) from all ONUs wishing to register, it assigns an ONU ID to each ONU in a determined order according to a certain standard and transmits an ONU ID allocation message to each ONU to create a second BW map. can also be transmitted together.

The repeater 110 may transition from the operating state of the serial number state to the ranging state based on the first received ONU ID allocation message. At this time, when the repeater 110 receives a second BW map for transmitting a registration message for each ONU from the OLT 120, the repeater 110 uses the received second BW map to transmit the registration message of the first ONU 140 (Time). (assumed to be A) can be identified. At this time, the second BW map may include data transmission time and transmission amount information for each ONU.

Thereafter, the repeater 110 may set the registration message transmission time (Time A) of the identified first ONU 140 to the reception time (Time A) of the corresponding registration message of the repeater 110. That is, the registration message transmitted at Time A from the first ONU 140 may arrive at the repeater 110 at the same time, Time A, and be transmitted to the OLT 120. In other words, each timer can be synchronized so that the registration message transmission time of the first ONU 140 is the same as the registration message reception time of the repeater 110.

Upon receiving the registration message from the first ONU 140, the OLT 120 measures the transmission distance for each ONU, calculates a compensation delay time (Equalization Delay, EqD), and then allocates a compensation delay time including the calculated compensation delay time. Messages can be transmitted to each ONU.

The repeater 110 and the first ONU 140 may transition to an operation state based on the compensation delay time allocation message received from the OLT 120, and the operation state included in the compensation delay time allocation message The timer can be delayed equally by the compensation delay time.

In this way, if the timer of the repeater 110 is adjusted to be the same as the timer of the OLT 120 using the first ONU 140 registered in the OLT 120 via the repeater 110, all ONUs registered thereafter The burst mode data may arrive at the repeater 110 according to the transmission time of the second BW map.

Accordingly, the repeater 110 can perform gain control of burst mode data received from a plurality of ONUs at high speed by resetting the limiting amplifier based on the data transmission time of the second BW map, and through this, the OLT 120 can reliably restore burst mode data received from ONUs.

Meanwhile, the method according to the present invention is written as a program that can be executed on a computer and can be implemented in various recording media such as magnetic storage media, optical read media, and digital storage media.

Implementations of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or combinations thereof. Implementations may include a computer program product, i.e., an information carrier, e.g., machine-readable storage, for processing by or controlling the operation of a data processing device, e.g., a programmable processor, a computer, or multiple computers. It may be implemented as a computer program tangibly embodied in a device (computer-readable medium) or a radio signal. Computer programs, such as the computer program(s) described above, may be written in any form of programming language, including compiled or interpreted languages, and may be written as a stand-alone program or as a module, component, subroutine, or part of a computing environment. It can be deployed in any form, including as other units suitable for use. The computer program may be deployed for processing on one computer or multiple computers at one site or distributed across multiple sites and interconnected by a communications network.

Processors suitable for processing computer programs include, by way of example, both general-purpose and special-purpose microprocessors, and any one or more processors of any type of digital computer. Typically, a processor will receive instructions and data from read-only memory or random access memory, or both. Elements of a computer may include at least one processor that executes instructions and one or more memory devices that store instructions and data. Generally, a computer may include one or more mass storage devices that store data, such as magnetic, magneto-optical disks, or optical disks, receive data from, transmit data to, or both. It can also be combined to make . Information carriers suitable for embodying computer program instructions and data include, for example, semiconductor memory devices, magnetic media such as hard disks, floppy disks, and magnetic tapes, and Compact Disk Read Only Memory (CD-ROM). ), optical media such as DVD (Digital Video Disk), magneto-optical media such as Floptical Disk, ROM (Read Only Memory), RAM , Random Access Memory), flash memory, EPROM (Erasable Programmable ROM), and EEPROM (Electrically Erasable Programmable ROM). The processor and memory may be supplemented by or included in special purpose logic circuitry.

Additionally, computer-readable media can be any available media that can be accessed by a computer, and can include both computer storage media and transmission media.

Although this specification contains details of numerous specific implementations, these should not be construed as limitations on the scope of any invention or what may be claimed, but rather descriptions of features that may be unique to particular embodiments of particular inventions. It should be understood as Certain features described herein in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination. Furthermore, although features may be described as operating in a particular combination and initially claimed as such, one or more features from a claimed combination may in some cases be excluded from that combination, and the claimed combination may be a sub-combination. It can be changed to a variant of a sub-combination.

Likewise, although operations are depicted in the drawings in a particular order, this should not be construed as requiring that those operations be performed in the specific order or sequential order shown or that all of the depicted operations must be performed to obtain desirable results. In certain cases, multitasking and parallel processing may be advantageous. Additionally, the separation of various device components in the above-described embodiments should not be construed as requiring such separation in all embodiments, and the described program components and devices are generally integrated together into a single software product or packaged into multiple software products. You must understand that it can happen.

Meanwhile, the embodiments of the present invention disclosed in the specification and drawings are merely provided as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art that in addition to the embodiments disclosed herein, other modifications based on the technical idea of the present invention can be implemented.

100: Passive optical network
110: repeater
120: Optical line terminal
130: optical splitter
140: Optical network unit

Claims (14)

In the distance extension method performed by the distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONU),
Receiving registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater;
synchronizing the timer of the first ONU and the timer of the repeater using registration information for the first ONU among the received registration information; and
Delaying the timer of the repeater synchronized with the timer of the first ONU by a compensation delay time according to the transmission distance from the OLT determined for each of the plurality of ONUs.
A distance extension method containing . According to paragraph 1,
The synchronization step is,
Timer and repeater of the first ONU by setting the transmission time of the registration message transmitted from the first ONU to the reception time of the corresponding registration message of the repeater based on the transmission time constituting the registration information for the first ONU Distance extension method to synchronize the timer of . According to paragraph 1,
identifying a boundary of burst mode data for each of the plurality of ONUs to be received by the repeater using registration information for each of the plurality of ONUs; and
Generating a control signal for controlling the operation of a limiting amplifier included in the OLT optical transceiver of the repeater based on a boundary of burst mode data to be received from each of the plurality of ONUs.
A distance expansion method further comprising: According to paragraph 3,
Comparing the predicted reception time of burst mode data and the actually measured reception time of burst mode data based on registration information for each of the plurality of ONUs.
It further includes,
The generating step is,
A distance extension method for modifying a control signal for controlling the operation of the limiting amplifier according to a comparison result between the predicted reception time of the burst mode data and the actually measured reception time of the burst mode data. According to paragraph 3,
The generating step is,
A distance extension method for generating a control signal to reset the limiting amplifier in a time period without burst mode data based on a boundary of burst mode data for each of the identified plurality of ONUs. In the distance extension method performed by the distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONU),
Receiving registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater;
Based on the registration information for the first ONU among the received registration information, the transmission time of the registration message to be transmitted from the first ONU is set to the reception time of the corresponding registration message of the repeater, thereby setting the timer of the first ONU and Synchronizing the repeater's timer;
identifying a boundary of burst mode data for each of the plurality of ONUs to be received by the repeater based on registration information for each of the plurality of ONUs; and
Generating a control signal for controlling the operation of a limiting amplifier included in the OLT optical transceiver of the repeater based on a boundary of burst mode data to be received from each of the plurality of ONUs.
A distance extension method containing . According to clause 6,
Comparing the predicted reception time of burst mode data and the actually measured reception time of burst mode data based on registration information for each of the plurality of ONUs.
A distance expansion method further comprising: In clause 7,
The generating step is,
A distance extension method for modifying a control signal for controlling the operation of the limiting amplifier according to a comparison result between the predicted reception time of the burst mode data and the actually measured reception time of the burst mode data. According to clause 6,
The generating step is,
A distance extension method for generating a control signal to reset the limiting amplifier in a time period without burst mode data based on a boundary of burst mode data for each of the identified plurality of ONUs. In the distance extension device of a repeater disposed between an optical line terminal (OLT) and a plurality of optical network units (ONUs),
The range extension device includes a processor,
The processor,
Receive registration information for each of a plurality of ONUs that have requested registration with the OLT via the repeater, and use the registration information for the first ONU among the received registration information to set the timer and repeater for the first ONU. A distance extension device that synchronizes the timer of and delays the timer of the repeater synchronized with the timer of the first ONU by a compensation delay time according to the transmission distance from the OLT determined for each of the plurality of ONUs. According to clause 10,
The processor,
Timer and repeater of the first ONU by setting the transmission time of the registration message transmitted from the first ONU to the reception time of the corresponding registration message of the repeater based on the transmission time constituting the registration information for the first ONU Distance extension device that synchronizes its timer. According to clause 10,
The processor,
A boundary of burst mode data to be received by the repeater is identified using registration information for each of the plurality of ONUs, and a boundary of burst mode data to be received from each of the plurality of ONUs is identified. A distance extension device that generates a control signal to control the operation of a limiting amplifier included in the OLT optical transceiver of the repeater. According to clause 12,
The processor,
Based on the registration information for each of the plurality of ONUs, the predicted burst mode data reception time and the actual burst mode data reception time are compared, and the predicted burst mode data reception time and the actual burst mode data reception time are compared. A distance extension device that modifies a control signal for controlling the operation of the limiting amplifier according to a comparison result of the reception time. According to clause 12,
The processor,
A distance extension device that generates a control signal to reset the limiting amplifier in a time period without burst mode data based on a boundary of burst mode data for each of the identified plurality of ONUs.

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