KR20110071372A - Repeating apparatus for wdm-pon - Google Patents

Abstract

PURPOSE: A relay equipment based on an WDM- PON(Wavelength Division Multiplexing-Passive Optical Network) is provided to process the long distance transmission of the seed light source for wavelength-locked. CONSTITUTION: A seed light source generating unit(240) creates the seed light used as a light source for a wavelength locking of an upward signal light transmitted from a subscriber side. A second light combination unit(230) is input a downward signal light amplified in a primary amplification section and the seed light created in the seed light source generating unit. A second light combination unit transmits the inputted lights to the subscriber side. A second optical coupling part outputs the upward signal light which is input from the subscriber side. A second amplifier(212) amplifies the upward signal light outputted from the second light combination unit.

Description

WDD-PON-based relay device {Repeating Apparatus for WDM-PON}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of optical communications, and in particular, for relaying signals between a station side device and a subscriber side optical terminal device (ONT) based on a Wavelength Division Multiplexing-Passive Optical Network (WDM-PON). It is a technology related to a relay device.

In general, wavelength division multiplexing passive optical subscriber network (WDM-PON) is widely recognized as the next generation ultimate optical subscriber network. The most important consideration in WDM-PON technology is that the optical transmitter must be wavelength independent despite the use of multiple light wavelengths. The WDM-PON technology that meets these requirements has been widely studied around the world, especially the WDM-PON of the 'wavelength locking' method is active.

Specifically, the conventional WDM-PON will be described.

1 is a diagram illustrating a conventional general WDM-PON.

The WDM-PON logically implements point-to-point connection by allocating dedicated uplink (λ _um ) and downlink wavelength (λ _dm ) to M subscribers, respectively. In the OLT 10, M optical transceivers 11, 12, and 13 assigned to each subscriber are installed, and they are combined in the WDM wavelength branch combiner 14 and transmitted by light, and WDM wavelengths installed in the remote node 20 are provided. The branch combiner 25 has a simple multiplexing structure that is distributed to each subscriber again by wavelength channel.

Although FIG. 1 illustrates a WDM-PON system for transmitting an Ethernet frame, the WDM system basically provides multiplexing at the physical layer (PHY), and thus guarantees transmission transparency at a higher layer. It is also possible to transmit a hierarchy / synchronous network (SONET), an asynchronous transfer mode (ATM), a generic frame procedure (GFP), and the like. This WDM-PON provides logically point-to-point connection through wavelength allocation compared to TDM-PON, provides better security than broadcast-based TDM-PON, and increases branching rate by simply adding wavelength. At the same time, there is an advantage that the bandwidth per optical fiber can be increased relatively easily, but it also has the disadvantage that the light source required for WDM is relatively expensive compared to the light source for TDM-PON. In addition, since an optical transceiver having different transmission and reception wavelengths is required for each of the M side and the subscriber side, there is a problem in that the cost for wavelength selection is increased to provide a high branching rate.

Meanwhile, as the WDM light source for the WDM-PON, a CWDM (coarse WDM), a DWDM (dense WDM) fixed wavelength light source, and a DWDM wavelength independent light source are used. As a DWDM wavelength independent light source technology, a tunable laser can be used. In addition, a method using a seed light source such as a broadband light source or a laser array can be used for a FP (Fabry-Perot) laser or a reflective semiconductor optical amplifier (RSAA). The seed light source is divided into spectra and injected. In addition, an optical link configuration method for generating uplink signals by remodulating downlink signals to RSOA is being researched and developed.

In particular, in the wavelength-locked method using the FP laser, when the seed light is injected into the FP laser, only the mode corresponding to the wavelength of the seed light injected into the FP-LD is oscillated, and the other modes are suppressed. Use In this case, a broadband light source (BLS) is used as the seed light source. In this system, two kinds of BLS are installed in a national company. One type of BLS provides seed fiber to a national optical device, or FP-LD located in an optical line termination (OLT), and the other type of BLS is mounted in a subscriber-side optical terminal device, or an optical network unit (ONU). Seed light to the FP-LD.

The light emitted from the BLS passes through the WDM MUX included in the OLT and the WDM MUX mounted in the Remote Node (RN), and the spectrum is split, and the spectral split seed light is transferred to the FP-LD. Is injected. However, there is a problem in that spectral segmented seed light is limited to long distance transmission.

In view of solving the above-mentioned problems, it is a first technical problem to provide a relay apparatus that enables long-range transmission of a wavelength-locked seed light source in a WDM-PON.

Another object of the present invention is to provide a relay device capable of transmitting a high quality seed light source by transmitting the seed light source to the subscriber optical terminal without amplifying the seed light source.

Another object of the present invention is to provide a relay device capable of increasing the amplification efficiency of the downlink signal light by using an upside light source transmitted from the Korean company side when amplifying the downlink signal light transmitted to the subscriber side.

However, the technical problem of the present invention is not limited to the above-mentioned matters, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

WDM-PON-based relay device according to the present invention for achieving the above technical problem, the first optical coupling section for branching the downlink signal and the uplink light transmitted from the country side, and branched from the first optical coupling unit A first amplifying unit for amplifying the downlink signal light, a seed light source generating unit for generating seed light used as a wavelength fixing light source of the uplink signal light transmitted from the subscriber, a downlink signal light amplified by the first amplifying unit and the A second optical coupling unit which receives the seed light generated by the seed light source generation unit, transmits the seed light to the subscriber side, and outputs the uplink signal light received by the subscriber side, and amplifies the upward signal light output from the second optical coupling unit. 2 Amplify.

The first optical coupling unit may receive the uplink signal light amplified by the second amplifying unit and transmit the received uplink signal light.

The second amplifier may include an optical isolator connected to the first optical coupling unit so that the upward seed light branched from the first optical coupling unit is input, and block the transmission of the upward seed light to the subscriber side. .

Also preferably, the second amplifying unit may be connected to the first optical coupling unit by a light path to transmit the uplink signal light amplified through the optical path to the first optical coupling unit. Here, the light path may further include an optical isolator for blocking the upward seed light branched from the first optical coupling unit from being input to the second amplifier.

The second optical coupling unit may include an optical circulator for receiving the uplink signal light and the seed light, transmitting the uplink signal light to the second amplification unit, and transmitting the seed light to a subscriber side.

The first and second amplifiers may be Erbium-doped fiber amplifiers (EDFAs).

Also preferably, the first amplifying unit may be an erbium doped fiber optical amplifier for amplifying the down-signal light of L-band (wavelength: 1570 ~ 1610nm).

In addition, the second amplifier may be an erbium-doped optical fiber optical amplifier for amplifying the C-band (wavelength: 1530 ~ 1560nm) uplink signal light.

The seed light source generator may use a C-band broadband light source (BLS).

On the other hand, in order to achieve the above technical problem, the WDM-PON-based relay device according to the present invention, amplifying the downward signal light by using the upside seed light transmitted from the country side as a secondary pump light for the amplification of the downlink signal light A first light source, a seed light source generator for generating a seed light used as a wavelength fixing light source of the uplink signal light transmitted from the subscriber side, a downward signal light amplified by the first amplifier and the seed light source generator An optical coupling unit which receives the received seed light and transmits it to the subscriber side and outputs the uplink signal light transmitted from the subscriber side, a second amplifying unit which amplifies the uplink signal light output from the optical coupling unit and an uplink transmitted from the national company side A seed light and a downlink signal light are received and transmitted to the first amplifying unit, and the upstream signal light amplified by the second amplifying unit is a station on the Korean history side. It comprises a first optical rotation to be transmitted to.

The optical coupling unit may include a second optical circulator configured to receive the uplink signal light and the seed light to transmit the uplink signal light to the second amplification unit, and to transmit the seed light to a subscriber side.

In addition, the first and second amplifiers may use an erbium doped fiber amplifier (EDFA).

Preferably, the first amplifier may be an erbium-doped optical fiber optical amplifier for amplifying the down-signal light of L-band (wavelength: 1570 ~ 1610nm).

In addition, the second amplifier may use an erbium-doped optical fiber optical amplifier that amplifies the C-band (wavelength: 1530 ~ 1560nm) uplink signal light.

The seed light source generation unit may use a C-band broadband light source (BLS).

According to the contents described throughout the specification, the WDM-PON-based relay device according to the present invention enables long-distance transmission of the wavelength-locked seed light source.

In addition, the present invention transmits the seed light source of high quality by transmitting to the subscriber optical terminal without amplifying the seed light source.

In addition, the present invention includes an advantage of increasing the amplification efficiency of the downlink signal light by using the upside light source transmitted from the side of the company when amplifying the downlink signal light transmitted to the subscriber side.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description herein, when a component is described as being connected to another component, this means that the component may be directly connected to another component or an intervening third component may be interposed therebetween. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. At this time, the configuration and operation of the present invention shown in the drawings and described by this will be described as at least one embodiment, by which the technical spirit of the present invention and its core configuration and operation is not limited.

First, prior to the description of the WDM-PON-based relay device according to the present invention will be described with respect to the WDM-PON employing a wavelength independent light source of the conventional seed light source injection method. By doing so, the existing problem to be solved by the present invention will be clearer.

2 is a view of a WDM-PON employing a wavelength independent light source of the conventional seed light source injection method.

As shown in FIG. 2, the conventional WDM-PON includes a WDM wavelength branch combiner 14, a first WDM filter 55, a second WDM filter 56, a first optical cycler 53, and a second light. The circulator 54, the C-band broadband light source 51, the L-band broadband light source 52, and the optical transceivers 11, 12, 13 are comprised.

Referring to FIG. 2, the seed light source injection method will be described below. The seed light for the downstream signal light (down seed light) is generated by the L-band broadband light source 52 and is incident to port 4 of the second light circulator 54. Output to port 1 The seed light source output to port 6 of the second optical circulator 54 is incident to the WDM wavelength branch combiner 14 through the first WDM filter 55.

In the WDM wavelength branch combiner 14, the down seed light is spectral-divided and incident on each optical transceiver 11. Although the optical transceiver 11 is not shown in the drawing, for example, the RSOA (Reflective Semiconductor Optical Amplifier) Or a FP-LD (Fabry Perot laser diode). The downside seed light incident thereto is amplified in the RSOA, induces wavelength locking of the FP-LD, modulated by the downlink data, and output from the optical transceiver 11 as the downlink signal light.

The downlink signal light is wavelength multiplexed together with the downlink signal light output from the other optical transceivers 12 and 13 at the WDM wavelength branch combiner 14. The wavelength multiplexed downlink signal light output from the WDM wavelength branch combiner 14 is input to port 6 of the second optical circuit 54 through the first WDM filter 55 and output to port 5. The wavelength multiplexed downlink signal light thus output is output to a feeder fiber through the second WDM filter 56 and transmitted to the subscriber side.

On the other hand, the wavelength-multiplexed uplink signal light from the subscriber side is input to port 2 of the first optical circulator 53 and output to port 3. The output uplink signal light is input to the WDM wavelength branch combiner 14 to separate wavelengths, and each of the uplink signal signals separated on the wavelength is input to the corresponding optical transceivers 11, 12, 13.

The seed signal for upward signal light (upward seed light) generated from the C-band broadband light source 51 is input to the first port of the first optical circulator 53 and output to the second port, and then through the optical fiber, the RN The wavelength is divided into the output port of the WDM wavelength branch combiner provided in the (Remote Node), and the wavelength-divided seed light is input to the corresponding ONU to generate the upward signal light by the injection-locking method as described above. To be sent to the side.

In order to use the injection-locked seed light for a long distance in the conventional WDM-PON method, the output optical power of the C-band BLS must be increased to compensate for transmission loss, and the output optical power of the downward and upward signal light is also increased. Need to be increased.

Therefore, the WDM-PON-based relay device according to the present invention will be described below as various embodiments.

3 is a block diagram of a WDM-PON-based relay device according to a first embodiment of the present invention.

As shown in FIG. 3. The WDM-PON-based relay device 100 according to the first embodiment includes a first optical coupling unit 120, a second optical coupling unit 130, a first amplifier 111, and a second amplifier 112. And a seed light source generator 140.

The first optical coupling unit 120 splits the downlink signal light S1 and the upside seed light BLS1 transmitted from the office to transmit the downlink signal light S1 to the first amplifying unit 111 to be described later.

The first amplifier 111 amplifies the downlink signal light S1 branched from the first optical coupler 120 and transmits the amplified downlink signal S1 to the second optical coupler 130, which will be described later. Typically, the first amplifier 111 may be an optical fiber type optical amplifier (optical amplifier). Preferably, an optical fiber type optical amplifier may use an Erbium Doped Fiber Amplifier (EDFA), which typically has an output saturation power such that the downlink signal light (S1) is delivered to a sufficient light output to the subscriber. More preferably, it is large enough.

The seed light source generator 140 generates the seed light BLS2 provided in the relay device 100 and used as a wavelength fixing light source of the uplink signal light transmitted from the subscriber.

The second optical coupler 130 receives the downlink signal light S1 amplified by the first amplifier 111 and the seed light BLS2 generated by the seed light source generator 140 and transmits the received signal to the subscriber. The uplink signal light S2 received from the signal is transmitted to the second amplifier 112 to be described later.

The second amplifier 112 is a means for amplifying the upward signal light (S2) output from the second optical coupler 130, the second amplifier 112 is an optical fiber type like the first amplifier 111 described above Optical amplification can be used, preferably an Erbium Doped Fiber Amplifier (EDFA) can be used. Other descriptions are the same as the descriptions of the first amplifying unit 111, and thus description thereof is omitted here.

The uplink signal light S2 amplified by the second amplifying unit 112 is transmitted to the side of the national company, which is normally input to the first optical coupling unit 120 and output from the first optical coupling unit 120 to the national history side.

4 is a block diagram of a WDM-PON-based relay device according to a second embodiment of the present invention.

As shown in FIG. 4, the WDM-PON-based relay device 100 according to the second embodiment includes a first optical coupling unit 120, a second optical coupling unit 130, and a first amplifying unit 111. ), A second amplifier 112, a seed light source generator 140, and an optical isolator 113.

In the second embodiment, the first light coupling unit 120, the second light coupling unit 130, the first amplifying unit 111, the second amplifying unit 112, and the seed light source generating unit 140 are provided in the first embodiment. As described in detail in the embodiments, for the sake of brief description of the specification, descriptions thereof will be omitted.

The optical isolation unit 113 is a means provided to block transmission of the upside seed light BLS1 input to the first optical coupling unit 120 to the subscriber side subscriber side. 112 is formed integrally with. That is, the second amplifying unit 112 and the first optical coupling unit 120 are connected by a light path so that the uplink signal light S2 amplified by the second amplifying unit 112 is transmitted to the first optical coupling unit 120. The downlink signal light S1 and the upside seed light BLS1 input to the first optical coupling unit 120 are branched from the first optical coupling unit 120 so that the downlink signal light S1 is transferred to the first amplifying unit 111. The uplink seed light BLS1 is transmitted to the second amplifier 112. Therefore, the optical isolator 113 is provided inside the second amplifier 112 to block the transmission of the upside seed light BLS1 to the subscriber.

5 is a block diagram of a WDM-PON-based relay device according to a third embodiment of the present invention, Figure 6 is a view showing the implementation of the WDM-PON-based relay device according to a third embodiment of the present invention Drawing.

As shown in FIG. 5, the WDM-PON-based relay device 100 according to the third embodiment may include a first optical coupling unit 120, a second optical coupling unit 130, and a first amplifying unit 111. ), A second amplifier 112, a seed light source generator 140, an optical isolator 113, and a light circulator 150.

In the third embodiment, the first optical coupling unit 120, the second optical coupling unit 130, the first amplifier 111, the second amplifier 112, the seed light source generator 140, and the optical isolator The description of the reference numeral 113 has been described in detail in the second embodiment, and the description is omitted here for the brief description of the specification. However, in the present exemplary embodiment, the optical isolation unit 113 may be provided on the optical path connecting the first optical coupling unit 120 and the second amplification unit 112 or may be embedded in the second amplification unit 112. have.

The light circulator 150 transmits the seed light BLS2 generated by the seed light source generator 140 to the subscriber and transmits the uplink signal light S2 transmitted from the subscriber to the second amplifier 112. Although the light circulator 150 is shown as being positioned between the second optical coupling unit 130 and the second amplifying unit 112 in FIG. 5, the optical circulation unit 150 may be located inside the second optical coupling unit 130. .

As shown in FIG. 5, when the light circulator 150 is located between the second amplifying unit 112 and the second optical coupling unit 130, the seed light BLS2 generated by the seed light source generating unit 140. Is input to port 1 of the optical circuit 150 and guided to output through port 2. In addition, the upward signal light S2 coming from the subscriber side is input to the second port of the optical circuit 150 and guided to the third port.

A detailed description of the operation of the WDM-PON-based relay device according to a third embodiment of the present invention with reference to FIG. As shown in FIG. 6, the WDM-PON-based relay device according to the third embodiment includes a first WDM filter 120, a second WDM filter 130, a first amplifier 111, and a second amplifier 112. ), An optical isolator 113, a C-band broadband light source 140, and an optical rotator 150.

The downlink signal light S1 and the upside seed light BLS1 transmitted to the relay device 100 from the office side are input to the first WDM filter 120. The first WDM filter 120 guides the downlink signal light S1 to the first amplifier 111 and guides the upside seed light BLS1 to the optical isolator 113.

The downlink signal light S1 input to the first amplifier 111 is amplified and transmitted to the second WDM filter 130. The second WDM filter 130 transmits the amplified downlink signal light S1 to a subscriber node or a local node (RN) located at the subscriber side.

Meanwhile, the upward seed light BLS2 generated by the C-band broadband light source 140 provided in the relay device 100 is input to port 1 of the optical rotator 150 and guided to port 2 along the optical path. . The upside seed light BLS2 outputted through port 2 is input to the second WDM filter 130 and transmitted to a subscriber station or a local node (RN) located at the subscriber side.

The subscriber side transmits the uplink signal light S2 whose wavelength is fixed by the upside seed light BLS2 by the C-band broadband light source 140 having the wavelength of 1530 to 1560nm to the national company side.

The upward signal light S2 is input to the second optical coupler 130 and input to port 2 of the optical rotator 150. The uplink signal light S2 input to the port 2 is output to the port 3 along the optical path of the optical rotator 150. The uplink signal light S2 output from the third port is amplified by the second amplifier 112 and output.

The uplink signal light S2 output from the second amplifier 112 is input to port 4 of the optical isolator 113, output to port 5, and then transmitted to the national company side via the first WDM filter 120. Since the optical isolator 113 permits only signal transmission from the port 4 to the port 5, the down seed light BLS1 output from the first WDM filter 120 is blocked by the optical isolator 113, and thus the second isolator 113 is blocked. Since it is not input to the amplifier 112, it is not transmitted to the subscriber side.

Next, a detailed description will be given of a fourth embodiment of a WDM-PON-based relay device according to the present invention.

 7 is a block diagram of a WDM-PON-based relay device according to a fourth embodiment of the present invention.

As illustrated in FIG. 7, the relay device 200 according to the fourth embodiment may include a first light circulation unit 221, a first amplifier 211, a second amplifier 212, and an optical coupling unit ( 230 and the seed light source generator 240.

The first light circulator 221 receives the downlink signal light S1 and the upside seed light BLS1 transmitted from the national company, and transmits both of them to the first amplifier 211.

The first amplifier 211 amplifies the downlink signal light S1 transmitted from the first light circulator 221 and transmits the amplified signal S1 to the optical coupler 230. In this case, the first amplifying unit 211 uses the upside seed light BLS1 to amplify the downlink signal light S1, and uses the upside seed light BLS1 as the secondary pump light of the first amplifying unit 211. As a result, the amplification efficiency of the downlink signal light S1 is improved.

The optical coupling unit 230 transmits the downlink signal light S1 received from the first amplifier 211 to a local node (RN, Remote Node) provided at the subscriber side or the subscriber side.

The seed light source generating unit 240 is provided inside the relay 200 and is transmitted to the subscriber side, for example, in a reflective semiconductor optical amplifier (RSOA) or fabric perot laser diode (FP-LD) of the subscriber side optical transceiver (not shown). Generate an incident downward signal.

The second amplifier 212 receives the uplink signal light S2 transmitted from the optical coupling unit 230 and amplifies and outputs the signal. The uplink signal light S2 amplified by the second amplifying unit 212 is input to the first optical cycle unit 221 and output to the national history side.

8 is a block diagram of a WDM-PON-based relay device according to a fifth embodiment of the present invention, Figure 9 is a view showing the implementation of the WDM-PON-based relay device according to a fifth embodiment of the present invention Drawing.

As shown in FIG. 8, the WDM-PON-based relay device 200 according to the fifth embodiment includes a first light circulator 221, an optical coupler 230, a first amplifier 211, The second amplifier 212, the seed light source generator 240, and the second light circulator 150 are included.

In the fifth embodiment, descriptions of the first light circulator 221, the first amplifier 211, the second amplifier 212, the optical coupler 230, and the seed light source generator 240 will be described. As described in detail in the embodiments, for the sake of brief description of the specification, descriptions thereof will be omitted.

In the present embodiment, the second light circulator 222 transmits the seed light BLS2 generated by the seed light source generator 240 to the subscriber side, and transmits the uplink signal light S2 transmitted from the subscriber side to the second amplifier 212. To send). Although the second light circulator 222 is illustrated as being positioned between the light coupling unit 230 and the second amplifying unit 212 in FIG. 8, the second light circulation unit 222 may be positioned inside the light coupling unit 230.

As shown in FIG. 8, when the second light circulator 222 is positioned between the second amplifier 212 and the optical coupler 230, the seed light BLS2 generated by the seed light source generator 240 is generated. Is input to port 6 of the second optical circuit 222 and guided to output through port 5. The uplink signal light S2 coming up from the subscriber side is input to port 5 of the second optical circuit 222 and guided to port 4.

Hereinafter, a detailed description of the operation of the WDM-PON-based relay device according to a fifth embodiment of the present invention. As shown in FIG. 9, the WDM-PON-based relay device according to the fifth embodiment includes a first optical rotator 221, a WDM filter 230, a first amplifier 211, a second amplifier 212, and the like. C-band broadband light source 240 and second optical rotator 222.

The downlink signal light S1 and the upside seed light BLS1 transmitted to the relay device 200 from the bureau side are input to port 1 of the first optical rotating machine 221 and output to port 3 along the optical path. That is, the first optical rotator 221 is formed to guide the downward signal light S1 and the upward seed light BLS1 to the first amplifier 211.

The downlink signal light S1 input to the first amplifier 211 is amplified and transmitted to the WDM filter 230. Here, the upside seed light BLS1 input to the first amplifier 211 becomes the secondary pump light used by the first amplifier 211 to amplify the downlink signal light S1. In general, the first amplifier 211 uses an L-band (1570-1610 nm) Erbium-doped fiber optical amplifier (EDFA), and maintains a low density reversal level of the erbium ions doped in the EDFA optical fiber. Due to the necessity, the optical fiber longer than the EDFA of the C-band is required, and since the efficiency of converting the pump light into the output light is low, an upward seed light source BLS2 input to the first amplifier 211 is used as a means for correcting this. We use as binary pump light.

That is, when the first amplifier 211 amplifies the downlink signal light S1, which is the pump light input to the first amplifier 211, the upside seed light BLS2, which is input together, for amplifying the downlink signal light S1. It is used as a secondary pump light to improve the amplification efficiency of the first amplifier BLS2.

The amplified downlink signal light S1 output from the first amplifier 211 is input to the WDM filter 230 and transmitted to a local node (RN, Remote Node) located at the subscriber side or the subscriber side.

On the other hand, the upward seed light BLS2 generated by the C-band broadband light source 240 provided in the relay 200 is input to port 6 of the second optical rotator 222 to port 5 along the optical path. Be guided. The uplink seed light BLS2 outputted through port 5 is input to the WDM filter 230 and transmitted to a subscriber station or a local node (RN) located at the subscriber side.

The subscriber side transmits the uplink signal light S2 whose wavelength is fixed by the upside seed light BLS2 by the C-band broadband light source 240 to the national company side.

The upward signal light S2 is input to the WDM filter 230 and input to port 5 of the second optical rotor 222. The upward signal light S2 input to the fifth port is output to the fourth port along the optical path of the second optical rotator 222. The uplink signal light S2 output from port 4 is amplified by the second amplifier 212 and output.

The uplink signal light S2 output from the second amplifier 212 is input to the second port of the first optical rotator 221, output to the first port, and transmitted to the national company side.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, it is intended that the scope of the invention be defined solely by the claims appended hereto, and that all equivalents or equivalent variations thereof fall within the spirit and scope of the invention.

1 is a view showing a conventional general WDM-PON,

2 is a view of a WDM-PON employing a wavelength independent light source of the conventional seed light source injection method,

3 is a block diagram of a WDM-PON-based relay device according to a first embodiment of the present invention;

4 is a block diagram of a WDM-PON-based relay device according to a second embodiment of the present invention;

5 is a block diagram of a WDM-PON-based relay device according to a third embodiment of the present invention;

FIG. 6 is a view illustrating a WDM-PON-based relay device according to a third embodiment of the present invention. FIG.

7 is a block diagram of a WDM-PON-based relay device according to a fourth embodiment of the present invention;

8 is a block diagram of a WDM-PON-based relay device according to a fifth embodiment of the present invention;

FIG. 9 is a diagram illustrating a WDM-PON-based relay device according to a fifth embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: relay 111: first amplifier

112: second amplifier 113: optical isolator

120: first optical coupling unit 130: second optical coupling unit

140: seed light source generation unit 150: light circulation unit

Claims (16)

WDM-PON based relay device, A first optical coupling part which splits the downlink signal light and the upside seed light transmitted from the national company side; A first amplifier configured to amplify the downlink signal light branched from the first optical coupler; A seed light source generating unit generating seed light used as a wavelength fixing light source of the uplink signal light transmitted from the subscriber side; A second optical coupler which receives the downlink signal light amplified by the first amplifier and the seed light generated by the seed light source generator and transmits the received signal to the subscriber and outputs the uplink signal received from the subscriber; And WDM-PON-based relay device comprising a second amplifier for amplifying the uplink signal light output from the second optical coupling unit. The method of claim 1, And the first optical coupling unit receives the uplink signal light amplified by the second amplifying unit and transmits the uplink signal light to a station. The method of claim 1, The second amplifying unit includes an optical isolator connected to the first optical coupling unit so that the upside seed light branched from the first optical coupling unit is input, and blocking the transmission of the upside seed light to the subscriber side. WDM-PON based relay device. The method of claim 2, And the second amplifying unit is connected to the first optical coupling unit by an optical path and transmits the uplink signal light amplified through the optical path to the first optical coupling unit. 5. The method of claim 4, The optical path includes a WDM-PON-based repeater, characterized in that it comprises an optical isolator to block the input of the upside seed light branched from the first optical coupling unit to the second amplifier. The method of claim 1, The second optical coupling unit receives the uplink signal light and the seed light and transmits the uplink signal light to the second amplification unit, and includes a light circulation unit for transmitting the seed light to the subscriber side WDM-PON-based Repeater. The method of claim 1, And the first and second amplifiers are Erbium-doped fiber amplifiers (EDFAs). The method of claim 7, wherein The first amplification unit is a WDM-PON-based repeater, characterized in that the erbium-doped optical fiber optical amplifier for amplifying the down-signal light of L-band (wavelength: 1570 ~ 1610nm). The method of claim 7, wherein The second amplification unit WDM-PON-based repeater, characterized in that the erbium-doped optical fiber optical amplifier for amplifying the C-band (wavelength: 1530 ~ 1560nm) uplink signal light. The method of claim 1, The seed light source generation unit is a WDM-PON-based relay device, characterized in that the C-band broadband light source (BLS, Broadband Light Source). WDM-PON based relay device, A first amplifying unit for amplifying the downlink signal light by using the upside seed light transmitted from a national company as a secondary pump light for amplifying the downlink signal light; A seed light source generating unit generating seed light used as a wavelength fixing light source of the uplink signal light transmitted from the subscriber side; An optical coupling unit configured to receive the downlink signal light amplified by the first amplification unit and the seed light generated by the seed light source generation unit and transmit the received downlink signal light to the subscriber side and output the uplink signal light transmitted from the subscriber side; A second amplifier for amplifying the uplink signal light output from the optical coupling unit; And WDM-PON-based relay comprising a first optical circulator for receiving the up-side seed light and the downlink signal light transmitted from the country side to the first amplifier and transmits the uplink signal light amplified by the second amplifier to the country side Device. The method of claim 11, The optical coupling unit includes a second optical circulator for receiving the uplink signal light and the seed light to transmit the uplink signal light to the second amplifying unit and transmitting the seed light to a subscriber side. Repeater. The method of claim 11, And the first and second amplifiers are Erbium-doped fiber amplifiers (EDFAs). The method of claim 13, The first amplification unit is a WDM-PON-based repeater, characterized in that the erbium-doped optical fiber optical amplifier for amplifying the down-signal light of L-band (wavelength: 1570 ~ 1610nm). The method of claim 13, The second amplification unit WDM-PON-based repeater, characterized in that the erbium-doped optical fiber optical amplifier for amplifying the C-band (wavelength: 1530 ~ 1560nm) uplink signal light. The method of claim 11, The seed light source generation unit is a WDM-PON-based relay device, characterized in that the C-band broadband light source (BLS, Broadband Light Source).

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