KR20050090232A - Wavelength division multiplexed passive optical network capable of independent self-healing - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a wavelength division multiplexing passive optical subscriber network capable of independent self-healing capable of recovering a network by sensing cut and degradation of trunk and distribution optical fibers.

2. The technical problem to be solved by the invention

An object of the present invention is to provide a wavelength division multiple access passive optical network capable of independent self-healing that can recover a network by detecting cutting and deterioration of trunk and distribution optical fibers in an optical subscriber network having a molded structure.

3. Summary of the Solution of the Invention

The present invention includes a central base station and a local base station connected to the central base station through an operating trunk optical fiber and a protective trunk optical fiber, and connected to a plurality of (N-1) subscriber devices through an operational distribution optical fiber and a protective distribution optical fiber. In a wavelength division multiplexing passive optical subscriber network capable of independent self-healing, one of the operation trunk fibers or the protection trunk fibers, data for transmitting to the plurality of subscriber devices, is provided through the downlink light source for each subscriber. A central base station for optically modulating a downlink optical signal multiplexed to the local base station and receiving and multiplexing the multiplexed uplink optical signals transmitted from the local base station for each subscriber station; Splitting the multiplexed downlink optical signal transmitted from the central base station and demultiplexing each split downlink optical signal for each subscriber device and delivers the splitted downlink optical signal to the corresponding subscriber device through the operation distribution fiber and the protection distribution fiber. And split the uplink optical signal from each subscriber device into one optical signal and split the split optical multiplexed uplink optical signal through the operational distribution fiber and the protective distribution fiber. The local base station for transmitting to; And modulating the downlink optical signal by receiving a modulated downlink optical signal corresponding to a predetermined subscriber station demultiplexed from the local base station through one of the operational distribution optical fiber and the protective distribution optical fiber, and optically demodulating the modulated downlink optical signal. And the plurality of subscriber stations for optically modulating and transmitting uplink signals to a base station.

4. Important uses of the invention

The present invention is used for wavelength division multiplex passive optical subscriber network.

Description

Wavelength Division Multiplexed Passive Optical Network capable of independent Self-healing

The present invention relates to a self-healing passive optical subscriber network capable of recovering a network on its own by detecting cuts and degradation of trunk and distribution optical fibers.

Wavelength-Division Multiplexed (WDM) Passive Optical Network (PON) gives each subscriber a unique wavelength to communicate, ensuring confidentiality of communication and requiring separate subscribers It can easily accommodate the expansion of communication service or communication capacity. And by adding the unique wavelengths that will be given to new subscribers, the number of subscribers can be easily expanded.

In general, the wavelength division multiplex passive optical subscriber network uses a double star structure. That is, the central base station (CO) to the local base station (RN) installed in the subscriber's adjacent area is connected by one feeder fiber, and the independent base station fiber is distributed from the local base station to each subscriber. To form a connection.

The multiplexed downlink signals are transmitted to a local base station through one trunk fiber, demultiplexed by a multiplexer / demultiplexer located in a local base station, and then each subscriber device through a distributed optical fiber independently connected to each subscriber. Is sent until.

And, the uplink signal output from the subscriber device is transmitted to the local base station through the distribution optical fiber independently connected to each subscriber, after each uplink signal for each subscriber input from the multiplexer / demultiplexer located in the local base station is multiplexed Is transmitted to the central base station.

In such a wavelength division multiplexing passive optical subscriber network, if an unexpected accident occurs, such as cutting off a trunk or a distributed optical fiber for each subscriber, even if the time of the accident is short, a large amount of transmitted data is lost. Therefore, the accident must be detected and recovered quickly.

Therefore, it is essential to develop a self-healing wavelength division multiplex passive optical subscriber network that can detect and repair accidents such as cutting of trunk and split optical fibers on the implemented optical link.

1A to 1B are exemplary views illustrating a conventional wavelength division multiplex self-healing annular network.

In general, as a method for smoothly recovering in case of an accident such as cutting of a transmission fiber in a wavelength division multiplex optical communication network, an annular network connecting annularly between nodes is mainly used.

In the conventional self-healing ring network, the central base station 100, the local base station 1 200, and the local base station 2 300 are connected by two optical fibers.

Here, the two strands of optical fibers are divided into working fibers and protection fibers, and under normal conditions, the central base station 100 transmits signals of various wavelengths to the two strands of optical fibers (for example, λ1 and λ2). The multiplexed 101 transmits the same optical signal (101, 102, 103). Then, the local base station 1 (200) or the local base station 2 (300) drop the optical signal coming from both strands to the unidirectional add / drop multiplexer (108, 109, 112, 113) The optical switching elements 110, 111, 114, and 115 are used to receive optical signals having good characteristics.

Similarly, the local base station 1 (200) or the local base station 2 (300) also transmits the same optical signal to the two strands of optical fiber, and the central base station 100 also demultiplexes the optical signals for each wavelength (106, 107) to the optical switching element ( 104 and 105 are used to selectively receive one of the two optical signals.

On the other hand, Figure 1b is a configuration diagram of one embodiment when a failure occurs in the system, such as cutting the optical fiber in the operating line.

In the conventional self-healing annular network, when a failure occurs in an operation line, the self-healing operation is performed.

First, assuming that the optical fiber is disconnected between the local base station 1 200 and the local base station 2 300, the local base station 2 300 may receive the second channel λ 2 in the counterclockwise direction through the operation line. Because it cannot be received, it receives channel 2 (λ2) coming in the clockwise direction through the protective fiber. In addition, since the local base station 1 200 cannot add and send the first channel λ1 in the counterclockwise direction through the operation line, the first base station λ1 is switched in the clockwise direction through the protective optical fiber by switching the optical switching element 110. ). As such, the conventional annular network enables self-healing in the event of a system failure.

Such a self-healing ring network is effective when the central base station and a plurality of regional base stations are separated by a certain distance (several kilometers), but passive optical fiber connecting the central base station, the regional base station, and the subscribers is effective. It is not appropriate to adopt such an annular network structure in the subscriber network. That is, since the passive optical subscriber network generally has a molded structure, a new concept of self-healing method must be devised from the self-healing method in the annular network structure.

The present invention has been proposed to solve the above problems, and the wavelength division multiplex passive type capable of independent self-healing by detecting the cutting and deterioration of the trunk and distribution optical fibers in the optical subscriber network having a molding structure and recovering the network by itself. The purpose is to provide an optical subscriber network.

The present invention for achieving the above object is connected to the central base station and the central base station and the operating trunk optical fiber and the protective trunk optical fiber, a plurality of (N-1) subscriber unit and the operation distribution optical fiber and the protective distribution optical fiber In an independent self-healing wavelength division multiplex passive optical subscriber network including a local base station connected through a network, data for transmission to the plurality of subscriber devices is transmitted through one of the operation trunk fiber or the protection trunk fiber. A central base station configured to optically modulate the multiplexed downlink optical signals through downlink light sources for each subscriber to the local base station, and receive multiplexed uplink optical signals transmitted from the local base station and demultiplex each subscriber device; Splitting the multiplexed downlink optical signal transmitted from the central base station and demultiplexing each split downlink optical signal for each subscriber device and delivers the splitted downlink optical signal to the corresponding subscriber device through the operation distribution fiber and the protection distribution fiber. And split the uplink optical signal from each subscriber device into one optical signal and split the split optical multiplexed uplink optical signal through the operational distribution fiber and the protective distribution fiber. The local base station for transmitting to; And modulating the downlink optical signal by receiving a modulated downlink optical signal corresponding to a predetermined subscriber station demultiplexed from the local base station through one of the operational distribution optical fiber and the protective distribution optical fiber, and optically demodulating the modulated downlink optical signal. And a plurality of subscriber stations for optically modulating and transmitting uplink signals to a base station.

In addition, the present invention is a regional base station is connected to the central base station, the main base station and the main optical fiber for protection and the main trunk optical fiber, the local base station is connected to a plurality of (N-1) subscriber devices and the operation distribution optical fiber and the protective distribution optical fiber In the wavelength division multiplexing passive optical subscriber network capable of independent self-healing comprising: a modulated multiplexed downlink optical signal for transmitting to the plurality of subscriber devices through one of the operation trunk fiber or the protection trunk fiber; The central base station for transmitting downlink signals multiplexed with the uplink light source optical signals used as the injection light in a plurality of subscriber apparatuses, and receiving multiplexed uplink optical signals transmitted from the local base station and demultiplexing the respective subscriber apparatuses; Splitting the downlink signal transmitted from the central base station and demultiplexing each split downlink signal into a downlink optical signal modulated by each subscriber device and an uplink light source signal for each subscriber device; It transmits through the protective distribution optical fiber to the corresponding subscriber device, and splits the uplink optical signal from each subscriber device into a single optical signal and splits each of the split up multiplexed uplink optical signals for the operation. A local base station transmitting the distributed optical fiber and the protective distributed optical fiber to the central base station; And optically demodulate the modulated downlink optical signal by receiving a modulated downlink optical signal for each subscriber device and an uplink light source for each subscriber device from the local base station through one of the operational distribution optical fibers and the protective optical fiber. And a plurality of subscriber stations for modulating and outputting data to be transmitted to a central base station using the uplink light source optical signal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same components in the drawings are represented by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a block diagram of a first embodiment of an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention.

As shown in FIG. 2, the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the first embodiment of the present invention includes a downlink light source 201-1-201 (n-1) and an uplink optical receiver ( 202-1 to 202- (n-1)), wavelength division multiplexers 203-1 to 203 (n-1), 1 × (N-1) multiplexer / demultiplexer (waveguide train diffraction grating) 204 A central base station 21 including a 1 × 2 optical switching element 205, one strand of operational optical fiber and one strand of protective fiber connecting the central base station 21 and the local base station 22, and a local base station 2x2 optical coupler 207, NxN multiplexer / demultiplexer (waveguide tube diffraction grating) 209 located at 22, the local base station 22 and each subscriber apparatus 23-1 through. One-ply operational optical fiber and one-ply protective optical fiber connecting 23- (n-1)), a downlink optical receiver 212 and an uplink light source 213, and a wavelength division multiplexer for branching / combining up-down signals (WDMC) ( 211, subscriber devices 23-1 to 23-(n-1) including a 1 × 2 optical switching element 210.

Referring to FIG. 2, the operation of the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the first embodiment of the present invention is as follows.

First, as to the downlink signal, the downlink light sources 201-1 to 201-(n-1) of the central base station 21 are assigned to each of the plurality of subscriber stations 23-1 to 23-(n-1). And downlink optical signals λ _d1 to λ _{d (n-1) that} are modulated by optically modulating respective data for delivery to a plurality of subscriber stations 23-1 to 23- _(n-1) . Outputs Each of the modulated downlink optical signals λ _d1 to λ _{d (n-1)} passes through a wavelength division multiplexer 203-1 to 203- (n-1) to 1 × (N-1) waveguide train diffraction grating. N-1 optical signals are inputted from the first terminal of the second side to the N-1th terminal of the second side of 204 and multiplexed into one optical signal so that the 1x (N-1) waveguide train diffraction grating 204 It is output to the 1st terminal of 1 side.

The multiplexed modulated downlink optical signal λ _down output from the first terminal on the first side of the 1 × (N-1) waveguide train diffraction grating 204 is transmitted to the 1 × 2 optical switching element 205. The multiplexed modulated downlink optical signal λ _down transmitted to the 1 × 2 optical switching element 205 is transmitted to the local base station 22 through any one of an operating trunk optical fiber and a protective trunk optical fiber.

The multiplexed modulated downlink optical signal λ _down transmitted from the central base station 21 to the local base station 22 through either the operating trunk fiber or the protective trunk fiber is 2 × 2 light located in the local base station 22. Input to an optical coupler 207. The multiplexed modulated downlink optical signal λ _down transmitted from the central base station 21 to the local base station 22 is converted from the 2 × 2 optical coupler 207 to two optical signals λ _down1 and λ _down2 . Splitted. At this time, one of the two split optical signals λ _down1 is input to the first terminal of the first side of the N × N waveguide train diffraction grating 209, and the second side of the N × N waveguide train diffraction grating 209 is provided. It is demultiplexed to terminal 1 to terminal N-1 and delivered to each subscriber device 23-1 to 23- (n-1) through an operational distribution optical fiber. In addition, the other one of the two split optical signals λ _down2 is input to the N-th terminal of the second side of the N × N waveguide train diffraction grating 209, and thus, the first of the N × N waveguide train diffraction grating 209. It is demultiplexed to the second terminals to the N-th terminal and transmitted to the respective subscriber apparatuses 23-1 to 23- (n-1) through the protective distribution optical fiber.

Each of the subscriber apparatuses 23-1 to 23- (n-1) is connected to an operational distribution optical fiber and a protective distribution optical fiber, respectively. The operation according to the subscriber apparatus 1 (23-1) is as follows.

The optical signal λ _d1 transmitted through the operational distribution optical fiber and the protective distribution optical fiber to the subscriber device 1 23-1 is input to two input nodes of the 1 × 2 optical switching element 210. The 1 × 2 optical switching element 210 selects one of two input nodes and receives a modulated downlink optical signal λ _d1 . Typically the 1 × 2 optical switching element 210 is switched to an input node connected to an operational distribution fiber. The modulated downlink optical signal λ _d1 received through the 1 × 2 optical switching element 210 is input to the downlink optical receiver 212 through a wavelength division multiplexer (WDMC) 211.

Next, referring to the uplink signal, the uplink light sources 213-1 to 213- (n-1) corresponding to each of the plurality of subscriber stations 23-1 to 23- (n-1) are connected to a central base station ( Each data to be transmitted to 21 is optically modulated to output modulated uplink optical signals λ _u1 to λ _{u (n-1)} . The modulated uplink optical signal λ _u1 to λ _{u (n-1)} passes through the wavelength division multiplexer 211 and is then operated by the 1 × 2 optical switching element 210. It is transmitted to the local base station 22 through one. In this way, the modulated uplink optical signals λ _u1 to λ _{u (n-1)} from each of the subscriber stations 23-1 to 23- (n-1) transmitted to the local base station 22 are N × N. The signal is multiplexed by the waveguide diffraction grating 209 and then input to a 2x2 optical coupler 207.

At this time, the modulated uplink optical signals λ _u1 to λ _{u (n-1)} from the respective subscriber stations 23-1 to 23- (n-1) transmitted to the local base station 22 through the operational distribution optical fiber _. ) Are input to the first terminal to the N-1 terminal of the second side of the N × N waveguide train diffraction grating 209 located in the local base station 22, and multiplexed into one uplink optical signal λ _up . It is output to the first terminal on the one side and input to the 2x2 optical coupler 207. In addition, the modulated uplink optical signal transmitted to the local base station 22 through the protective distribution optical fiber is transferred to the second to N terminals of the first side of the N × N waveguide train diffraction grating 209 located in the local base station 22. They are input and multiplexed into one uplink optical signal λ _up, respectively, and are output to the second N-th terminal and input to the 2 × 2 optical coupler 207.

The multiplexed modulated uplink optical signal λ _up input to the 2x2 optical coupler 207 is split into two optical signals. In this case, the split two optical signals λ _{up1 and} λ _up2 are transmitted to the central base station 21 through the operation trunk optical fiber and the protection trunk optical fiber, respectively.

Two multiplexed modulated uplink optical signals λ _up1, λ _up2 transmitted to the central base station 21 via the operating trunk fiber and the protective trunk fiber are 1 × 2 optical switching elements 205 located in the central base station 21. Only one is input by. That is, the 1 × 2 optical switching element 205 selectively switches either an input node connected to an operational distribution optical fiber or an input node connected to a protective distribution optical fiber to provide two multiplexed modulated uplink optical signals applied to two input nodes. Only one of (λ _up1, λ _up2 ) is input. As such, the multiplexed modulated uplink optical signal input through the 1 × 2 optical switching element 210 (assuming that λ _up1 is input through an operation distribution optical fiber) is an N × N waveguide string. The first terminal of the diffraction grating 203 is input to the first terminal of the diffraction grating 203, and then demultiplexed, and is then output to the first through N-1 terminals of the second side of the N × N waveguide train diffraction grating 203. The modulated uplink optical signals λ _u1 to λ _{u (n-1} ) that are demultiplexed and output as described above are passed through respective wavelength division multiplexers 203-1 to 203- (n-1), respectively. (23-1 to 23- (n-1)), which are inputted to the uplink optical receivers 202-1 to 202- (n-1), and detected as electrical signals.

3 is a diagram illustrating an embodiment of a wavelength band of a downward light source and a wavelength band of an upward light source according to the present invention.

As shown in FIG. 3, the wavelength band 31 of the downlink light source and the wavelength band 32 of the upstream light source according to the present invention are bidirectional wavelength division multiplexed passive light simultaneously transmitting up and down signals using a single fiber. In the subscriber network, the downlink wavelength band and the uplink wavelength band are allocated so as to be distinguished from each other. That is, the waveguide train diffraction gratings 203 and 209 used as the multiplexer / demultiplexer have a periodic pass characteristic with a free spectral range (FSR), so that one waveguide train diffraction grating is distinguished even if the up and down wavelength bands are separated from each other. Up and down signals can be multiplexed / demultiplexed simultaneously by using (203, 209).

FIG. 4 is a diagram illustrating an embodiment of an optical fiber failure for operation in an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention.

As shown in FIG. 4, each subscriber station 23-1 to 23- (n-1) in the case of failure of the main optical fiber for operation in the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the present invention. The uplink optical signals λ _u1 to λ _{u (n−1)} transmitted by λ are not transmitted to the central base station 21 through the trunk fiber for operation. Then, the 1 × 2 optical switching element 205 of the central base station 21 switches the switching state so that communication between the central base station 21 and the subscriber stations 23-1 to 23- (n-1) is carried out through the protective optical fiber. To be done. At this time, since the same uplink optical signal is transmitted to the 1x2 optical switching element 205 of the central base station 21 through the protective trunk fiber by the 2x2 optical coupler 207 located in the local base station 22. Recovery is complete.

FIG. 5 is a block diagram of an embodiment of a distribution optical fiber for operation in a wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the present invention.

As shown in FIG. 5, in the case of failure of a distribution optical fiber for operation in a wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the present invention (in the embodiment of the present invention, the subscriber device 1 (23-1) illustrates that a barrier to copper action distribution fibers), the first of the 1 × 2 optical switch element 210 in the input (the subscriber 1 (23-1), so λ _d1) the extinction of the received downstream optical receiver 212 As the state is switched, the downlink optical signal λ _d1 is received through the protective distribution optical fiber. At this time, the state of the 1 × 2 optical switch element 210 in the remaining optical subscribers 23-2 to 23- (n-1) does not change. In the case of the central base station 21, the uplink optical signal λ _u1 corresponding to the subscriber 1 (23-1) is transmitted through the protective trunk optical fiber, and the remaining optical subscribers 23-2 to 23- (n-1). Uplink optical signals λ _u2 to λ _{u (n-1)} corresponding to ₎ ) are continuously transmitted through the trunk fiber for operation. In addition, the subscriber device 1 (23-1) informs the central base station 21 of the state of the 1x2 optical switching element 210 to confirm the failure of the distributed optical fiber between the local base station 22 and the subscriber 23-1. To help.

6 is a block diagram of a second embodiment of an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention.

As shown in FIG. 6, the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the second embodiment of the present invention includes a downward light source 301-1 to 301 (n-1) and an upward optical receiver ( 302-1 to 302- (n-1)), an NxN multiplexer / demultiplexer (waveguide train diffraction grating) 303, one wavelength division multiplexer 304, and a 1x2 optical switching element 305 A central base station 31 is included. The configuration of the local base station 22 and each of the subscriber apparatuses 23-1 to 23- (n-1) is the same as in the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the first embodiment of the present invention. Since the configuration has a detailed description thereof will be omitted.

The wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the second embodiment of the present invention has a central base station 21 in the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the first embodiment of the present invention. ) Is another example. That is, the central base station 21 according to the second embodiment of the present invention, like the central base station 21 according to the first embodiment of the present invention, multiple (n-1) wavelength division multiplexers corresponding to each channel and 1 ×. (N-1) A waveguide multiplexer and an N × N waveguide train diffraction grating are used instead of the waveguide train diffraction grating.

Referring to FIG. 6, the operation of the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the second embodiment of the present invention will be described.

First, referring to the downlink signals, the downlink light sources 301-1 through 301- (n-1) of the central base station 31 are allocated to each of a plurality of subscriber apparatuses, and are transmitted to the plurality of subscriber apparatuses. Each data is optically modulated to output a modulated downlink optical signal lambda _d1 to lambda _{d (n-1)} . Each of the modulated downlink optical signals λ _d1 to λ _{d (n-1)} includes N _-1 optical signals from the first terminal of the second side of the N × N waveguide train diffraction grating 303 to the N-1 terminal. The signal is input as a signal, multiplexed by one optical signal λ _down , and output to the first terminal of the first side of the N × N waveguide train diffraction grating 303.

The multiplexed modulated downlink optical signal λ _down output from the first terminal of the N × N waveguide train diffraction grating 303 passes through the wavelength division multiplexer 304 to provide a 1 × 2 optical switching element 305. Is delivered. The multiplexed modulated downlink optical signal λ _down transmitted to the 1 × 2 optical switching element 305 is transmitted to the local base station 22 through any one of an operating trunk optical fiber and a protective trunk optical fiber.

The multiplexed modulated downlink optical signal λ _down transmitted from the central base station 21 to the local base station 22 via either the operating trunk fiber or the protective trunk fiber is a 2 × 2 optical coupler located at the local base station 22. 207). The multiplexed modulated downlink optical signal λ _down transmitted from the central base station 21 to the local base station 22 is split into two optical signals λ _down1 and λ _down2 at the 2 × 2 optical coupler 207. The split, (λ _down1) of putting the two optical signals (λ _down1, λ _down2) is input to the first-side first terminal of the N × N waveguide thermal diffraction grating (209) N × N waveguide heat grating ( 209 is demultiplexed (λ _d1 to λ _{d (n-1)} ) to the first terminal to the N- _th terminal of the second side, and each subscriber 23-1 to 23- (n− 1)). Also, it split the other of putting the two optical signals _{(λ down1, λ down2) (} λ down2) is input to the second side the N terminal of the N × N waveguide thermal diffraction grating (209) N × N waveguide heat diffraction The subscriber terminals 23-1 to 23- (are demultiplexed with the second terminals to the Nth terminals on the first side of the grating 209 ((λ _d1 to λ _{d (n-1)} )) through a protective distribution optical fiber. n-1)).

Each of the subscriber apparatuses 23-1 to 23- (n-1) is connected to an operational distribution optical fiber and a protective distribution optical fiber, respectively. The operation according to the subscriber apparatus 1 (23-1) is as follows.

The optical signal transmitted through the operating distribution optical fiber and the protective distribution optical fiber to the subscriber device 1 (23-1) is input to two input nodes of the 1x2 optical switching element 210. Typically the 1 × 2 optical switching element 210 is switched to an input node connected to an operational distribution fiber. The optical signal λ _d1 input through the 1 × 2 optical switching element 210 is input to the downlink optical receiver 212 through the wavelength division multiplexer (WDMC) 211.

Next, referring to the uplink signal, the uplink light sources 213-1 to 213- (n-1) corresponding to each of the plurality of subscriber stations 23-1 to 23- (n-1) are connected to the central base station ( Each data to be transmitted to 21 is optically modulated to output modulated uplink optical signals λ _u1 to λ _{u (n-1)} . The modulated uplink optical signal λ _u1 to λ _{u (n-1)} passes through the wavelength division multiplexer 211 and is then operated by the 1 × 2 optical switching element 210. It is transmitted to the local base station 22 through one. In this way, the modulated uplink optical signals λ _u1 to λ _{u (n-1)} from each of the subscribers 23-1 to 23- (n-1) transmitted to the local base station 22 are N × N waveguides. Multiplexed by the thermal diffraction grating 209 and then input to the 2x2 optical coupler 207.

At this time, the modulated uplink optical signal λ _u1 ˜ _{u (n-1)} transmitted to the local base station 22 through the operation distribution fiber is N × N waveguide train diffraction grating 209 located in the local base station 22. After input to the first terminal of the second side to the N-th terminal of the N) multiplexed and then output to the first terminal of the first side is input to the 2 × 2 optical coupler (207). In addition, the modulated uplink optical signals λ _u1 ˜ _{u (n-1)} transmitted through the protective distribution optical fiber to the local base station 22 are N × N waveguide train diffraction gratings 209 located at the local base station 22. After input to the second terminal to the N-th terminal of the first side multiplexed, and then multiplexed to the second terminal (N) terminal is input to the 2 × 2 optical coupler 207.

The multiplexed modulated uplink optical signal λ _up input to the 2 × 2 optical coupler 207 is split into two optical signals λ _up1 , λ _up2 . In this case, the split two optical signals λ _up1 and λ _up2 are transmitted to the central base station 31 through the operation trunk optical fiber and the protection trunk optical fiber, respectively.

The two multiplexed modulated uplink optical signals λ _up1 and λ _up2 transmitted to the central base station 31 through the operating trunk fiber and the protective trunk fiber are 1 × 2 optical switching elements 305 located in the central base station 31. Only one is input by. That is, the 1 × 2 optical switching element 305 selectively switches either one of an input node connected to an operational distribution optical fiber or an input node connected to a protective distribution optical fiber to provide two multiplexed modulated uplink optical signals applied to two input nodes. Only one of (λ _up1 , λ _up2 ) is input. In the embodiment of the present invention, it is assumed that λ _up1 is input through an operation distribution optical fiber. In this way, the modulated upward optical signal λ _up1 input through the 1 × 2 optical switching element 310 passes through the wavelength division multiplexer 304 to the N- _th terminal of the first side of the N × N waveguide train diffraction grating 303. After demultiplexing (λ _u1 to λ _{u (n-1)} ), the signals are output to the first through N-1 terminals of the second side of the N × N waveguide train diffraction grating 303. The modulated uplink optical signals λ _u1 to λ _{u (n-1} ) that are demultiplexed and output as described above are uplink optical receivers 202-1 to respective subscribers 23-1 to 23- (n-1). 202- (n-1)) and detected as an electrical signal.

7 is a configuration diagram of a third embodiment of an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention.

As shown in FIG. 7, the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the third embodiment of the present invention is a wavelength division multiplexing self-healing passive optical subscriber network using a wavelength injection method. (401-1 to 401- (n-1)) and upward optical receivers 402-1 to 402- (n-1), N × N multiplexer / demultiplexer (waveguide train diffraction grating) 403, downward light source Broadband light source (BLS) 406, broadband light source (BLS) 410 for upward light source, first and second circulators 408 and 412 for determining the optical path, wavelength division multiplexer 404 ), A central base station 41 including a 1 × 2 optical switching element 405. The configuration of the local base station 22 and each of the subscriber apparatuses 23-1 to 23- (n-1) is similar to that of the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the first embodiment of the present invention. Since it has a configuration, detailed description thereof will be omitted.

In the third embodiment of the present invention, a broadband light source for the first circulator, the second circulator, and the upward or downward light source is compared with the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the second embodiment of the present invention. (Broadband Light Source) is further included.

Referring to FIG. 7, the operation of the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the third embodiment of the present invention will be described.

First, as to the downlink signal, the downlink light source BLS 406 of the central base station 41 passes through the first circulator 408 to the first terminal of the first side of the N × N waveguide train diffraction grating 403. Is entered. The input BLS 406 for the downlink light source is demultiplexed. At this time, the demultiplexing of the N × N waveguide train diffraction grating 403 is performed by the downlink light source BLS 406 inputted to the first terminal of the first side of the N × N waveguide train diffraction grating 403. N-1 wavelength-specific optical signals are separated from the first terminal of the second side of the thermal diffraction grating 403 to the N-1th terminal.

Each of the demultiplexed optical signals for each wavelength is used as the down-injected light for down-modulation, thereby transmitting the transmission data in the down-light sources 401-1 to 401- (n-1) assigned to each subscriber. Modulate.

Each optical signal λ _d1 to λ _{d (n−1)} modulated by the downlink light sources 401-1 to 401- _{n-1 is} the second of the N × N waveguide train diffraction grating 403. N-1 optical signals are input from the first terminal to the N-1 terminal and multiplexed into one optical signal (λ _down ) to the first terminal of the N × N waveguide train diffraction grating 403. Is output.

As described above, the multiplexed modulated optical signal λ _down output from the first terminal of the N × N waveguide train diffraction grating 403 is transmitted to the wavelength division multiplexer 404 through the first circulator 408. Delivered. In addition, the multiplexed modulated optical signal λ _down transmitted to the wavelength division multiplexer 404 is a BLS 410 (λ _u1 to λ _{u (n-1} ) for upstream light sources transmitted through the second circulator 410. ₎ And once again are multiplexed into a downlink optical signal λ _sum and are transmitted to the 1 × 2 optical switching element 405. The multiplexed downlink optical signal λ _sum transmitted to the 1 × 2 optical switching element 405 is transmitted to the local base station 22 through any one of an operation trunk optical fiber and a protection trunk optical fiber.

The multiplexed downlink optical signal λ _sum transmitted from the central base station 21 to the local base station 22 through either the operating trunk fiber or the protective trunk fiber is a 2 × 2 optical coupler located at the local base station 22. Coupler). In the central office 21, local base station 22, the multiplexed downstream optical signals (λ _sum) transferred to the 2 × 2 optical coupler (Optical Coupler) (207) from the two downstream optical signals (λ _sum1, λ _sum2) Splitted. The splitting the two downstream optical signals (λ _sum1, λ _sum2) a (λ _sum1) is input to the first-side first terminal of the N × N waveguide thermal diffraction grating 209 of the N × N waveguide heat grating After the demultiplexed (λ _d1 + λ _u1 to λ _{d (n-1)} + λ _{u (n-1)} ) to the first terminal to the N−1th terminal of the second side of 209, through the distribution optical fiber for operation Each subscriber 23-1 to 23- (n-1). Also, it split the other of putting the two optical signals _{(λ sum1, λ sum2) (} λ sum2) is input to the second side the N terminal of the N × N waveguide thermal diffraction grating (209) N × N waveguide heat diffraction After demultiplexing the second side to the Nth terminal of the first side of the grating 209 (λ _d1 + λ _u1 to λ _{d (n-1)} + λ _{u (n-1)} ), Is delivered to subscriber devices 23-1 through 23- (n-1).

Each of the subscriber apparatuses 23-1 to 23- (n-1) is connected to an operational distribution optical fiber and a protective distribution optical fiber, respectively. The operation according to the subscriber apparatus 1 (23-1) is as follows.

The downlink optical signal λ _d1 + λ _u1 transmitted through the operating distribution optical fiber and the protective distribution optical fiber to the subscriber device 1 23-1 is input to two input nodes of the 1 × 2 optical switching element 210. The 1 × 2 optical switching element 210 selects one of two input nodes and receives the transmitted downlink optical signal λ _d1 + λ _u1 . Typically the 1 × 2 optical switching element 210 is switched to an input node connected to an operational distribution fiber. Further, the downlink optical signal λ _d1 + λ _u1 input through the 1 × 2 optical switching element 210 is demultiplexed and modulated by the wavelength division multiplexer (WDMC) 211 to modulate the downlink optical signal λ _d1 . Is input to the downward light receiver 212, and the optical signal λ _u1 for the upward light source is injected into the upward light source 213.

Next, in the upstream signal, the upstream light source 213 receives the upstream light source optical signal λ _u1 transmitted from the central base station 406 to the corresponding subscriber device 23-1 through the local base station 22. It modulates the data to be transmitted to the central base station 406 by using the modulated uplink optical signal.

The modulated uplink optical signal λ _u1 is then passed through the wavelength division multiplexer 211 and then transmitted to the local base station 22 through a distribution fiber for operation currently connected by the 1 × 2 optical switching element 210. .

Each uplink signal λ _u1 λ _{u (n-1)} from each of the subscribers 23-1 to 23- (n-1) transmitted to the local base station is N × N waveguide train diffraction grating 209. After transmission to the central base station 41 through the trunk optical fiber and the protective distribution optical fiber after the multiplexed by (λ _up ).

Here, modulation for each subscriber 23-1 to 23- (n-1) transmitted from each subscriber 23-1 to 23- (n-1) to the local base station 22 with an operational distribution optical fiber. The optical signals λ _u1 to λ _{u (n-1)} are input to the first through N-1 terminals of the second side of the N × N waveguide train diffraction grating 209 located in the local base station 22, thereby Multiplexed by the multiplexed uplink optical signal λ _up1 and output to the first terminal of the first side of the N × N waveguide train diffraction grating 209, and to the central base station 21 through the operating trunk optical fiber and the protective trunk optical fiber. Delivered. In addition, modulated light for each subscriber 23-1 to 23- (n-1) transmitted from each subscriber 23-1 to 23- (n-1) to the local base station 22 as a protective distribution optical fiber. After the signals λ _u1 to λ _{u (n-1)} are input and multiplexed to the second to Nth terminals of the first side of the N × N waveguide train diffraction grating 209 located in the local base station 22 (λ) _up2 ) The second terminal of the N × N waveguide train diffraction grating 209 is output to the central base station 41 through the protective distribution optical fiber.

In addition, the 1 × 2 optical switching element 405 located in the central base station 41 selectively switches any one of an input node connected to an operation trunk optical fiber or an input node connected to a protective trunk optical fiber to be applied to two input nodes. Only one of the multiplexed modulated uplink optical signals λ _up1 and λ _up2 is received. In the embodiment of the present invention, it is assumed that λ _up1 is input through an operation trunk optical fiber. As such, the multiplexed modulated uplink optical signal λ _up1 input through the 1 × 2 optical switching element 405 passes through the second circulator 412 through the wavelength division multiplexer 404 and passes through the N × N waveguide train. It is input to the Nth terminal of the first side of the diffraction grating 403. The multiplexed modulated uplink optical signal λ _up1 is demultiplexed into the respective modulated uplink optical signals λ _u1 to λ _{u (n-1)} in the N × N waveguide train diffraction grating 403. Upward optical receivers 205 respectively output through the second to Nth terminals of the second side of the N × N waveguide train diffraction grating 403 and according to the respective subscriber apparatuses 23-1 to 23- (n-1). -1 to 205- (n-1)). Each uplink optical receiver 205-1 to 205- (n-1) detects an electrical signal from the input modulated uplink optical signals λ _u1 to λ _{u (n-1)} .

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, the present invention provides the wavelength division multiplexing passive optical subscriber network capable of independent self-healing, thereby improving the efficiency of the optical fiber by transmitting the uplink signal and the downlink signal through the optical fiber for operation and protection. .

In addition, the present invention economically and efficiently by using a waveguide thermal diffraction grating for the central base station and the local base station and by using a protective optical fiber that connects the central base station and the subscriber to detect the failure such as the cleavage of the optical fiber to recover quickly It is effective to manage.

1A to 1B illustrate an exemplary embodiment of a conventional wavelength division multiplex self-healing annular network.

Figure 2 is a block diagram of a first embodiment of a wavelength division multiplex self-healing passive optical subscriber network according to the present invention.

Figure 3 illustrates an embodiment of the wavelength band of the downlink light source and the wavelength band of the upward light source according to the present invention.

Figure 4 is an embodiment configuration of the failure of the trunk optical fiber for operation in the wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the present invention.

FIG. 5 is a diagram illustrating an embodiment of a failure of a distribution optical fiber for operation in a wavelength division multiplexing passive optical subscriber network capable of independent self-healing according to the present invention. FIG.

6 is a block diagram of a second embodiment of an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention;

7 is a block diagram of a third embodiment of an independent self-healing wavelength division multiplex passive optical subscriber network according to the present invention;

Claims (11)

An independent magnetic field comprising a central base station and a local base station connected to the central base station through an operational trunk fiber and a protective trunk fiber, and connected through a plurality of (N-1) subscriber devices with an operational distribution fiber and a protective distribution fiber. In the wavelength division multiplex passive optical subscriber network that can heal, Through one of the operation trunk optical fiber or the protection trunk optical fiber, the data to be transmitted to the plurality of subscriber devices through the downlink light source for each subscriber through the optical modulation to transmit the multiplexed downlink optical signal to the local base station, The central base station receiving the multiplexed uplink optical signal transmitted from the local base station and demultiplexing each subscriber device; Splitting the multiplexed downlink optical signal transmitted from the central base station and demultiplexing each split downlink optical signal for each subscriber device and delivers the splitted downlink optical signal to the corresponding subscriber device through the operation distribution fiber and the protection distribution fiber. And split the uplink optical signal from each subscriber device into one optical signal and split the split optical multiplexed uplink optical signal through the operational distribution fiber and the protective distribution fiber. The local base station for transmitting to; And Receives a modulated downlink optical signal corresponding to a predetermined subscriber station demultiplexed from the local base station through one of the operational distribution optical fiber or the protective distribution optical fiber, and optically demodulates the modulated downlink optical signal, and the central base station An independent self-healing wavelength division multiplex passive optical subscriber network comprising the plurality of subscriber devices for optically modulating and transmitting an uplink signal to the apparatus. The method of claim 1, wherein the central base station, A plurality of (N-1) downlink light sources for modulating respective data for delivery to the plurality of subscriber devices; A plurality of N-1 uplink optical receivers for receiving and demodulating the light modulated uplink optical signal; 1 × (N-1) for multiplexing down-modulated downlink optical signals from the plurality of (N-1) downlight sources and receiving multiplexed uplink optical signals transmitted from the local base station and demultiplexing for each subscriber device Multiplexer / demultiplexer; The downlink light source and the uplink optical receiver for each subscriber device are provided between the 1 × (N-1) multiplexer / demultiplexer, and the light modulated downlink optical signal from the downlight source for each subscriber device is converted into 1 ×. (N-1) multiplexing multiplexer (N-1) wavelength division multiplexers for transmitting to the multiplexer / demultiplexer and transferring an uplink optical signal from the 1x (N-1) multiplexer / demultiplexer to the uplink optical receiver (WDMC); And To provide a multiplexed downlink optical signal from the 1 × (N-1) multiplexer / demultiplexer and to receive a multiplexed uplink optical signal from the local base station through one of the operational trunk fiber or the protective trunk fiber. An independent self-healing wavelength division multiplex passive optical subscriber network comprising a first switching unit. The method of claim 2, wherein the local base station, The multiplexed downlink optical signals are demultiplexed by the subscriber apparatuses, respectively, and transmitted to the plurality of subscriber apparatuses through the operational distribution fiber and the protective distribution optical fiber, and multiplexed respective uplink optical signals transmitted from the plurality of subscriber apparatuses. An N × N multiplexer / demultiplexer for outputting multiplexed uplink optical signals; And Splitting the multiplexed downlink optical signal transmitted from the central base station through one of the operational trunk optical fiber or the protective trunk optical fiber to provide to the N × N multiplexer / demultiplexer, and from the N × N multiplexer / demultiplexer And splitting the multiplexed uplink optical signal to provide the central base station to the central base station through the operation trunk optical fiber and the protection trunk optical fiber. Optical subscriber network. The method of claim 3, wherein the plurality of subscriber devices, An upstream light source for optically modulating data for transmission to the central base station; A second for receiving a demultiplexed downlink optical signal from the N × N multiplexer / demultiplexer through one of the operational distribution optical fiber or the protective distribution optical fiber, and for providing a light modulated upstream optical signal through the upstream light source Switching unit; A downlink optical receiver receiving and demodulating the modulated downlink optical signal corresponding to the predetermined subscriber device provided through the second switching unit; and The downward optical receiver and the upward light source and the second switching unit is provided between, and transmits the downward optical signal transmitted from the second switching unit to the downward optical receiver, the upward optical signal transmitted from the upward light source And a wavelength division multiplexer (WDMC) for transmitting to the N × N multiplexer / demultiplexer. The method of claim 1, wherein the central base station, A plurality of (N-1) downlink light sources for modulating respective data for delivery to the plurality of subscriber devices; A plurality of N-1 uplink optical receivers for receiving and demodulating the light modulated uplink optical signal; N × N multiplexer / demultiplexer for multiplexing down-modulated downlink optical signals from the plurality of (N-1) downlight sources and receiving multiplexed uplink optical signals transmitted from the local base station and demultiplexing for each subscriber device ; A first for providing the multiplexed downlink optical signal from the N × N multiplexer / demultiplexer and receiving the multiplexed uplink optical signal from the local base station through one of the operational trunk optical fiber or the protective trunk optical fiber Switching unit; And The NxN multiplexer / demultiplexer is provided between the first switching unit and transmits the multiplexed downlink optical signal from the NxN multiplexer / demultiplexer to the first switching unit, and from the first switching unit. And a wavelength division multiplexer (WDMC) for transmitting the multiplexed uplink optical signal to the N × N multiplexer / demultiplexer. The method of claim 5, wherein the local base station, The multiplexed downlink optical signals are demultiplexed by the subscriber apparatuses, respectively, and transmitted to the plurality of subscriber apparatuses through the operational distribution fiber and the protective distribution optical fiber, and multiplexed respective uplink optical signals transmitted from the plurality of subscriber apparatuses. An N × N multiplexer / demultiplexer for outputting multiplexed uplink optical signals; And Splitting the multiplexed downlink optical signal transmitted from the central base station through one of the operational trunk optical fiber or the protective trunk optical fiber to provide to the N × N multiplexer / demultiplexer, and from the N × N multiplexer / demultiplexer And splitting the multiplexed uplink optical signal to provide the central base station to the central base station through the operation trunk optical fiber and the protection trunk optical fiber. Optical subscriber network. The method of claim 5, wherein the plurality of subscriber devices, An upstream light source for optically modulating data for transmission to the central base station; A second for receiving a demultiplexed downlink optical signal from the N × N multiplexer / demultiplexer through one of the operational distribution optical fiber or the protective distribution optical fiber, and for providing a light modulated upstream optical signal through the upstream light source Switching unit; A downlink optical receiver receiving and demodulating the modulated downlink optical signal corresponding to the predetermined subscriber device provided through the second switching unit; and The downward optical receiver and the upward light source and the second switching unit is provided between, and transmits the downward optical signal transmitted from the second switching unit to the downward optical receiver, the upward optical signal transmitted from the upward light source And a wavelength division multiplexer (WDMC) for transmitting to the N × N multiplexer / demultiplexer. An independent magnetic field comprising a central base station and a local base station connected to the central base station through an operational trunk fiber and a protective trunk fiber, and connected through a plurality of (N-1) subscriber devices with an operational distribution fiber and a protective distribution fiber. In the wavelength division multiplex passive optical subscriber network that can heal, A downlink obtained by multiplexing a modulated multiplexed downlink optical signal for transmitting to the plurality of subscriber apparatuses and an upstream light source optical signal used in the plurality of subscriber apparatuses through one of the operation trunk optical fiber or the protection trunk optical fiber The central base station which transmits a signal and demultiplexes each subscriber station by receiving a multiplexed uplink optical signal transmitted from the local base station; Splitting the downlink signal transmitted from the central base station and demultiplexing each split downlink signal into a downlink optical signal modulated by each subscriber device and an uplink light source signal for each subscriber device; It transmits through the protective distribution optical fiber to the corresponding subscriber device, and splits the uplink optical signal from each subscriber device into a single optical signal and splits each of the split up multiplexed uplink optical signals for the operation. A local base station transmitting the distributed optical fiber and the protective distributed optical fiber to the central base station; And Optical demodulation of the modulated downlink optical signal by receiving a modulated downlink optical signal for each subscriber device and an uplink light source for each subscriber device from the local base station through one of the operational distribution optical fiber and the protective optical fiber, and An independent self-healing wavelength division multiplex passive optical subscriber network including the plurality of subscriber apparatuses for modulating and outputting data to be transmitted to a central base station using an upstream light source optical signal. The method of claim 8, wherein the central base station, A broadband light source for a downlink light source providing a wide band optical signal; The plurality of (N-1) down light sources for modulating light using down-injected light for data transmission to the plurality of (N-1) subscriber devices; The down injection light for each subscriber device, which demultiplexes the broadband optical signal from the broadband light source for the downward light source, is transmitted to the plurality of (N-1) down light sources, respectively, and is provided from the plurality of (N-1) down light sources. 1 × (N-1) multiplexing / demultiplexing operation for multiplexing the modulated downlink optical signal, and 1 for receiving multiplexed uplink optical signals from the local base station and demultiplexing them into a plurality of (N-1) uplink optical receivers. A first N × N multiplexer / demultiplexer for performing a (N−1) multiplexing / demultiplexing operation; A broadband light source for an upward light source providing a wide band optical signal; To provide the wideband optical signal from the broadband light source for the downlink light source to the first N × N multiplexer / demultiplexer and to receive the modulated multiplexed downlink optical signal from the first N × N multiplexer / demultiplexer A first circulator for setting an optical path; A second circuit for receiving an uplink optical signal from the local base station and providing the first N × N multiplexer / demultiplexer and setting an optical path for receiving the wideband optical signal from the broadband light source for the upstream light source; Radar; Receiving the modulated multiplexed downlink optical signal from the first N × N multiplexer / demultiplexer through the first circulator, and receiving an uplink light source optical signal from the broadband light source for the upstream light source through the second circulator; A wavelength division multiplexer (WDMC) for receiving and multiplexing the downlink signal; and And a switching unit configured to transmit a downlink signal output from the wavelength division multiplexer to the local base station through one of the operating trunk fiber or the protective trunk optical fiber, and receive a modulated multiplexed uplink optical signal from the local base station. Wavelength division multiplexing passive subscriber network with independent self-healing. The method of claim 9, wherein the local base station, Splitting and providing the downlink signal transmitted from the central base station, splitting the multiplexed uplink optical signal for transmission to the central base station, and providing the multiplexed uplink optical signal to the central base station through the operation trunk fiber and the protection trunk fiber. 2 x 2 light splitters; And Receives the downlink signal split through the 2 × 2 optical splitter, respectively, and demultiplexes the modulated downlink optical signal for each subscriber device and the upstream light source optical signal for each subscriber device to divide the operation distribution optical fiber and the protection distribution; An N × N multiplexer / demultiplexer for transmitting the multiplexed uplink optical signal from each subscriber device to the corresponding 2x2 optical splitter by transmitting to the corresponding subscriber device through an optical fiber and multiplexing the uplink optical signal from each subscriber device. A wavelength division multiplexing passive optical subscriber network capable of independent self-healing comprising. The method of claim 9, wherein the plurality of subscriber devices, Receiving a demultiplexed modulated downlink optical signal and an uplink light source optical signal from the local base station through one of the operational distribution optical fiber or the protective distribution optical fiber, and providing the uplink optical signal to the local base station; 2 switching unit; A downlink optical receiver for receiving and demodulating the modulated downlink optical signal corresponding to the predetermined subscriber device; and An upward light source that receives the optical signal for the upward light source and modulates upward data; An optical signal for the upstream light source from the second switching unit, the downlink optical receiver being provided between the downlink light receiver and the upstream light source and the second switching unit, and transmitting the downlink optical signal from the second switching unit to the downlink optical receiver; And a wavelength division multiplexer which transmits to the upward light source and provides the upward optical signal modulated by the upward light source to the second switching unit. 2. .