KR20150090667A - Remote node and central office node for protecting wdm ring network - Google Patents

Abstract

The present invention relates to a remote node and a central office node for protecting a wavelength division multiplexing ring network. The remote node according to the present invention includes at least four filters, at least two optical power dividers, at least four optical fiber ports for communicating with an optical fiber of a bidirectional path used in the wavelength division multiplexing ring network, and at least two optical fiber ports for communicating with a remote light transceiver used in the wavelength division multiplexing ring network.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote node and a node for use in protection switching of a wavelength division multi-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of optical communication, and more particularly, to a remote node and a station-use node for protection switching of a wavelength division multiplexing ring network.

As shown in FIG. 1, a wavelength division multiplexing ring network, which has been used for a metro network and a transport network, includes an optical add 2, 3, 4, 5, 6, 7 and 8 between the optical add / drop multiplexers (OADMs) 10, 20, 30, 40, 50, 60, 70, To form a wavelength division multiplexed loop network to perform optical communication. Two paths are used for protection switching of WDM networks. For example, a path through which an optical signal is transmitted in a clockwise direction (East Path) is connected between the OADMs 10, 20, 30 and 40 via optical fibers 1, 2, 3 and 4, The path through which the optical signal is transmitted to the optical path is connected between the OADMs 50, 60, 70, and 80 by the optical fibers 5, 6, 7, and 8.

The protection switching function of the wavelength division multiplexed ring network is performed by a remote device including two optical transceivers 38 and 39 on the basis of a remote device including two optical transceivers 18 and 19 as shown in Fig. And a method of communicating in an east direction (East Path) and a west direction (West Path). For example, a signal transmitted in the east direction on the basis of a remote device including two optical transceivers 18 and 19 is transmitted from the transmitter of the optical transceiver 19 to the OADM 10 through the optical fiber (2) -> OADM (20) -> optical fiber (3) -> OADM (30) to the receiver of optical transceiver (38) In the meantime, a signal received in the east path starts from the transmitter of the optical transceiver 38 and is transmitted to the OADM 70, the optical fiber 7, the OADM 60, the optical fiber 6, To the receiver of the optical transceiver (19). A signal transmitted in the west direction starts from the transmitter of the optical transceiver 18 and is transmitted to the OADM 50 through the optical fiber 5 to the OADM 80 to the optical fiber 8 to the OADM 70 Lt; RTI ID = 0.0 > 39 < / RTI > The signal received in the west direction starts from the transmitter of the optical transceiver 39 and is transmitted from the OADM 30 to the optical fiber 4 to the OADM 40 to the optical fiber 1 to the OADM 10 To the receiver of the optical transceiver 18. In the normal case, communication is performed only in the east path, and when an error occurs in the optical fiber in the east direction, the protection switching circuit can be configured to perform communication in the west direction (west path).

FIG. 2 is a diagram illustrating the configuration of an OADM 10 for a wavelength division multiplexed ring network. Referring to FIG. OADM is the k-th wavelength (λ _k) for transmitting or reflecting and the other wavelength _{(λ 1, ..., λ k} -1, λ k + 1, ..., λ N) is the filter for reflecting or transmitting ( 11, and 12, respectively, and one port for adding and dropping the k-th wavelength ( _k ) signal, respectively.

The general description of the communication of the wavelength division multiplexed ring network is a known technology described in ITU-T (International Telecommunications Union Telecommunication) ITU-T G.695, ITU-T G.698.1, etc. Therefore, It is omitted.

Korean Patent Publication No. 10-2004-0048467 (published on Jun. 10, 2004)

The present invention provides a remote node and a station-use node for protection switching of a wavelength division multiplexing ring network.

A remote node for protection switching of a wavelength division multiplexing ring network of the present invention comprises at least four filters and at least two optical power splitters, At least four fiber optic ports for communicating with the optical fiber of the path and at least two optical fiber ports for communicating with the remote optical transceiver used in the WDM ring network.

Also, a station-use node for protection switching of a wavelength division multiplexing ring network of the present invention includes at least four filters and at least two optical switches, and two (2) switches used in the wavelength division multiplexing ring network. At least four fiber optic ports for communicating with optical fibers in the directional path and at least two optical fiber ports for communicating with the station-used optical transceiver used in the wavelength division multiplexed ring network.

The wavelength division multiplexing ring network of the present invention also includes at least one remote node and at least one station use node connected to the at least one remote node, The node comprises at least four filters and at least two optical power splitters, at least four fiber ports for communicating with the optical fibers of the two-way path used in the wavelength division multiplexed ring network, and at least one optical fiber port in the wavelength division multiplexed ring network And at least two optical fiber ports for communicating with a remote optical transceiver used, the at least one station using node comprising at least four filters and at least two optical switches, and at least one optical switch for use in the wavelength division multiplexed ring network At least four optical fiber ports for communicating with the optical fibers of the two-way path, And at least two fiber optic ports for communicating with the station-using optical transceiver used in the long-division multi-cyclic network.

The wavelength division multiplexing ring network of the present invention also includes at least one remote node and at least one optical add / drop multiplexer (OADM) pair connected to the at least one remote node. , Said at least one remote node comprises at least four filters and at least two optical power splitters, at least four optical fiber ports for communicating with two-way path optics used in said WDM ring network, Wherein the at least one optical Add / Drop Multiplexer (OADM) pair comprises at least two filters and at least two filters for communicating with a remote optical transceiver used in a split multi- At least two optical fiber ports for communicating with the optical fiber of the wavelength division multiplexing ring network Includes at least two optical fiber ports for communicating with the station using optical transceiver.

The wavelength division multiplexing ring network of the present invention also includes at least one remote node and a centralized office connected to the at least one remote node, At least four optical fiber ports for communicating with a two-way optical fiber used in the wavelength division multiplexing ring network, at least four optical fiber ports for use in the wavelength division multiplexing ring network, Wherein the centralized office includes at least two wavelength multiplexers and at least two wavelength demultiplexers and at least one pair of optical switches and at least two station optical transceivers for communicating with the optical transceiver, .

According to the present invention, it is possible to reduce the number of optical transceivers used for protection switching of a wavelength division multiplexing ring network, and since a remote node does not include a separate protection switching function, an economical wavelength division multiplexing ring network And can constitute a highly reliable wavelength division multiplexed ring network due to protection switching.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary view showing a configuration of a wavelength division multiplexed ring network. FIG.
FIG. 2 is a diagram showing an example of a configuration of an OADM for a wavelength division multiplexed ring network; FIG.
3 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention.
4 is a diagram illustrating a configuration of a remote node for a WDM network according to an exemplary embodiment of the present invention.
5 is a diagram illustrating a configuration of a node for a wavelength division multiplexing ring network according to an embodiment of the present invention.
FIG. 6 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention; FIG.
FIG. 7 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

The present invention relates to remote nodes that are composed of passive optical devices located at different remote locations and stations that are located in a centralized office and that are connected to a station device having a protection switching function and are connected to two optical fibers And more particularly, to a method of configuring a remote node and a station-use node in a wavelength division multiplexing ring network system.

3 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention.

3, the wavelength division multiplexed ring network includes remote nodes 210, 220 and 230, which are composed of passive optical fibers, and optical transceivers 219, 229 and 239 for connection with the optical transceivers 219, 229 and 239, respectively. 320, and 330 connected to the optical transmitters / receivers 319, 329, and 339 for communicating with the optical fibers 301, {302, 306}, {303, 307}, {304, 308} to constitute a WDM network having a protection switching function. The optical signal is transmitted in the clockwise direction through the loop composed of the first optical fibers 301, 302, 303 and 304 and the optical signal is transmitted through the loop composed of the second optical fibers 305, 306, 307, The optical signal can be transmitted in the direction of the optical axis. In some cases, in order to perform an efficient protection switching operation, the centralized optical fiber transceivers 319, 329 and 339, the station use nodes 310, 320 and 330 and the circuit for protection switching ) Can be constituted by a single device.

4 is a diagram illustrating a configuration of a remote node for a WDM ring network according to an embodiment of the present invention.

4, the remote nodes 210, 220 and 230 transmit or reflect the k-th wavelength λ _k , and the remaining wavelengths λ ₁ , ..., λ _k-1 , λ _{k +1,} ..., two with respect to λ _N) is a drop filter for reflecting or transmitting (11a, 11b) and add filter (12a, 12b) one or two of the filter group (11a + 12a, 11b + 12b connected to) An optical power splitter 13a connected to the drop filters 11a and 11b and an optical power splitter 13b connected to the two add filters 12a and 12b. The remote nodes 210, 220 and 230 receive the clockwise optical signal using the optical fiber port P1 included in the drop filter 11a and use the optical fiber port P3 included in the add filter 12b So that it can receive a counterclockwise optical signal. The remote nodes 210, 220 and 230 transmit the clockwise optical signal using the optical fiber port P2 included in the add filter 12a and the optical fiber port P4 included in the drop filter 11b. It is possible to transmit the counterclockwise optical signal. The optical fiber port P5 included in the optical power splitter 13a is connected to a receiver port (not shown) of the optical transceivers 219, 229 and 239, (P6) and a transmitter port (not shown) of the optical transceivers 219, 229, and 239 may be connected.

5 is a diagram illustrating an exemplary configuration of a node for a wavelength division multiplexing ring network according to an embodiment of the present invention.

5, the station uses the nodes (310, 320, 330) is a k th wavelength (λ _k), the transmission or reflection and the other wavelength (λ _1, ..., λ _{k-1, k} λ _+1, ..., two with respect to λ _N) is a drop filter for reflecting or transmitting (14a, 14b) and add filter (15a, 15b) one or two of the filter group (14a + 15a, 14b + 15b connected to) An optical switch 16a connected to the drop filters 14a and 14b and an optical switch 16b connected to the two add filters 15a and 15b. Each of the station use nodes 310, 320 and 330 receives the clockwise optical signal using the optical fiber port P11 included in the drop filter 14a and transmits the clock optical signal to the optical fiber port P13 included in the add filter 15b It is possible to receive the counterclockwise optical signal. Meanwhile, the station use nodes 310, 320 and 330 transmit clockwise optical signals using the optical fiber port P12 included in the add filter 15a, and the optical fiber ports P14 ) Can be used to transmit a counterclockwise optical signal. The optical fiber port P15 included in the optical switch 16a is connected to a receiver port (not shown) of the stationary optical transceivers 319, 329 and 339, (P16) and the transmitter ports of optical transceivers (319, 329, 339).

A protection switching method of a wavelength division multiplexed loop network will be described with reference to FIGS. 3, 4 and 5. FIG. The optical switches 16a and 16b included in the station use node 310 connected to the station use optical transceiver 319 may be set to be connected to the drop filter 14a and the add filter 15b at normal times. In this case, the optical signal transmitted from the optical fiber transmitter 319 can be received by the optical fiber transceiver 219 through the optical fiber 301, the optical fiber 301, and the remote node 210. The optical signal received by the optical fiber transmitter 319 may be transmitted from the optical transceiver 219 and received through the remote node 210 to the optical fiber 305 and the node 310. When an abnormality occurs on the normal transmission / reception path including the optical fiber 301 or 305, the station-use optical transceiver 319 outputs a LOS (loss of signal), a loss of frame (LOF) An abnormal signal can be detected by using the optical signal quality information and the optical switches 16a and 16b included in the station use node 310 using the abnormal signal transmitted from the station use optical transmitter / (14b) and the add filter (15a). In this case, the optical signal transmitted from the optical fiber transceiver 319 is transmitted to the node 310, the node 320, the remote node 230, the optical fiber 307, May be received at optical transceiver 219 through node 220 -> optical fiber 306 -> remote node 210. The optical signal received by the optical fiber transmitter 319 is transmitted from the optical transceiver 219 to the remote node 210 to the optical fiber 302 to the remote node 220 to the optical fiber 303. -> station use node 330 -> station use node 320 -> station use node 310. That is, the station-use optical transceiver 319 can always maintain the connection state with the optical transceiver 219 at the remote place in the normal or protection switching situation.

6 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention.

6, the configurations of the remote nodes 610, 620, and 630 are the same as those described in FIG. 3 and FIG. In one embodiment, a plurality of optical add / drop multiplexer pairs {510, 540}, {520, 550}, {530, 560} and a plurality of stations Optical transceiver pairs {519, 529}, {539, 549}, {559, 569} may be connected and configured. The configuration of the individual OADMs 510, 520, 530, 540, 550, and 560 may be the same as that described with reference to FIG.

A protection switching method for a WDM network will be described with reference to FIG. Only the first station optical transceiver 519 among the station optical transceiver pairs {519, 529} can be set to operate normally. In this case, the optical signal transmitted from the first-station optical transceiver 519 can be received at the remote optical transceiver 619 through the OADM 540, the optical fiber 601, and the remote node 610. Meanwhile, the optical signal received by the first-station optical transceiver 519 may be transmitted from the remote optical transceiver 619 and received through the remote node 610 through the optical fiber 605 and the OADM 510 .

In this situation, when an error occurs on the normal transmission / reception path including the optical fiber 601 or 605, the first station optical transceiver 519 uses a loss of signal (LOS), a loss of frame (LOF) the optical signal transceiver 529 can be operated using the optical signal quality information such as the optical signal quality information such as a bit error rate and the like and the second station optical transceiver 529 can be operated using the abnormal signal transmitted from the first station optical transceiver 519 And stops the operation of the first-station optical transceiver 519. In this case, the optical signal transmitted from the second station optical transmitter 529 is transmitted through the OADM 510, the OADM 520, the optical fiber 607, the remote node 620, and the optical fiber 606 ) -> remote node 610 to the remote optical transceiver 619. The optical signal received by the second station optical transceiver 529 is transmitted from the remote optical transceiver 619 to the remote node 610 to the optical fiber 602 to the remote node 620 to the optical fiber 603, > ... -> OADM 550 -> OADM 540. That is, in the normal or protection switching situation, the station-use optical transceiver pair 519, 529 can always maintain the connection state with the optical transceiver 619 at the remote location.

7 is a diagram illustrating a configuration of a wavelength division multiplexing ring network according to an embodiment of the present invention.

7, the configuration of the remote nodes 710, 720, and 730 of the wavelength division multiplexed ring network is the same as the configuration described with reference to FIG. 3 and FIG. 7 includes two wavelength multiplexers 810 and 830, two wavelength demultiplexers 820 and 840, a plurality of optical switches 811, 812, 841 and 842, And a plurality of station-use optical transceivers 819 and 829 may be connected.

A protection switching method of a wavelength division multiplexed loop network using the remote optical transceiver 719 and the local optical transceiver 819 shown in FIG. 7 will be described. The optical switches 811 and 812 connected to the station-use optical transceiver 819 can be set to be connected to the wavelength multiplexer 810 and the wavelength demultiplexer 820 at normal times. In this case, the optical signal transmitted from the optical transceiver 819 can be received by the optical transceiver 719 at the remote site through the wavelength multiplexer 810, the optical fiber 701, and the remote node 710. Meanwhile, the optical signal received by the optical fiber transmitter 819 may be transmitted from the remote optical transmitter / receiver 719 and received through the remote node 710 -> the optical fiber 705 -> the wavelength demultiplexer 820 .

In this situation, when an error occurs on the normal transmission / reception path including the optical fiber 701 or 705, the LOS (loss of signal), LOF (loss of frame), or BER The optical switches 811 and 812 are connected to the wavelength multiplexer 830 by using the abnormal signal transmitted from the station-use optical transceiver 819, And the wavelength demultiplexer 840, as shown in FIG. In this case, the optical signal transmitted from the optical fiber transmitter 819 is transmitted through the wavelength multiplexer 830, the optical fiber 708, the remote node 730, the optical fiber 707, the remote node 720, (706) -> remote node (710) to the remote transceiver (719). Meanwhile, the optical signal received by the optical fiber transceiver 819 is transmitted from the optical transceiver 719 at the remote location, and transmitted to the remote node 710, the optical fiber 702, the remote node 720, the optical fiber 703, > Remote node 730 -> optical fiber 704 -> wavelength demultiplexer 840. That is, in the normal or protection switching situation, the station use optical transceiver 819 can always maintain the connection state with the optical transceiver 719 at the remote place.

Although the method has been described through particular embodiments, the method may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

70, 70, 70, 70, 70, 70, 708,
40, 50, 60, 70, 80, 510, 520, 530, 540, 550,
29, 39, 48, 49, 219, 229, 239, 319, 329, 339, 519, 529, 539, 549, 559, 599, 699, 629,
11, 12: filters 11a, 11b, 14a, 14b: drop filter
12a, 12b, 15a, 15b: an add filter 13a, 13b: an optical power splitter
16a, 16b, 811, 812, 841, 842:
1000,2000,3000: centralized country state 310,320,330: station use node
210, 220, 230, 610, 620, 630, 710, 720, 720:

Claims (7)

A remote node for protection switching of a wavelength division multiplexing ring network,
At least four filters and at least two optical power splitters,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with a remote optical transceiver used in the WDM ring network. A station node for protection switching of a wavelength division multiplexing ring network,
At least four filters and at least two optical switches,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with a station-use optical transceiver used in the WDM ring network. As a wavelength division multiplexing ring network,
At least one remote node and at least one station use node connected to the at least one remote node,
Wherein the at least one remote node comprises:
At least four filters and at least two optical power splitters,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with a remote optical transceiver used in the wavelength division multiplexing ring network,
Wherein the at least one station-
At least four filters and at least two optical switches,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with the station-use optical transceiver used in the wavelength division multiplexed ring network. The method of claim 3,
Wherein the at least four filters included in the at least one station use node include a first drop filter, a second drop filter, a first add filter, and a second add filter,
Wherein the at least two optical switches comprise:
The first drop filter, the first add filter, and the station optical transmitter / receiver are connected to each other,
And sets the second drop filter and the second add filter to connect to the station-use optical transceiver when an abnormal signal is received from the station-use optical transceiver. As a wavelength division multiplexing ring network,
At least one remote node and at least one optical add / drop multiplexer (OADM) pair connected to the at least one remote node,
Wherein the at least one remote node comprises:
At least four filters and at least two optical power splitters,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with a remote optical transceiver used in the wavelength division multiplexing ring network,
The at least one Optical Add / Drop Multiplexer (OADM)
At least two filters,
At least two optical fiber ports for communicating with the optical fibers of the two-way path,
And at least two optical fiber ports for communicating with a station-use optical transceiver used in the wavelength division multiplexed ring network. As a wavelength division multiplexing ring network,
At least one remote node and a centralized state server connected to the at least one remote node,
Wherein the at least one remote node comprises:
At least four filters and at least two optical power splitters,
At least four optical fiber ports for communicating with two-way optical fibers used in the wavelength division multiplexing ring network,
And at least two optical fiber ports for communicating with a remote optical transceiver used in the wavelength division multiplexing ring network,
The centralized state-
At least two wavelength multiplexers and at least two wavelength demultiplexers,
At least a pair of optical switches and at least two station-use optical transceivers. The method according to claim 6,
Wherein the at least two wavelength multiplexers included in the convergence station include a first wavelength multiplexer and a second wavelength multiplexer, the at least two wavelength demultiplexers include a first wavelength demultiplexer and a second wavelength demultiplexer,
Wherein the at least one pair of optical switches comprises:
The first wavelength multiplexer and the first wavelength demultiplexer are connected to the optical transmitter / receiver using the station,
Wherein the second wavelength multiplexer and the second wavelength demultiplexer are connected to the station-use optical transceiver when an abnormal signal is received in the optical transceiver using the station.

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