JP2006217468A - Optical signal quality assurance method for optical transmission system and optical transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical signal quality assurance method for an optical transmission system capable of assuring the quality of a wavelength path that dynamically changes, and an optical transmission system. <P>SOLUTION: The optical transmission system is provided with a data plane X formed by an optical communication network 28 comprising one or a plurality of nodes 30A, 30B, 32A and 32B, including the node 32B on which an all-optical reproducing device 38 is mounted and links 34A to F, a control plane Z provided with control means 14 and 36A to D for setting a path comprising specific nodes and links from a specific transmitting station 10 to a receiving station 18 while the all-optical reproducing device 38 is not applied and provided independently of the data plane X, and a measurement plane Y provided with optical signal quality measuring means 24 and 26 for measuring optical signal quality of a set path after the path is set in the control plane Z and determining whether the measured optical signal quality is equal to or higher than a threshold and provided independently of the data plane X. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical signal quality assurance method and an optical transmission system in an optical transmission system using an optical communication network, and more particularly to an optical signal quality assurance method and an optical transmission system suitable for a high-speed optical transmission system such as an all-optical network communication system. About.

  2. Description of the Related Art In recent years, with the development of data communication technology, there is a need to communicate a large amount of data at high speed, and therefore an optical transmission system formed by an optical communication network composed of a plurality of nodes and links is used. In particular, in recent years, in order to realize an all-optical transmission system that performs data transfer without performing electrical signal processing, all-optical regeneration devices such as an optical 2R regeneration device and an optical 3R regeneration device, and an optical cross-connect device (PXC) Research is actively conducted.

  By the way, the all-optical transmission system has a feature that topology is free, that is, a wavelength path that is a path between users dynamically changes. When the wavelength path changes, the optical fiber through which the optical signal passes changes, and as a result, various optical fiber parameters on the wavelength path change. When the optical fiber parameter changes, there is a problem that the quality of the signal on the receiving side changes. Therefore, it is necessary to perform quality management and quality assurance of the dynamically changing wavelength path.

  Patent Document 1 describes that optical waveform shaping is optimally realized by using an optical 2R regenerator in order to realize compensation for signal quality deteriorated in an all-optical transmission system. The optical 2R regenerator is usually installed at a relay node or the like, and performs waveform shaping of an optical signal passing through the relay node.

Further, as a method for ensuring the quality of dynamically changing wavelength paths, for example, in Patent Document 2, before establishing a wavelength path in an all-optical transmission system, by linking the GMPLS control plane and the data plane, There is described a method of always guaranteeing the signal quality of the wavelength path by calculating the total chromatic dispersion by the optical fiber in the wavelength path and realizing the chromatic dispersion compensation of the wavelength path.
Japanese Patent Laid-Open No. 2002-23208 JP 2004-274238 A

  However, installing optical 2R regenerators at all the relay nodes and shaping the waveform of the optical signal that passes through increases the cost, and the 2R function even when the quality of the optical signal is not degraded, for example. Therefore, the apparatus cannot be used efficiently.

  In addition, what is described in Patent Document 2 only compensates for chromatic dispersion, and other PMD (polarization mode dispersion), optical SN ratio, and the like are not taken into consideration, and are influenced by effects other than chromatic dispersion. It is impossible to compensate for signal degradation.

  SUMMARY An advantage of some aspects of the invention is that it provides an optical signal quality assurance method for an optical transmission system and an optical transmission system that can guarantee the quality of a wavelength path that dynamically changes.

  In order to achieve the above object, the present invention is independent of a data plane formed by an optical communication network including a plurality of nodes and links each including at least one node on which an all-optical regenerator is mounted. A path setting step in which the control means sets a path composed of a specific node and link from a specific transmitting station to a receiving station via the control plane provided in a state where the all-optical regenerator is not applied, and the path setting After the path is set by the process, the optical signal quality measuring means measures the optical signal quality of the set path through the measurement plane provided independently from the data plane, and the measured light An optical signal quality measurement and determination step for determining whether or not the signal quality is equal to or higher than a threshold value, and a case where the optical signal quality is determined to be not higher than the threshold value by the optical signal quality measurement and determination step. The control means comprises an all-optical regenerator operating step for operating the all-optical regenerator, and when the optical signal quality is determined to be greater than or equal to a threshold value by the optical signal quality measurement and determination step, the data When the all-optical regenerator is activated in the all-optical regenerator operation process by performing optical communication from the transmitting side to the receiver via the set path in the plane, the control means An optical signal quality assurance method for an optical transmission system, wherein the optical signal quality measurement and determination step is performed in a state where an optical regenerator is in operation.

  In the optical signal quality assurance method of the optical transmission system, when the node on which the all-optical regenerator is mounted is not included in the set path, in the all-optical regenerator operation step, the node Preferably, the message is transmitted to the control means, and the control means resets a path of a route different from the set path from a specific transmitting station to the receiving station when the error message is received.

  In order to achieve the above object, according to the present invention, the control means uses a specific transmission station via a control plane provided independently of a data plane formed by an optical communication network including a plurality of nodes and links. A path setting step for setting a path consisting of a specific node and link from the mobile station to the receiving station, and after a path is set by the path setting step, via a measurement plane provided independently for the data plane An optical signal quality measuring and measuring step in which an optical signal quality measuring unit measures the optical signal quality of the set path and determines whether or not the measured optical signal quality is equal to or higher than a threshold; and A path for resetting a path of a route different from the set path from a specific transmitting station to a receiving station when it is determined by the quality measurement and determination process that the optical signal quality is not higher than the threshold value A setting step, and when the optical signal quality is determined to be greater than or equal to a threshold value by the optical signal quality measurement and determination step, in the data plane, from the transmission side to the reception side via the set path An optical signal quality assurance method for an optical transmission system, wherein optical communication is performed.

  In this optical signal quality assurance method for an optical transmission system, when a path is reset by the path resetting step, it is preferable to perform the optical signal quality measurement and determination step for the reset path.

  Furthermore, in order to achieve the above object, the present invention relates to a data plane formed by an optical communication network including a plurality of nodes and links each including one or more nodes on which all-optical regenerators are mounted. The control means includes a specific node and a link from a specific transmitting station to a receiving station via a control plane provided independently, and includes a node on which at least one or more of the all-optical regenerators are mounted. A path setting step for setting a path in a state where the all-optical regenerator is not applied, and an optical signal via a measurement plane provided independently of the data plane after the path is set by the path setting step. An optical signal quality measurement and determination step in which the quality measurement means measures the optical signal quality of the set path and determines whether the measured optical signal quality is equal to or higher than a threshold; And when the optical signal quality measurement and determination step determines that the optical signal quality is equal to or higher than a threshold value, the data plane performs optical communication from the transmission side to the reception side via the set path. When the optical signal quality measurement and determination step determines that the optical signal quality is not equal to or higher than a threshold value, the control means performs the optical signal quality measurement and determination step with the all-optical regenerator operating. An optical signal quality assurance method for an optical transmission system.

  In these optical transmission system optical signal quality assurance methods, if the optical signal quality is determined to be not greater than or equal to a threshold value as a result of performing the optical signal quality measurement and determination process while the all-optical regenerator is in operation, It is preferable that a path with a route different from the set path from the transmitting station to the receiving station is reset, and the optical signal quality measurement and determination step is performed for the reset path.

  Further, the optical signal quality assurance method for these optical transmission systems further includes a transmission characteristic compensation step for compensating the transmission characteristic of the path set by the path setting step before the optical signal quality measurement and judgment step, In the quality measurement and determination step, it is preferable to measure the optical signal quality of the path whose transmission characteristics are compensated by the transmission characteristic compensation step, and chromatic dispersion compensation means can be used as the transmission characteristic compensation means.

  In order to achieve the above object, the present invention provides a data plane formed by an optical communication network including a plurality of nodes and links each including at least one node on which an all-optical regenerator is mounted; A path including a node having a specific node and link from a specific transmitting station to a receiving station and including the at least one all-optical regenerator is set without applying the optical regenerator. A control plane provided independently of the data plane, and after the path is set in the control plane, the optical signal quality of the set path is measured, and the measured light Optical signal quality measuring means for determining whether or not the signal quality is equal to or higher than a threshold, and a measurement plane provided independently of the data plane, When the signal quality measurement means determines that the optical signal quality is equal to or higher than the threshold, the control means causes the data plane to perform optical communication from the transmission side to the reception side via the set path, When the optical signal quality measuring unit determines that the optical signal quality is equal to or higher than the threshold value, the control unit operates the all-optical regenerator, and the optical signal quality is measured by the optical signal quality measuring unit in the operating state. This is an optical transmission system characterized in that measurement is performed.

  Furthermore, the present invention comprises a data plane formed by an optical communication network composed of a plurality of nodes and links, and a specific node and link from a specific transmitting station to a receiving station without applying the all-optical regenerator. A control unit configured to set a path; a control plane provided independently of the data plane; and after a path is set in the control plane, measure optical signal quality of the set path; Optical signal quality measuring means for determining whether or not the measured optical signal quality is equal to or higher than a threshold, and a measurement plane provided independently of the data plane, and the optical signal quality When the measurement unit determines that the optical signal quality is equal to or higher than the threshold value, the control unit is configured to transmit the data plane from the transmission side via the set path. When the optical signal quality measurement means determines that the optical signal quality is not equal to or higher than a threshold value, the control means includes the set path from a specific transmitting station to the receiving station. An optical transmission system is characterized in that a path of a different route is reset, and the optical signal quality measuring unit is caused to measure the optical signal quality for the set path.

  Still further, the present invention does not apply a data plane formed by an optical communication network including one or more nodes and links including a node on which the all-optical regenerator is mounted, and the all-optical regenerator. Control means for setting a path consisting of a specific node and link from a specific transmitting station to a receiving station in a state, and a control plane provided independently for the data plane, and a path in the control plane After the setting, the optical path quality measuring means for measuring the optical signal quality of the set path and determining whether or not the measured optical signal quality is equal to or higher than a threshold is provided for the data plane. A measurement plane provided independently, and when the optical signal quality measuring means determines that the optical signal quality is equal to or higher than a threshold value, the control means When the optical signal quality is determined by the optical signal quality measurement unit to be not higher than a threshold value, the control unit is configured to perform the optical communication from the transmission side to the reception side via the set path. The all-optical regenerator is operated, and in the operated state, the optical signal quality measuring means measures the optical signal quality, and the set path includes a node on which the all-optical regenerator is mounted. If not, the node transmits an error message to the control means, and when the control means receives the error message, it re-routes a path with a route different from the set path from a specific transmitting station to the receiving station. The optical transmission system is characterized in that the optical signal quality measuring means is set to measure the optical signal quality for the set path.

  The optical transmission system according to the present invention further comprises transmission characteristic compensation means for compensating a transmission characteristic of a path set by the control means before measurement and determination by the optical signal quality measurement means, and the optical signal quality measurement The means preferably measures the optical signal quality of the path whose transmission characteristic is compensated by the transmission characteristic compensation means, and a chromatic dispersion compensation means can be used as the transmission characteristic compensation means.

  As described above, according to the optical signal quality guarantee method and the optical transmission system of the optical transmission system according to the present invention, the optical communication service is started when the optical signal quality of the set path is equal to or higher than the threshold, and the optical signal If the quality is not higher than the threshold value, the all-optical regenerator is operated or changed to another route, so even if the wavelength path changes dynamically, an optical communication service with a certain quality or higher is provided. be able to. Further, since the all-optical regenerator is operated only when the optical signal quality is not equal to or higher than the threshold value, an apparatus such as the all-optical regenerator can be used efficiently.

  In the optical signal quality assurance method and the optical transmission system of the optical transmission system according to the present invention, the optical signal quality to be measured includes, for example, a Q value. The Q value is a parameter that is proposed as a system evaluation parameter in an optical transmission system or the like, that is, a signal-to-noise ratio in a digital signal assuming that the noise signal is Gaussian noise. It is expressed by the amplitude (μ) and the effective value (σ) of the noise amplitude, and is defined by Q = Abs (μ1−μ0) / (σ1 + σ0). μ1 and μ0 represent signal average levels of 1 level and 0 level. [sigma] 1 and [sigma] 0 represent standard deviations of the noise distribution of the 1st level and 0th level. Here, Abs (μ1-μ0) represents the absolute value of μ1-μ0. Further, as the transmission characteristic to be compensated, for example, there is a chromatic dispersion value.

  As described above, according to the present invention, it is possible to provide an optical signal quality assurance method and an optical transmission system for an optical transmission system that can guarantee the quality of dynamically changing wavelength paths.

  Next, a first embodiment of the optical transmission system according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a main part of the optical transmission system according to the first embodiment. In the optical transmission system according to the first embodiment, the transmitting station 10 includes a transmitting device 12, a control device 14 that controls the transmitting device 12, and a measuring instrument control terminal 16. A receiving station 18 controls the receiving device 20 and controls it. A control device 22, a measuring instrument control terminal 24, and an optical signal quality measurement device 26. The transmission device 12 and the reception device 20 are connected via an optical communication network 28. The optical communication network 28 includes edge nodes 30A and 30B, relay nodes 32A and 32B, and links 34A to 34F made of optical fibers interconnecting them, and information to be transmitted is transmitted at a high speed of, for example, 40 Gbit / s. The data plane X is configured. Each of the edge nodes 30A and 30B and the relay nodes 32A and 32B includes an optical cross connect (PXC). The relay node 32B includes an all-optical regenerator 38. The all-optical regenerator 38 includes a 2R function and a 3R function. The 2R function is amplitude regeneration or reamplification and waveform shaping or reshaping. The 3R function is obtained by further adding timing reproduction or retiming. The 2R function can be provided by combining a waveform shaper and an optical amplifier, or by using a waveform shaper having an optical amplification function. In addition, a 3R function can be obtained by using a clock regenerator in parallel. Can be provided. In the optical transmission system according to the first embodiment, an all-optical regenerator having a 2R function and a 3R function is used. A device having either the 2R function or the 3R function may be used, and the all-optical regenerator 38 may be provided not only in the relay node 32B but also in other nodes 30A, 30B, 32A and the like.

  Each of the nodes 30A, 30B, 32A, and 32B is connected to control devices 36A to 36D that control them. Among them, the control device 36C that is connected to the relay node 32B is connected to the all-optical regenerator 38. Is also connected. The control devices 14, 22, 36A to 36D are configured to give path settings to the transmission device 12, the reception device 20, and the nodes 30A, 30B, 32A, 32B, respectively. An optical signal quality measurement instruction is provided to the measuring instrument control terminals 16 and 24, and the control device 36C is further configured to give an instruction to operate the 2R function to the all-optical regenerator 38. . The control devices 14, 22, 36 </ b> A to 36 </ b> D are interconnected via a hub or the like, for example, and constitute a control plane Z that performs mutual communication independently of the data plane X. In the first embodiment, the path setting operation on the control plane Z can be performed based on an RSVP-TE (Resource Reservation Protocol-Traffic Engineering) message used in GMPLS signaling. As is well known, MPLS has fixed-length label information separately from the original destination address of the packet, and transfers the packet based on this label information. Each node 30A, 30B, 32A, 32B holds a label table indicating the relationship between the output label and the output interface (IF) with respect to the input label and the input interface (IF). The next transfer destination node is determined based on the label, not the destination, and the label of the received packet is rewritten and transferred to the next transfer destination node. By repeating this from the transmission unit to the reception unit, packet data is transmitted along the set path. Paths are sequentially set in a hop-by-hop manner from the start point to the end point for nodes on the path to be established. The control plane Z may be based on general control that is not based on GMPLS control.

  The measuring instrument control terminal 16 of the transmitting station 10 and the measuring instrument control terminal 24 of the receiving station 18 are interconnected via, for example, a hub or the like, and communicate with each other independently of the data plane X together with the optical signal quality measuring device 26. The measurement plane Y to be performed is configured. The optical signal quality measurement device 26 is configured to measure the Q value as the optical signal quality of the path set between the transmission device 12 and the reception device 20. The Q value is measured by, for example, extracting a target wavelength λi (i = 1 to n) from the optical signal branched from the link 34F by a narrowband filter, amplifying the intensity by INLINE-AMP, and then applying DCF (dispersion compensation fiber). ) By monitoring the optical signal whose waveform has been shaped by the Q value monitor.

  Next, the path setting operation of the optical transmission system according to the first embodiment will be described. FIG. 2 is a diagram showing a message flow between the nodes at the time of setting a path in the control plane and a message flow between the transmitting station 10 and the receiving station 18 at the time of measurement in the measurement plane. It is a flowchart of the path setting operation | movement of the optical transmission system which concerns on an Example. First, when a path setting request is input to the control device 14 of the transmitting station 10 (S100), the control device 14 issues a path setting request with channel information by an RSVP-PATH message (S102). This RSVP-PATH message is based on the GMPLS protocol, and as shown in FIG. 2, the control devices 14, 36A, 36B, 36D of the transmission device 12, the edge node 30A, the relay node 32A, the edge node 30B, and the reception device 20, respectively. , 22 are sequentially transferred, and a path is established in each node sequentially.

  When receiving the path setting request (RSVP-PATH message), the control device 22 of the receiving station 18 outputs a path setting securing notification (RSVP-RESV message) (S104). As shown in FIG. 2, the path setting reservation notification (RSVP-RESV message) output from the control device 22 of the receiving station 18 is received from the receiving device 20, the edge node 30B, the relay node 32A, the edge node 30A, and the transmitting device 12. The data is sequentially transferred to each control device 22, 36D, 36B, 36A, 14. When the control device 14 receives the notification of securing the path setting, the control device 14 sets a test mode path that is one of the monitoring modes in the transmission device 12 in the data plane X → the edge node 30A → the relay node 32A → the edge node 30B → the reception device 20. Message to be transmitted to each control device 36A, 36B, 36D, 22 (S106). When the testing mode path is set, the control device 14 transmits a measurement signal passing through the path from the transmission device 12 to the reception device 20, and the control devices 14 and 22 include the measuring instrument control terminal 16 and An optical signal quality measurement operation start instruction is given to 24, and the measuring instrument control device 24 causes the optical signal quality measurement device 26 to start measuring the Q value as shown in FIG. 2 (S108). The optical signal quality measuring device 26 measures the Q value by monitoring the measurement signal branched from the link 34F according to the instruction from the measuring device control device 24 (S110), and the measurement result is measured by the receiving station 18. Is transmitted to the device control terminal 24 (S112). Upon receiving the measurement result of the Q value, the measuring instrument control terminal 24 determines whether or not the Q value exceeds the threshold value (S114). As a result, if the Q value exceeds the threshold value, The terminal 24 gives an instruction to release the testing mode of the path set in the data plane X to the control device 14 via the measuring instrument control terminal 16 and perform optical communication in the normal mode (S116). Transmits a message to each of the control devices 36A, 36B, 36D, 22 to cancel the testing mode and start optical communication of the transmission device 12 → the edge node 30A → the relay node 32A → the edge node 30B → the reception device 20 (S118).

  If it is determined in step 114 that the Q value does not exceed the threshold value, the measuring instrument control terminal 24 gives an instruction to improve the Q value to the control device 14 via the measuring instrument control terminal 16 (S120). 14 transmits a message for operating the 2R function to the control devices 36A, 36B, and 36D of the nodes 30A, 32A, and 30B that have set the testing mode path (S122). When the 2R function operation message is received, the control device of the node having the 2R function operates the 2R function, transmits the operated message to the control device 14, and the control device of the node not having the 2R function The error message is transmitted to the control device 14. Since each of the nodes 30A, 32A, and 30B that set the path of the testing mode does not include the all-optical regeneration device 38, a message that activates the 2R function is not transmitted to the control device 14. Absent. When the control device 14 receives an error message from the control devices of all the nodes for which the testing mode path is set (S124), the control device 14 operates the 3R function in the control devices 36A, 36B, and 36D of the nodes 30A, 32A, and 30B. The message to be sent is transmitted (S126). When the 3R function operation message is received, the control device of the node having the 3R function operates the 3R function, transmits the operated message to the control device 14, and the control device of the node not having the 3R function The error message is transmitted to the control device 14. Since each of the nodes 30A, 32A, and 30B that set the path of the testing mode does not include the all-optical regeneration device 38, a message that activates the 3R function is not transmitted to the control device 14. Absent. When the control device 14 receives an error message from the control devices of all the nodes for which the testing mode path is set (S128), the control device 14 passes a route that does not pass through the relay node 32A, for example, the relay node 32B instead of the relay node 32A. A route is selected (S130), and then the same operation is performed from step 102 to step 122 regarding the testing mode path for the transmission device 12, the edge node 30A, the relay node 32B, the edge node 30B, and the reception device 20.

  Since the relay node 32B includes the all-optical regeneration device 38 having the 2R function, in step 124, the control device 14 receives a message indicating that the 2R function is activated from the control device 36C of the relay node 32B. When this message is received, the optical signal quality measuring device 26 measures the Q value of the path in the same manner as in steps 108 to 112, and transmits the measurement result to the measurement control device 24 (S132). Upon receiving the measurement result, the measuring instrument control terminal 24 determines whether or not the Q value exceeds the threshold value (S134). As a result, if the Q value exceeds the threshold value, Similarly, the control devices 14 and 22 cancel the testing mode and start optical communication of the transmission device 12 → the edge node 30A → the relay node 32B → the edge node 30B → the reception device 20 (S136).

  If it is determined in step 134 that the Q value does not exceed the threshold value, the measuring instrument control terminal 24 gives an instruction to improve the Q value to the control device 14 via the measuring instrument control terminal 16 (S138). Then, the control device 14 transmits a message for operating the 3R function to the control devices 36A, 36C, and 36D of the nodes 30A, 32B, and 30B together with a message for releasing the 2R function to the relay node 32B.

  Since the relay node 32B includes the all-optical regeneration device 38 having the 3R function, in step 128, the control device 14 receives a message indicating that the 3R function is activated from the control device 36C of the relay node 32B. When this message is received, the optical signal quality measurement device 26 measures the Q value of the path in the same manner as in steps 108 to 112, and transmits the measurement result to the measurement control device 24 (S140). Upon receiving the measurement result, the measuring instrument control terminal 24 determines whether or not the Q value exceeds the threshold value (S142). As a result, if the Q value exceeds the threshold value, Similarly, the control devices 14 and 22 cancel the testing mode and start optical communication of the transmission device 12 → the edge node 30A → the relay node 32B → the edge node 30B → the reception device 20 (S144). If it is determined in step 142 that the Q value does not exceed the threshold value, the process proceeds to step 130, a route that does not pass through the relay node 32B is selected, and the operation from step 102 is performed thereafter.

  Next, another operation of the optical transmission system according to the first embodiment will be described with reference to the flowchart shown in FIG. In the second operation, steps 200 to 218 operate in the same manner as steps 100 to 118 described above. If it is determined in step 214 that the Q value does not exceed the threshold value, the measuring instrument control terminal 24 gives an instruction to improve the Q value to the control device 14 via the measuring instrument control terminal 16 (S220). 14 transmits a message for operating the 2R function or the 3R function to the control devices 36A, 36B, and 36D of the nodes 30A, 32A, and 30B that set the path of the testing mode (S222). Whether the 2R function is activated or the 3R function is activated depends on the Q value. That is, when the Q value is lower than the predetermined value, a message for operating the 3R function is transmitted, and when the Q value is equal to or greater than the predetermined value, a message for operating the 2R function is transmitted. When a message for operating the 2R function or the 3R function is received, the control device of the node having the 2R function or the 3R function operates the 2R function or the 3R function, and transmits the operated message to the control device 14. Alternatively, the control device of the node that does not have the 3R function transmits an error message to the control device 14. When the control device 14 receives an error message from the control devices of all the nodes for which the testing mode path is set (S224), the control device 14 passes a route that does not pass through the relay node 32A, for example, the relay node 32B instead of the relay node 32A. A route is selected (S226), and then the same operation is performed from step 202 to step 222 regarding the testing mode path for the transmission device 12, the edge node 30A, the relay node 32B, the edge node 30B, and the reception device 20.

  In step 224, when the control device 14 receives a message indicating that the 2R function or the 3R function is activated from the control device 36C of the relay node 32B, the optical signal quality measurement device 26, as in steps 208 to 212 described above, The Q value is measured, and the measurement result is transmitted to the measurement control device 24 (S228). Upon receiving the measurement result, the measuring instrument control terminal 24 determines whether or not the Q value exceeds the threshold value (S230). As a result, if the Q value exceeds the threshold value, Similarly, the control devices 14 and 22 cancel the testing mode and start optical communication of the transmission device 12 → the edge node 30A → the relay node 32B → the edge node 30B → the reception device 20 (S232). If it is determined in step 230 that the Q value does not exceed the threshold value, the process proceeds to step 230, a route that does not pass through the relay node 32B is selected, and the operation from step 202 is performed thereafter.

  Next, as a second embodiment of the optical transmission system according to the present invention, an optical transmission system performing transmission characteristic compensation using a chromatic dispersion compensator will be described with reference to the drawings. FIG. 5 is a conceptual diagram of an optical transmission system according to the second embodiment. Unlike the first embodiment, the transmitting station 10 of the optical transmission system according to the second embodiment includes a chromatic dispersion measuring transmitter 40. The chromatic dispersion measurement transmitter 40 outputs, for example, a sinusoidal chromatic dispersion measurement signal based on a chromatic dispersion measurement signal transmission instruction output from the measurement instrument control terminal 16 after setting the testing mode path. Unlike the first embodiment, the receiving station 18 receives a chromatic dispersion compensator 42 that performs a compensation operation for received information based on the set chromatic dispersion, a chromatic dispersion measurement signal, and receives the received chromatic dispersion. A chromatic dispersion measuring receiver 44 that measures chromatic dispersion from a measurement signal, and a control unit 46 that sets the chromatic dispersion compensator 42 based on the measurement value of the chromatic dispersion measuring receiver 44 are provided. As the chromatic dispersion compensator 42, for example, a switch that uses a plurality of fiber Bragg gratings (FBGs) having different chromatic dispersion characteristics can be used. The chromatic dispersion measurement receiver 44 receives a chromatic dispersion measurement signal based on channel information for path setting input from the control device 22 via the control plane Z to the measurement instrument control terminal 24. The channel information includes, for example, a channel number (wavelength) and a bit rate.

  The operation of the optical transmission system according to the second embodiment will be described based on the flowchart shown in FIG. In the optical transmission system according to the second embodiment, when the testing mode path is set from the transmission device 12 to the reception device 20 in step 108 in the operation of the optical transmission system according to the first embodiment, the control device 14 A chromatic dispersion compensation operation start instruction is output to the measuring instrument control terminal 16 (S300). In response to this, the measuring instrument control terminal 16 instructs the chromatic dispersion measuring transmitter 40 to transmit the chromatic dispersion measuring signal to the receiving apparatus 20 via the testing mode path set by the data plane X. Giving (S302), the chromatic dispersion measuring transmitter 40 transmits the chromatic dispersion measuring signal to the receiving device 20 in accordance with the message (S304). Next, the chromatic dispersion measurement receiver 44 receives the measurement signal of the bit rate specified by the specified WDM channel, and measures the chromatic dispersion such as the chromatic dispersion value from the received signal (S306). After the measurement, the measuring instrument control terminal 16 outputs a chromatic dispersion compensation start instruction to the chromatic dispersion measuring receiver 44 via the measuring instrument control terminal 24 (S308). Further, the control unit 46 sets a characteristic opposite to the measured chromatic dispersion in the chromatic dispersion compensator 42 (S310). When the setting operation to the chromatic dispersion compensator 210 is completed, the process returns to step 110 in the operation of the optical transmission system according to the first embodiment, and the optical signal quality measurement device 26 measures the Q value (S312), Thereafter, the same operation as that of the optical transmission system according to the first embodiment is performed.

It is a block diagram which shows the principal part of 1st Example of the optical transmission system which concerns on this invention. It is a figure which shows the flow of the message at the time of the path setup in the optical transmission system based on 1st Example, and the time of optical signal quality measurement. It is a flowchart which shows the path setting operation | movement of the optical transmission system which concerns on 1st Example. It is a flowchart which shows the other operation | movement of the path setting of the optical transmission system which concerns on 1st Example. It is a block diagram which shows the principal part of 2nd Example of the optical transmission system which concerns on this invention. It is a flowchart which shows the chromatic dispersion compensation operation | movement of the optical transmission system which concerns on 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transmitting station 12 Transmitting device 16 Measuring device control terminal 14, 22, 36A-D Control device 18 Receiving station 20 Receiving device 24 Measuring device control terminal 26 Optical optical signal quality measuring device 28 Optical communication network 30A, 30B Edge node 32A, 32B Relay node 34A-F Link 38 All-optical regenerator X Data plane Y Measurement plane Z Control plane

Claims (11)

Control means is provided via a control plane provided independently of a data plane formed by an optical communication network including a plurality of nodes and links each including one or more nodes on which the all-optical regenerator is mounted. A path setting step for setting a path consisting of a specific node and link from a specific transmitting station to a receiving station without applying the all-optical regenerator;
After the path is set by the path setting step, the optical signal quality measuring unit measures the optical signal quality of the set path through a measurement plane provided independently of the data plane, and the measurement is performed. Optical signal quality measurement and determination step for determining whether the optical signal quality is equal to or higher than a threshold value;
When it is determined by the optical signal quality measurement and determination step that the optical signal quality is not equal to or higher than a threshold, the control means includes an all-optical regenerator operating step for operating the all-optical regenerator,
With
When it is determined by the optical signal quality measurement and determination step that the optical signal quality is equal to or higher than a threshold value, in the data plane, optical communication from the transmission side to the reception side is performed via the set path,
When the all-optical regenerator is activated by the all-optical regenerator operation step, the control means performs the optical signal quality measurement and determination step while the all-optical regenerator is in operation. Optical signal quality assurance method for optical transmission systems. When the node on which the all-optical regenerator is mounted is not included in the set path, in the all-optical regenerator operation step, the node transmits an error message to the control unit,
2. The optical transmission system according to claim 1, wherein when the error message is received, the control unit resets a path of a route different from the set path from a specific transmitting station to a receiving station. Signal quality assurance method. A path consisting of a specific node and link from a specific transmitting station to a receiving station via a control plane provided independently for a data plane formed by an optical communication network consisting of a plurality of nodes and links A path setting process for setting
After the path is set by the path setting step, the optical signal quality measuring unit measures the optical signal quality of the set path through a measurement plane provided independently of the data plane, and the measurement is performed. Optical signal quality measurement and determination step for determining whether the optical signal quality is equal to or higher than a threshold value;
A path resetting step of resetting a path of a route different from the set path from a specific transmitting station to a receiving station when the optical signal quality is determined not to be greater than or equal to a threshold value by the optical signal quality measurement and determination step; ,
With
When it is determined by the optical signal quality measurement and determination step that the optical signal quality is equal to or higher than a threshold value, in the data plane, optical communication from the transmission side to the reception side is performed via the set path. An optical signal quality assurance method for an optical transmission system.        4. The optical signal quality guarantee method for an optical transmission system according to claim 2, wherein when the path is reset, the optical signal quality measurement and determination step is performed for the reset path. Control means is provided via a control plane provided independently of a data plane formed by an optical communication network including a plurality of nodes and links each including one or more nodes on which the all-optical regenerator is mounted. A path including a specific node and link from a specific transmitting station to a receiving station and including at least one node on which the all-optical regenerator is mounted is set without applying the all-optical regenerator. Path setting process;
After the path is set by the path setting step, the optical signal quality measuring unit measures the optical signal quality of the set path through a measurement plane provided independently of the data plane, and the measurement is performed. Optical signal quality measurement and determination step for determining whether the optical signal quality is equal to or higher than a threshold value;
With
When it is determined by the optical signal quality measurement and determination step that the optical signal quality is equal to or higher than a threshold value, in the data plane, optical communication from the transmission side to the reception side is performed via the set path,
When it is determined by the optical signal quality measurement and determination step that the optical signal quality is not greater than or equal to a threshold value, the control unit operates the all-optical regenerator, and the optical signal quality measurement and determination step in the operated state. An optical signal quality assurance method for an optical transmission system.        As a result of performing the optical signal quality measurement and determination process in a state where the all-optical regenerator is in operation, when it is determined that the optical signal quality is not equal to or higher than a threshold, the set from a specific transmitting station to a receiving station 6. The optical signal quality guarantee method for an optical transmission system according to claim 1, wherein a path of a route different from the path is reset, and the optical signal quality measurement and determination step is performed on the reset path. A transmission characteristic compensation step for compensating for the transmission characteristic of the path set by the path setting step before the optical signal quality measurement and determination step;
7. The optical signal quality of the optical transmission system according to claim 1, wherein the optical signal quality measurement and determination step measures the optical signal quality of the path whose transmission characteristics are compensated by the transmission characteristic compensation step. Guarantee method. A data plane formed by an optical communication network composed of a plurality of nodes and links each including at least one node on which the all-optical regenerator is mounted;
Setting of a path including a specific node and link from a specific transmitting station to a receiving station in a state where the all-optical regenerator is not applied, and including a node on which the at least one all-optical regenerator is mounted A control plane that is provided independently of the data plane;
Optical path quality measuring means for measuring the optical signal quality of the set path after the path is set in the control plane and determining whether the measured optical signal quality is equal to or higher than a threshold value; A measurement plane provided independently of the data plane;
With
When the optical signal quality measuring means determines that the optical signal quality is equal to or higher than the threshold value, the control means performs optical communication from the transmitting side to the receiving side via the set path in the data plane. Let
When the optical signal quality measuring means determines that the optical signal quality is not equal to or higher than the threshold, the control means operates the all-optical regenerator, and in the operated state, the optical signal quality measuring means An optical transmission system characterized in that measurement is performed. A data plane formed by an optical communication network composed of a plurality of nodes and links;
A control plane provided independently of the data plane, comprising control means for setting a path consisting of a specific node and link from a specific transmitting station to a receiving station without applying the all-optical regenerator When,
Optical path quality measuring means for measuring the optical signal quality of the set path after the path is set in the control plane and determining whether the measured optical signal quality is equal to or higher than a threshold value; A measurement plane provided independently of the data plane;
With
When the optical signal quality measuring means determines that the optical signal quality is equal to or higher than the threshold value, the control means performs optical communication from the transmitting side to the receiving side via the set path in the data plane. Let
When the optical signal quality measuring means determines that the optical signal quality is not equal to or higher than the threshold, the control means resets a path of a route different from the set path from a specific transmitting station to the receiving station, and An optical transmission system, characterized in that an optical signal quality measuring unit is configured to measure optical signal quality for a set path. A data plane formed by an optical communication network composed of one or more nodes and links each including a node on which the all-optical regenerator is mounted;
A control plane provided independently of the data plane, comprising control means for setting a path consisting of a specific node and link from a specific transmitting station to a receiving station without applying the all-optical regenerator When,
Optical path quality measuring means for measuring the optical signal quality of the set path after the path is set in the control plane and determining whether the measured optical signal quality is equal to or higher than a threshold value; A measurement plane provided independently of the data plane;
With
When the optical signal quality measuring means determines that the optical signal quality is equal to or higher than the threshold value, the control means performs optical communication from the transmitting side to the receiving side via the set path in the data plane. Let
When the optical signal quality measuring means determines that the optical signal quality is not equal to or higher than the threshold, the control means operates the all-optical regenerator, and in the operated state, the optical signal quality measuring means Make measurements,
When the node on which the all-optical regenerator is mounted is not included in the set path, the node transmits an error message to the control unit, and the control unit receives the error message, An optical signal characterized by resetting a path of a route different from the set path from a specific transmitting station to a receiving station, and causing the optical signal quality measuring means to measure the optical signal quality for the set path. Transmission system. Transmission characteristic compensation means for compensating for transmission characteristics of a path set by the control means before measurement and determination by the optical signal quality measurement means,
11. The optical transmission system according to claim 8, wherein the optical signal quality measurement unit measures the optical signal quality of the path whose transmission characteristics are compensated by the transmission characteristic compensation unit.

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