JPWO2017033223A1 - Optical communication control apparatus and optical communication control method - Google Patents

Abstract

An optical communication control apparatus and method for setting an optical path in a network using a plurality of subcarriers, effectively using fragmented wavelengths by assigning subcarriers to vacant wavelengths of a plurality of paths, and Necessary to transmit the optical signal included in the route information by selecting the route corresponding to the route information when receiving an optical path setting / change request in order to maximize the optical path that can be used in the entire system. If the transmitting side node device is controlled to allocate a subcarrier with a frame configuration corresponding to the redundancy of the selected path to an empty wavelength for the fixed error correction code to be The transmission side node apparatus is controlled so that a subcarrier having a frame structure corresponding to the redundancy of the other path is allocated to an empty wavelength.

Description

  The present invention relates to an optical communication control apparatus and an optical communication control method for setting an optical path in a network using a plurality of subcarriers.

  With the rapid increase in traffic, there is an increasing need for long-distance and large-capacity optical communication systems. In order to increase the speed and capacity of an optical transmission network, wavelength division multiplex communication (WDM: Wavelength Division Multiplex) that multiplexes and transmits a plurality of different wavelengths is widely used.

Recently, in order to transmit a large-capacity client signal of 400 Gbps / 1 Tbps, in the optical communication system for the metro core, the technology is changed from the conventional single carrier transmission using only one carrier per optical path to multicarrier transmission. It has shifted (for example, refer nonpatent literature 1). In this case, a large-capacity optical path is configured by bundling a plurality of subcarriers and assigning them to consecutive wavelengths on the same path.
In the following description, an optical path and a route are used as synonyms.

  Further, in an optical transmission system, as the transmission speed is improved, the influence of noise generated on the transmission path increases, so that a high-performance error correction technique is required. In an optical communication system, ITU-T G.I. An OTU (Optical-channel Transport Unit) frame to which (forward) error correction parity information (FEC: Forward Error Correction) is added to the 709 recommendation is defined. A variable rate error correction coding method that stores an error correction code in a payload area that stores information data of an OTU frame has been proposed (see, for example, Patent Document 1). In this case, the redundancy of the error correction code is increased by adding a variable rate error correction code to the fixed error correction code of the OTU frame, and a high coding gain is obtained.

R. Freund et al. "Single-multi-carrier technologies to build up Tb / s per channel transmission systems," Transparent Optical Networks (ICTON), Tu. D1.4, 2010, pp. 1-7.

Patent No. 5687362

  In multi-carrier transmission, one subcarrier is arranged for one wavelength, and an optical path is configured using a plurality of wavelengths in which subcarriers are arranged. In the current optical communication system, the number of required wavelengths differs depending on the data rate of the transmission request. For example, when 100 Gbps transmission is possible per wavelength, 4 wavelengths are used for a transmission request of 400 Gbps, and 10 wavelengths are used for a transmission request of 1 Mbps. When the optical path of 400 Gbps is set after deleting the optical path of 1 Tbps, six unused wavelengths are generated.

  In this way, when setting / deleting / changing the optical path is repeated in response to a transmission request, the empty wavelengths on the path become fragmented, so that continuous empty wavelengths on the path cannot be used, and new The optical path cannot be set. Therefore, since continuous wavelengths cannot be used for multicarrier transmission, wavelength resources cannot be effectively used, and there is a problem that optical paths that can be used in the entire optical communication system are reduced.

  On the other hand, in the variable-rate error correction code method described in Patent Document 1 above, a method for setting an error correction code according to the transmission conditions of an optical path has been proposed, but this is applied to multicarrier transmission. The optical communication control apparatus and its control method when subcarriers are assigned to a plurality of paths are not considered.

  The present invention has been made to solve the above-described problems, and can effectively use fragmented free wavelengths by assigning subcarriers to free wavelengths of a plurality of paths, and thus can be used in the entire system. An object of the present invention is to provide an optical communication control apparatus and an optical communication control method capable of maximizing the number of optical paths.

  To achieve the above-described object, an optical communication control apparatus according to the present invention is an optical communication control apparatus that sets an optical path in a network using a plurality of subcarriers, and holds path information in the network. And a path selection corresponding to the path information when receiving an optical path setting / change request, and the fixed error correction code required for transmitting an optical signal included in the path information. The transmitting side node apparatus is controlled so that subcarriers having a frame configuration corresponding to the redundancy of the selected path are allocated to vacant wavelengths, and if the amount of transmission data is insufficient at the time of wavelength allocation, another path is added additionally And a processor that controls the transmitting side node device to select and assign a subcarrier having a frame configuration according to the redundancy of the other path to an empty wavelength. That.

  According to the present invention, there is also provided an optical communication control method for setting an optical path in a network using a plurality of subcarriers, the first step for holding route information in the network, and an optical path setting / changing request. A frame configuration corresponding to the redundancy of the selected path with respect to a fixed error correction code required for transmitting an optical signal included in the path information, performing path selection corresponding to the path information when received The transmission side node device is controlled so as to allocate subcarriers having vacant wavelengths, and when the transmission data amount is insufficient at the time of wavelength allocation, another path is additionally selected, and the redundancy of the other path is set. There is provided an optical communication control method comprising: a second step of controlling the transmitting side node device so as to assign subcarriers having a corresponding frame configuration to vacant wavelengths.

  According to the optical communication control device and the optical communication control method according to the present invention, subcarriers having a frame configuration corresponding to the redundancy required for each path selected corresponding to the path information are allocated to empty wavelengths, and at the time of wavelength allocation When the amount of transmission data is insufficient, another path is additionally selected, and the transmitting side node apparatus is controlled so that a subcarrier having a frame configuration corresponding to the redundancy of the other path is allocated to an empty wavelength. Since it is configured, it is possible to transmit an optical signal through an optical path having a long distance and a large number of intermediate nodes by increasing the redundancy of the error correction code. In addition, since the free wavelengths fragmented over a plurality of paths can be used effectively, the number of optical paths that can be provided by the entire optical transmission system can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating an entire optical communication system in which an optical communication control device according to a first embodiment of the present invention is combined with a node device. FIG. 2 is a functional block diagram of a route calculation engine constituting the optical communication control device in FIG. 1. FIG. 2 is a functional block diagram of an optical communication system including the optical communication control device, the transmission-side node device, and the reception-side node device shown in FIG. 1. FIG. 2 is a block diagram showing an optical path setting flow by the optical communication control device shown in FIG. 1. It is a flowchart which shows the route calculation process in the route calculation engine shown in FIG. It is the figure which showed an example (Table 1) of the path | route information database which comprises the optical communication control apparatus shown in FIG. FIG. 3 is a diagram illustrating a processing procedure of a redundancy calculation unit illustrated in FIG. 2 and an example (Table 2) of a redundancy calculation table obtained thereby. FIG. 2 is a block diagram illustrating a process of transmitting subcarriers divided into two paths as an example by the optical communication control apparatus illustrated in FIG. 1. FIG. 9 is a diagram more specifically illustrating a transmission process of subcarriers illustrated in FIG. 8. It is the format figure which showed the structural example of the OTU4 frame used for this invention. It is a figure for demonstrating the subcarrier aggregation in the receiving side node apparatus connected to the optical communication control apparatus in this invention.

  Embodiments of an optical communication control apparatus and an optical communication control method according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
An optical communication network to which the present invention shown in FIG. 1A is applied includes an optical communication control apparatus 101 according to the present invention that controls the entire network, and node apparatuses 102 to 105 that transmit optical signals. The configuration of each node device is the same. Further, for the sake of explanation, here, a configuration example using four node devices 102 to 105 is given, but it goes without saying that the present invention is not limited to them.

  The optical communication control apparatus 101 performs management control of the entire optical communication system such as management of path information and optical path setting. The optical communication control apparatus 101 includes a route information database 111, a route calculation engine 112, and an optical path setting unit 113.

  The operation of the path information database 111 is roughly represented by path information in the optical communication network, that is, the distance of each path, the type of fiber, ROADM (Reconfigurable Optical Add / Drop Multiplexer) information, transmission characteristics (to be described later) It holds information such as the received OSNR (Optical Signal to Noise Ratio) and other optical signal quality degradation amounts) and free wavelengths. When there is a new transmission request (transmission command), the route calculation engine 112 performs route selection, wavelength assignment, and redundancy calculation using the route information held in the route information database 111. Based on the result of this route selection and wavelength allocation, the optical path setting unit 113 transmits an optical path setting request to each of the node devices 102 to 105.

  Each of the node devices 102 to 105 transmits a control optical signal to the adjacent node device, so that each received node device acquires transmission characteristics such as the degradation amount of the optical signal on the path. As will be described later, the acquired transmission characteristics may be transmitted to the optical communication control apparatus 101, but the present invention is not limited thereto.

When each of the node apparatuses 102 to 105 receives an optical path setting request from the optical communication control apparatus 101, each of the node apparatuses 102 to 105 configures each subcarrier, secures a wavelength for arranging the subcarrier, and sets an optical path according to the request. . When receiving an optical path deletion request, each of the node apparatuses 102 to 105 releases the corresponding wavelength. When an optical path change request is received, the wavelength used so far is released and changed to the wavelength specified in the change request.
In the following description, an optical path setting request will be mainly described as an example, but the same applies to an optical path change request.

  FIG. 2 shows a configuration example of the route calculation engine 112 in the optical communication control apparatus 101. The route calculation engine 112 includes a candidate route selection unit 121, a redundancy calculation unit 122, and a subcarrier configuration determination unit 123. The candidate route selection unit 121 selects an optimum route for the received optical path setting request and optical path change request. For candidate route selection, a plurality of route calculation algorithms such as Dijkstra method, breadth-first search, and genetic algorithm can be applied. In addition, a route is calculated in consideration of a plurality of metrics such as a distance, a transmission delay, and a transmission route penalty. Therefore, a route can be calculated with an appropriate link cost and route calculation algorithm in accordance with the transmission request.

  The redundancy calculation unit 122 calculates the required error correction code redundancy for the route selected by the candidate route selection unit 121. In other words, the redundancy calculation unit 122 uses the optical signal degradation amount (for example, received OSNR) of the path held in the path information database 111 illustrated in FIG. In order to transmit the signal, the Q value is obtained, and the necessary coding gain of the error correction code is obtained. Further, the redundancy is obtained from the coding gain. These are all obtained from the table. This will be described later with reference to Table 3 with respect to FIG.

In the subcarrier configuration determination unit 123, based on the redundancy of the error correction code calculated by the redundancy calculation unit 122, a data area for storing the client signal of the OTU frame arranged in the subcarrier, and the FEC for storing the error correction code Determine the area.
In contrast to the redundancy calculated by the redundancy calculation unit 122, the subcarrier configuration determination unit 123 (1) OTU increases the error correction code redundancy when the fixed FEC region of the OTU frame is insufficient. It has two functions: a function of expanding the FEC area of the frame and a function of (2) assigning an error correction code to the data area (payload area) of the OTU frame.

  In the case of (2) above in which the error correction code is assigned to the data area of the frame, for example, the variable rate error correction code disclosed in Patent Document 1 can be applied. In accordance with the redundancy to be increased, error correction codes are arranged in units of tributary slots of the OTU frame. Since the amount of client signals that can be transmitted per frame decreases, the subcarrier configuration determination unit 123 determines the sizes of the data area and the FEC area, and determines the number of subcarriers necessary for transmitting the client signal of the transmission request. calculate. This will be described later with reference to FIG.

  FIG. 1B shows a hardware block diagram of the optical communication control apparatus 101 in FIG. 1A, and the memory M1 stores route information held in the route information database 111, Based on this route information, the processor P1 performs calculations in the route calculation engine 112 via the bus BUS, and performs optical path setting (route setting) from the optical path setting unit 113.

  That is, the memory M1 holds route information in the network. Further, the processor P1, when receiving an optical path setting / change request, selects a path corresponding to the path information, and is a fixed error correction code necessary for transmitting an optical signal included in the path information. The transmitting side node device is controlled to allocate a subcarrier having a frame configuration corresponding to the redundancy of the selected path to an empty wavelength, and another path is added when the transmission data amount is insufficient at the time of the wavelength allocation. The transmission side node device is controlled so that a subcarrier having a frame configuration corresponding to the redundancy of the other path is allocated to an empty wavelength.

  FIG. 3 shows a configuration example of the transmission-side node device 102 and the reception-side node device 105 under the control of the optical communication control device 101. The transmission-side node device 102 includes a control light signal transmission unit 201, a client signal accommodation unit 202, a frame generation unit 203, and a subcarrier transmission unit 204. The reception side node device 105 includes a control optical signal reception unit 301, a signal quality degradation amount acquisition unit 302, a control device communication unit 303, a subcarrier reception unit 304, a frame termination unit 305, and a client signal transmission unit 306. ing.

  Note that these node devices 102 and 105 are merely examples, and the configuration of the other node devices is the same. In FIG. 3, only the functions to be used are extracted and shown. Also, since any node device can be a transmission side node device or a reception side node device, they have the same configuration.

  First, as an initial operation, the transmission path 106.1 to 106. The control optical signal is transmitted to the receiving-side node device 105 via n (hereinafter may be collectively referred to as reference numeral 106). In the receiving side node device 105, the control light signal receiving unit 301 receives the control light signal. Thereafter, the optical signal quality degradation amount (reception OSNR) in the case of passing through the transmission path 106 is acquired from the signal quality degradation amount acquisition unit 302. The acquired signal quality degradation amount is transmitted from the control device communication unit 303 to the optical communication control device 101, and stored / updated in the path information database 111. Although an example in which the signal quality degradation amount is estimated / acquired using the control light signal is described here, other methods may be used.

  Next, as a normal operation, the transmission side node device 102 accommodates client signals of different rates in the client signal accommodation unit 202. The frame generation unit 203 generates a data area and an FEC area of the OTU frame according to the request transmitted from the optical path setting unit 113 of the optical communication control apparatus 101. The generated OTU frame is transmitted by the subcarrier transmission unit 204 to one or a plurality of transmission paths 106 as described later.

  In the subcarrier receiving unit 304 of the receiving-side node device 105, different transmission paths 106.1 to 106. The subcarrier transmitted via n is received. Further, the frame termination unit 305 reconfigures the subcarriers (subcarrier aggregation), and returns the OTU frame arranged on the subcarriers to the original transmission request signal. Finally, the returned client signal is transmitted by the client signal transmission unit 306.

Next, the optical path setting process by the optical communication control apparatus of the present invention will be described with reference to FIG.
First, as an initial operation, a transmission request is transmitted from the optical communication control apparatus 101 to the transmission side node apparatus 102 (step S101). The transmission-side node device 102 that has received this transmission request transmits a control light signal to all adjacent node devices, that is, the node devices 103 to 105 in the illustrated example (step S102).

  The receiving side node device 105 that has received the control light signal receives the control light signal that passes through all the routes between the transmitting side node device 102 and the receiving side node device 105, and passes through these routes. The optical signal quality degradation amount (reception OSNR) is acquired and transmitted to the optical communication control apparatus 101 (step S103). The optical communication control apparatus 101 stores the optical signal quality degradation amount as path information in the database 111.

  Thereafter, when the optical communication control apparatus 101 receives an optical path setting request (or an optical path change request) (step S104), the path calculation engine 112 performs path selection, wavelength allocation, and redundancy calculation, and subcarriers. The configuration is determined, and the paths of all the node devices are determined (step S105). This will be described later in Table 3 of FIG.

  Then, a transmission side setting request (step S106.1) is sent from the optical communication control apparatus 101 to the transmission side node apparatus 102. In the transmitting side node device 102, a subcarrier is set to the wavelength assigned in the selected path, and in this case, a subcarrier data area and a fixed error coding (FEC) area are set based on the redundancy, and an intermediate node is set. The data is sent to the devices 103 and 104. This will also be described in detail later.

  The optical communication control apparatus 101 sends a relay setting request as a path setting request to each of the intermediate node apparatuses 103 and 104 on the selected path (steps S106.2 to S106.3). As a result, the frame is transferred via the intermediate node devices 103 and 104.

  Finally, the optical communication control apparatus 101 sends a reception side setting request to the reception side node apparatus 105, and performs settings so that the reception side node apparatus 105 can perform subcarrier aggregation.

In this way, both the frame that reaches the receiving side node device 105 directly from the transmitting side node device 102 and the frame that reaches the receiving side node device 105 via the intermediate node devices 103 and 104 are generated. However, this is the case of FIG. 8 and FIG. 9 described later, and it goes without saying that the frame may only reach the receiving side node device 105 directly from the transmitting side node device 102.
The path setting (steps S106.1 to 106.n) is performed by instructing switching of the input / output ports of the optical switch in each node device.

Next, a calculation process in the route calculation engine 112 of the optical communication control apparatus 101 shown in FIG. 1 will be described with reference to FIG.
First, the received OSNR of each path measured as described above is acquired from the path information database 111 as a parameter for evaluating the optical signal quality degradation amount (step S201). The received OSNR is set as the link cost, and k candidate routes are calculated by the k-shortest method (step S202). Since the optical signal quality degradation in the route with the large received OSNR is small, the route is selected from the candidate routes in descending order (step S203). In the selected route, if the received OSNR of the route is sufficient for the transmission of the optical signal (Yes in step S204), the subcarriers are assigned in the order of the free wavelength numbers by the First Fit method (step S206).

  If the received OSNR is insufficient (No in step S204), an error correction code necessary for transmitting the optical signal is calculated, and the subcarrier configuration is determined (step S205). Then, based on the above channel configuration, subcarriers are assigned to vacant wavelengths (step S206).

  If the data capacity of the free wavelength for allocating subcarriers is sufficient (Yes in step S207), an optical path is set based on the allocation result (step S208). If the available wavelengths are insufficient (No in step S207), the process returns to the candidate route selection step (step S203), selects another route from the candidate routes, and repeats the above steps (steps S203 to S207) again. Run.

  By repeating the above steps, route selection and wavelength assignment for transmitting a transmission request are performed. Although an example using the k-shortest algorithm and the first fit method is shown here, the present invention is not limited to this, and other calculation algorithms may be used.

  The algorithm used in the above candidate path calculation step (step S202) and the subcarrier allocation step (step S206) is an example, and other calculation algorithms can be applied. What is necessary is just to switch to an appropriate calculation algorithm in response to a transmission request such as high-speed path calculation or path priority with many empty wavelengths.

  In the above candidate route selection step (step S202), information held in the route information database 111 is referred to. An example of the route information database 111 is shown in Table 1 of FIG. As shown in the figure, this route information database 111 holds node information 1111 passing through the route, route distance 1112, received OSNR 1113, and free wavelength 1114 on the route. The information on the change in the vacant wavelength is transmitted from each node device, that is, the node device 105 in the example of FIG. 3, to the optical communication control device 101, and the path information database 111 is updated.

An example of a detailed flow of the redundancy calculation and subcarrier configuration determination (step S205) shown in FIG. 5 is shown in FIG.
The received OSNR is converted into a high-speed optical signal quality evaluation parameter Q value according to the characteristics of the optical signal processor (not shown) of the node device (step S301). For the Q value required in the optical transmission system, the Q value is calculated from the received OSNR of the transmission path and the characteristics of the optical signal processor of the node device. For example, when the Q value required in the optical transmission system is 18 dB, an optical signal may be transmitted when the result of adding the coding gain of the error correction code to the Q value calculated from the received OSNR is 18 dB or more. it can.

  On the other hand, if the Q value calculated from the received OSNR is smaller than 18 dB, the necessary coding gain is calculated (step S302). Based on the coding gain, the redundancy of the error correction code that satisfies this is calculated (step S303). Finally, the subcarrier configuration is determined based on the redundancy obtained in step S303 (step S304). As shown in Table 2 of FIG. 7, the sizes of the data area and the FEC area of the frame are determined based on the redundancy Ri, Rj, and Rk. The route information obtained from the signal quality degradation amount acquisition unit 302 may be other than the received OSNR. For example, if the measurement result of the Q value is held, step S301 can be omitted.

  When there is not enough free wavelength in one path, the transmitting-side node device 102 transmits subcarriers divided into a plurality of paths. For example, as shown in FIG. 8, the subcarriers are transmitted by being divided into two paths A and B. The subcarriers arrive at the node apparatuses 103 and 104 via different paths A and B, respectively. Thereafter, the receiving side node device 105 combines subcarriers via different paths (subcarrier aggregation) and returns the original client signal. In the route calculation, it is determined which route is used by each subcarrier in the process of determining the use route from a plurality of routes as shown in step S202 and step S203. If there is a delay restriction in the subcarrier combining process, it is reflected in the path calculation process. For example, ITU-T G. When the frame alignment method described in the 709 recommendation is used, a route is selected so that a delay difference between subcarriers is within a range in which signals can be combined by the frame alignment method.

<Example>
A specific example of the above-described optical communication control apparatus will be described with reference to FIG. Here, an optical communication system including the optical communication control apparatus 101, the transmission side node apparatus 102, the intermediate node apparatus 104, and the reception side node apparatus 105 is taken as an example.

  In this example, it is assumed that the path A of the node devices 102-105 has two vacant wavelengths, the received OSNR is 21.3 dB, and the obtained Q value is 6.8 dB. Further, it is assumed that the path B of the node device 102-104-105 has three or more vacant wavelengths, the received OSNR is 16.3 dB, and the obtained Q value is 2.5 dB. Each wavelength has a communication capacity of 100 Gbps, and the fixed error correction code (FEC) redundancy of the OTU frame is 20%. In addition, it is assumed that a coding gain of 11.5 dB is obtained by an error correction code having a redundancy of 20%, and a coding gain of 16 dB is obtained by an error correction code having a redundancy of 80%. Furthermore, it is assumed that the Q value required in the optical transmission system is 18 dB.

In such a configuration example, an operation when there is a 400 Gbps transmission request between the node device 101 and the node device 105 will be described.
First, in this optical communication system, the optical communication control apparatus 101 determines the configuration of a frame to be transmitted. That is, the optical communication control apparatus 101 has path candidates as shown in Table 3 in the database 111, and among these, the path A of the node apparatus 102-105, which is the path with the larger received OSNR, is given priority. Select When optical signal transmission is performed via the path A between the node apparatuses 102 and 105, the value obtained by adding the coding gain 11.5 dB of the fixed error correction code to the Q value 6.8 dB obtained in the path A exceeds 18 dB. . Therefore, the optical communication control apparatus 101 assigns subcarriers # 1 and # 2 to the empty wavelength of the path A between the node apparatuses 102-105.

  Since the path A of the node apparatus 102-105 has only two free wavelengths, 100 × 2 = 200 Gbps, and 200 Gbps is insufficient to transmit a 400 Gbps client signal. Therefore, the remaining 200 Gbps is allocated to the path B of the detour node device 102-104-105.

  However, it is obtained when passing through the route B between the node devices 102-104-105 (this can also be considered to be preferentially selected when there are other selected routes). Since the Q value is as low as 2.5 dB, the Q value required in the optical transmission system does not satisfy 18 dB with the addition of the coding gain of 11.5 dB obtained from the redundancy (20%) of the fixed error correction code.

  Therefore, when an optical signal is transmitted using the path B between the node apparatuses 102-104-105, the optical communication control apparatus 101 arranges the 33 Gbps FEC area in the data area of the 100 Gbps OTU4 frame, thereby increasing the redundancy. By setting 80% and obtaining a coding gain of 16 dB, the transmission-side node device 102 is set so that 18 dB can be obtained by adding the Q value of 2.5 dB. The transmittable data is 67 Gbps × 3 = 201 Gbps, and the above shortage is compensated by assigning subcarriers # 3 to # 5 to vacant wavelengths in the path B between the node devices 102-104-105. Is possible.

In this way, the optical communication control apparatus 101 sets the transmission side node apparatus 102 as shown in steps S106.1 and S107 in FIG. 4 and transmits the subcarrier-configured frame to the intermediate node apparatuses 103 and 104. Then, it reaches the receiving side node device 105 via these intermediate node devices 103 and 104.
In the receiving side node device 105, the received subcarriers # 1 to # 5 are aggregated and returned to the original client signal.

  FIG. 10 shows a configuration example of the OTU4 frame arranged on the subcarriers # 1 to # 5. Subcarriers # 1 and # 2 are transmitted without changing the configuration of the OTU4 frame because there is no need to increase the redundancy. In the case of subcarriers # 3 to # 5, 20 tributary slots in the data area of the OTU4 frame are used as variable FEC areas. # 55 to # 80 are variable FEC areas.

An example in which subcarrier aggregation is performed in the receiving-side node device 105 is shown in FIG.
In the receiving side node device 105, the FEC areas of the subcarriers # 1 and # 2 passing through the route of the node device 102-105 and the subcarriers # 3 to # 5 passing through the route of the node device 102-104-105 are removed, Combine the data areas back into the client signal. For subcarriers # 3 to # 5, the optical path setting request transmitted from the optical communication control apparatus 101 has confirmed that the tributary slots # 55 to # 80 in the data area are variable FEC areas. Tributary slots # 55 to # 80 in the data area are removed, and only data is extracted.

  Note that it is also possible to determine the frame configuration arranged on the subcarrier and the optical path configuration for transmitting the client signal based on the amount of parity stored in the payload area.

  In this way, each node device is set by the optical communication control device 101 of the present invention, so that it can be provided within the network, for example, directly from the transmitting side node device or via an intermediate node device as necessary. It is possible to send a frame composed of subcarriers corresponding to the degree of redundancy to the receiving side node apparatus in a state in which a simple optical path is maximized.

Claims (8)

An optical communication control apparatus for setting an optical path in a network using a plurality of subcarriers,
A memory for holding route information in the network;
When an optical path setting / change request is received, a route is selected in accordance with the route information, and the selected route for the fixed error correction code required for transmitting the optical signal included in the route information is selected. The transmission side node device is controlled to allocate a subcarrier having a frame configuration corresponding to the redundancy to an empty wavelength, and when a transmission data amount is insufficient at the time of the wavelength allocation, another path is additionally selected, An optical communication control device comprising: a processor that controls the transmitting side node device so as to assign a subcarrier having a frame configuration according to the redundancy of another path to an empty wavelength. The memory includes route information including distance information of each route, fiber type, ROADM (Reconfigurable Optical Add / Drop Multiplexer) information, transmission characteristics including optical signal quality degradation amount, and free wavelength information. Database,
The processor performs path selection corresponding to the path information, performs wavelength assignment for the selected path, and performs the path for the fixed error correction code required for transmitting an optical signal included in the path information. The path calculation engine for calculating the redundancy of the transmission path, and an optical path setting unit that controls the transmission side node device so as to become a frame of a subcarrier configuration according to the redundancy. Optical communication control device. The optical communication control device according to claim 1, wherein the processor performs path setting for all node devices when controlling the transmission-side node device so as to have the frame configuration. The processor obtains an optical signal quality degradation amount on the path from the receiving side node device by mutually transmitting a control optical signal from the transmitting side node device to the node devices in the network at the time of initial setting. The optical communication control device according to claim 1, wherein the optical communication control device is included in the route information. The optical communication control apparatus according to claim 4, wherein the processor obtains the redundancy from a received OSNR (Optical Signal to Noise Ratio) that is the optical signal quality degradation amount. The processor increases the redundancy of the error correction code by expanding a redundancy area outside the frame when the redundancy of the fixed error correction code is insufficient with respect to the redundancy. The optical communication control apparatus according to 1 or 2. When the redundancy of the fixed error correction code is insufficient with respect to the redundancy, the processor stores the error correction code in a payload area inside the frame and changes the transmission rate of the frame. The optical communication control device according to claim 1, wherein the redundancy is increased without increasing the redundancy. An optical communication control method for setting an optical path in a network using a plurality of subcarriers,
A first step of maintaining route information in the network;
When an optical path setting / change request is received, a route is selected in accordance with the route information, and the selected route for the fixed error correction code required for transmitting the optical signal included in the route information is selected. The transmission side node device is controlled to allocate a subcarrier having a frame configuration corresponding to the redundancy to an empty wavelength, and when a transmission data amount is insufficient at the time of the wavelength allocation, another path is additionally selected, An optical communication control method comprising: a second step of controlling the transmitting side node device so as to assign a subcarrier having a frame configuration according to the redundancy of another path to an empty wavelength.

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