JP2012070303A - Optical wavelength sharing system, optical wavelength sharing method, and optical wavelength sharing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical wavelength sharing system, an optical wavelength sharing method, and an optical wavelength sharing program that consider an utilization efficiency of an optical signal transmitted in a network.SOLUTION: Wavelength-based utilization efficiency determination means 12 determines an utilization efficiency for each wavelength, for each received optical signal. Sharing possibility/impossibility determination means 13 determines whether or not a plurality of optical signals with different wavelengths can share one common specific wavelength by using the determination result. Optical signal transmission means 14 sends these optical signals together to the next node while these optical signals share the one specific wavelength when the sharing possibility/impossibility determination means 13 determines that sharing is possible.

Description

  The present invention relates to an optical wavelength sharing system, an optical wavelength sharing method, and an optical wavelength sharing program that use the wavelength of light for communication, and in particular, an optical wavelength sharing system and an optical wavelength that aim to effectively utilize a communication band within one optical wavelength. The present invention relates to a sharing method and an optical wavelength sharing program.

  The communication capacity of an optical fiber is determined by the number of wavelengths that can be wavelength multiplexed. In the case where an optical fiber is used for the backbone network as an example, it is mainly 10 Gbps (gigabit / second) × 80 channel multiplexing or 40 Gbps × 40 channel multiplexing. Therefore, the communication capacity is about 0.8 to 1.6 Tbps (terabit / second) per optical fiber. Here, 1 Tbps means 1 trillion bits / second.

  In recent years, each communication company tends to use various application software for communication, which tends to increase the amount of information. For such an increase in the amount of information, it has been proposed as a first related technique of the present invention to increase the communication capacity per optical fiber by further promoting multiplexing of light wavelengths. (For example, refer to Patent Document 1).

  However, this complicates the path control for each wavelength in the network node to which the optical fiber is connected. Further, if the wavelength of light used for communication is divided more finely and multiplexed, an interference pattern due to proximity occurs between adjacent wavelengths, and there is a concern about deterioration in communication quality.

  Among these, the second related technique of the present invention exists as a countermeasure to the complicated route control (see, for example, Patent Document 2). In the second related technique, a link used by an existing path is virtually released to generate a virtual topology table in an unused state. Then, an optimum route to the node device at the end point is calculated using this virtual topology table.

  However, the services of connection providers such as providers will continue to improve. Therefore, measures for maintaining the quality of data for individual users are required in an increase in traffic. Thus, it has been proposed as a third related technique of the present invention to divide destination nodes into groups and assign a unique wavelength to each group (see, for example, Patent Document 3).

FIG. 12 shows an outline of the configuration of the optical wavelength sharing system according to the third related technique. In the optical wavelength sharing system 100, the 0th to _nth optical fibers 101 _{0 to} 101 _n constitute an optical fiber ring network. The 0th node 102 ₀ to the 6th node 102 ₆ are connected to each other via the multiplexing / demultiplexing device 103.

FIG. 13 shows a state in which destination nodes transmitted from each node in the third related technique are divided into groups. Here, the destination node is divided into three different groups with group names A, B, and C. The transmission wavelength addressed to each group is different from λ ₁ , λ ₂ ,...

Accordingly, the optical wavelength sharing system 100, a first group A from node 102 ₀ of the zeroth, the to fifth node 102 _1, 102 _5, and transmits the optical signal of the wavelength lambda ₁ to the fiber 101 ₀ of the 0 . From the 0th node 102 ₀ to the second and third nodes 102 ₂ and 102 ₃ of the group B, an optical signal having a wavelength λ ₂ is transmitted to the 0th optical fiber 101 ₀ . The optical signal having the wavelength λ ₄ is transmitted from the 0th node 102 ₀ to the fourth and sixth nodes 102 ₄ and 102 ₆ of the group C to the 0th optical fiber 101 ₀ .

Although the description has been limited to the transmission from the _0th node 102 ₀ , the corresponding first fiber 101 is similarly applied when transmitting from the first node 102 ₁ to the sixth node 102 _6. with ₁ to fiber 101 ₆ sixth, the same transmission wavelength for each group is used.

  According to the third related technique, a band that can be transmitted by one wavelength is shared by a plurality of nodes in the same group. As a result, the link capacity does not need to be the sum of the maximum usable bandwidths of the destination nodes belonging to the same group, a statistical multiplexing effect is expected, and the use efficiency of the link can be increased.

JP 2000-165353 A (paragraphs 0021 to 0023, FIG. 1) Japanese Patent Laying-Open No. 2010-130272 (paragraph 0032, FIG. 12) JP 2001-168842 (paragraphs 0009 to 0012, FIG. 1)

  As described above, according to the third related technique, optical signals having a plurality of wavelengths grouped inside one optical fiber are transmitted. Therefore, the communication capacity per optical fiber can be increased as in the first related technology.

  However, in the third related technique, as shown in FIG. 13, the destination node and the transmission wavelength are uniformly allocated without considering the use frequency. Therefore, when the frequency of use for each destination node varies with time, even if it is possible to transmit all destination nodes grouped at a certain point in time at the same wavelength, these destination nodes at another point in time This causes a problem that only a part of the transmission can be performed at the same wavelength.

  Accordingly, an object of the present invention is to provide an optical wavelength sharing system, an optical wavelength sharing method, and an optical wavelength sharing program in consideration of the utilization efficiency of optical signals transmitted in a network.

  In the present invention, (b) optical signal receiving means for receiving optical signals to be sent to other network nodes via the own node, and (b) optical signals received by the optical signal receiving means, (C) Using the discrimination results of the wavelength-based usage efficiency discrimination means for discriminating the usage efficiency at the wavelengths used for transmission, and (c) using the discrimination results of the wavelength-specific usage efficiency discrimination means, Shareability determining means for determining whether or not optical signals of different wavelengths can be shared by a common one specific wavelength, and (d) sharing by the specific one wavelength described above is possible by this shareability determining means. When discriminated, the optical wavelength sharing system includes optical signal transmitting means for sharing the optical signals of the plurality of different wavelengths at the specific one wavelength and transmitting each optical signal to the next node. To.

  In the present invention, (b) an optical signal receiving step for receiving an optical signal to be sent to another network node via its own node, and (b) each of the optical signals received in this optical signal receiving step. And (c) using the discrimination results obtained by the wavelength-based utilization efficiency discrimination step for discriminating the utilization efficiency at the wavelengths used for the transmission, and sending out the same route. A shareability determination step of determining whether or not a plurality of optical signals of different wavelengths can be shared by a common one specific wavelength; and (d) sharing by the specific one wavelength described above by this shareability determination step. When it is determined that it is possible, the optical signal having the plurality of different wavelengths is shared by the specific one wavelength, and each optical signal is transmitted to the next node. Optical wavelength sharing method and signal step comprises.

  Further, according to the present invention, the optical wavelength sharing program is transmitted to the computer as (a) an optical signal receiving process for receiving an optical signal to be sent to another network node via the own node, and (b) receiving the optical signal. For each of the optical signals received in the processing, the same usage efficiency discrimination processing for discriminating the usage efficiency at the wavelength used for these transmissions, and (c) the discrimination result by this wavelength-specific usage efficiency discrimination processing, A shareability determination process for determining whether or not a plurality of optical signals having different wavelengths transmitted toward the path can be shared by a single common wavelength, and (d) the shareability determination process described above. When it is determined that sharing by one specific wavelength is possible, the optical signals having the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. To execute the optical signal transmission processing to be sent to.

  As described above, according to the present invention, the utilization efficiency at the wavelength used for transmission is determined for each of the optical signals, and a plurality of optical signals of different wavelengths transmitted toward the same path are shared. When it can be shared by one specific wavelength, it is shared by one specific wavelength and transmitted to the next node. As a result, the communication band within one wavelength of light can be fully utilized, and the number of wavelengths to be used can be reduced. As a result, it is possible to suppress signal interference with other wavelengths that are close to each other and improve communication quality. Further, by combining with GMPLS (Generalized Multi-Protocol Label Switching), control for each optical wavelength becomes easy.

It is a claim correspondence diagram of the optical wavelength sharing system of the present invention. It is a claim corresponding | compatible figure of the optical wavelength sharing method of this invention. It is a claim corresponding | compatible figure of the optical wavelength sharing program of this invention. 1 is a system configuration diagram showing an outline of a configuration of an optical wavelength sharing system according to an embodiment of the present invention. It is a schematic block diagram showing the structure of the relay node and its periphery in a backbone network of this Embodiment. FIG. 6 is a block diagram specifically illustrating a configuration of a control plane unit illustrated in FIG. 5. Is an explanatory diagram showing the contents of a memory table at time t ₀ of this embodiment. It is an explanatory diagram showing the contents of a memory table at time t ₁ + Δ ₁ of the present embodiment. It is an explanatory diagram showing the contents of a memory table at time t ₁ + Δ ₂ of the present embodiment. It is explanatory drawing showing an example of the memory table in the control plane part of the relay node after this relay node of this Embodiment. It is a flowchart which generalized and represented the mode of the selection process of the wavelength of the optical signal shared in the optical wavelength sharing system of this Embodiment. It is a system configuration | structure figure showing the outline | summary of the structure of the optical wavelength sharing system by the 3rd related technique. It is explanatory drawing showing the state which divided | segmented the destination node transmitted from each node in a 3rd related technique into a group.

  FIG. 1 is a diagram corresponding to claims of the optical wavelength sharing system of the present invention. The optical wavelength sharing system 10 of the present invention includes an optical signal receiving unit 11, a wavelength-based utilization efficiency determining unit 12, a sharing possibility determining unit 13, and an optical signal transmitting unit 14. Here, the optical signal receiving unit 11 receives an optical signal to be transmitted to another network node via its own node. The wavelength-based utilization efficiency determining unit 12 determines the utilization efficiency at the wavelength used for transmission of each of the optical signals received by the optical signal receiving unit 11. Whether the sharability determination unit 13 can share a plurality of optical signals of different wavelengths transmitted to the same path with a single specific wavelength using the determination result of the wavelength-based utilization efficiency determination unit 12 Determine whether or not. When the optical signal transmission unit 14 determines that the sharing by the specific one wavelength is possible by the sharing possibility determination unit 13, the optical signal transmission unit 14 shares the optical signals having the different wavelengths with the specific one wavelength. Each optical signal is sent to the next node.

  FIG. 2 is a diagram corresponding to claims of the optical wavelength sharing method of the present invention. The optical wavelength sharing method 20 of the present invention includes an optical signal receiving step 21, a wavelength-based utilization efficiency determining step 22, a sharing possibility determining step 23, and an optical signal transmitting step 24. Here, in the optical signal receiving step 21, optical signals to be sent to other network nodes are received via the own node. In the use efficiency discrimination step 22 for each wavelength, for each of the optical signals received in the optical signal reception step 21, the use efficiency at the wavelength used for the transmission is discriminated. In the shareability determination step 23, is it possible to share a plurality of optical signals of different wavelengths transmitted toward the same path with a single specific wavelength using the determination result obtained by the wavelength-based utilization efficiency determination step 22? Determine whether or not. In the optical signal transmission step 24, when it is determined in the sharing possibility determination step 23 that sharing by the specific one wavelength is possible, the optical signals having the plurality of different wavelengths are shared by the specific one wavelength. Each optical signal is sent to the next node.

  FIG. 3 is a diagram corresponding to claims of the optical wavelength sharing program of the present invention. The optical wavelength sharing program 30 of the present invention causes a computer to execute an optical signal reception process 31, a wavelength-specific utilization efficiency determination process 32, a shareability determination process 33, and an optical signal transmission process 34. Here, in the optical signal reception process 31, optical signals to be sent to other network nodes are received via the own node. In the use efficiency discrimination processing 32 for each wavelength, for each of the optical signals received in the optical signal reception processing 31, the use efficiency at the wavelength used for the transmission is discriminated. In the shareability determination process 33, whether or not a plurality of optical signals having different wavelengths transmitted toward the same route can be shared by a single specific wavelength using the determination result obtained by the wavelength-based use efficiency determination process 32 Determine whether or not. In the optical signal transmission process 34, when it is determined by the sharing possibility determination process 33 that sharing by the specific one wavelength is possible, the optical signals having the plurality of different wavelengths are shared by the specific one wavelength. Each optical signal is sent to the next node.

  <Embodiment of the Invention>

  Next, an embodiment of the present invention will be described.

FIG. 4 shows an outline of the configuration of the optical wavelength sharing system according to the embodiment of the present invention. The optical wavelength sharing system 200 of this embodiment includes a backbone network 201. The backbone network 201 is connected to the _first backbone network 203 ₁ via the _first backbone network node 202 ₁ , connected to the second backbone network 203 ₂ via the _second backbone network node 202 ₂ , It is connected to the _third backbone network 203 ₃ via the third backbone network node 202 ₃ . The relay node 204 is one of the backbone network nodes in the backbone network 201. The relay node 204 is connected to the _first to third backbone network nodes 202 _{1 to} 202 ₃ .

The first to third backbone network nodes 202 _{1 to} 202 ₃ basically have the same configuration. In FIG. 4, this is specifically illustrated and described for the first backbone network node 202 ₁ . The first backbone network node 202 ₁ includes a plurality of edge nodes 211. The edge node 211 is a node at the end (edge) closest to the end user 212, and is usually configured by a device such as a router or a VPN (Virtual Private Network) device.

In this optical wavelength sharing system 200, it is assumed that the data communication from a first core network 203 ₁ and the third backbone network 203 ₃ to the second core network 203 ₂ is performed. In this case, the wavelength of the first backbone network 203 ₁ assigned to the optical signal and lambda _a, the wavelength of the third optical signal assigned to the backbone network 203 ₃ to lambda _b. Relay node 204 multiplexes optical signals transmitted, and sends toward the ₂ second backbone network 203 as an optical signal of wavelength lambda.

  By the way, the optical wavelength sharing system 200 of this embodiment uses a routing technique called GMPLS. In GMPLS, a label is attached to each wavelength of an optical signal. There is MPLS (Multi-Protocol Label Switching) as a term related to GMPLS. In MPLS, a label is added to a packet to specify a routing route.

  In GMPLS, since a label is attached to the wavelength of an optical signal, switching can be performed without converting the optical signal into an electrical signal. Therefore, in GMPLS, a control channel is provided separately from the data channel. The control channel communicates control messages and controls predetermined items such as optical path settings.

In the control channel, each backbone network node sets an optical path toward the target backbone network node. For example between different backbone networks like the first backbone network 203 ₁ and the third backbone network 203 _3, the case of transmitting data to the common backbone network to those as in the second core network 203 ₂ Think. In this case, the relay node 204 of the backbone network 201 common to the first and third backbone networks 203 ₁ and 203 ₃ sets an optical path, converts it into an optical signal having a predetermined wavelength λ, and transfers data. Will do.

  FIG. 5 shows a relay node and its peripheral configuration in the backbone network. The relay node 204 includes an optical switch unit 221 that turns on / off and distributes an optical signal, a wavelength multiplexing unit 222 that multiplexes the optical signal that has passed through the optical switch unit 221, and a control plane unit 223 that performs various controls. ing.

  FIG. 6 specifically shows the configuration of the control plane unit. The control plane unit 223 includes a CPU (Central Processing Unit) 231, a control program executed by the CPU 231, a memory 232 including a predetermined memory table 232 </ b> A, and a timer 233 that performs a timing operation using a clock used by the CPU 231. It has. In addition, the control plane unit 223 includes an O / E (Optical / Electrical) conversion unit 236 that converts an optical signal having a predetermined wavelength transmitted from the data channel 234 and the control channel 235 into an electric signal, and vice versa. E / O (Electrical / Optical) conversion unit 239 that converts the signal into an optical signal having a predetermined wavelength and transmits it as a data channel 237 and a control channel 238.

  In the optical switch unit 221 shown in FIG. 5, a predetermined optical path is switched for the optical signal of the data channel 234 entering the relay node 204 using the optical switch control command 241 sent from the control plane unit 223. Do. At this time, the switch switching control information stored in the memory table 232A in the control plane unit 223 shown in FIG. 6 is referred to.

  The control plane unit 223 uses the information from the control channel 235 input via the O / E conversion unit 236 to generate and update the memory table 232A.

  The CPU 231 acquires time stamp information as date / time information from the timer 233, and outputs an optical switch control command 241 to which the time stamp information is added. Furthermore, the CPU 231 refers to the updated memory table 232A, regenerates the control channel, and outputs the control channel from the E / O conversion unit 239 to the next node as the control channel 238. Further, the CPU 231 selects the wavelength of the optical signal (data channel 234) that can be shared based on the wavelength utilization efficiency / sharing determination information stored in the memory table 232A.

  With respect to the selected optical signal having a sharable wavelength (data channel 234), the input data converted by the O / E converter 236 is stored once in the memory 232. This is to adjust the transmission timing of two types of signals having the same wavelength. The electrical signal stored in the memory 232 is output by output control based on the sharable wavelength information, passes through the E / O conversion unit 239, is converted into an optical wavelength (data channel 237), and the optical switch unit 221 (FIG. 5). Wavelength sharing is performed by re-inputting to.

  When the wavelength sharing of the data regarding the two types of optical signals is performed in this way, the CPU 231 updates the wavelength conversion information and the sharable wavelength information in the memory table 232A. Then, the selection of the shared optical wavelength (data channel 234) is performed as the next processing.

FIG. 7 shows the contents of the memory table at a certain time t ₀ . The memory table 232A converts the information sent from the control channel 235 shown in FIG. 5 or FIG. 6 into an electrical signal by the O / E conversion unit 236, and uses this to generate or update the contents of the table. ing.

The memory table 232A, at time t ₀ the following items assumed to be stored in association with each.
(1) Input light wavelength information;
It represents the wavelength of the input optical signal. A label by GMPLS corresponding to each wavelength λ _b , λ _s ,...
(2) Switch switching control information (route information);
In GMPLS, optical paths such as α and θ are set using the control channel 235 (FIG. 6).
(3) Wavelength utilization efficiency;
This is the utilization rate of the wavelength used for each optical signal. When two types of optical signals share one wavelength, the sum of these wavelength utilization efficiencies needs to be 100% or less. Wavelength utilization efficiency is statistically calculated by the relay node 204.
(4) Wavelength conversion information;
This is information indicating the wavelength after conversion. For example, when the input optical wavelength information is the wavelength λ _b , the wavelength conversion information from the relay node 204 is λ by the memory table 232A.
(5) Sharing judgment information;
Based on the information sent from the control channel 235, the control plane unit 223 determines whether the two types of optical signals from the relay node 204 can be shared.

Here, when the sharing determination information is “◯”, it is determined that the wavelength can be shared without any problem. For example, if the wavelength utilization efficiencies of two types of optical signals are less than 30%, it is determined that sharing these optical signals does not reach 100% even if they are converted to the same wavelength and can be shared. Become. In the example shown in FIG. 7, the wavelength sharing ratio of the wavelength λ _b is 15% at time t ₀ . Thus, in this example, for the optical signal of the wavelength lambda _b that have been already transmitted from the third core network node ₂₀₂₃ at time t ₀ the wavelength sharing ratio is in a state of "○".

  When the sharing determination information is “Δ”, it is determined that wavelength sharing is possible limitedly. For example, when the wavelength utilization efficiency for one optical signal is 30% to 70%, the sharing judgment information of the sharing partner is “◯”, and the wavelength utilization efficiency is less than 30%. In this case, it is determined that the same wavelength can be shared.

When the sharing determination information is “x”, it is determined that it is better not to share the wavelength. For example, this is a case where the wavelength utilization efficiency of at least one of the two types of optical signals is 70% or more.
(6) Shareable wavelength information;
The wavelength which can share a wavelength is shown. In the portion marked “−” in this column, there is no sharable wavelength at time t ₀ .

Now, it is assumed that the memory table 232A is in the state shown in FIG. 7, in this state, the subsequent arbitrary time t _1, the optical signal of the first core network 203 ₁ from the wavelength lambda _a relay node shown in FIG. 4 Assume that transmission has started for 204.

Figure 8 is a diagram showing the contents of a memory table at time t ₁ + Δ ₁ which elapsed slightly time from time t _1. Optical signal of the first core network 203 ₁ from the wavelength lambda _a is so sent to the relay node 204 shown in FIG. 4, CPU 231 shown in FIG. 6 stores data relating to the wavelength lambda _a in the memory table 232A. The wavelength utilization efficiency 28% of the optical signal of wavelength lambda _a, if it was less than 30 percent, sharing judgment information that is "○". The fact that the wavelength utilization efficiency is 28% is statistically calculated by the CPU 231 while the predetermined amount of time Δ ₁ elapses.

FIG. 9 shows that after the optical signals having the wavelengths λ _a and λ _b with the second backbone network node as a common destination are gathered, the CPU determines whether these optical signals can be shared and stores the result in the memory. It shows a change in the contents of the memory table at time t ₁ + Δ ₂ reflected in the table. Here, the amount of time Δ ₂ is obtained by adding the time Δ in predetermined data processing to the time Δ ₁ .

At this time t ₁ + Δ ₂ , the CPU 231 shown in FIG. 6 sets the sharable wavelength information for the input light wavelength information λ _b to “λ _a ”, and the sharable wavelength information for the input light wavelength information λ _a is “Λ _b ” is set. Therefore, the optical signal having the wavelength λ _{a and} the optical signal having the wavelength λ _b can be shared as one optical signal having a new wavelength “λ”.

By the way, the sharing of the route from the relay node 204 to the second backbone network node 202 ₂ shown in FIG. 4 which is focused on this time is transmitted to each of the first backbone network node 202 ₁ and the third backbone network node 202 _3. Consideration is limited to two optical signals as nodes. While considering optical signals from other transmitting nodes via the relay node 204 to the second backbone network node 202 ₂ at the same time, the path from the relay node 204 to the second backbone network node 202 ₂ We are not considering sharing.

Therefore, the relay node 204 assigns a new wavelength λ for the time being in relation to the two types of optical signals of wavelength λ _a and wavelength λ _b . Then, using the three wavelength relations of the wavelengths λ _a , λ _b, and λ determined in FIG. 9 in the memory table 232A, the first backbone network node 202 ₁ and the third backbone network node 202 ₃ to the second backbone. The sharing of the wavelength of the optical signal reaching the network node 202 ₂ is started.

FIG. 10 shows an example of a memory table at a predetermined time in the control plane unit of the relay node after the current relay node. FIG. 4 shows a case where there is a single communication path from the relay node 204 to the second backbone network node 202 ₂ . It is assumed that there is a communication path in the backbone network 201 from the relay node 204 to the second backbone network node 202 ₂ via another relay node (hereinafter referred to as the relay node 251). .

In the case of this latter example, it is assumed that an optical signal having _a wavelength λ _a and a wavelength λ _b is transmitted to the relay node 204 and transmitted from the relay node 204 to the relay node 251 as an optical signal having a new wavelength λ. The control plane unit in the relay node 204 at this time is a control plane unit 253, and its memory table is a memory table 252A. FIG. 10 shows the contents of the memory table 252A.

One of the input optical wavelength information of the memory table 252A is “λ”, which is information of the shared optical signal transmitted from the relay node 204 in FIG. The wavelength utilization efficiency is “43” (“percent”) of “26” (percent) in “λ _a ” of the input light wavelength information and “15” (percent) in “λ _b ” of the input light wavelength information shown in FIG. (Percent). Therefore, the sharing judgment information is lowered by one step to “Δ”. Further, in the normal case, the destination node is carved from the transmission node in the normal case, but at the wavelength λ where the wavelength is shared, the node that started sharing is stored as information instead of the transmission node.

By the way, an optical signal having a low wavelength utilization efficiency (for example, an optical signal having a wavelength λ _q ) with sharing judgment information “◯” is sent from the other node to the new relay node 251 described above. Therefore, sharing of the optical signal with the input optical wavelength information “λ _q ” and the optical signal with the input optical wavelength information “λ” sent from the relay node 204 may be newly determined by the relay node 251. It is natural.

  FIG. 11 shows a generalized state of the selection processing of the wavelength of the optical signal shared in the optical wavelength sharing system described above. This will be described with reference to FIGS.

  The CPU 231 determines whether a predetermined unit time has elapsed (step S301), and if it has elapsed (Y), while referring to each input optical wavelength information in the relay node 204 at that time, various types of wavelength utilization efficiency, etc. The information of is calculated. Then, these values at the present time are calculated, and the memory table 232A is updated to the latest state (step S302).

  When the memory table 232 </ b> A is updated, the sharing judgment information that is “◯” becomes “△” or “×”, or two wavelengths that have been shared until now have their wavelength utilization efficiency. In some cases, the shared state cannot be maintained at one wavelength due to the decrease. Therefore, the CPU 231 determines whether a path that can hold the share still exists in the own node (step S303).

When such a path still exists in the current node (Y), the CPU 231 checks whether the current sharing can be maintained with the traffic amount within the wavelength in the backbone network 201 (step S304). As a result, if the CPU 231 determines that the sharing can be maintained (Y), the control channel 235 maintains the current relevant path and maintains the sharing relationship as it is (step S305). In this case, transmission of data from the first to the third core network node 202 _{1-202 3} in the backbone network system 201 is performed conventionally, the process returns to step S301 (RETURN).

On the other hand, if it is determined in step S304 that sharing cannot be maintained (N), the CPU 231 cancels the sharing relationship of the current path through the control channel 235. Then, a different wavelength is assigned to each optical signal transmitted from the corresponding relay node as an optical signal of one wavelength, and the optical path after release is controlled (step S306). In this case take place along the path after delivery change data from the first to third core network node 202 _{1-202 3} in the backbone network system 201, the process returns to step S301 (RETURN).

On the other hand, if it is determined in step S303 that there is no longer a path for sharing the wavelength at the currently focused node (self node) (N), the CPU 231 shares the wavelength with the other nodes in the backbone network 201. Is checked (step S307). If possible (Y), the control channel 238 is used to share the wavelength with the corresponding other relay node (step S308). Specifically, the switch unit 221 is used to select a route toward another relay node that can share wavelengths with respect to a plurality of optical signals. Thereafter, transmission of data from the first to the third core network node 202 _{1-202 3} in the backbone network system 201 is performed conventionally, the process returns to step S301 (RETURN).

If the CPU 231 determines in step S307 that other nodes in the backbone network 201 cannot share wavelengths (N), wavelength sharing is not performed. That is, data transmission from the _first to third backbone network nodes 202 _{1 to} 202 ₃ is performed using the initial optical path in the backbone network 201, and the process returns to step S301 (Return). ).

  As described above, according to the optical wavelength sharing system 200 of this embodiment, the CPU at the relay node in the backbone network 201 looks at the status of each optical signal input, and optical signals having two different wavelengths. Is shared as an optical signal of one wavelength, the wavelength is shared. By sharing the wavelength, the number of wavelengths of the optical signal used in the backbone network 201 can be reduced. Along with the reduction in the number of wavelengths of light, interference with other adjacent wavelengths can be reduced. When there are fluctuations such as thermal fluctuations due to environmental changes, the wavelength of light is likely to be affected by frequency fluctuations due to ambient temperature, and the closer to the adjacent frequency band, the more risk to environmental temperature arises. According to the present embodiment, since interference with other light wavelengths can be reduced by reducing the wavelength of light, it is possible to ensure communication quality regardless of the operating environment. Moreover, the utilization efficiency of each light wavelength can be raised. In addition, optical wavelengths with low wavelength utilization efficiency communicate with each other using the same optical wavelength, thereby realizing optimization of utilization efficiency within the optical wavelength and communication bandwidth (wavelength at which communication is possible) associated with a reduction in the number of wavelengths. Can be secured.

  In addition, according to the present embodiment, by reducing the number of optical wavelengths accompanying the improvement in communication efficiency, the control circuit of the optical switch unit 221 shown in FIG. 5 can be simplified and the power consumption can be reduced due to the reduction in the number of components. Can be planned. As a result, it is possible to reduce the size and cost of the apparatus constituting the optical wavelength sharing system 200.

  <Deformability of invention>

  In the embodiment described above, the O / E conversion unit 236 and the E / O conversion unit 239 shown in FIG. 6 are required for sharing the wavelength of light. However, if the information of the control channel is extracted as light using an optical memory so that it can be determined, a switching control command to the optical switch unit 221 can be instantaneously performed without O / E conversion. In addition, by eliminating the need for the O / E conversion unit 236 and the E / O conversion unit 239, it is possible to suppress signal processing delays associated with O / E conversion and E / O conversion.

  Further, the configuration of the memory table described in the embodiment is not limited to the items illustrated in FIG. For example, if the memory table has traffic information on the optical fiber through which each optical wavelength passes and traffic information on the optical fiber that is assumed to pass through each wavelength, the optical path is selected again. It becomes possible to suppress the occurrence of congestion.

  Further, QoS (Quality of Service) information may be added to the control channel. This makes it possible to perform QoS control such as not sharing wavelengths with VoIP (Voice over Internet Protocol) information that does not allow delay generation.

  Some or all of the embodiments described above are described as in the following supplementary notes, but are not limited to the following descriptions.

(Appendix 1)
An optical signal receiving means for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received by this optical signal receiving means, the use efficiency determining means for each wavelength for determining the use efficiency in the wavelength used for these transmissions,
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a single specific wavelength using the discrimination result of the utilization efficiency discrimination unit for each wavelength Discrimination means;
When it is determined by the sharability determining means that sharing by the specific one wavelength is possible, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical wavelength sharing system comprising: an optical signal transmission means for transmitting to the optical network.

(Appendix 2)
The optical signal received by the optical signal receiving means is constituted by a data channel representing the content of data of the optical signal and a control channel used for various controls such as path setting of the optical signal. The optical wavelength sharing system according to appendix 1.

(Appendix 3)
Whether or not sharing is possible is determined based on the utilization efficiency at the same wavelength of the plurality of optical signals determined that the sharing possibility determining unit can share the specific one wavelength, and whether or not the sharing state of these optical signals in the own node can be maintained Discrimination means;
When it is determined that the shared state cannot be held in the own node by the shared hold enable / disable determining unit, the shared release of the optical signal by one wavelength is released by assigning different wavelengths to the plurality of optical signals. The optical wavelength sharing system according to claim 1, further comprising: means.

(Appendix 4)
When it is determined that the shared state cannot be maintained with a specific other node starting from the own node by the sharing holding possibility determination unit, the direct connection from the own node to other than the specific other node Another node sharability determination unit that determines whether the wavelength can be shared up to a predetermined node, and the other node sharability determination unit determines that the wavelength can be shared. 4. The optical wavelength sharing system according to appendix 3, further comprising: another path selection unit that performs path selection as a path for sharing a wavelength up to a predetermined directly connected node other than the first node.

(Appendix 5)
The other node sharability determination unit collects information through a control channel used for various controls such as path setting of the optical signal, and updates optical switch switching control information for route selection. The optical wavelength sharing system according to appendix 4.

(Appendix 6)
3. The optical wavelength sharing system according to claim 2, further comprising an optical-electrical signal discriminating unit that determines the information of the control channel by converting the information from light into an electrical signal.

(Appendix 7)
The optical wavelength sharing system according to claim 2, further comprising: an optical information direct determination unit that extracts and determines information of the control channel as light.

(Appendix 8)
An optical signal receiving step for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received in this optical signal reception step, a utilization efficiency determination step for each wavelength that determines the utilization efficiency at the wavelength used for these transmissions;
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a specific one common wavelength using the discrimination result in the use efficiency discrimination step for each wavelength A determination step;
When it is determined that sharing by the specific one wavelength is possible by the sharing possibility determination step, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical signal transmission step of transmitting to the optical wavelength sharing method.

(Appendix 9)
Whether or not sharing is possible can be maintained based on the utilization efficiency at the same wavelength of the plurality of optical signals determined to be sharable at the specific one wavelength in the sharability determining step. A determination step;
When it is determined that the shared state cannot be held in the own node in the shared hold enable / disable determining step, the shared state of the optical signal with one wavelength is released by assigning different wavelengths to the plurality of optical signals. The optical wavelength sharing method according to claim 8, further comprising a step.

(Appendix 10)
When it is determined in the sharing hold enable / disable determining step that the shared state cannot be held with another specific node starting from the own node, other direct connection other than the specific other node from the own node Determining whether or not other nodes can share the wavelength up to a predetermined node, and
When it is determined that the wavelength can be shared in the other node sharing possibility determination step, the path selection is performed from the own node to a predetermined directly connected node other than the specific other node as a wavelength sharing path. The optical wavelength sharing method according to appendix 9, further comprising: another path selection step.

(Appendix 11)
On the computer,
An optical signal receiving process for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received in this optical signal reception process, a use efficiency discrimination process for each wavelength that determines the use efficiency in the wavelength used for these transmissions,
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a single specific wavelength using the discrimination result by the use efficiency discrimination processing for each wavelength Discrimination processing;
When it is determined that sharing by the specific one wavelength is possible by this sharing possibility determination processing, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical wavelength sharing program that executes an optical signal transmission process to be transmitted to the network.

(Appendix 12)
Whether or not sharing is possible can be maintained based on the utilization efficiency at the same wavelength of the plurality of optical signals determined to be sharable by the specific wavelength in the sharability determination process. Discrimination processing;
When it is determined that it is not possible to hold the shared state in the node by this shared hold enable / disable determining process, the shared release of the optical signal by one wavelength is released by assigning different wavelengths to the plurality of optical signals. The optical wavelength sharing program according to appendix 11, wherein the processing is further executed by a computer.

(Appendix 13)
When it is determined that the shared state cannot be held with a specific other node starting from the own node in the sharing hold possibility determination process, the direct connection from the own node to other than the specific other node Other node sharability determination process for determining whether wavelength sharing to a predetermined node is possible,
When it is determined that the wavelength can be shared by the other node sharability determination process, route selection is performed from the own node to a predetermined node directly connected other than the specific other node as a wavelength sharing route. 13. The optical wavelength sharing program according to appendix 12, further causing the computer to execute another path selection process.

DESCRIPTION OF SYMBOLS 10, 200 Optical wavelength sharing system 11 Optical signal receiving means 12 Wavelength-based utilization efficiency determining means 13 Sharing availability determining means 14 Optical signal transmitting means 20 Optical wavelength sharing method 21 Optical signal receiving step 22 Wavelength-based usage efficiency determining step 23 Sharing availability determination Step 24 Optical Signal Transmission Step 30 Optical Wavelength Sharing Program 31 Optical Signal Reception Processing 32 Wavelength-Based Usage Efficiency Determination Processing 33 Sharing Availability Determination Processing 34 Optical Signal Transmission Processing 201 Basic Network Network 202 ₁ First Basic Network Node 202 ₂ Second Basic network node 202 ₃ Third basic network node 203 ₁ First basic network 203 ₂ Second basic network 203 ₃ Third basic network 204 Relay node 221 Optical switch unit 222 Wavelength multiplexing unit 223 Control plane unit 231 CPU
232 memory 232A memory table 234, 237 data channel 235 control channel 236 O / E converter 239 E / O converter

Claims (9)

An optical signal receiving means for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received by this optical signal receiving means, the use efficiency determining means for each wavelength for determining the use efficiency in the wavelength used for these transmissions,
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a single specific wavelength using the discrimination result of the utilization efficiency discrimination unit for each wavelength Discrimination means;
When it is determined by the sharability determining means that sharing by the specific one wavelength is possible, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical wavelength sharing system comprising: an optical signal transmission means for transmitting to the optical network.   The optical signal received by the optical signal receiving means is constituted by a data channel representing the content of data of the optical signal and a control channel used for various controls such as path setting of the optical signal. The optical wavelength sharing system according to claim 1. Whether or not sharing is possible is determined based on the utilization efficiency at the same wavelength of the plurality of optical signals determined that the sharing possibility determining unit can share the specific one wavelength, and whether or not the sharing state of these optical signals in the own node can be maintained Discrimination means;
When it is determined that the shared state cannot be held in the own node by the shared hold enable / disable determining unit, the shared release of the optical signal by one wavelength is released by assigning different wavelengths to the plurality of optical signals. The optical wavelength sharing system according to claim 1, further comprising: means.   When it is determined that the shared state cannot be maintained with a specific other node starting from the own node by the sharing holding possibility determination unit, the direct connection from the own node to other than the specific other node Another node sharability determination unit that determines whether the wavelength can be shared up to a predetermined node, and the other node sharability determination unit determines that the wavelength can be shared. 4. The optical wavelength sharing system according to claim 3, further comprising another path selection means for performing path selection as a path sharing a wavelength up to a predetermined node directly connected to other than the first node.   The other node sharability determination unit collects information through a control channel used for various controls such as path setting of the optical signal, and updates optical switch switching control information for route selection. The optical wavelength sharing system according to claim 4.   3. The optical wavelength sharing system according to claim 2, further comprising optical-electrical signal discriminating means for determining the information of the control channel by converting light to an electric signal.   3. The optical wavelength sharing system according to claim 2, further comprising an optical information direct determination unit that extracts and determines information of the control channel as light. An optical signal receiving step for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received in this optical signal reception step, a utilization efficiency determination step for each wavelength that determines the utilization efficiency at the wavelength used for these transmissions;
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a specific one common wavelength using the discrimination result in the use efficiency discrimination step for each wavelength A determination step;
When it is determined that sharing by the specific one wavelength is possible by the sharing possibility determination step, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical signal transmission step of transmitting to the optical wavelength sharing method. On the computer,
An optical signal receiving process for receiving optical signals to be sent to other network nodes via the own node;
For each of the optical signals received in this optical signal reception process, a use efficiency discrimination process for each wavelength that determines the use efficiency in the wavelength used for these transmissions,
Whether to share a plurality of optical signals of different wavelengths transmitted toward the same path with a single specific wavelength using the discrimination result by the use efficiency discrimination processing for each wavelength Discrimination processing;
When it is determined that sharing by the specific one wavelength is possible by this sharing possibility determination processing, the optical signals of the plurality of different wavelengths are shared by the specific one wavelength, and each optical signal is transmitted to the next node. An optical wavelength sharing program that executes an optical signal transmission process to be transmitted to the network.

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