WO2019014877A1 - Wavelength selection method, apparatus and system - Google Patents

Abstract

The present invention relates to the field of optical communication technologies, and in particular, to a wavelength selection technique. In a possible wavelength selection method, the destination node device receives indication information of a working path wavelength and a protection path wavelength from a network device upstream thereof, where the working path wavelength and the protection path wavelength are used to carry the same service, The indication information includes a wavelength parameter for wavelength selection; the upstream network device is a head node device or an intermediate node device; and then the destination node device determines the working path wavelength and the protection path wavelength according to the indication information. The wavelength to be turned off; subsequently, the destination node turns off the wavelength to be turned off, and receives the service from wavelengths of the working path wavelength and the protection path wavelength that are not turned off. The solution provided by the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information, thereby improving the correctness of the protection switching.

Description

Wavelength selection method, device and system Technical field

Embodiments of the present invention relate to the field of optical communication technologies, and in particular, to wavelength selection techniques.

Background technique

At present, the optical transport network uses the electrical layer switching technology to photoelectrically convert the wavelength before each service scheduling, introducing higher cost and larger power consumption. With the rapid growth of network bandwidth and the scale application of high-rate photoelectric conversion modules (for example, 100Gbps), all-optical wavelength switching technology has begun to be favored. Different from the electrical layer switching technology, the all-optical wavelength switching technology uses the all-optical technology to pass through the wavelength-level service at the intermediate node of the network, without photoelectric conversion, and only needs to use the photoelectric conversion device and the electrical layer device to realize the customer service at the head node and the destination node. Hosted. This switching technology matches the future business's low network latency, high energy efficiency and high capacity.

The reliability of wavelength services has always been an important measure of the performance of optical transport networks. Therefore, optical transport networks based on all-optical wavelength switching also need to use wavelength protection switching schemes to improve the reliability of wavelength services. There are many protection switching schemes, including 1+1 protection. 1+1 protection improves the reliability of the service through dual-selection, that is, the service is not affected when the network fails, and can continue to be transmitted in the network. Specifically, the first node implements dual-issue for the service, that is, the service data is sent to the destination node through the working path and the protection path respectively; and the destination node receives the service by selecting a path that is not faulty or degraded in the two paths. To ensure the continuity / reliability of business delivery.

In the current optical layer 1+1 protection scheme, the destination node measures the optical power of the two wavelengths received, thereby selecting one wavelength of the optical power to implement the protection switching of the service. This method is simple, but its accuracy needs to be improved. In other words, this method may cause incorrect protection switching. There are many reasons for this problem. For example, the wavelength accumulates noise during transmission. Even if the protection path wavelength fails, its optical power may be larger because the accumulation of noise power is greater than the optical power of its corresponding working path wavelength. Therefore, relying on the optical power to determine whether to perform the switching may cause the destination node to switch to the wavelength of the protection path of the fault, but in practice, this may result in an erroneous protection switching.

Therefore, a new optical layer protection scheme is needed to improve the correctness of the optical layer 1+1 protection switching.

Summary of the invention

This document describes methods, devices, and systems for wavelength selection to improve the correctness of optical layer protection switching.

In a first aspect, an embodiment of the present invention provides a method of wavelength selection, the method comprising:

Receiving indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the indication information includes a wavelength parameter used for wavelength selection;

Determining, according to the indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength;

Turning off the wavelength to be turned off;

The traffic is received from wavelengths of the working path wavelength and the protection path wavelength that are not turned off.

In a possible implementation, the indication information includes a forward defect indication FDI, a path trace identifier At least one of TTI and wavelength signal quality information. The FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal failure SF; the indication information includes that the TTI includes an identifier of a source node and a destination node of the service; and the wavelength signal The quality information is used to indicate the signal quality that carries the working path wavelength and the protection path wavelength.

In one possible design, the receiving the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength includes: using a 2:1 optical selective light to remove light from the working path wavelength and protection A wavelength that is not turned off in the path wavelength receives the traffic; or a coupler is used to receive the traffic from a wavelength that is not turned off in the working path wavelength and the guard path wavelength.

In a possible design, the indication information is transmitted in an optical monitoring channel OSC, wherein the working path wavelength, the protection path wavelength, and the wavelength used by the OSC carrying the indication information are different.

In a second aspect, an embodiment of the present invention provides an optical network device, where the optical network device includes a first receiving module, a processing module, a wavelength switch, and a second receiving module, where:

The first receiving module is configured to receive indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the indication information includes a wavelength parameter used for wavelength selection;

The processing module is configured to determine, according to the indication information, a wavelength of the working path and a wavelength to be turned off among the protection path wavelengths;

The wavelength switch is configured to turn off the wavelength to be turned off;

The second receiving module is configured to receive the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength.

In one possible design, the indication information includes at least one of a forward defect indication FDI, a path trace identification TTI, and wavelength signal quality information. The FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal failure SF; the TTI includes identification information of a source node and a destination node of the service; and the wavelength signal quality information is used. Indicates a signal quality that carries the working path wavelength and the protection path wavelength.

In a possible implementation, the second receiving module comprises a coupler or a 2:1 optical selection switch, and the coupler or 2:1 optical selection switch is used to receive the working path wavelength and the protection path wavelength. Wavelength that has not been turned off.

In a possible implementation, the second receiving module further includes a photoelectric conversion module, and the photoelectric conversion module is configured to perform photoelectric conversion on the wavelengths of the working path wavelength and the protection path wavelength that are not turned off, thereby extracting Out of the business.

In a third aspect, an embodiment of the present invention provides an optical network system, where the system includes a head node device, an intermediate node device, and a destination node device, where:

The head node device is used to:

Obtaining first indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the first indication information includes a wavelength parameter used for wavelength selection;

Sending the first indication information;

The intermediate node device is configured to: receive the first indication information, and generate second indication information according to the first indication information and parameter information that is known by the intermediate node, where the second indication information includes a wavelength parameter included in the first indication information processed by the intermediate node device; sending the second indication information;

The destination node device is configured to:

Receiving the second indication information;

Determining, according to the second indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength;

Turning off the wavelength to be turned off;

The traffic is received from wavelengths of the working path wavelength and the protection path wavelength that are not turned off.

In a possible design, the sending the first indication information and the sending the second indication information are performed by transmitting the first indication information and the second indication information on an optical monitoring channel OSC, where The working path wavelength, the protection path wavelength, and the wavelength used by the OSC are different.

In a possible design, the first indication information and the second indication information comprise a forward defect indication FDI, and the FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal fault SF. . The FDI included in the second indication information is determined according to the FDI included in the first indication information and the link state of the network device and the neighbor device located upstream of the network device.

In another possible design, the first indication information and the second indication information include a path trace identifier TTI, where the TTI includes an identifier of a source node and a destination node of the service. The first indication information includes a TTI and the second indication information includes the same TTI.

In still another possible design, the first indication information and the second indication information comprise wavelength signal quality information, where the wavelength signal quality information is used to indicate that the working path wavelength and the protection path wavelength are carried. Signal quality. The wavelength signal quality information included in the second indication information is determined according to the wavelength signal quality information included in the first indication information and the additional noise information introduced by the network node.

It should be noted that the first indication information and the second indication information may include multiple parameters, and the correctness of the protection switching may be further improved compared to a single parameter.

In one possible design, the receiving the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength includes: using a 2:1 optical selective light to remove light from the working path wavelength and protection The traffic is received in a wavelength that is not turned off in the path wavelength; or the coupler is used to receive the traffic from wavelengths of the working path wavelength and the guard path wavelength that are not turned off.

In a fourth aspect, the present invention provides yet another method of wavelength selection, the method comprising:

Obtaining indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same customer service, and the indication information includes a wavelength parameter used for wavelength selection;

Send the indication information.

In a possible design, the sending the indication information is that the sending the indication information is that the indication information is carried on an optical monitoring channel OSC, where the working path wavelength and the protection path are The wavelength and the wavelength used by the OSC are different.

In one possible design, the indication information includes a forward defect indication FDI, a path trace identifier At least one of TTI and wavelength signal quality information. The FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal failure SF; the TTI includes an identifier of a source node and a destination node of the service; and the wavelength signal quality information is used to indicate A signal quality of the working path wavelength and the protection path wavelength is carried.

In a fifth aspect, an embodiment of the present invention provides another optical network device, where the optical network device includes a processing unit and a sending unit, where:

The processing unit is configured to obtain indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same customer service, and the indication information includes a wavelength parameter used for wavelength selection;

The sending unit is configured to send the indication information.

In a possible design, the sending the indication information is that the sending the indication information is that the indication information is carried on an optical monitoring channel OSC, where the working path wavelength and the protection path are The wavelength and the wavelength used by the OSC are different.

In one possible design, the indication information includes at least one of a forward defect indication FDI, a path trace identification TTI, and wavelength signal quality information. The FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal failure SF; the TTI includes an identifier of a source node and a destination node of the service; and the wavelength signal quality information is used to indicate A signal quality of the working path wavelength and the protection path wavelength is carried.

It should be noted that the TTI mentioned in the above aspects can also be replaced by the destination node, which can save optical layer overhead. Further, the wavelength signal quality information may also be optical signal quality information or wavelength signal quality information. Specifically, the signal quality is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio.

In a sixth aspect, an embodiment of the present invention provides another method of wavelength selection, the method comprising:

The network device acquires first indication information of at least one of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same customer service, and the first indication information includes a wavelength parameter used for wavelength selection. ;

The network device acquires second indication information according to the first indication information;

The network node sends the second indication information.

In a possible design, the sending the second indication information is to send the indication information on an optical monitoring channel OSC, where the working path wavelength, the protection path wavelength, and the OSC The wavelengths used are different.

In a possible design, the first indication information and the second indication information comprise a forward defect indication FDI, wherein the FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal fault SF. The FDI included in the second indication information is determined according to the FDI included in the first indication information and the link state of the network device and the upstream neighbor device located in the network device.

In another possible design, the first indication information and the second indication information further include a path trace identifier TTI, where the TTI includes an identifier of a source node and a destination node of the service, where the first The indication information includes a TTI and the second indication information includes the same TTI.

In another possible design, the first indication information and the second indication information include wavelength signal quality information, where the wavelength signal quality information is used to indicate a signal quality that carries the working path wavelength and the protection path wavelength. The wavelength signal quality information included in the second indication information is determined according to the wavelength signal quality information included in the first indication information and the additional noise information introduced by the network node. Specifically, the signal quality is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio.

It should be noted that the first indication information and the second indication information may include multiple parameters, and the correctness of the protection switching may be further improved compared to a single parameter.

In a sixth aspect, an embodiment of the present invention provides another optical network device, where the network device includes a receiving unit, a sending unit, and a processing unit, where:

The receiving unit is configured to acquire first indication information of at least one of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same customer service, and the first indication information is used to: Wavelength parameter selected by wavelength;

The processing unit is configured to acquire the second indication information according to the first indication information;

The sending unit is configured to send the second indication information.

In a possible design, the sending the second indication information is to send the indication information on an optical monitoring channel OSC, where the working path wavelength, the protection path wavelength, and the OSC The wavelengths used are different.

In a possible design, the first indication information and the second indication information comprise a forward defect indication FDI, wherein the FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal fault SF. The FDI included in the second indication information is determined according to the FDI included in the first indication information and the link state of the network device and the upstream neighbor device located in the network device.

In another possible design, the first indication information and the second indication information further include a path trace identifier TTI, where the TTI includes an identifier of a source node and a destination node of the service, where the first indication The information includes a TTI and the second indication information includes the same TTI.

In still another possible design, the first indication information and the second indication information comprise wavelength signal quality information, where the wavelength signal quality information is used to indicate a signal quality that carries the working path wavelength and the protection path wavelength. The wavelength information quality information included in the second indication information according to the wavelength signal quality information included in the first indication information, and the noise introduced by the network node and a link located at an upstream neighboring node of the network node Information is decided together. Specifically, the signal quality is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio.

Specifically, the signal quality is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio.

It should be noted that the first indication information and the second indication information may include multiple parameters, and the correctness of the protection switching may be further improved compared to a single parameter.

Compared with the prior art, the embodiment of the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information, thereby preventing erroneous protection switching caused by the misconnection, and improving the protection. The correctness of the change.

DRAWINGS

The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings:

FIG. 1 is a schematic diagram of a possible application network according to an embodiment of the present invention; FIG.

FIG. 2 is a schematic diagram of a possible 1+1 protection service transmission according to an embodiment of the present invention;

FIG. 3 is a flowchart of a possible first node processing according to an embodiment of the present invention;

FIG. 4 is a flowchart of a possible intermediate node processing according to an embodiment of the present invention;

FIG. 5 is a flowchart of another possible intermediate node processing according to an embodiment of the present invention;

FIG. 6 is a flowchart of possible end node processing according to an embodiment of the present invention;

FIG. 7 is a flowchart of a possible network device structure according to an embodiment of the present invention;

FIG. 8 is a flowchart of another possible network device structure according to an embodiment of the present invention;

[Correct according to Rule 91 21.08.2017]

Detailed ways

The network architecture and the service scenario described in the embodiments of the present invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of the present invention, and do not constitute a limitation of the technical solutions provided by the embodiments of the present invention. The technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems.

General overview:

The present invention is applicable to a wavelength division optical network (sometimes referred to as an optical transmission network), and is particularly suitable for a wavelength division optical network using all-optical switching technology. FIG. 1 is a schematic diagram of a possible application network of the present invention. As shown in FIG. 1, the example network is composed of seven network devices (N1, N2, ..., N7) connected to each other through an optical fiber. As an example, FIG. 1 shows an example of a working path and a protection path carrying a service, namely: N1-N2-N3-N5-N4 and N1-N7-N6-N5-N4, to implement optical layer 1+1. protection. In a scenario without wavelength conversion capability, each node on a path must use the same wavelength for this service transmission. In addition, the wavelengths used by different optical layer services must be different. For example, in a 80-wave wavelength division optical network, the service working path and the protection path in FIG. 1 can adopt λ1 and λ10, respectively. The specific wavelength information needs to be determined according to the actual wavelength resource usage of the network, and the present invention does not impose any limitation.

When the existing optical layer 1+1 protection scheme is adopted, after the destination node N4 receives the wavelengths λ1 and λ10 respectively, the intermediate node N5 measures the optical power of the two wavelengths, thereby selecting a wavelength in which the optical power value is large to receive the service. . This method may result in incorrect protection switching. For example, the accumulation of the wavelength of the protection path after the failure occurs due to the accumulation of noise may result in its power being greater than the power of the corresponding working path wavelength. Therefore, this method will cause the destination node to select the wrong wavelength, that is, switch to the wavelength of the fault protection path. For another example, a wavelength may be sent to the wrong destination node due to a cross-configuration error of the intermediate node. Such an error cannot be known by comparing the optical power size, and thus may cause the destination node to receive the correct service data through protection. Receive incorrect business data after switching.

In order to solve the problems existing in the current solution, an embodiment of the present invention proposes a new optical layer 1+1 protection scheme. The solution transmits the indication information of the wavelength to ensure that the destination node selects the correct wavelength for service reception, improves the correctness of the protection switching, and even ensures the correctness of the protection switching. The example of the wavelength parameter that the indication information may include and the meaning thereof are as shown in Table 1.

Table 1 indicates an example of information contained in the information

It should be noted that the indication information is transmitted through a single channel (or wavelength). That is to say, the wavelength indicating the information transmission is different from the transmission wavelength of the two paths (ie, the working path and the protection path). For example, through the Optical Supervisory Channel (OSC). It should be noted that the OSC is a channel in the optical network for transmitting operation, management, and maintenance (OAM) information. In general, OSC uses a single wavelength.

Figure 2 shows an example of service transmission, the service data passing through the working path and the protection path, and the wavelength transmission diagram carrying the indication information. Specifically, the service data is dual-issued by the first node through the wavelengths of the working paths N1-N2-N3-N5-N4 and the wavelengths of the protection paths N1-N7-N6-N5-N4, respectively. In addition, the first node N1 needs to separately generate indication information of the working path wavelength and the protection path wavelength, and the transmission is carried on another wavelength (for example, the wavelength used by the OSC). It should be noted that the indication information of the working path wavelength and the indication information of the protection path wavelength may be transmitted through the same OSC. This information may also be transmitted via different OSCs. For example: N7 and N2 use different OSCs to pass indication information to devices downstream, namely N3 and N6. For another example, N5 transmits the transmission indication information of two wavelengths to the downstream device, that is, the destination node N3 through the same OSC. It should be noted that the wavelengths used by the OSCs of different nodes may be the same. The present invention does not impose any limitation on the wavelength values used by the specific OSC.

The embodiments of the present invention will be further described in detail below based on the general aspects of the invention described above.

Example 1

One embodiment of the present invention provides a method, network device, and system for wavelength selection. The system includes a head node and a destination node (sometimes referred to as a last node). Optionally, the network device further includes an intermediate node. It should be noted that the operations of the various types of nodes for the service data are prior art, and the present invention does not describe them. For example, the first node performs dual transmission of service data, and the intermediate node needs to establish a cross to forward the number of services. According to the data, the destination node needs to receive service data.

Referring to Figure 3, the following is a brief description of the action flow of different devices in the system:

Step 301: The first node generates indication information of a working path wavelength and a protection path wavelength.

In this embodiment, the indication information is FDI. For the specific meaning of FDI, please refer to Table 1, which is not described here. For examples of other types of wavelength parameters included in the indication information, refer to Embodiment 2-4, and details are not described herein.

Step 302: The first node sends the indication information.

Specifically, the head node carries the information on one wavelength and sends it to its neighboring downstream network device. For example: use OSC. The wavelength of the OSC is different from the wavelength used by the working path and the protection path of the transmission service. It should be noted that the downstream network device may be an intermediate node or a destination node. The description is exemplified in FIG. 3 by taking the downstream as an intermediate node.

It should also be noted that step 301 generates two indication information, one includes a wavelength parameter of a working path wavelength (also referred to as an optical signal), and the other includes a wavelength parameter that protects the path wavelength. If the downstream node of the first node on the protection path and the working path is the same device, the two indications can be sent through the same OSC. Conversely, if the downstream network devices of the head node on the protection path and the working path are different devices, the two pieces of information need to be respectively sent on different OSCs for transmission.

Step 303: The intermediate node generates new indication information according to the indication information it receives.

Specifically, after receiving the indication information sent by the upstream network device, the intermediate node needs to generate new indication information according to the information. Taking the information as the FDI as an example, the intermediate node needs to comprehensively determine according to the received FDI information and the link state between the intermediate node and the network device upstream thereof. For example, if the received FDI information is 1 (indicating that the upstream node detects that the wavelength is faulty), the new FDI value needs to be set to 1 regardless of the link state between the intermediate node and its upstream network device. If the received FDI information is 0 (indicating that there is no fault), then the value of the new FDI is set depending on whether the link state between the intermediate node and its upstream network device is faulty. It should be noted that the specific parameter types of the indication information are different, and the operations of the intermediate nodes may be different. For the operation example of the other types of information included in the indication information, refer to Embodiment 2-3, and details are not described herein.

It should be noted that the upstream network device is the first node in this example. In other possible implementations, multiple intermediate devices may be included, and the upstream network device may also be an intermediate device. It should also be noted that if there are intermediate node devices, there may be one or more. That is, the indication information of the working path wavelength and the protection path wavelength is sent to one or more intermediate nodes, and after a certain processing, the indication information of the two wavelengths (ie, the working path wavelength and the protection path wavelength) will be Reach the destination node.

Step 304: The intermediate node sends the new indication information.

This step is similar to step 302, and only the main body is different, and no further description is made here.

Step 305: The destination node determines the wavelength to be turned off according to the new indication information; turns off the wavelength to be turned off; and receives the service from another wavelength that is not turned off.

Specifically, the destination node receives the new indication information from a network device upstream thereof. The upstream network device is an intermediate node in this example. In other implementations, it may be the first node. Then, the destination node determines the need for two wavelengths (ie, the working path wavelength and the protection path wavelength) according to the indication information. The wavelength that is turned off. The destination node performs a shutdown operation on the selected waveform that needs to be turned off, and receives traffic from another wavelength that is not turned off.

The embodiment of the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information, thereby improving the correctness of the protection switching.

In the following, the actions of the destination node will be further described in conjunction with more figures. Figure 4 shows the steps of the destination node, which are described as follows:

S401: Receive indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the indication information includes a wavelength parameter used for wavelength selection.

It should be noted that the destination node may obtain the indication information from one or two upstream devices.

S402: Determine, according to the indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength;

Taking the FDI mentioned in step 303 of FIG. 3 described in the above process as an example, if the destination node receives the FDI of the two wavelengths A and B respectively, it is 1 and 0, and integrates the FDI information of the node to obtain the wavelength. The FDIs of A and B are 1 and 0, respectively, and the destination node determines that the wavelength to be turned off is A. On the other hand, if the obtained FDIs of the two wavelengths A and B are 0 and 1, respectively, it is determined that the wavelength to be turned off is B.

S403: Turn off the wavelength to be turned off;

It should be noted that the destination node needs to receive two wavelengths respectively, that is, the working path wavelength and the protection path wavelength. One of the wavelengths is turned off depending on the result of the step S402. Specifically, an optical switch, a dimmable attenuator, or the like can be employed to implement the wavelength turn-off function.

S404: Receive the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength.

It should be noted that this step can be implemented by a 2:1 optical selection switching device or an optocoupler device. Specifically, if a 2:1 selection switch is employed, the device needs to be set to receive the wavelength that is not turned off in step S403. If an optocoupler is used, no setup is required for the device. It can be seen that the scheme using the optocoupler is simpler. Moreover, optocouplers are passive devices because of the lower cost and reliability of this approach.

Example 2

One embodiment of the present invention provides yet another method, apparatus and system for wavelength selection. This method is similar to the method steps described in Embodiment 1, and will not be described herein. The difference is that the information included in the indication information in this embodiment is different and is TTI. Specifically, in this embodiment, the operation of different nodes is different from that of Embodiment 1 in the operation of the indication information at different nodes. The specific description is as follows:

1: the first node action: different from step 301 of FIG. 3, in this embodiment, the indication information generated by the first node is TTI;

2: Intermediate node action: Different from step 303 of FIG. 4, in this embodiment, the intermediate node directly parses the received indication information (ie, TTI) as new indication information and transmits it to the downstream section. point;

3: Destination node action: Different from the processing method described in step 402 in FIG. 4, in this embodiment, the destination node obtains the endpoint corresponding to the service by parsing the indication information (ie, TTI) (for example, the destination node, For example, the identifiers of the first node and the destination node determine whether to turn off the corresponding wavelength by determining whether the destination node in the endpoint matches the information of the node. For example, if the TTI included in the indication information of the two wavelengths received, the TTI included in one path is consistent with the identifier of the local node, and the other path is inconsistent. Then, the destination node turns off the wavelength of the inconsistency of the identification and receives the service data from the other path.

It should be noted that a node may have multiple identifiers. The present invention does not impose any limitation on the type of identifier information carried by the indication information. If the destination node has multiple identifiers, when the TTI is received, it is necessary to match the multiple identifiers one by one until it is confirmed that the matching is successful or the matching identifier is not found at all. It should also be noted that it is also possible to determine whether the connection is wrong by carrying the destination address information. Carrying destination address information can save overhead compared to TTI.

The embodiment of the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information instead of simply determining the level of the optical power, thereby preventing erroneous protection switching caused by the misconnection, and improving the correct protection switching. Sex.

Example 3

One embodiment of the present invention provides yet another method, apparatus and system for wavelength selection. This method is similar to the method steps described in Embodiment 1, and will not be described herein. The difference is that the information included in the indication information in this embodiment is different, and is optical signal quality information. Specifically, in this embodiment, the operation of different nodes is different from that of Embodiment 1 in the operation of the indication information at different nodes. The specific description is as follows:

1: The first node action is different from the step 301 of FIG. 3, in this embodiment, the indication information generated by the first node is optical signal quality information; for example, the optical signal quality information may be an optical signal to noise ratio (Optical Signal) Noise Ratio (OSNR), Optical Noise Signal Ratio (ONSR), Signal Noise Ratio (SNR), and Noise Signal Ratio (NSR). It will be understood by those skilled in the art that SNR and NSR refer to quality information of electrical signals carried by wavelengths. Specifically, it can be obtained by electrical signal power and linear noise and nonlinear noise introduced by light. The present invention does not impose any limitation on the method for obtaining the various optical signal quality parameters described above, and may adopt a current general technical method or a new calculation method that may occur as technology advances.

2: Intermediate node action: Different from step 303 of FIG. 3, in this embodiment, after the intermediate node parses the received indication information (ie, optical signal quality information), the intermediate node calculates the quality parameter calculated by the upstream node. And performing a certain mathematical operation to obtain new optical signal quality parameter information of the wavelength to the intermediate node as new indication information. For example, if the optical signal quality information is ONSR, then the optical node can obtain a new ONSR by increasing the amount of noise introduced by the node on the received information. If the optical signal quality information is OSNR, the optical node needs to obtain a new ONSR value in a more complicated manner (for example, after reciprocating the inverse of the noise amount of its upstream node to the node, superimposed on the OSNR);

2: Destination node action: Unlike the processing method of step 402 in FIG. 4, in the present embodiment, the destination node obtains optical signal quality information by analyzing the indication information (ie, optical signal quality information). Pass This information of the comparison working path and the protection path wavelength is used to judge the wavelength to be turned off, that is, the wavelength of the optical signal quality parameter is selected to receive the service data, and the other wavelength is turned off. Taking the optical signal quality information as the ONSR as an example, the destination node selects the wavelength of the parameter with the larger value of the parameter to be turned off.

The embodiment of the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information instead of simply determining the level of the optical power, thereby improving the correctness of the protection switching.

It should be noted that even if the wavelengths of the two paths are not faulty, the method of selecting the receiving wavelength by using the quality of the optical signal is better than the method of simply using the optical power. Specifically, the method of comparing optical signal quality can enable the destination node to obtain better quality wavelengths and thus provide better reception performance (for example, a smaller error rate).

Example 4

One embodiment of the present invention provides another method, apparatus and system for wavelength selection. This method is similar to the method steps described in Embodiment 1, and will not be described herein. The difference is that the information included in the indication information in this embodiment is multiple, that is, at least two. For example: any two or three shown in Table 1. Specifically, in this embodiment, the operation of different nodes is different from that of Embodiment 1 in the operation of the indication information at different nodes. The specific description is as follows:

1: Head node action: Unlike step 301 of FIG. 3, in the present embodiment, the indication information generated by the head node is a plurality of pieces of information. For example: including optical signal quality and TTI. Another example: including destination address identification and FDI. Another example: including all the information described in Table 3.

2: Intermediate node action: Different from step 303 of FIG. 3, in this embodiment, after the intermediate node parses the received indication information, different types of information need to be processed differently. For specific operation methods, refer to the description of Embodiment 1-3, and details are not described herein.

2: Destination node action: Unlike step 402 in FIG. 4, in the present embodiment, the destination node obtains a plurality of pieces of information after parsing the indication information. When deciding which way to switch the working path wavelength and the protection path wavelength, it is necessary to sort the obtained information and make one-to-one judgment. The following includes the information including FDI, TTI and optical signal quality information as an example, but the present invention does not limit the specific parameters and specific judgment principles. First, judge FDI. If the two-way wavelength FDI indicates that there is a signal failure, then the wavelength is selected to be turned off. If the FDI indications of the two wavelengths are normal, that is, there is no signal failure, then the TTI corresponding to the two wavelengths is continuously determined. If the destination node indicated by one of the paths does not match the current destination node, the wavelength of the path is selected to be turned off. If the TTI of both wavelengths can match the current destination node, then the optical signal quality information of the two wavelengths is compared, and the wavelength indicating which the noise amount is larger is selected to be turned off. It should be noted that the determination of the order and the rules of the multiple information may be made according to specific needs, and the present invention does not impose any limitation.

The embodiment of the present invention ensures that the destination node selects the correct wavelength for service reception by transmitting the indication information including the plurality of wavelength parameters instead of simply determining the level of the optical power, thereby greatly improving the correctness of the protection switching.

Example 5

FIG. 5 is a schematic structural diagram of a possible network device, and specifically, the schematic diagram shows the above method. A possible structural diagram of the head node involved in the embodiment. The head node includes a processing unit 501 and a sending unit 502, wherein:

The processing unit 501 is configured to perform an internal action performed by the head node described in the foregoing method embodiment. For example: performing step 301 in FIG. 3;

The sending unit 502 is configured to perform the sending action performed by the head node described in the foregoing method embodiment. For example; step 302 in Figure 3 is performed.

FIG. 6 is a schematic structural diagram of still another possible network device. Specifically, the schematic diagram shows a possible structure of an intermediate node involved in the foregoing method embodiment. The intermediate node includes a receiving unit 601, a processing unit 602, and a transmitting unit 603, where:

The receiving unit 601 is configured to perform the receiving action performed by the intermediate node described in the foregoing method embodiment. For example, receiving the indication information from the upstream device as described in Embodiment 1;

The processing unit 602 is configured to perform the internal actions performed by the intermediate node described in the foregoing method embodiments. For example: performing step 303 in FIG. 3;

The sending unit 603 is configured to perform the sending action performed by the intermediate node described in the foregoing method embodiment. For example; step 304 in Figure 3 is performed.

FIG. 7 is a schematic structural diagram of another possible network device. Specifically, the schematic diagram shows a possible structure of a destination node involved in the foregoing method embodiment. The destination node includes a first receiving unit 701, a processing unit 702, a wavelength switch 703, and a second receiving unit 704, where:

The first receiving unit 701 is configured to perform the receiving action performed by the destination node described in the foregoing method embodiment. For example, receiving the indication information from the upstream device as described in Embodiment 1;

The processing unit 702 is configured to perform the determining action performed by the destination node described in the foregoing method embodiment. Specifically, "determining the wavelength to be turned off according to the new indication information" described in step 305 in FIG. 3 is performed;

The wavelength switch 703 is configured to perform a wavelength turn-off operation performed by the destination node described in the foregoing method embodiment;

The second receiving unit is configured to perform a service action from a wavelength that is turned off, performed by the destination node described in the foregoing method embodiment.

It should be noted that the second receiving unit may include a coupler or a 2:1 optical selection switch, or an optical device having a similar function (ie, receiving wavelength), and the present invention does not impose any limitation.

It should be noted that the second receiving unit further includes a photoelectric conversion module, and the photoelectric conversion module is configured to perform photoelectric conversion on the wavelengths of the working path wavelength and the protection path wavelength that are not turned off, thereby extracting the Business. Encapsulating the wavelength-receiving and opto-electronic conversion modules into a single module has the advantage of being implemented in two modules: better integration, resulting in a smaller device and better reliability.

It will be appreciated that Figure 8 only shows a simplified design of the destination node. In practical applications, the network device may include any number of receiving units, wavelength switches, etc., and all network devices that can implement the present invention are within the scope of the present invention.

Figure 8 provides an implementation of a possible destination node. Specifically, the destination node includes: a wavelength selection module 801, a first wavelength switch 802, and a second wavelength switch 803, and a wavelength receiving processing module 804. The connection relationship of each module is shown in Figure 8. The function of each module is described as follows:

The wavelength selection module 801 is configured to implement the actions performed by the first receiving unit 701 and the processing unit 702 in FIG. 7 . That is, the wavelength selection module first receives the indication information, and then determines the wavelength that needs to be turned off according to the information;

The first wavelength switch 802 and the second wavelength switch 803 are configured to perform wavelength turn-off. Specifically, a dimmable attenuator or an optical device such as an optical switch can be used. Which of these two wavelengths needs to be turned off needs to be determined by the wavelength selection module 801. Those skilled in the art can understand that the two wavelength switches need a working path wavelength and a protection path wavelength transmitted from an upstream device that receives the destination node;

The wavelength receiving processing module 804 is configured to perform the action of the second receiving unit in FIG. 7. That is, the wavelength reception processing module 804 is configured to receive and perform photoelectric conversion on a wavelength that is not turned off. It should be noted that the wavelength receiving processing module 804 may be further divided into an optical coupler 8041 and a photoelectric conversion module 8042 for respectively receiving a wavelength that is not turned off and photoelectrically converting the received wavelength to receive a service.

It should be noted that, as described in Embodiment 1, the coupler can also be replaced with a 2:1 photoelectric conversion switch. For the benefit of using the optical coupler, refer to the related description of Embodiment 1, and no further details are provided herein.

It should be noted that the above processing unit, the sending unit and the receiving unit may also be a processor, a transmitter and a receiver, respectively, or a processing module, a sending module and a receiving module. Vice versa, for example, the wavelength selection module can also be a wavelength selection unit.

A person skilled in the art may understand that all or part of the steps of implementing the above embodiments may be completed by hardware, or may be instructed by a program to execute related hardware, and the program may be stored in a computer readable storage medium. The storage medium mentioned may be a read only memory, a magnetic disk or an optical disk or the like. Specifically, for example, the processing unit or processor may be a central processing unit, a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device. , transistor logic, hardware components, or any combination thereof. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that Modifications may be made to the technical solutions described in the foregoing embodiments, or some or all of the technical features may be equivalently replaced. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims (21)

A method of wavelength selection, characterized in that the method comprises: Receiving indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the indication information includes a wavelength parameter used for wavelength selection; Determining, according to the indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength; Turning off the wavelength to be turned off; The traffic is received from wavelengths of the working path wavelength and the protection path wavelength that are not turned off. The method of claim 1, wherein the indication information comprises a forward defect indication FDI, the FDI being used to indicate whether the working path wavelength and the protection path wavelength have a signal failure SF. The method according to claim 1 or 2, wherein the indication information comprises a path trace identifier TTI, and the TTI comprises an identifier of a source node and a destination node of the service. The method according to any one of claims 1 to 3, wherein the indication information comprises wavelength signal quality information, and the wavelength signal quality information is used to indicate that the working path wavelength and the protection path wavelength are carried. Signal quality. The method of claim 4 wherein said signal quality is any one of optical signal to noise ratio OSNR, optical noise signal ratio ONSR, signal to noise ratio SNR, and noise signal ratio. The method according to any one of claims 1 to 5, wherein the receiving the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength comprises: Receiving the service from a wavelength that is not turned off in the working path wavelength and the guard path wavelength using a 2:1 optical selective turn-off; or The traffic is received using a coupler from wavelengths of the working path wavelength and the guard path wavelength that are not turned off. The method according to any one of claims 1 to 6, wherein the indication information is transmitted in an optical monitoring channel OSC, wherein the working path wavelength, the protection path wavelength, and the indication information are carried The wavelengths used by OSC vary. An optical network device, where the optical network device includes: a first receiving module, configured to receive indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the indication information includes a wavelength parameter used for wavelength selection; a processing module, configured to determine, according to the indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength; a wavelength switch for turning off the wavelength to be turned off; And a second receiving module, configured to receive the service from a wavelength that is not turned off in the working path wavelength and the protection path wavelength. The device according to claim 8, wherein the indication information comprises a forward defect indication FDI, and the FDI is used to indicate whether the working path wavelength and the protection path wavelength have a signal. Fault SF. The device according to claim 8 or 9, wherein the indication information comprises a path trace identifier TTI, and the TTI comprises identification information of a source node and a destination node of the service. The device according to any one of claims 8 to 10, wherein the indication information comprises wavelength signal quality information, and the wavelength signal quality information is used to indicate a signal carrying the working path wavelength and the protection path wavelength quality. The apparatus according to claim 11, wherein said signal quality information is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio. The apparatus according to any one of claims 8 to 12, wherein said second receiving module comprises a coupler or a 2:1 optical selective switch, said coupler or 2:1 optical selection switch for receiving said working path wavelength And wavelengths that are not turned off in the protection path wavelength. The apparatus according to any one of claims 8 to 13, wherein the second receiving module further comprises a photoelectric conversion module, wherein the photoelectric conversion module is configured to perform wavelengths of the working path wavelength and the protection path wavelength that are not turned off. Photoelectric conversion to extract the business. An optical network system, characterized in that the system comprises: The first node device, the intermediate node device, and the destination node device, where: The head node device is used to: Obtaining first indication information of a working path wavelength and a protection path wavelength, where the working path wavelength and the protection path wavelength are used to carry the same service, and the first indication information includes a wavelength parameter used for wavelength selection; Sending the first indication information; The intermediate node device is configured to: receive the first indication information, and generate second indication information according to the first indication information and parameter information that is known by the intermediate node, where the second indication information includes a wavelength parameter included in the first indication information processed by the intermediate node device; sending the second indication information; The destination node device is configured to: Receiving the second indication information; Determining, according to the second indication information, a wavelength to be turned off in the working path wavelength and the protection path wavelength; Turning off the wavelength to be turned off; The traffic is received from wavelengths of the working path wavelength and the protection path wavelength that are not turned off. The system according to claim 15, wherein the transmitting the first indication information and the sending the second indication information are to carry the first indication information and the second indication information on an optical monitoring channel Transmitted on the OSC, wherein the working path wavelength, the protection path wavelength, and the wavelength used by the OSC are different. The system according to claim 15 or 16, wherein the first indication information and the second indication information comprise a forward defect indication FDI, the FDI being used to indicate the working path wavelength and the protection Whether there is a signal fault SF in the path wavelength; the second indication information includes the FDI according to the The FDI included in the first indication information and the link state of the network device and the neighbor device located upstream of the network device are jointly determined. The system according to any one of claims 15 to 17, wherein the first indication information and the second indication information comprise a path trace identifier TTI, and the TTI comprises a source node and a destination node of the service. And the TTI and the second indication information included in the first indication information are the same as the TTI. The system according to any one of claims 15 to 18, wherein the first indication information and the second indication information comprise wavelength signal quality information, and the wavelength signal quality information is used to indicate that the working path is carried a wavelength and a signal quality of the protection path wavelength; wherein the second indication information includes wavelength signal quality information according to the wavelength signal quality information included in the first indication information, and the additional noise information introduced by the network node Decide. The system according to claim 19, wherein said signal quality is any one of an optical signal to noise ratio OSNR, an optical noise signal ratio ONSR, a signal to noise ratio SNR, and a noise signal ratio. The system according to any one of claims 15 to 20, wherein said receiving said service from said wavelength of said working path wavelength and said protection path wavelength that is not turned off comprises: Receiving the service from a wavelength that is not turned off in the working path wavelength and the guard path wavelength using a 2:1 optical selective turn-off; or, using a coupler from the working path wavelength and the guard path wavelength The service is received in a broken wavelength.

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