WO2022143023A1 - Path computation method, path computation element, and communication system - Google Patents

Abstract

A path computation method, a path computation element, and a communication system. The method comprises: a path computation element (PCE) receiving a path computation request message sent by a path computation client (PCC) (S102); the PCE performing path computation according to the path computation request message and a service transmission parameter set by a software defined optical (SDO) module (S104); and the PCE sending a path computation result to the PCC (S106).

Description

Path calculation method, path calculation server and communication system

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the Chinese patent application with the application number of 202011606217.9 and the filing date of December 28, 2020, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is incorporated herein by reference.

technical field

The embodiments of the present application relate to the field of communication, and in particular, to a path calculation method, a path calculation server, and a communication system.

Background technique

In the existing technology, the direction of intelligence focuses on the optical transport network (Optical Transport Network, OTN) product solution, and on the basis of the traditional network, by adding a new generation of intelligent and open management and control products, the network from the traditional network to the autonomous network is realized. Intelligent evolution. This part will be implemented by adding related functions to the OTN equipment and the management and control platform respectively based on the existing OTN equipment and management and control plane.

Path Computation Element Communication Protocol (PCEP) is a communication protocol and an application layer protocol based on Transmission Control Protocol (TCP). In the OTN SDN (Software Defined Network) solution, PCEP protocol It is a southbound interface protocol. The PCEP protocol defines the communication standard between the path calculation server (Path Computation Element, PCE) and the path calculation request client (Path Computation Client, PCC) or PCE. The PCEP protocol mainly transmits the Layered Service Provider (LSP) ) forwarding path information, after the SDN controller calculates the path, it converts it into an SR label stack, and sends it to the OTN device control plane through the PCEP protocol. The PCEP protocol is a communication protocol used for the interaction between the OTN device and the management and control plane.

Due to the limitation of the existing technology, the PCE in the PCEP protocol standard is a functional entity specially responsible for path calculation. At present, the business function is relatively single, and the goal of true optical layer intelligence cannot be realized. For optical layer transmission, the capacity, distance, and spectrum seriously affect the optical transmission performance. For example, if the distance is too long, the optical transmission performance is degraded, or the current signal is degraded and the transmission capacity is damaged, or the non-optimal transmission spectrum leads to poor service quality. In other cases, the traditional solution is to adjust the optical transmission performance by replacing hardware optical modules, adding relay sites, deleting services and adjusting transmission channels, which is bound to have high labor and technical costs.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a path calculation method, a path calculation server, and a communication system.

According to an embodiment of the present application, a path calculation method is provided, including: a path calculation server PCE receives a path calculation request message sent by a path calculation request client PCC; the PCE calculates a path according to the path calculation request message and a software-defined optical fiber The service transmission parameters set by the module SDO perform path calculation; the PCE sends the path calculation result to the PCC.

According to another embodiment of the present application, a route calculation server PCE is provided, comprising: a communication module configured to receive a path calculation request message sent by a route calculation request client PCC, and send a path calculation result to the PCC The software-defined optical module SDO is set to set service transmission parameters; the path calculation module is set to perform path calculation according to the path calculation request message and the service transmission parameters set by the SDO.

According to another embodiment of the present application, a communication system based on the path calculation unit communication protocol PCEP is also provided, the communication system includes: one or more of the path calculation servers PCE in the above embodiments, and one or more calculation A road request client PCC, wherein the interaction between the PCE and the PCC is based on the PCEP protocol.

In an exemplary embodiment, the PCE's path computation model includes: a PCE-controlled centralized computation model or a plurality of PCE-controlled distributed computation models.

According to yet another embodiment of the present application, a computer-readable storage medium is also provided, and a computer program is stored in the computer-readable storage medium, wherein the computer program is configured to execute any one of the above methods when running steps in the examples.

According to yet another embodiment of the present application, an electronic device is also provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute any one of the above Steps in Method Examples.

Description of drawings

1 is a flowchart of a path calculation method according to an embodiment of the present application;

2 is a structural block diagram of a route calculation server according to an embodiment of the present application;

3 is a structural block diagram of a route calculation server according to another embodiment of the present application;

4 is a schematic structural diagram of a communication system based on a PCE centralized computing model according to an embodiment of the present application;

5 is a schematic diagram of a PCC/PCE basic communication model based on the PCEP protocol according to an embodiment of the present application;

Fig. 6 is the PCEP protocol+SDO realization design block diagram of the embodiment of the present application;

7 is a schematic diagram of the relevant parameter content of the service board based on the SDO technology according to the embodiment of the present application;

8 is a schematic diagram of an application scenario of SDO optimization in a long-distance transmission scenario according to an embodiment of the present application;

9 is a schematic diagram of an optimized application scenario under the OADM/ROADM cascaded networking scenario of the embodiment of the present application;

FIG. 10 is a schematic diagram of an application scenario of SDO spectral shaping dispersion pre-compensation according to an embodiment of the present application.

Detailed ways

Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments.

It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence.

Example 1

A path calculation method is provided in this embodiment, and FIG. 1 is a flowchart of a method according to an embodiment of the present application. As shown in FIG. 1 , the process includes the following steps:

Step S102, the path calculation server PCE receives the path calculation request message sent by the path calculation request client PCC;

Step S104, the PCE performs path calculation according to the path calculation request message and the service transmission parameters set by the software-defined optical module SDO;

Step S106, the PCE sends the path calculation result to the PCC.

Before step S102 in this embodiment, the PCE establishes a communication link with the PCC based on the path computation element communication protocol PCEP.

Before step S104 in this embodiment, the method may further include: setting the service transmission parameter in the SDO according to a service transmission scenario.

In this embodiment, the service transmission parameters include at least one of the following: signal type, modulation code type, FEC coding error correction type, grid width, and DSP parameters.

In step S104 of this embodiment, the PCE parses the path calculation request message, and uses the routing information stored in the traffic engineering database TED to match the service transmission parameters based on the transmission performance of the path to generate an optical layer modulation command set.

In step S106 of this embodiment, the PCE sends the optical layer modulation command set to the PCC.

In this embodiment, the optical layer modulation command set includes at least one of the following: coding modulation shaping, spectrum shaping, and dynamic impairment shaping.

In this embodiment, after the PCE sends the optical layer modulation command set to the PCC, the method may further include: the PCE receiving the feedback from the PCC to modulate the optical module based on the optical layer modulation command set or adjustment results.

From the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products are stored in a storage medium (such as ROM/RAM, magnetic disk, CD-ROM), including several instructions to make a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) execute the methods described in the various embodiments of this application.

In this embodiment, a path calculation server (PCE) is also provided, and the PCE is used to implement the above embodiments and implementation manners, and what has been described will not be repeated. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, implementations in hardware, or a combination of software and hardware, are also possible and contemplated.

Example 2

FIG. 2 is a structural block diagram of a route calculation server according to an embodiment of the present application. As shown in FIG. 2 , the route calculation server includes:

The communication module 10 is configured to receive the path calculation request message sent by the path calculation request client PCC, and send the path calculation result to the PCC;

a software-defined optical module (SDO) 20, which is set to set service transmission parameters;

The path calculation module 30 is configured to perform path calculation according to the path calculation request message and the service transmission parameters set by the SDO.

In one embodiment, the communication module 10 is further configured to establish a communication link with the PCC based on the path computation unit communication protocol PCEP.

Example 3

FIG. 3 is a structural block diagram of a route calculation server according to another embodiment of the present application. As shown in FIG. 3 , the route calculation server includes a traffic engineering database 40 in addition to all the modules shown in FIG. 2 . The traffic engineering database 40 is arranged to store routing information. In this embodiment, after parsing the path calculation request message, the path calculation module 20 uses the routing information stored in the traffic engineering database 40 to match the service transmission parameters based on the transmission performance of the paths to generate optical Layer modulation command set. In this embodiment, the optical layer modulation command set includes at least one of the following: coding modulation shaping, spectrum shaping, and dynamic impairment shaping.

In one embodiment, the communication module 10 is further configured to receive a result of adjusting the optical module based on the optical layer modulation command set fed back by the PCC.

It should be noted that the above modules can be implemented by software or hardware, and the latter can be implemented in the following ways, but not limited to this: the above modules are all located in the same processor; or, the above modules can be combined in any combination The forms are located in different processors.

In order to facilitate the understanding of the technical solutions provided in the present application, the following will be described in detail in conjunction with embodiments of specific scenarios.

Example 4

This embodiment provides a communication system based on the PCEP protocol standard of a software-defined optical module (SDO). In this embodiment, the communication system includes four parts: PCE, PCC, PCEP protocol and SDO.

In this embodiment, the PCE is a functional entity in the network that is specially responsible for path calculation. Based on the known network topology and constraints, an optimal path that meets the constraints is calculated according to the PCC's request. The matching work of the service transmission parameters set by SDO is added. PCC submits a path calculation request to PCE and obtains the path calculation result; PCEP protocol, as a communication protocol for interaction between PCE and PCC, establishes reliable communication and flow control work based on TCP protocol; The system's bandwidth, distance, and complexity are weighed to achieve the best spectrum utilization rate and better adapt to changes in services and scenarios. The relevant parameters of the main service boards are signal type, modulation code type, and FEC code error correction. Type, grid width, DSP parameters, etc. The integration of PCEP protocol and software-defined optical module (SDO) technology is a solution to effectively improve the self-adaptive service transmission performance of the optical layer, realize the optimal matching of capacity and distance, and improve network survivability.

In this embodiment, the path calculation model of the PCE includes: a centralized computing model controlled by one PCE or a distributed computing model controlled by multiple PCEs.

In this embodiment, the computing models of PCE are mainly divided into two types, one is a centralized computing model, that is, all path computations in a given domain are completed by a centralized PCE; the other is a distributed computing model, that is, a There may be multiple PCEs within a domain. For the generality of the PCE, the communication between the PCC and the PCE is unified, and the interaction between the PCE and the PCE is to treat the PCE in which the path request is sent as the PCC.

In this embodiment, the PCEP protocol may include the following stages: a process of establishing a PCEP session, a PCEP initialization stage, a path calculation request/response stage, a request queuing stage, an error message stage, and a channel closing stage.

In this embodiment, the implementation process of the PCEP protocol may sequentially include: PCC message initialization, PCC packaging request message, PCC send request message, PCE receive request message, PCE analysis request message, path calculation, and PCC receive response message.

In this embodiment, after the PCE receives the request message, the service transmission parameters set by the SDO are passed into the path calculation module of the PCE, and the PCE will match the transmission parameters according to the different requirements of the service and the scene environment, and generate specific adjustments. command set. In addition, the path calculation module of the PCE uses the routing information stored in the TED and other optical layer optimization algorithms to complete the calculation of the optimal path and the optimal spectrum utilization efficiency, and finally matches the optimal optical transmission system where the PCC is located. Calculation result of transmission performance.

In this embodiment, the software-defined optical module (SDO) enables the optical transmission component to have programmability, which means that the subcarrier multiplexing mode and modulation mode of the optical transmission system are variable, the damage compensation algorithm is variable, and Variable FEC type and format, variable grid width, etc. By balancing bandwidth, distance, and complexity, it achieves the best spectrum utilization efficiency and better adapts to changes in services and scenarios.

In this embodiment, the SDO technology realizes self-defined control of the transmitted/received signals of the optical module through the management and control system, and can be divided into coding modulation shaping, spectrum shaping and dynamic impairment according to different adjustment and matching methods set for service parameters. Three types of shaping. Code modulation shaping is to select a more suitable modulation method and coding method to transmit effective information to achieve better transmission performance; spectrum shaping mainly considers the mismatch between the physical bandwidth and the transmission signal in the channel. , improve the high-frequency component of the signal spectrum or compress the spectral bandwidth to obtain better anti-filtering characteristics, punch-through ability or anti-crosstalk ability; dynamic damage shaping is mainly to adjust the DSP parameters of the transceiver transceiver of the optical module to improve the dynamic damage caused by the optical module in the system (such as The ability to track or compensate for polarization effects, nonlinear effects, etc.).

Example 5

FIG. 4 is a schematic structural diagram of a communication system based on the PCE centralized computing model. In this embodiment, the PCE centralized computing model in the PCEP protocol is taken as an example. As shown in Figure 4, the OTN management and control plane is mainly composed of a centralized PCE dedicated server, and there are six PCC nodes at the OTN device level, and the interconnection between them is as shown in the figure. The right side of the PCE dedicated server is a block diagram of the internal structure of PCE, which is mainly divided into TED traffic engineering database, SDO transmission parameters, path calculation module, PCE communication module and other related optical layer optimization algorithms. Among them, the SDO transmission parameters are specified by the user for the service type, and the PCE dedicated server matches the best modulation code to obtain better transmission performance. Based on the PCEP protocol, the lower light-emitting layer modulation command set is performed, and the command set is used by the OTN equipment. Carry out specific work.

Figure 5 shows the basic communication model of PCC/PCE based on the PCEP protocol. As shown in FIG. 5 , the process of establishing the PCEP session mainly includes the following stages.

Initialization phase: The first step is the establishment of the TCP connection, that is, the three-way handshake between the PCC and the PCE, the second step is to establish the PCEP channel based on the TCP connection, and then send the Open message to establish the session and the Keepalive message to maintain the session;

Path calculation request/response phase: PCC sends a path calculation request, i.e. PCReq message, to PCE. When PCE receives the information carried in the PCReq message and the TED (traffic engineering database, which stores the information required by PCE for path calculation) and LSP-DB (Label Switching Path Database) information for path calculation;

Request queuing stage: When a large number of service requests are sent to the PCE, the PCC will wait in line according to different priorities. If the response time is too long, the PCE will send a PCNtf message to the PCC to notify the PCC of the waiting time. After the PCC receives the message , through a series of judgments, to decide whether to end the current path calculation request and send the request to other PCEs;

Error message stage: When the message is transmitted on the PCEP channel, there may be an error that the PCE cannot recognize, then the PCE will send a PCErr message to the PCC to indicate a protocol error, or when the PCE's computing power is insufficient, it will also notify the PCC; the channel is closed stage , after the PCC accepts the path calculation request response sent by the PCE, and there are no other service requests, it sends a Close message to close the channel, and then disconnects the TCP connection.

FIG. 6 is a block diagram of the implementation design of the PCEP protocol+SDO according to an embodiment of the present application. As shown in Figure 6, the process is roughly divided into the initialization of the PCC message. The PCC needs to send the source node, destination node, path, switching granularity, bandwidth and other related information of the route to the PCE, so that it can complete the initialization setting of the request information; PCC packages the request message. After the message is initialized, the message is packaged and sent; the PCC sends the request message, and sends the packaged message to the PCE through Socket programming based on the TCP protocol; the PCE receives the request message, and after the message reaches the PCE, the PCE passes the The communication module receives the message; the PCE analyzes the request message, and after receiving the message, the PCE unpacks and analyzes the message; after the PCE receives the message, the path calculation module uses the routing information stored in the TED, the imported SDO to set transmission parameters and other Optical layer optimization algorithm, etc., complete the calculation of the best path and the best spectrum utilization efficiency, so as to complete the PCE service expansion related content, and finally match the best transmission performance message; the final path calculation result message is initialized, packaged, The sending process is returned to the PCC; the PCC accepts the response message, and the PCC receives the relevant path calculation results and various messages packaged and returned by the PCE, and reads the response message.

In this embodiment, the reconstruction of the transmission parameters of the SDO can be performed. That is, SDO targets the path structure of the transport layer where the PCC is located, and operators choose different modulation methods according to their own needs to meet the requirements for transmission distance and spectrum efficiency in different application scenarios.

FIG. 7 is the content of all parameters of the service board based on the SDO technology according to the embodiment of the present application. As shown in Figure 7, the transmitted signal types can be divided into 100G, 200G, 400G, 1T and other super-100G signals, and the FEC coding redundancy can be adjusted into 0, 20%, 40%, 60%, etc. The modulation methods are BPSK, QPSK, 8QAM, 16QAM, etc., DSP parameters include pulse shaping, fiber CD and self-phase modulation (SPM), etc., grid width multi-level (37.5GHZ, 50GHZ, 100GHZ, etc.) adjustable mode and other operation contents.

In this embodiment, the SDO implements self-defined control of the transmitted/received signals of the optical module through the management and control system. According to different adjustment methods for setting service parameters, it can be divided into three types: coding modulation shaping, spectrum shaping and dynamic impairment shaping. category.

Example 6

In this embodiment, the coding modulation shaping adjustment method is taken as an example for description.

Coded modulation shaping is to select a more suitable modulation mode and coding mode to transmit valid information to achieve better transmission performance. At present, the commonly used coding shaping techniques mainly include the following four types: error correction coding shaping, hybrid modulation, probability shaping and geometric shaping. The line-side long-distance coherent optical modules in the current products include multiple service rates, multiple encoding methods, and multiple FEC encoding methods with different overheads. For example, at a specific service rate, using low-order modulation patterns or high-overhead FEC coding can obtain stronger noise tolerance or longer transmission distance, and using high-order modulation patterns or low-overhead FEC coding can achieve higher spectral efficiency and better network penetration. Therefore, for services of a specific rate, using different modulation codes and coding methods, the OSNR threshold, filtering cost, and nonlinear cost of the optical module of the system link will be different, so that the optical transmission service presents different transmission performance. . Code modulation shaping is to select the appropriate modulation code type and coding method through manual selection or automatic adjustment algorithm to meet the needs of specific services and scenarios.

Optimization application 1: In the long-distance transmission scenario, the SDO code modulation and shaping function can be used to optimize the optical transmission performance. In this scenario, under a specific optical route and a specific service rate requirement, according to the link information such as the fiber type, span loss, channel spacing, line-side optical module type, OA model, etc. of the selected route, select the one that meets the transmission performance of the link. The optimal code modulation configuration is to select and configure the relevant transmission parameters of the service board to obtain the best OSNR margin to ensure the long-term stability of the system.

Figure 8 shows the SDO optimization process in a long-distance transmission scenario. As shown in Figure 8, the process is as follows:

(1) The user builds services according to various link information of the optical layer equipment to specify the signal type, modulation code type, etc.

related information.

(2) The PCC establishes a communication link with the PCE based on the PCEP protocol.

(3) According to the transmission parameters set by the SDO, the PCE matches the optimal modulation code pattern under the constraint of the user's maximum transmission distance, obtains better optical path performance, and generates a specific code modulation command set. The modulation code of the optical module supports traditional modulation codes such as BPSK, QPSK, 8QAM, 16QAM, 32QAM, 64QAM, etc. In order to achieve the scenario of long-distance transmission, the mixed modulation code of timing interleaving is adopted. Therefore, when SDO calculates paths, it needs to traverse the mixed modulation table in the order of high rate, low spectral width to low rate, and high spectral width to determine a list of possible mixed modulation types for calculating service paths. If no available route calculation result is returned, the next optimal route is calculated. Under different hybrid modulation modes, the channel bandwidth, signal spectral efficiency, and OSNR tolerance are different. Taking 200G/27% FEC hybrid modulation as an example, the OSNR and baud rate data under different spectrums are shown in Table 1.

Table 1

OSNR Tolerance (dB)	Baud rate (GHz)	spectral effect	The mixing ratio
13.10	69.44	2	128:0
13.13	68.90	2.015625	126:2
13.16	68.63	2.0234375	125:3
13.19	68.10	2.0390625	123:5
13.22	67.59	2.0546875	121:7
13.25	67.08	2.0703125	119:9
13.28	66.57	2.0859375	117:11
13.30	66.08	2.1015625	115:13
13.33	65.59	2.1171875	113:15
13.36	65.11	2.1328125	111:17
13.74	61.08	2.2734375	93:35
....	....	....	....

(4) The light-emitting layer adjustment command set under the PCE communication module.

(5) The optical layer device performs specific modulation.

(6) The modulation result is fed back to the PCE.

In this embodiment, by implementing flexible switching of coding and modulation, the system transmission capability and transmission feasibility can be maximized, thereby increasing the space for path selection. For the path selection of the SDN controller, the available paths are no longer limited to network resources of fixed coding and modulation, but become network resources of dynamic variable coding and modulation. The advantage of this is that the modulation method is changed to on-demand modulation, which will greatly improve the intelligence level of the network, maximize the carrying capacity, and improve the service recovery ability.

Example 7

In this embodiment, the spectrum shaping adjustment method is taken as an example for description.

Spectrum shaping mainly considers the mismatch between the physical bandwidth in the channel and the transmitted signal, which leads to serious signal attenuation, which brings the cost of filtering damage. Therefore, it is possible to improve the high frequency component of the signal spectrum or compress the spectral bandwidth by shaping the spectrum at the transmitting end, so as to obtain better anti-filtering characteristics, punch-through capability or anti-crosstalk capability. At present, the main adjustment methods of spectral shaping are spectral pre-emphasis and Nyquist shaping. In the OADM/ROADM cascade scenario, the system may have serious optical filtering effects. In this scenario, the deeper the pre-emphasis level or the higher the Nyquist shaping compression level, the stronger the signal light penetration performance. However, spectral shaping will affect the OSNR threshold of the optical module, so it is necessary to comprehensively consider the link filter bandwidth and transmission distance to select the spectrum shaping solution with the best overall performance.

In this embodiment, the second optimization application, that is, in the OADM/ROADM cascade networking scenario, adopts the SDO spectrum shaping solution to improve the service penetration capability as an example.

In this embodiment, the SDO spectrum shaping needs to be set by the SDN controller according to the number of cascaded optical filters in the link and the bandwidth. In this scenario, the optical module implements spectrum shaping at the originating end to obtain better punch-through performance and realize the adaptive optimization application of the optical layer. Based on the feasibility and simple controllability of technical implementation, the current SDO spectrum shaping scheme is mainly a Nyquist shaping scheme. Table 2 shows the spectrum shaping strategies of the existing optical modules that can support the Nyquist shaping function in different application scenarios.

Table 2

As shown in Figure 9, it is an optimized application scenario under the OADM/ROADM cascade networking scenario. The process is as follows:

(1) Verify the filter damage during service expansion. When the system filter cost exceeds the limit, a spectrum shaping response system needs to be adopted.

system filter damage. The user performs spectrum shaping to deal with the system filtering impairment scheme.

(2) The PCC establishes a communication link with the PCE based on the PCEP protocol.

(3) The PCE adopts a spectrum shaping scheme for the optical module according to the constant requirements of the modulation code type, service rate and link power, and generates a specific adjustment command set. According to the above spectrum shaping strategy table, setting the service rate, modulation code type, FEC overhead and channel interval data to match the fixed parameter values can ensure the normal application state of the Nyquist shaping function in the hardware optical module.

(4) The light-emitting layer adjustment command set under the PCE communication module.

(5) The optical layer device performs specific adjustments.

(6) The adjustment result is fed back to PCE.

In this embodiment, the main purpose of Nyquist spectrum shaping is to compress the spectrum width and improve the spectrum utilization rate. This function does not conflict with the SDO code modulation shaping function in the previous application scenario. In the scenarios of service creation and dynamic restoration, the Nyquist shaping function and the coding modulation shaping function can be directly applied in combination.

Example 8

In this embodiment, the dynamic damage shaping adjustment method is taken as an example for description.

Dynamic damage shaping mainly adjusts the transceiver DSP parameters of the optical module to improve the tracking or compensation capability of the optical module for dynamic damage (such as polarization effects, nonlinear effects, etc.) in the system. Dynamic damage shaping mainly deals with the real-time variable optical damage during service optical transmission. In the existing long-distance optical transmission system, it includes polarization mode dispersion (PMD), polarization state deflection (SOP), fiber nonlinear interference and laser phase In the actual system, polarization modal dispersion and phase noise can be almost completely compensated without sacrificing other performance indicators of the optical module, while SOP damage and nonlinear damage can be improved by dynamically adjusting DSP parameters. These parameters need to be reasonably configured based on the degree of optical damage of the link and the degradation of the OSNR tolerance performance of the optical module itself.

In this embodiment, the optimization application 3, that is, dynamic damage shaping suppresses nonlinear damage of the optical path by using the dispersion pre-complement function at the transmitting end, and improves the transmission performance of the system as an example for description.

In this embodiment, the SDN controller can configure a more efficient damage shaping algorithm through the dynamic damage shaping algorithm without changing the modulation format and service rate of the existing optical path according to the fiber type, fiber length, and fiber input power distribution of the link. Accurate dispersion pre-complement amount, suppress the nonlinear damage of the link to improve the transmission performance of the system. The preset value of dispersion pre-compensation is related to the fiber type and power distribution of the link.

As shown in Figure 10, it is the application scenario of SDO spectral shaping dispersion pre-compensation. The process is as follows:

(1) According to the actual scenario of the link (fiber type, loss, incoming fiber power, etc.), the user combines nonlinear damage verification

As a result, it is determined whether a dispersion pre-compensation scheme needs to be performed.

(2) The PCC establishes a communication link with the PCE based on the PCEP protocol.

(3) The PCE adjusts the optical module according to the requirements of executing the dispersion pre-compensation scheme, and generates a specific adjustment command set. According to the configuration strategy of the pre-compensation dispersion function of the transmitter inside the optical module, set the executable parameters of the DSP and deliver the

The normal application state of the dispersion pre-compensation working mode in the hardware optical module can be guaranteed.

(4) The light-emitting layer code modulation command set under the PCE communication module.

(5) The optical module in the optical layer device is switched to the working mode with dispersion pre-compensation.

(6) The adjustment result is fed back to PCE.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, wherein the computer program is configured to execute the steps in any one of the above method embodiments when running.

In an exemplary embodiment, the above-mentioned computer-readable storage medium may include, but is not limited to, a USB flash drive, a read-only memory (Read-Only Memory, referred to as ROM for short), and a random access memory (Random Access Memory, referred to as RAM for short) , mobile hard disk, magnetic disk or CD-ROM and other media that can store computer programs.

Embodiments of the present application further provide an electronic device, including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

In an exemplary embodiment, the above-mentioned electronic device may further include a transmission device and an input-output device, wherein the transmission device is connected to the above-mentioned processor, and the input-output device is connected to the above-mentioned processor.

Embodiments of the present application provide a path calculation method, a path calculation server, and a communication system, so as to at least solve the problem of adjusting optical transmission performance by replacing hardware optical modules, adding relay sites, deleting services and adjusting transmission channels in some cases. The resulting higher labor and technology costs.

In the embodiment of the present application, by integrating the software-defined optical module SDO technology with PCEP, the service transmission performance of optical layer adaptation can be effectively improved, the optimal matching scheme of capacity and distance can be realized, and the network survivability can be improved.

For specific examples in this embodiment, reference may be made to the examples described in the foregoing embodiments and exemplary implementation manners, and details are not described herein again in this embodiment.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present application can be implemented by a general-purpose computing device, and they can be centralized on a single computing device, or distributed in a network composed of multiple computing devices On the other hand, they can be implemented in program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, can be performed in a different order than shown here. Or the described steps, or they are respectively made into individual integrated circuit modules, or a plurality of modules or steps in them are made into a single integrated circuit module to realize. As such, the present application is not limited to any particular combination of hardware and software.

The above descriptions are only several embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the principles of this application shall be included within the protection scope of this application.

Claims (18)

1. A path calculation method, comprising:

   The path calculation server PCE receives the path calculation request message sent by the path calculation request client PCC;

   The PCE performs path calculation according to the path calculation request message and the service transmission parameters set by the software-defined optical module SDO;

   The PCE sends the path calculation result to the PCC.
2. The method according to claim 1, wherein before the path calculation server PCE receives the path calculation request message sent by the PCC, the method further comprises:

   The PCE establishes a communication link with the PCC based on the path computation element communication protocol PCEP.
3. The method according to claim 1, wherein before the PCE performs the path calculation according to the path calculation request message and the service transmission parameters set by the software-defined optical module SDO, the method further comprises:

   The service transmission parameters are set in the SDO according to a service transmission scenario.
4. The method according to claim 1, wherein the service transmission parameter includes at least one of the following: signal type, or modulation code type, or FEC coding error correction type, or grid width, or DSP parameter.
5. The method according to claim 1, wherein the PCE performs path calculation according to the path calculation request message and service transmission parameters set by the SDO, comprising:

   The PCE parses the path calculation request message, and uses the routing information stored in the traffic engineering database TED to match the service transmission parameters based on the transmission performance of the path to generate an optical layer modulation command set.
6. The method of claim 1, wherein the PCE sending the path calculation result to the PCC comprises:

   The PCE sends the optical layer modulation command set to the PCC.
7. The method according to claim 6, wherein the optical layer modulation command set includes at least one of the following: coding modulation shaping, or spectral shaping, or dynamic impairment shaping.
8. The method according to claim 6, wherein after the PCE sends the optical layer modulation command set to the PCC, the method further comprises:

   The PCE receives the result of modulating or adjusting the optical module based on the optical layer modulation command set fed back by the PCC.
9. A route calculation server PCE, comprising:

   The communication module is configured to receive the path calculation request message sent by the path calculation request client PCC, and send the path calculation result to the PCC;

   The software-defined optical module SDO is set to set service transmission parameters;

   The path calculation module is configured to perform path calculation according to the path calculation request message and the service transmission parameters set by the SDO.
10. The PCE of claim 9, wherein,

    The communication module is further configured to establish a communication link with the PCC based on the path calculation unit communication protocol PCEP.
11. The PCE according to claim 9, wherein the service transmission parameters include at least one of the following: signal type, or modulation code type, or FEC coding error correction type, or grid width, or DSP parameter.
12. The PCE of claim 9, further comprising:

    The traffic engineering database TED, is set to store routing information;

    The path calculation module is configured to parse the path calculation request message, and use the routing information stored in the TED to match the service transmission parameters based on the transmission performance of the path to generate an optical layer modulation command set.
13. The PCE according to claim 12, wherein the optical layer modulation command set includes at least one of the following: coding modulation shaping, spectrum shaping, or dynamic impairment shaping.
14. The method of claim 12, wherein,

    The communication module is further configured to receive a result of modulating or adjusting the optical module based on the optical layer modulation command set fed back by the PCC.
15. A communication system based on the path calculation unit communication protocol PCEP, comprising one or more path calculation servers PCE according to any one of claims 9 to 14, and one or more path calculation request clients PCC, wherein the The interaction between the PCE and the PCC is based on the PCEP protocol.
16. The communication system according to claim 15, wherein the path calculation model of the PCE comprises: a centralized computing model controlled by one PCE or a distributed computing model controlled by a plurality of PCEs.
17. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, wherein when the computer program is executed by a processor, the method described in any one of claims 1 to 8 is implemented A step of.
18. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the claims 1 to 8 when executing the computer program The steps of the method of any one.

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