A method and system for allocating elastic optical track network resources

Abstract

The invention discloses a method and system for allocating elastic optical track network resources in the field of network resource allocation, which comprises: grouping destination nodes according to the levels of modulation formats; searching for transmission paths from source nodes to destination nodes of low-order modulation formats to construct transmission optical tracks; considering each destination node group in turn, and cyclically adding destination nodes with the shortest path length increase to share the transmission optical track; optimizing the existing transmission optical track by a node deletion algorithm after the new transmission optical track is built; optimizing the existing transmission optical track by a node deletion algorithm after the new transmission optical track is built; allocating routes and spectrum resources of each link of the transmission optical track established according to the service request, and the destination nodes share the transmission optical track; the invention avoids the destination nodes from occupying too many resources during the optical track transmission process under the condition of satisfying each multicast request, thereby improving the network resource utilization rate of the elastic optical network (EON) and reducing the spectrum consumption of the elastic optical network.

Description

Technical Field

[0001] The invention belongs to the field of network resource allocation, and in particular relates to a method and system for allocating elastic optical track network resources. Background Art

[0002] Internet traffic has shown tremendous growth over the past few decades. Among them, multicast traffic has exploded in recent years. At the same time, multicast services usually require a lot of bandwidth, such as ultra-high-definition television, virtual reality / augmented reality, and database synchronization and backup between geographically distributed data centers. In order to support multicast in a more efficient way, elastic optical networks (EONs) have been proposed to improve resource utilization and are therefore considered as potential candidates for the next generation of optical transmission networks.

[0003] Elastic Optical Network (EON) adopts a finer granularity grid, allowing flexible bandwidth allocation to connections, which requires better spectrum utilization. By adjusting the amount of spectrum bandwidth, connections that support different data rate requirements can be efficiently established in EON. In addition, for a fixed spectrum bandwidth, EON can also provide different capacities through adaptive modulation technology. Through adaptive modulation, the connection adaptively selects the modulation format of the signal according to its channel conditions. For distance adaptive spectrum positioning, more spectrally efficient modulation can be used for connections with shorter distances, thereby saving spectrum resources.

[0004] Flexible bandwidth allocation makes routing and spectrum allocation (RSA) issues in elastic optical networks (EON) much more complicated than those in traditional WDM networks. In the prior art, the destination node occupies too many resources during the optical track transmission process, resulting in low utilization of network resources in the elastic optical network (EON). Summary of the invention

[0005] The object of the present invention is to provide a method and system for allocating resources of an elastic optical track network, which can avoid the destination node from occupying too many resources during the optical track transmission process under the condition of satisfying various multicast requests, improve the network resource utilization of the elastic optical network (EON), and reduce the spectrum consumption of the elastic optical network.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A first aspect of the present invention provides a method for allocating elastic optical track network resources, comprising:

[0008] After receiving a routing spectrum allocation request for a multicast service, obtaining service parameters of the current multicast service;

[0009] According to resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network, the destination nodes are grouped according to the class of the modulation format;

[0010] Search the transmission path from the source node to the destination node of the low-order modulation format to build a transmission optical track, add the destination nodes in each order modulation format group to share the transmission optical track, and cyclically add the destination node with the shortest path length increase to share the transmission optical track; repeatedly establish multiple transmission optical tracks, and after the new transmission optical track is created, optimize the existing transmission optical track through the node deletion algorithm;

[0011] The transmission optical track established according to the service request is allocated with a route and spectrum resources of each link thereof, and the destination node shares the transmission optical track.

[0012] Preferably, the method for searching for a transmission path from a source node to a destination node of a low-order modulation format includes:

[0013] Search for the shortest transmission path from the path source node to each destination node of the low-order modulation format, record the transmission node sequence N and path sequence P in each transmission path; select the transmission path that covers the most destination nodes.

[0014] Preferably, the priority order of adding destination nodes in the transmission path is from low-order to high-order modulation format destination nodes.

[0015] Preferably, the method for adding a transmission path to share a transmission optical track with a destination node in a given modulation format group includes:

[0016] A method of adding a destination node in a given modulation format group in the middle of a transmission path, disconnecting the links between the destination nodes on the transmission path, obtaining the shortest path from the destination node in the given modulation format group in the transmission path to the destination nodes at both ends of the disconnected link in the transmission path, and adding the destination node in the given modulation format group to the transmission path under the transmission length restriction condition;

[0017] A method of adding a destination node in a given modulation format group to the end of a transmission path, obtaining the shortest path from the destination node at the end of the transmission path to the destination node in a given modulation format group, and adding the destination node in a given modulation format group to the transmission path under the transmission length restriction condition;

[0018] The destination node is added in a manner with the shortest increase in path length by selecting the manner in which the destination node in a given modulation format group is added in the middle of the transmission path and the manner in which the destination node in a given modulation format group is added at the end of the transmission path.

[0019] Preferably, the method for optimizing the existing transmission light track by using a node deletion algorithm after creating a new transmission light track includes:

[0020] When checking that the terminal destination node in the existing transmission optical track is covered by the newly created transmission optical track, the terminal destination node of the existing transmission optical track is deleted; repeatedly checking and deleting the terminal destination node of the existing transmission optical track until the terminal destination node in the existing transmission optical track is not covered by the new transmission optical track;

[0021] Recheck whether the terminal destination node in the existing transmission optical track is covered by other transmission optical tracks, select the terminal destination node of the transmission optical track for deletion with the purpose of saving the most spectrum resources, and repeatedly check and delete the terminal destination node of each transmission optical track until the terminal destination node in the existing transmission optical track is not covered by other transmission optical tracks, and terminate the inspection.

[0022] Preferably, the allocation method further includes: when the newly created transmission optical track under a given modulation format exceeds the set transmission distance, lowering the modulation format requirement of the destination node, and adding the shared transmission optical track of the destination nodes in each order modulation format group of the transmission path after re-establishing the transmission optical track.

[0023] A second aspect of the present invention provides a system for allocating optical track elastic optical track network resources, comprising:

[0024] A modeling module, configured to obtain service parameters of a current multicast service upon receiving a routing spectrum allocation request for the multicast service;

[0025] A class grouping module, which groups the destination nodes according to the class of the modulation format according to the resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network;

[0026] A transmission optical track establishment module is used to search for a transmission path from a source node to a destination node of a low-order modulation format to build a transmission optical track, add destination nodes in each order modulation format group to share the transmission optical track, cyclically add the destination node with the shortest path length increase to share the transmission optical track, and repeatedly establish multiple transmission optical tracks;

[0027] The transmission light track optimization module is used to optimize the existing transmission light track through the node deletion algorithm after the new transmission light track is created;

[0028] The network resource allocation module allocates the route and spectrum resources of each link of the transmission optical track established according to the service request, and the destination node shares the transmission optical track.

[0029] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for allocating optical track elastic optical track network resources.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention searches for a transmission path from a source node to a destination node of a low-order modulation format to construct a transmission optical track, adds destination nodes in each order modulation format group to share the transmission optical track, cyclically adds destination nodes with the shortest path length increase to share the transmission optical track, and repeatedly establishes multiple transmission optical tracks; allocates routes and spectrum resources of each link thereof according to the service request of the established transmission optical track, realizes sharing of the transmission optical track, avoids the destination node from occupying too many resources when adding multiple optical tracks, improves the network resource utilization of the elastic optical network, and reduces the spectrum consumption of the elastic optical network.

[0032] In the present invention, after a new transmission optical track is created, the existing transmission optical track is optimized by a node deletion algorithm. When checking whether the terminal destination node in the existing transmission optical track is covered by the newly created transmission optical track, the terminal destination node of the existing transmission optical track is deleted; the terminal destination node of the existing transmission optical track is repeatedly checked and deleted until the terminal destination node in the existing transmission optical track is not covered by the new transmission optical track; recheck whether the terminal destination node in the existing transmission optical track is covered by other transmission optical tracks, select the terminal destination node of the transmission optical track for deletion with the purpose of saving spectrum resources as much as possible, and repeatedly check and delete the terminal destination node of each transmission optical track until the inspection is terminated when the terminal destination node in the existing transmission optical track is not covered by other transmission optical tracks; by deleting the terminal destination node, the network resources of the elastic optical network (EON) are saved to the maximum extent, and the utilization rate of network resources is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural diagram of a light track elastic light track network resource allocation system provided by an embodiment of the present invention;

[0034] Figure 2 The present invention is a flowchart of a method for allocating elastic optical track network resources provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0036] Embodiment 1

[0037] like Figure 1 As shown, a method for allocating elastic optical track network resources includes:

[0038] After receiving a routing spectrum allocation request for a multicast service, obtaining service parameters of the current multicast service;

[0039] According to resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network, the destination nodes are grouped according to the class of the modulation format;

[0040] The transmission path from the source node to the destination node of the low-order modulation format is searched to construct a transmission optical track. The method includes: finding the shortest transmission path from the path source node to each destination node of the low-order modulation format, recording the transmission node sequence N and the path sequence P in each transmission path; and selecting the transmission path covering the most destination nodes to construct the transmission optical track.

[0041] The priority order of adding destination nodes in a transmission path is from the destination nodes of a low-order to a high-order modulation format; the method of adding a transmission path to share a transmission optical track of a destination node in a given modulation format group includes:

[0042] A method of adding a destination node in a given modulation format group in the middle of a transmission path, disconnecting the links between the destination nodes on the transmission path, obtaining the shortest path from the destination node in the given modulation format group of the transmission path to the destination nodes at both ends of the disconnected link in the transmission path, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition;

[0043] A method of adding a destination node in a given modulation format group to the end of a transmission path, obtaining the shortest path from the destination node at the end of the transmission path to the destination node in a given modulation format group, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition;

[0044] The destination node is added in a manner with the shortest increase in path length by selecting the manner in which the destination node in a given modulation format group is added in the middle of the transmission path and the manner in which the destination node in a given modulation format group is added at the end of the transmission path.

[0045] The destination node with the shortest path length increase is added cyclically to share the transmission optical track; multiple transmission optical tracks are repeatedly established, and the existing transmission optical tracks are optimized through the node deletion algorithm after the new transmission optical track is established. When the newly built transmission optical track exceeds the set transmission distance under a given modulation format, the modulation format requirement of the destination node is lowered, and after the transmission optical track is re-established, the destination nodes in the modulation format groups of each order of the transmission path are added to share the transmission optical track.

[0046] The method of optimizing the existing transmission light track by using the node deletion algorithm after the transmission light track is newly created includes:

[0047] When checking that the terminal destination node in the existing transmission optical track is covered by the newly created transmission optical track, the terminal destination node of the existing transmission optical track is deleted; repeatedly checking and deleting the terminal destination node of the existing transmission optical track until the terminal destination node in the existing transmission optical track is not covered by the new transmission optical track;

[0048] Recheck whether the terminal destination node in the existing transmission optical track is covered by other transmission optical tracks, select the terminal destination node of the transmission optical track for deletion with the purpose of saving the most spectrum resources, and repeatedly check and delete the terminal destination node of each transmission optical track until the terminal destination node in the existing transmission optical track is not covered by other transmission optical tracks, and terminate the inspection.

[0049] Deleting the destination node at the end of the existing transmission light track will create spectrum holes, making the spectrum more dispersed. In order to provide a large number of continuous idle frequency slots to better accommodate future requests, we repeatedly try to drag the transmission light track to fill the newly released spectrum.

[0050] The transmission optical track established according to the service request is allocated with a route and spectrum resources of each link thereof, and the destination node shares the transmission optical track.

[0051] This implementation provides a specific algorithm example, such as Figure 2 As shown in , the process of deleting some destination nodes and filling spectrum holes is shown. Figure 2 A portion of the network resource utilization shown in a is assumed to accommodate multicast requests <A; {B,C,D,E,F}. First, a transmission optical track T1:AECB is found, such as Figure 2 b. Then find the second transmission optical track T2:ABD, as shown in Figure 2 As shown in Fig. 3, this new transmission track covers a destination node, namely, node B, which is the end node of the previous transmission track. Therefore, MTD is performed on the previous transmission track. Node B and the associated link CB are deleted from the transmission track T1, and the new transmission track end node C is not deleted. Here, the modified transmission track T1' is AEC. Since the transmission track is shorter, the transmission track can use a more spectrally efficient modulation format, thereby using less spectrum, such as Figure 2 d. Afterwards, another new transmission optical track aimed at adding destination node F is found to be T3:ABDF, as shown in Figure 2 As shown in e. Then, MTD is performed on the transmission light tracks T1' and T2. T3 does not cover the destination node of T1', so the node of T1' cannot be deleted. Since all its destination nodes (i.e. B and D) are covered by T3, the transmission light track T2 is completely deleted to T2'. Then check again whether T1' and T2' are likely to be deleted. For T1', the transmission light track end node C does not exist in all other transmission light tracks, i.e. T2' and T3, so deletion is not performed. Since T2' does not cover the destination node, deletion cannot be performed on it.

[0052] After removing a link from the transmission light track and releasing the associated frequency slot, a connection using FS can be dragged behind it to fill the gap. The final result of the algorithm is shown in Figure 2f. It requires two optical paths, a total of 8 frequency slots and 2 transmitters. Figure 2 g shows the result of not performing the specific destination node deletion. It requires 3 transmission optical tracks, a total of 16 frequency slots and 3 transmitters. In this example, deleting some nodes and associated links in multiple transmission optical tracks and filling the spectrum gaps helps save 1 transmitter and 8 frequency slots.

[0053] In order to obtain better performance, a multi-iteration process is adopted, in which multiple random sequences of requests are considered and the best result among the results generated by the sequence is selected as the final result. The more sequences we consider, the better performance the algorithm can achieve. In order to reduce the computation time caused by multiple iterations, techniques such as parallel computing can be utilized, in which each sequence is processed by a machine. This multi-iteration method can achieve a time requirement close to that of a single iteration; the service request is allocated to the routing and the spectrum resources of each link according to the transmission optical track established by the final result, so as to realize the sharing of the transmission optical track.

[0054] Embodiment 2

[0055] like Figure 2 As shown, a distribution system of optical track elastic optical track network resources, the distribution system provided in this embodiment can be applied to the distribution system described in Example 1, and the distribution system includes:

[0056] A modeling module, configured to obtain service parameters of a current multicast service upon receiving a routing spectrum allocation request for the multicast service;

[0057] A class grouping module, which groups the destination nodes according to the class of the modulation format according to the resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network;

[0058] A transmission optical track establishment module is used to search for a transmission path from a source node to a destination node of a low-order modulation format to build a transmission optical track, add destination nodes in each order modulation format group to share the transmission optical track, cyclically add the destination node with the shortest path length increase to share the transmission optical track, and repeatedly establish multiple transmission optical tracks;

[0059] The transmission light track optimization module is used to optimize the existing transmission light track through the node deletion algorithm after the new transmission light track is created;

[0060] The network resource allocation module allocates the route and spectrum resources of each link of the transmission optical track established according to the service request, and the destination node shares the transmission optical track.

[0061] Embodiment 3

[0062] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method for allocating optical track elastic optical track network resources described in Example 1 are implemented.

[0063] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0064] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0065] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0066] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for allocating elastic optical track network resources, characterized in that: include: After receiving a routing spectrum allocation request for a multicast service, obtaining service parameters of the current multicast service; According to resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network, the destination nodes are grouped according to the class of the modulation format; Searching for the transmission path from the source node to the destination node of the low-order modulation format to build a transmission optical track, adding the destination nodes in each order modulation format group to share the transmission optical track, specifically including: A method of adding a destination node in a given modulation format group in the middle of a transmission path; disconnecting the links between the destination nodes on the transmission path, obtaining the shortest path from the destination node in the given modulation format group of the transmission path to the destination nodes at both ends of the disconnected link in the transmission path, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition; A method of adding a destination node in a given modulation format group to the end of a transmission path; obtaining the shortest path from the destination node at the end of the transmission path to the destination node in a given modulation format group, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition; The destination node is added in a manner with the shortest path length increase from the manner of adding the destination node in a given modulation format group in the middle of the transmission path and the manner of adding the destination node in a given modulation format group at the end of the transmission path; the priority order of adding the destination node in the transmission path is from the destination node of the low order modulation format to the high order modulation format; Circularly add the destination node with the shortest path length growth to share the transmission light track; repeatedly establish multiple transmission light tracks; After the new transmission light track is created, the existing transmission light track is optimized through the node deletion algorithm, including: When checking that the terminal destination node in the existing transmission optical track is covered by the newly created transmission optical track, the terminal destination node of the existing transmission optical track is deleted; repeatedly checking and deleting the terminal destination node of the existing transmission optical track until the terminal destination node in the existing transmission optical track is not covered by the new transmission optical track; Recheck whether the terminal destination node in the existing transmission optical track is covered by other transmission optical tracks, select the terminal destination node of the transmission optical track for deletion for the purpose of saving spectrum resources as much as possible, and repeatedly check and delete the terminal destination node of each transmission optical track until the terminal destination node in the existing transmission optical track is not covered by other transmission optical tracks, and terminate the inspection; The transmission optical track established according to the service request is allocated with a route and spectrum resources of each link thereof, and the destination node shares the transmission optical track.

2. The method for allocating elastic optical track network resources according to claim 1, characterized in that: Searching for a transmission path from a source node to a destination node of a low-order modulation format, the method comprising: Search for the shortest transmission path from the path source node to each destination node of the low-order modulation format, record the transmission node sequence N and path sequence P in each transmission path; select the transmission path that covers the most destination nodes.

3. The method for allocating elastic optical track network resources according to claim 1, characterized in that: Allocation methods also include: When the newly created transmission optical track under a given modulation format exceeds the set transmission distance, the modulation format requirement of the destination node is lowered, and after the transmission optical track is re-established, the destination node shared transmission optical track in each order modulation format group of the transmission path is added.

4. A system for allocating elastic optical track network resources, characterized in that: include: A modeling module, configured to obtain service parameters of a current multicast service upon receiving a routing spectrum allocation request for the multicast service; A class grouping module, which groups the destination nodes according to the class of the modulation format according to the resource configuration information and service requests in each destination node of the multicast service in the elastic optical track network; The transmission optical track establishment module is used to search for the transmission path from the source node to the destination node of the low-order modulation format to build the transmission optical track, add the destination nodes in each order modulation format group to share the transmission optical track, cyclically add the destination node with the shortest path length growth to share the transmission optical track, and repeatedly establish multiple transmission optical tracks; The transmission light track optimization module is used to optimize the existing transmission light track through the node deletion algorithm after the new transmission light track is created; A network resource allocation module allocates routes and spectrum resources of each link of the transmission optical track established according to the service request, and the destination node shares the transmission optical track; The transmission optical track establishment module adds the destination node shared transmission optical track in each order modulation format group, specifically including: A method of adding a destination node in a given modulation format group in the middle of a transmission path; disconnecting the links between the destination nodes on the transmission path, obtaining the shortest path from the destination node in the given modulation format group of the transmission path to the destination nodes at both ends of the disconnected link in the transmission path, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition; A method of adding a destination node in a given modulation format group to the end of a transmission path; obtaining the shortest path from the destination node at the end of the transmission path to the destination node in a given modulation format group, and adding the destination nodes in each order modulation format group to the transmission path under the transmission length restriction condition; The destination node is added in a manner with the shortest path length increase from the manner of adding the destination node in a given modulation format group in the middle of the transmission path and the manner of adding the destination node in a given modulation format group at the end of the transmission path; the priority order of adding the destination node in the transmission path is from the destination node of the low order modulation format to the high order modulation format; The transmission light track optimization module optimizes the existing transmission light track through a node deletion algorithm after creating a new transmission light track, specifically including: When checking that the terminal destination node in the existing transmission optical track is covered by the newly created transmission optical track, the terminal destination node of the existing transmission optical track is deleted; repeatedly checking and deleting the terminal destination node of the existing transmission optical track until the terminal destination node in the existing transmission optical track is not covered by the new transmission optical track; Recheck whether the terminal destination node in the existing transmission optical track is covered by other transmission optical tracks, select the terminal destination node of the transmission optical track for deletion with the purpose of saving the most spectrum resources, and repeatedly check and delete the terminal destination node of each transmission optical track until the terminal destination node in the existing transmission optical track is not covered by other transmission optical tracks, and terminate the inspection.

5. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for allocating elastic light track network resources as described in any one of claims 1 to 3.

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