Control device, control method, and program

Abstract

A control device 1 includes a control unit 11 that, in a case in which resource requirements of a cell including at least one slice exceeds resource availability of the cell, extracts a terminal that can be handed over to another cell in an overlay relationship, from among terminals connected to each slice, and a terminal management unit 12 that causes the terminal that can be handed over, to be handed over to the other cell. The control unit 11 determines resource allocations of each slice of the cell on the basis of resource requirements of each slice of the cell after the handover.

Description

Control Device, Control Method, and Program

[0001] The present disclosure relates to a control device, a control method, and a program.

[0002] Services provided by 5G RAN are diversified, and the quality requirements for each service, such as high capacity and low latency, are different. Therefore, in order to provide various services on the network, the network may be virtually divided into a plurality of slices.

[0003] In order to realize the communication quality required by each service, the required amount of resources to be allocated to each slice varies depending on the communication situation, such as the number of terminals connected to the slice. The amount of resource allocation assigned to each slice in the cell is determined based on the required amount of resources.

[0004] Patent Document 1 describes a technique for allocating resources to each slice.

[0005] Japanese Patent Application Laid-Open No. 2023-68145

[0006] Mobile network operators are considering two types of slice provision forms: slices that can be used over a wide area such as the whole country according to the service provision range, and slices that can be used only in some spot-limited areas.

[0007] In Patent Document 1, on the premise that the total required amount of resources for each slice constituting the cell is less than or equal to the resource holding amount of the cell, resources allocated to each slice within one cell are distributed. Therefore, in Patent Document 1, when the total required amount of resources required by each slice exceeds the resource holding amount within the cell, a slice that cannot secure the required amount of resources will occur. Due to resource shortage, in a slice that cannot secure the required amount of resources, the communication quality of the terminal deteriorates.

[0008] The present disclosure has been made in view of the above circumstances, and the object of the present disclosure is to provide a technology capable of preventing a deterioration in communication quality even when the total required amount of resources required by each slice in the cell exceeds the resource holding amount of the cell.

[0009] To achieve the above objective, one aspect of the present disclosure is a control device comprising: a control unit that, when the resource requirement of a cell containing at least one slice exceeds the resource capacity of the cell, extracts terminals from among the terminals connected to each slice that can be handed over to other cells in an overlay relationship; and a terminal management unit that handed over the handed-over terminals to the other cells, wherein the control unit determines the resource allocation amount for each slice of the cell based on the resource requirement of each slice of the cell after the handover.

[0010] One aspect of the present disclosure is a control method performed by a control device, wherein if the resource requirement of a cell containing at least one slice exceeds the resource capacity of the cell, terminals that can be handed over to other cells in an overlay relationship are extracted from among the terminals connected to each slice, the handed-over-capable terminals are handed over to the other cells, and the resource allocation amount for each slice of the cell is determined based on the resource requirement of each slice of the cell after the handover.

[0011] One aspect of the present disclosure is a program in which, when the resource requirements of a cell containing at least one slice exceed the resource capacity of the cell, a computer functions as a control unit that extracts terminals that can be handed over to other cells in an overlay relationship from among the terminals connected to each slice, and a terminal management unit that handed over the handed-over terminals to the other cells, wherein the control unit determines the resource allocation amount for each slice of the cell based on the resource requirements of each slice of the cell after the handover.

[0012] According to this disclosure, it is possible to provide a technology that can prevent a decrease in communication quality even when the total amount of resources required by each slice within a cell exceeds the resource capacity of the cell.

[0013] Figure 1 shows an example of the configuration of the network system of this embodiment. Figure 2 shows an example of cell information. Figure 3 is an explanatory diagram for explaining an example of the control device's processing (procedure 1). Figure 4 is an explanatory diagram for explaining an example of the control device's processing (procedures 2 to 5). Figure 5 is an explanatory diagram for explaining an example of the control device's processing (procedure 6). Figure 6 shows the resource requirements and resource allocation amounts in Figures 3 to 5. Figure 7 is an explanatory diagram for explaining an example of the control device's processing (procedures 7 and 8). Figure 8 is an explanatory diagram for explaining an example of the control device's processing (procedure 9). Figure 9A is a flowchart (part 1) showing the control device's processing. Figure 9B is a flowchart (part 2) showing the control device's processing. Figure 9C is a flowchart (part 3) showing the control device's processing. Figure 10 is an example of the hardware configuration.

[0014] The embodiments of this disclosure will be described below with reference to the drawings.

[0015] Figure 1 shows an example of the configuration of the network system of this embodiment. The illustrated network system comprises base stations 3A and 3B located in the RAN (Radio Access Network), a core network 7, at least one service provider 81 or 82, a RAN management device 2, and a control device 1 (resource allocation device).

[0016] The RAN is a network located between the core network 7 and the terminal 6, and includes base stations 3A and 3B. Base stations 3A and 3B control the radio layer and communicate wirelessly with the terminal 6. Each base station 3A and 3B has at least one cell S under its control. A cell S represents the coverage area (communication area) covered by base stations 3A and 3B. In the illustrated example, four cells S (cells 1 to 4) and the coverage area U of each cell S are shown.

[0017] For example, two cells S (cell 1 and cell 2) are configured under base station 3A. Cell 1 consists of multiple slices T (slice 1 and slice 2), and multiple terminals 6 exist within the coverage area of ​​cell 1. Cell 2, similar to cell 1, consists of multiple slices T (slice 1 and slice 2), and multiple terminals 6 exist within the coverage area of ​​cell 2.

[0018] Under base station 3B, two cells S (cell 3 and cell 4) are configured. Cell 3 consists of one slice T (slice 1), and multiple terminals 6 exist within the coverage area of ​​cell 3. Cell 4 consists of one slice T (slice 1), and one terminal 6 exists within the coverage area of ​​cell 4.

[0019] In this embodiment, the physical network is virtually divided (sliced), and each cell S is configured using a slice T. In the illustrated example, slice 1 is a slice of service provider 81 that provides service A, and slice 2 is a slice of service provider 82 that provides service B.

[0020] For example, slice 1 may be a widely available slice, and could be a service slice for companies with branches nationwide. Slice 2 may be a slice that is only available on a limited, spot basis, and could be a service slice for companies with branches only in certain regions. The number of cells containing each slice also varies depending on the scope of service provision; for example, slice 1, which is widely available, may have many cells containing slice 1, while slice 2, which is only available on a limited, spot basis, may have fewer cells containing slice 2.

[0021] Cells S whose coverage ranges U overlap are called cells S in an overlay relationship. Terminals 6 located in the area where the coverage ranges U overlap can connect to any cell S among the cells S in an overlay relationship. In this embodiment, if a resource shortage occurs within one cell S, the terminal 6 can be reconnected to another cell S in an overlay relationship to reduce the resource requirements within the cell S and avoid resource shortages.

[0022] In the example shown in Figure 1, the other cell that has an overlay relationship with cell 1 is cell 2. The other cells that have an overlay relationship with cell 2 are cell 1 and cell 3. The other cells that have an overlay relationship with cell 3 are cell 2 and cell 4. The other cell that has an overlay relationship with cell 4 is cell 3.

[0023] The RAN management device 2 controls base stations 3A and 3B and generates slice T. The service provision devices 81 and 82 provide services to terminal 6 via the core network 7 and base stations 3A and 3B.

[0024] The control device 1 comprises a control unit 11, a terminal management unit 12, and a storage unit 13.

[0025] The control unit 11, when the resource requirement of a cell S containing at least one slice T exceeds the resource capacity of the cell S, extracts terminals 6 connected to each slice T that can be handed over to other cells S in an overlay relationship. The control unit 11 may also obtain the resource capacity of each cell S, the resource requirement of each slice T of each cell S, the resource surplus of each cell S, etc., from the RAN management device 2.

[0026] The terminal management unit 12 hands over a handover-capable terminal 6 to another cell S in an overlay relationship. The terminal management unit 12 may hand over terminals 6 from one cell S to another cell S in order starting with the slice T that has the most other cell S. The terminal management unit 12 may also hand over the handover-capable terminals 6 to other cell S in order starting with the other cell S that has the most surplus resources.

[0027] The control unit 11 determines the resource allocation amount for each slice T of cell S based on the resource requirements of each slice T of cell S after the handover. The control unit 11 may also determine the resource allocation amount for each slice T of the other cell S based on the resource requirements of each slice T of the other cell S after the handover.

[0028] The terminal management unit 12 may, after handing over all the handover-capable terminals 6 to the other cell S, hand over the terminals 6 that were handed over to the other cell S again to the cell S if the resource requirements of the cell S exceed the resource capacity of the cell S. The control unit 11 may determine the resource allocation amount for each slice T of the cell S based on the resource requirements of each slice T of the cell S after the second handover and the resource capacity of the cell S.

[0029] The memory unit 13 stores cell information related to each cell S.

[0030] Figure 2 shows an example of cell information. The cell information shown is a table in which latitude, longitude, antenna length, antenna orientation, power transmission power, etc. are stored for each cell S. The control unit 11 can obtain other cells that are in an overlay relationship with each cell S by referring to the cell information in the storage unit 13.

[0031] In the illustrated example, the control device 1 is a separate device from the RAN management device 2, but the RAN management device 2 and the control device 1 may be integrated into a single device. For example, the RAN management device 2 may implement each of the functions of the control device 1.

[0032] Next, the processing of the control device 1 in this embodiment will be described.

[0033] Figures 3 to 8 are explanatory diagrams illustrating specific examples of the processing performed by the control device 1.

[0034] Figure 3 shows that a new terminal 61 is connected to slice 2 of cell 2, increasing the resource requirements of slice 2, which in turn causes the resource requirements in cell 2 to exceed the resource capacity of cell 2. In the illustrated example, the resource requirements of slice 1 are 60% of the resource capacity of cell 2, and the resource requirements of slice 2 are 50% of the resource capacity of cell 2, resulting in a total resource requirement of cell 2 of 110% of the resource capacity of cell 2.

[0035] In this case, in step 1, the control unit 11 determines that the resource requirement of cell 2 exceeds the resource capacity of cell 2.

[0036] In Figure 4, in step 2, the control unit 11 counts the number of other cells in an overlay relationship for each slice 1 and 2 of cell 2. In the illustrated example, slice 1 has two other cells in an overlay relationship (cells 1 and 3), and slice 2 has one other cell (cell 1). Then, the control unit 11 performs step 3 in order, starting with slice 1, which has the most other cells.

[0037] In step 3, the control unit 11 calculates the amount of surplus resources for each other cell in the overlay relationship of slice 1. In the illustrated example, the amount of surplus resources for cell 1 is assumed to be 30%, and the amount of surplus resources for cell 3 is assumed to be 70%.

[0038] In step 4, the terminal management unit 12 determines whether there are any terminals that can be handed over from cell 2 to cell 3, which has the largest amount of surplus resources. In the illustrated example, the terminal management unit 12 determines that terminal 62, which is located in the area where cell 2 and cell 3 overlap, is a terminal that can be handed over.

[0039] In step 5, the terminal management unit 12 hands over terminals 62 that can be handed over from cell 2 to cell 3, provided that the resource requirements of cell 3 do not exceed the resource capacity of cell 3.

[0040] In Figure 5, in step 6, the control unit 11 determines the resource allocation amount for each slice of cell 2 and 3 based on the resource requirements of each slice of cell 2 and 3. In the illustrated example, because the terminal 62 was handed over from cell 2 to cell 3 in step 5, the resource requirement for slice 1 of cell 2 decreased from 60% to 50%, and the total resource requirement for slices 1 and 2 became 100%. As a result, the control unit 11 can allocate the same amount of resources to the resource allocation amounts of slices 1 and 2 of cell 2 as the resource requirement.

[0041] On the other hand, in Cell 3, since the resource requirement of Slice 1 in Cell 3 increased from 30% to 40% due to the handover of Terminal 62 from Cell 2 to Cell 3, the control unit 11 allocates 40% (40% of the resource holding amount), which is the same amount as the resource requirement, to the resource equivalent of Slice 1 in Cell 3.

[0042] FIG. 6 is a diagram showing the resource requirement and resource equivalent of each slice of Cells 2 and 3 before and after the execution of the processing of the control device 1 in FIGS. 3 to 5.

[0043] As shown in the figure, when the resource requirement of Cell 2 exceeds the resource holding amount of Cell 2, the resource requirement is dispersed to Cell 3 in an overlay relationship. That is, the amount of resources lacking in Cell 2 is filled with the surplus resources of Cell 3.

[0044] Thus, in the present embodiment, when a new terminal is connected to a slice, when the amount of resources used by the terminal increases, etc., when the resource requirement within the cell exceeds the resource holding amount held by the cell, by handing over the possible terminals to other cells in an overlay relationship, it is possible to prevent the communication quality of the terminals from deteriorating.

[0045] FIG. 7 is a diagram for explaining the processing when the resource requirement of Cell 2 does not become less than or equal to the resource holding amount (100% or less) even when using all the surplus resources of all other cells in an overlay relationship. Specifically, when the resource requirement of Cell 2 does not become less than or equal to the resource holding amount even when handing over the terminals 62 and 63 that can be handed over in the above-described step 5 to other cells, the control device executes the following steps 7 and 8.

[0046] In step 7, the terminal management unit 12 hands over the terminals 62 and 63 that have been handed over to other Cells 1 and 3 in an overlay relationship with Cell 2 back to Cell 2 again.

[0047] In step 8, the control unit 11 allocates the resource holding amount of cell 2 to slices 1 and 2 as the resource amounts allocated by dividing the resource holding amount of cell 2 by the resource required amounts of slices 1 and 2 of cell 2. In the example shown in FIG. 7, the resource required amount of slice 1 is 60%, and the resource required amount of slice 2 is 50%. In this case, the control unit 11 sets the resource allocation amount of slice 1 to 54% of the resource holding amount and the resource allocation amount of slice 2 to 45% of the resource holding amount.

[0048] FIG. 8 is a diagram for explaining the case where the total of the resource required amounts of slices 1 and 2 of cell 2 is less than or equal to the resource holding amount held by cell 2.

[0049] In step 9, the control unit 11 determines the resource allocation amounts that satisfy the resource required amounts of slices 1 and 2 and ends the resource allocation. In the illustrated example, the total of the resource required amounts of slices 1 and 2 (50% + 40%) ≤ the resource holding amount of cell 2 (100%). Therefore, the control unit 11 allocates the resource allocation amounts that satisfy the resource required amounts of slices 1 and 2. For example, the control unit 11 allocates resources equal to or more than the resource required amount to each slice. Here, the control unit 11 sets the resource allocation amount of slice 1 to 50% of the resource holding amount and the resource allocation amount of slice 2 to 40%.

[0050] FIGS. 9A, 9B, and 9C are flowcharts showing the processing of the aforementioned control device 1. The control device 1 shall perform the processing of FIGS. 9A, 9B, and 9C for each cell at a predetermined timing.

[0051] In FIG. 9A, the control unit 11 determines whether the resource required amount of the target cell (hereinafter, "target cell") exceeds the resource holding amount held by the target cell (S11).

[0052] When the resource required amount of the target cell is less than or equal to the resource holding amount (S11: NO), the process proceeds to FIG. 9C, and the control unit 11 determines the resource allocation amounts that satisfy the resource required amounts of each slice, allocates the determined resources to each slice, and ends the process (S24).

[0053] Returning to Figure 9A, if the resource requirement of the target cell exceeds the available resources (S11: YES), the control unit 11 counts the number of other cells in an overlay relationship (hereinafter referred to as "other cells") for each slice of the target cell (S12). Then, the control unit 11 sets i=1 (S13) and performs the processing from S14 onwards, starting with the slice that has the i-th number of other cells.

[0054] If there is a slice with the i-th largest number of other cells (S14: YES), the control unit 11 calculates the amount of surplus resources for each of the other cells in that i-th slice (S15).

[0055] The terminal management unit 12, with j=1 (S16), performs the processing from S17 onwards, starting with the cell with the j-th largest amount of surplus resources, until the resource requirement of the target cell becomes less than or equal to the resource amount held. If there is a cell with the j-th largest amount of surplus resources (S17: YES), the control unit 11 extracts (determines) a terminal that can be handed over from the target cell to the other cell at that j-th position (S18).

[0056] The terminal management unit 12 hands over a terminal that is eligible for handover to the j-th other cell from the target cell (S19). The terminal management unit 12 performs the handover within the limits of not exceeding the amount of surplus resources in the j-th other cell to which the handover is to be performed.

[0057] After the handover in S19, the control unit 11 determines whether the resource requirement of the target cell has become less than or equal to the resource capacity of the target cell (S20). If the resource requirement has become less than or equal to the resource capacity (S20: YES), the control unit 11 determines and allocates the resource allocation amount for each slice of the target cell and the j-th other cell based on the resource requirement of each slice of the target cell and the j-th other cell (S21).

[0058] If the required resource amount exceeds the available resource amount (S20: NO), the control unit 11 sets j = j + 1 (S23), returns to S17, and then repeats the subsequent processing for the j-th cell which has the largest amount of surplus resources.

[0059] If there is no cell with the j-th largest amount of surplus resources, that is, if all other cells have been processed (S17: NO), the control unit 11 sets i = i + 1 (S22), returns to S14, and repeats the subsequent processing for the i-th slice which has the next largest number of other cells in an overlay relationship.

[0060] If there is no slice with the i-th largest number of other cells, that is, if all slices of the target cell have been processed (S14: NO), the process proceeds to Figure 9B, where the terminal management unit 12 hands over the terminal that was handed over in S19 to the target cell again (S25). Then, the control unit 11 determines the resource amount obtained by dividing the resource amount held by the target cell by the resource requirements of each slice of the target cell, assigns the determined resource amount to each slice, and terminates the process (S26).

[0061] The control device 1 of this embodiment, as described above, includes a control unit 11 that, when the resource requirement of a cell containing at least one slice exceeds the resource capacity of the cell, extracts terminals that can be handed over to other cells in an overlay relationship from among the terminals connected to each slice, and a terminal management unit 12 that handed over the handover-capable terminals to the other cells. The control unit 11 determines the resource allocation amount for each slice of the cell based on the resource requirement of each slice of the cell after the handover.

[0062] According to this embodiment, even if the total amount of resources required by each slice within a cell exceeds the cell's resource capacity, a decrease in communication quality can be prevented.

[0063] Specifically, in this embodiment, when a cell experiences a resource shortage, the resource allocation for each slice is determined by considering the status of other cells that are in an overlay relationship with that cell. This allows the resource requirements within a cell to be reduced and resource shortages to be avoided by reconnecting terminals to other cells in an overlay relationship when resources become insufficient within a cell. Therefore, in this embodiment, it is possible to prevent a deterioration in the communication quality of terminals when new terminals are connected to a slice or when the amount of resources used by terminals increases.

[0064] Furthermore, the terminal management unit 12 of this embodiment may hand over the handover-capable terminals to other cells in order starting from slices with a large number of other cells in an overlay relationship. Alternatively, the terminal management unit 12 of this embodiment may hand over the handover-capable terminals to other cells in order starting from other cells in an overlay relationship with a large amount of surplus resources. In this embodiment, when there are multiple other cells in an overlay relationship, the terminal 6 can be handed over to an appropriate other cell.

[0065] The control device 1 described above can use, for example, a general-purpose computer system as shown in Figure 10. The illustrated computer system includes a CPU (Central Processing Unit, processor) 901, memory 902, storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), communication device 904, input device 905, and output device 906. The memory 902 and storage 903 are storage devices. In this computer system, the functions of the control device 1 are realized when the CPU 901 executes a predetermined program loaded onto the memory 902.

[0066] The control device 1 may be implemented on one computer or on multiple computers. Alternatively, the control device 1 may be a virtual machine implemented on a computer. The program of the control device 1 can be stored on a computer-readable recording medium such as an HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc), or distributed over a network. A computer-readable recording medium is, for example, a non-transitory recording medium.

[0067] This disclosure is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence.

[0068] 1: Control device 11: Control unit 12: Terminal management unit 13: Memory unit 2: RAN management device 3A, 3B: Base station 6, 61, 62, 62: Terminal 7: Core network 81, 82: Service provision device S: Cell T: Slice U: Cell coverage area

Claims

1. A control device comprising: a control unit that, when the resource requirement of a cell containing at least one slice exceeds the resource capacity of the cell, extracts terminals from among the terminals connected to each slice that can be handed over to other cells in an overlay relationship; and a terminal management unit that handed over the handed-over terminals to the other cells, wherein the control unit determines the resource allocation amount for each slice of the cell based on the resource requirement of each slice of the cell after the handover.

2. The control device according to claim 1, wherein the terminal management unit hands over the handover-capable terminals from one cell to another, starting with the slices that have the most other cells.

3. The control device according to claim 1, wherein the terminal management unit hands over the handover-capable terminals to other cells in order, starting with the other cells that have the most surplus resources.

4. The control device according to claim 1, wherein the control unit determines the resource allocation amount for each slice of the other cell based on the resource requirements of each slice of the other cell after the handover.

5. The control device according to claim 1, wherein, after the terminal management unit has handed over all the handover-capable terminals to the other cell, if the resource requirements of the cell exceed the resource holdings of the cell, the terminals that were handed over to the other cell are handed over again to the cell, and the control unit determines the resource allocation amount for each slice of the cell based on the resource requirements of each slice of the cell after the second handover and the resource holdings of the cell.

6. A control method performed by a control device, wherein if the resource requirement of a cell containing at least one slice exceeds the resource capacity of the cell, the control device extracts terminals that can be handed over to other cells in an overlay relationship from among the terminals connected to each slice, handed over the handed-over terminals to the other cells, and determines the resource allocation amount for each slice of the cell based on the resource requirement of each slice of the cell after the handover.

7. A program which, when the resource requirements of a cell containing at least one slice exceed the resource capacity of the cell, includes a control unit that extracts terminals from among the terminals connected to each slice that can be handed over to other cells in an overlay relationship, and a terminal management unit that causes the computer to function as a terminal management unit to handed over the handed-over terminals to the other cells, and the control unit determines the resource allocation amount for each slice of the cell based on the resource requirements of each slice of the cell after the handover.

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