Base station control system, base station control method, base station control device and program

Abstract

The present invention provides a base station control system including a first base station the position of which is not determined and a base station control device. The base station control device includes: a clustering unit that when the position of an existing second base station to which multiple terminals are connected is fixed, repeats clustering for dividing the multiple terminals into clusters for each of the first base station and the second base station while changing the position of the first base station; a calculation unit that calculates the number of first terminals to be connected to the first base station and the number of second terminals to be connected to the second base station for each of multiple levels of transmission power of the first base station when the first base station is placed in a position at the time of completion of the clustering; and a selection unit that selects one of the levels of the transmission power of the first base station on the basis of the number of the first terminals and the number of the second terminals. With this configuration, the base station control device reduces the imbalance in the number of terminals connected to each base station.

Description

[Technical field]

[0001] The present invention relates to a base station control system, a base station control method, a base station control device, and a program. [Background technology]

[0002] If wireless base stations are evenly distributed throughout an area to efficiently ensure area coverage, it is possible that communication quality in a particular area may decline due to terminal congestion, obstruction, etc. In response to this, technology is being considered to dynamically distribute mobile base stations in areas where communication quality has declined to improve communication quality (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Takuto Arai, Daisuke Goto, Masashi Iwabuchi, Tatsuhiko Iwakuni, Kazuki Maruta, "Proposal of an Adaptive Mobile AP System to Improve Offload Efficiency," IEICE Technical Report, vol. 116, no. 46, RCS2016-43, pp. 107-112, May 2016. Summary of the Invention [Problem to be solved by the invention]

[0004] However, when dynamically deploying a mobile base station, if the received power from that mobile base station at each terminal becomes too high compared to other base stations, many terminals may autonomously connect to that mobile base station, resulting in excessive bias in terminal connections and a deterioration in communication quality.

[0005] Figure 1 is a diagram for explaining the problems with the conventional technology. Figure 1 explains an example in which two mobile base stations are installed in an environment with three existing base stations and 11 terminals. Figure 1 (1) shows the state before the mobile base stations are installed, and (2) shows the state after the mobile base stations are installed.

[0006] Before the mobile base station is deployed (1), there is one terminal connected to the existing base station on the far left, and five terminals are connected to each of the other two existing base stations. The dashed lines connecting each terminal to the existing base station indicate the connection relationship between the terminal and the existing base station. In this state, the two existing base stations are congested. Therefore, we aim to eliminate or alleviate the congestion by deploying one mobile base station for each of the two existing base stations.

[0007] In the conventional technology, the location of a mobile base station is calculated by clustering 10 terminals connected to one of two congested existing base stations. As a result, a mobile base station is installed, for example, as shown in (2). In (2), each cluster is shown by a curved frame line, and a mobile base station is installed at the center of gravity of each cluster.

[0008] In general wireless systems, when a terminal can receive signals from multiple base stations, it connects to the base station with the strongest reception power. Therefore, when mobile base stations are arranged as in (2), five terminals will connect to one mobile base station, and two terminals will connect to the other mobile base station. As a result, the congestion at the existing base station that was congested in (1) is eliminated, but congestion occurs at one of the mobile base stations. Thus, according to conventional technology, there is a possibility that excessive imbalance will occur in the number of terminals connected to each base station (existing base station or mobile base station).

[0009] The present invention has been made in consideration of the above-mentioned points, and has an object to reduce the imbalance in the number of terminals connected to each base station. [Means for solving the problem]

[0010] In order to solve the above problem, the present invention provides a base station control system including a first base station whose location has not been decided, and a base station control device, the base station control device having a clustering unit that fixes the location of an existing second base station to which a plurality of terminals are connected, and repeats clustering to divide the plurality of terminals into clusters each of the first base station and the second base station while changing the location of the first base station, a calculation unit that calculates, for a case in which the first base station is located at a location at the time when the clustering is completed, the number of first terminals connected to the first base station and the number of second terminals connected to the second base station for each of a plurality of transmission powers of the first base station, and a selection unit that selects the transmission power of the first base station based on the number of first terminals and the number of second terminals. Effect of the Invention

[0011] The imbalance in the number of terminals connected to each base station can be reduced. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram for explaining a problem with the conventional technology. [Diagram 2] 1 is a diagram illustrating an example of a configuration of a communication system 1 according to an embodiment of the present invention. [Diagram 3] 2 is a diagram illustrating an example of a hardware configuration of a control station 10 according to the embodiment of the present invention. [Figure 4] 2 is a diagram illustrating an example of a functional configuration of a control station 10 according to the embodiment of the present invention. [Diagram 5] 10 is a flowchart illustrating an example of a processing procedure executed by the control station 10. [Figure 6] 2 is a diagram showing a specific example of a connection state of a terminal 50 to an existing base station 30. FIG. [Figure 7] FIG. 13 is a diagram showing an example of a candidate pattern. [Figure 8] 13 is a diagram showing an example of a calculation result of an evaluation value X of each candidate pattern. FIG. [Figure 9]FIG. 13 is a diagram showing an example of a calculation result of an evaluation value Yi of each candidate pattern. [Figure 10] 11 is a flowchart illustrating an example of a procedure for a clustering process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 2 is a diagram showing an example of the configuration of a communication system in an embodiment of the present invention. As shown in Fig. 2, a communication system 1 includes one or more existing base stations 30, one or more mobile base stations 20, one or more relay base stations 40, a control station 10, etc. Note that a base station refers to a base station (access point) for wireless communication (for example, wireless LAN).

[0014] In this embodiment, the existing base station 30 is an already installed base station. In this embodiment, the existing base station 30 is not a target for movement, but the existing base station 30 may be movable.

[0015] The mobile base station 20 is a mobile base station, and in this embodiment, is a base station that is newly deployed (the deployment location has not been decided). For example, when communication is congested at an existing base station 30, the mobile base station 20 is dynamically deployed. The driving means for moving the mobile base station 20 is not limited to a specific one. For example, the driving means may be a vehicle or a drone. The mobile base station 20 may also be configured to move on rails that have been laid in advance.

[0016] The relay base station 40 is a base station that relays communication between the mobile base station 20 and the control station 10. The relay base station 40 is connected to the mobile base station 20 by wireless communication. Therefore, the mobile base station 20 is movable within a range where wireless communication with the relay base station 40 is possible.

[0017] In the following, when there is no need to distinguish between the existing base station 30 and the mobile base station 20, they are simply referred to as "base station." Although not shown in the figure, there are multiple terminals (hereinafter, terminals 50) that wirelessly connect to any of the base stations and communicate. Each terminal connects to any of the base stations through autonomous control. The autonomous control is, for example, a control in which a terminal connects to a base station with a relatively large reception power at the terminal.

[0018] The control station 10 is one or more computers that control the placement of the mobile base station 20 and the transmission power of the mobile base station 20. The control station 10 is connected to each existing base station 30 and each relay base station 40 via a network (whether wired or wireless). The control station 10 controls the placement of the mobile base station 20 and the transmission power of the mobile base station 20 based on information collected from each base station and terminal via the network.

[0019] Fig. 3 is a diagram showing an example of a hardware configuration of a control station 10 in an embodiment of the present invention. The control station 10 in Fig. 3 includes a drive device 100, an auxiliary storage device 102, a memory device 103, a CPU 104, and an interface device 105, which are all connected to each other via a bus B.

[0020] A program for implementing the processing in the control station 10 is provided by a recording medium 101 such as a CD-ROM. When the recording medium 101 storing the program is set in the drive device 100, the program is installed from the recording medium 101 to the auxiliary storage device 102 via the drive device 100. However, the program does not necessarily have to be installed from the recording medium 101, but may be downloaded from another computer via a network. The auxiliary storage device 102 stores the installed program as well as necessary files, data, and the like.

[0021] When an instruction to start a program is received, the memory device 103 reads out the program from the auxiliary storage device 102 and stores it. The CPU 104 executes functions related to the control station 10 in accordance with the program stored in the memory device 103. The interface device 105 is used as an interface for connecting to a network.

[0022] Fig. 4 is a diagram showing an example of a functional configuration of a control station 10 in an embodiment of the present invention. In Fig. 4, the control station 10 has a clustering unit 11, an arrangement unit 12, a generation unit 13, a calculation unit 14, a selection unit 15, and a setting unit 16. Each of these units is realized by a process in which one or more programs installed in the control station 10 are executed by a CPU 104.

[0023] The following describes the process steps executed by the control station 10. FIG 5 is a flowchart for explaining an example of the process steps executed by the control station 10.

[0024] In step S101, the clustering unit 11 selects an existing base station 30 (hereinafter referred to as a "target existing base station 30") as a target for installation of a movable base station 20 (a base station whose load is reduced by the movable base station 20) based on the number of connected terminals of each of the multiple existing base stations 30. For example, some existing base stations 30 in which terminal connections are relatively congested (the number of connected terminals is relatively large) are selected as the target existing base station 30. In this case, the clustering unit 11 judges whether the terminal connections of each existing base station 30 are congested. For example, the clustering unit 11 judges that an existing base station 30 in which the number of connected terminals 50 (the number of connected terminals) is equal to or greater than a predetermined threshold is congested.

[0025] 6 is a diagram showing a specific example of a connection state of a terminal 50 to an existing base station 30. In this embodiment, it is assumed that three existing base stations 30 are installed, and two movable base stations 20 are additionally installed in a state in which eleven terminals 50 are connected to any of the existing base stations 30. In addition, in the figure, the dashed lines connecting the terminals 50 and the existing base stations 30 indicate the connection relationship between the terminals 50 and the existing base stations 30 (which existing base station 30 the terminal 50 is connected to). Therefore, in the example of FIG. 6, the number of connected terminals of the existing base station 30-1 is 1, the number of connected terminals of the existing base station 30-2 is 5, and the number of connected terminals of the existing base station 30-3 is 5.

[0026] 6, if the threshold for determining whether the existing base station 30 is congested is 5, two existing base stations 30, the existing base station 30-2 and the existing base station 30-3, are determined to be congested. Therefore, these two existing base stations 30 are selected as the target existing base stations 30.

[0027] Alternatively, as another determination method, it may be determined that a base station is congested if the number of connected terminals is included in the top α% of all existing base stations 30, and that a base station is not congested if the number is not included in the top α% of all existing base stations 30. α is a parameter, and for example, when α=50, the top 50% of existing base stations 30 are in a congested state.

[0028] Alternatively, as another determination method, an existing base station 30 in which the number of connected terminals exceeds the average number of connected terminals of all the existing base stations 30 may be determined to be in a congested state.

[0029] Next, the clustering unit 11 executes clustering (non-hierarchical clustering (k-menas++ method)) on the terminals 50 connected to the target existing base station 30, thereby dividing the terminals 50 connected to the target existing base station 30 into (the number of target existing base stations+the number of movable base stations) clusters (one cluster for each target existing base station 30 and one cluster for each movable base station 20) (S102). At this time, the clustering unit 11 repeats clustering with the constraint that the position of the target existing base station 30 is fixed while changing the position of the movable base station 20, until the clustering result does not change. Details of step S102 will be described later.

[0030] Next, the placement unit 12 determines the position of each mobile base station 20 at the time when the clustering is completed as the placement position of each mobile base station 20, and performs control to place each mobile base station 20 at the placement position (S103). Specifically, the placement unit 12 transmits an instruction to each mobile base station 20 to move the mobile base station 20 to the placement position determined for that mobile base station 20. Each mobile base station 20 moves to the placement position specified in the instruction.

[0031] Once the deployment of each mobile base station 20 is complete, the generation unit 13 generates a plurality of different patterns for combinations of transmission power adjustment amounts for each mobile base station 20 (S104). Hereinafter, these patterns are referred to as "candidate patterns." Note that the transmission power adjustment amount refers to the amount of power reduction relative to the maximum transmission power. For example, since the transmission power that can be set varies depending on the country, in this embodiment, a relative value based on the maximum value is used. However, instead of the transmission power adjustment amount, the absolute value of the transmission power may form the candidate pattern.

[0032] Fig. 7 is a diagram showing an example of a candidate pattern. As shown in Fig. 7, in step S104, a candidate pattern number and a transmission power adjustment amount sequence are generated for each candidate pattern. The candidate pattern number is an identification number of the candidate pattern. The transmission power adjustment amount sequence is a combination of transmission power adjustment amounts for each mobile base station 20. For example, in [0,0] in Fig. 7, the first 0 indicates a transmission power adjustment amount for one mobile base station 20, and the second 0 indicates a transmission power adjustment amount for the other mobile base station 20.

[0033] Next, the calculation unit 14 calculates evaluation parameters for each candidate pattern based on the position of each base station, the position of each terminal 50 (each terminal 50 connected to any of the target base stations), the transmission power of each base station, etc. In this embodiment, the evaluation parameters are (a) the number of terminals connected to the existing base station, (b) the number of terminals connected to the movable base station 20, and (c) terminals that cannot be connected to a base station.

[0034] The (a) number of connected terminals of an existing base station in a certain candidate pattern refers to the number of terminals 50 connected to each target existing base station 30 when the transmission power adjustment amount of each mobile base station 20 is as per the candidate pattern.

[0035] The (b) number of connected terminals to a mobile base station 20 in a certain candidate pattern refers to the number of terminals 50 connected to each mobile base station 20 when the transmission power adjustment amount of each mobile base station 20 is as per the candidate pattern.

[0036] The (c) base station connection incapable terminal of a certain candidate pattern refers to a terminal 50 that is present in an area in which an existing base station 30 is located and that cannot connect to any of the movable base stations 20 and the target existing base station 30 when the transmission power adjustment amount of each movable base station 20 is as per the candidate pattern. The value of (c) is 0 when a terminal 50 that corresponds to a base station connection incapable terminal exists, and is 1 when a terminal 50 that corresponds to a base station connection incapable terminal does not exist.

[0037] For (a) and (b), the calculation unit 14 calculates the received power at each terminal 50 from the target existing base station 30 and the movable base station 20 based on the distance between each terminal 50 and each target existing base station 30 and each movable base station 20, and the respective transmission power of each target existing base station 30 and each movable base station 20, and calculates the number of connected terminals for each base station when the terminal 50 is connected to the base station with the highest received power.

[0038] Regarding (c), the calculation unit 14 determines as a judgment result whether or not there is a terminal 50 for which the maximum value of the received power calculated for each base station for each terminal 50 regarding (a) and (b) (the maximum value of the received power from each target existing base station 30 and the received power from each movable base station 20) is below a predetermined threshold value (required received power).

[0039] Next, the calculation unit 14 calculates an evaluation value X for each candidate pattern based on (a) to (c) (S106). Here, as an example, the product of (a), (b), and (c) ((a)×(b)×(c)) is calculated as the evaluation value X.

[0040] Fig. 8 is a diagram showing an example of the calculation result of the evaluation value X for each candidate pattern. Fig. 8 shows an example of the values ​​(a) to (c) and an example of the evaluation value X for each candidate pattern.

[0041] Next, the selection unit 15 judges whether there are multiple candidate patterns with the maximum evaluation value X (S107). If there is one candidate pattern with the maximum evaluation value X (N in S107), the selection unit 15 selects the candidate pattern (S108) and proceeds to step S116. Note that the candidate pattern with the maximum evaluation value X is a pattern with a small bias in the number of connected terminals between base stations and with no terminals that cannot connect to a base station, and therefore it is possible to identify a transmission power adjustment amount with a small bias in terminal connections for each mobile base station 20.

[0042] On the other hand, if there are multiple candidate patterns with the maximum evaluation value X (i.e., if a candidate pattern cannot be uniquely selected by the evaluation value X) (Y in S108), the selection unit 15 calculates (d) the minimum value of the received power of the existing base station connected terminal and (e) the minimum value of the received power of the movable base station connected terminal for each candidate pattern with the maximum evaluation value X, and sets the i-th (i=1, 2) value (i.e., the i-th smallest value) in ascending order of (d) and (e) as the evaluation value Yi of the candidate pattern (S109). Note that the existing base station connected terminal in a certain candidate pattern refers to a terminal 50 (a terminal 50 whose received power from the target existing base station 30 is greater than that from the movable base station 20) that connects to the target existing base station 30 when the transmission power adjustment amount of each movable base station 20 is as in the candidate pattern. Furthermore, a mobile base station connected terminal in a certain candidate pattern refers to a terminal 50 (a terminal 50 whose received power from the mobile base station 20 is greater than that from the target existing base station 30) that connects to the mobile base station 20 when the transmission power adjustment amount of each mobile base station 20 is as per the candidate pattern. Therefore, (d) the minimum value of received power of a terminal connected to an existing base station refers to the minimum value of the power of signals received from the existing base station 30 at each existing base station connected terminal. (e) The minimum value of received power of a terminal connected to a mobile base station refers to the minimum value of the power of signals received from the mobile base station 20 at each mobile base station connected terminal. The received power at the terminal 50 from each base station can be calculated based on the distance between each base station and the terminal 50 and the transmission power of each base station, etc.

[0043] Fig. 9 is a diagram showing an example of the calculation result of the evaluation value Yi of each candidate pattern. Fig. 9 further shows, for the candidate pattern with the maximum evaluation value X, (d) the minimum value of the received power of the terminal connected to the existing base station, (e) the minimum value of the received power of the terminal connected to the movable base station, the evaluation value Y1, and the evaluation value Y2.

[0044] Next, the selection unit 15 assigns 1 to the variable i (S110). Next, the selection unit 15 determines whether there are multiple candidate patterns with the maximum evaluation value Yi (S111). If there is only one candidate pattern with the maximum evaluation value Yi (N in S111), the selection unit 15 selects that candidate pattern (S112) and proceeds to step S116.

[0045] On the other hand, if there are multiple candidate patterns with the maximum evaluation value Yi (Y in S111), the selection unit 15 selects the candidate pattern with the maximum evaluation value Yi. max It is determined whether or not the value matches the value (S113). max is the total number of target existing base stations 30 and mobile base stations 20. max If it does not match (N in S113), the selection unit 15 adds 1 to i (S114) and repeats step S111 and subsequent steps.

[0046] i is i max 9 (having the smallest candidate pattern number) among the candidate patterns having the largest evaluation value Yi (Y in S113), the selection unit 15 selects the candidate pattern which is first in the sorting order in Fig. 9 (having the smallest candidate pattern number) (S115), and proceeds to step S116. By steps S109 and onwards, a candidate pattern having a higher minimum received signal power at the terminal 50 can be selected.

[0047] In step S116, the setting unit 16 sets, for each mobile base station 20, the transmission power adjustment amount in the candidate pattern selected in step S108, S112 or S115.

[0048] Next, step S102 will be described in detail. Fig. 10 is a flowchart illustrating an example of a processing procedure of the clustering process.

[0049] In step S201, the clustering unit 11 randomly selects one of the multiple terminals 50 (hereinafter referred to as "target terminal 50") connected to any of the target existing base stations 30 for each mobile base station 20, and sets a position near the target terminal 50 as the initial position of the mobile base station 20. The position near the terminal 50 is, for example, any position within a predetermined radius from the terminal 50. Alternatively, the position near the terminal 50 may be a position where there is no other terminal 50 closer than the terminal 50.

[0050] Next, the clustering unit 11 assigns 1 to a variable i (S202). The variable i is a variable for storing the number of times steps S203 and subsequent steps are executed.

[0051] Next, the clustering unit 11 calculates the distance between each target terminal 50 and each target existing base station 30 and the distance between each movable base station 20, and assigns each target terminal 50 to a cluster related to the base station with the shortest distance (S203). That is, a cluster is generated for each movable base station 20 and target existing base station 30, and each target terminal 50 is assigned to a cluster related to the closest base station among the movable base station 20 and the target existing base station 30.

[0052] Next, the clustering unit 11 judges whether the variable i is greater than 1 (S204). If the variable i is equal to or less than 1 (N in S204), the clustering unit 11 moves each movable base station 20 to the center of gravity of the cluster related to that movable base station 20 (the center of gravity of the group of target terminals 50 belonging to that cluster) (S205). Next, the clustering unit 11 adds 1 to i (S206) and executes steps S203 and onward.

[0053] If the variable i is 2 or less (Y in S204), the clustering unit 11 determines whether the current clustering result is the same as the previous clustering result (at i-1) (S207). The clustering result refers to information indicating which cluster is associated with which base station each target terminal 50 belongs.

[0054] If the current clustering result differs from the previous clustering result (that is, if the clustering has not converged) (N in S207), clustering unit 11 executes steps S205 and onwards.

[0055] If the current clustering result is the same as the previous clustering result (that is, if the clustering has not converged) (N in S207), the clustering unit 11 outputs the current clustering result (S208).

[0056] Through the above process, clustering is performed under the condition that the existing base station 30 does not move and only the location of the movable base station 20 is changed, and the location of the movable base station 20 can be determined.

[0057] As described above, according to this embodiment, it is possible to reduce the imbalance in the number of terminals connected to each base station, which is expected to improve communication quality.

[0058] If the base station can set different transmission powers for the beacon signal and the data signal, the transmission power may be reduced only for the beacon signal without reducing the signal transmission power for the data signal.

[0059] In addition, the placement options for the mobile base station 20 may be limited in advance, taking into consideration the communication area of ​​the backhaul line that accommodates the mobile base station 20.

[0060] Furthermore, if the height of the mobile base station 20 can be adjusted, multiple placement options for the mobile base station 20 in the height direction may also be prepared.

[0061] Furthermore, when the mobile base station 20 can change the beam transmission direction (such as the direction of analog beamforming or the selection of antenna patterns for digital beamforming), the candidate patterns may be further differentiated depending on when the beam transmission direction is switched.

[0062] Furthermore, this embodiment may be applied not only to the mobile base station 20 but also to the placement of fixed base stations, etc. For example, this embodiment may be applied to determining the placement position and transmission power of a newly established fixed base station.

[0063] In this embodiment, the mobile base station 20 is an example of a first base station, the existing base station 30 is an example of a second base station, and the control station 10 is an example of a base station control device. [Explanation of symbols]

[0064] 1. Communication Systems 10 Control Station 11 Clustering Department 12 Placement section 13 Generation part 14 Calculation section 15 Selection section 16 Setting section 20 Mobile base station 40 Relay base station 30 Existing base stations 50 terminals 100 Drive device 101 Recording media 102 Auxiliary storage 103 Memory device 104 CPU 105 Interface device B Bus

Claims

1. A base station control system including a first base station whose location has not been determined and a base station control device, The base station control device, a clustering unit that repeats clustering for dividing the plurality of terminals into clusters for each of the first base station and the second base station while fixing a position of an existing second base station to which a plurality of terminals are connected and changing a position of the first base station; a calculation unit that calculates the number of first terminals connected to the first base station and the number of second terminals connected to the second base station for each of a plurality of transmission powers of the first base station when the first base station is located at a position at the time when the clustering is completed; a selection unit that selects a transmission power of the first base station based on the number of the first terminals and the number of the second terminals; A base station control system comprising:

2. The second base station is a base station among a plurality of existing base stations to which a number of terminals connected is equal to or greater than a threshold value.

2. The base station control system according to claim 1.

3. the calculation unit calculates, for each of a plurality of transmission powers of the first base station, a number of third terminals that cannot be connected to either the first base station or the second base station; The selection unit selects a transmission power of the first base station based on the number of the first terminals, the number of the second terminals, and the number of the third terminals.

3. The base station control system according to claim 1, wherein:

4. When one transmission power cannot be selected, the selection unit further selects a transmission power of the first base station based on a reception power of the first terminal from the first base station and a reception power of the second terminal from the second base station, which are specified for each of the transmission powers.

4. The base station control system according to claim 1, wherein the base station control system further comprises:

5. a base station control device that controls a first base station whose location has not been decided, a clustering step of repeating clustering in which a position of an existing second base station to which a plurality of terminals are connected is fixed and the position of the first base station is changed while dividing the plurality of terminals into clusters for each of the first base station and the second base station; a calculation step of calculating the number of first terminals connected to the first base station and the number of second terminals connected to the second base station for each of a plurality of transmission powers of the first base station when the first base station is located at a position at the time when the clustering is completed; a selection step of selecting a transmission power of the first base station based on the number of the first terminals and the number of the second terminals; A base station control method comprising the steps of:

6. A base station control device that controls a first base station whose location has not been determined, a clustering unit that repeats clustering for dividing the plurality of terminals into clusters for each of the first base station and the second base station while fixing a position of an existing second base station to which a plurality of terminals are connected and changing a position of the first base station; a calculation unit that calculates the number of first terminals connected to the first base station and the number of second terminals connected to the second base station for each of a plurality of transmission powers of the first base station when the first base station is located at a position at the time when the clustering is completed; a selection unit that selects a transmission power of the first base station based on the number of the first terminals and the number of the second terminals; A base station control device comprising:

7. 7. A program for causing a computer to function as the base station control device according to claim 6.

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