WO2023157064A1

WO2023157064A1 - Station placement designing apparatus, station placement designing method, and program

Info

Publication number: WO2023157064A1
Application number: PCT/JP2022/005901
Authority: WO
Inventors: 元晴佐々木; 俊朗中平; 貴庸守山
Original assignee: 日本電信電話株式会社
Priority date: 2022-02-15
Filing date: 2022-02-15
Publication date: 2023-08-24

Abstract

This station placement designing apparatus is for designing installation positions of wireless base stations for constructing a wireless area, and comprises: a division unit for dividing a plurality of terminal positions, serving as assessment points in the wireless area, into clusters, the number of which corresponds to the number of wireless base stations to be installed in the wireless area; an assessment unit that assigns priority orders, for the respective clusters, to wireless base station installation position candidates indicated by the wireless station positions or a combination of the wireless station positions and the orientation of antennas, on the basis of an assessment result including the number of the terminal positions where a required reception electric power is satisfied and/or the degree at which the required reception electric power is satisfied at each of the terminal positions in the cluster; and a determination unit for determining the installation position of the wireless base station for each of the clusters.

Description

Station placement design device, station placement design method, and program

The present invention relates to a station placement design device, a station placement design method, and a program.

A station placement design device and a station placement design method for designing appropriate installation positions of wireless base stations for constructing a wireless area are known.

JP 2019-213148 A

In the conventional station placement design method, based on the results of radio communication quality simulations such as received power at multiple terminal positions that are evaluation points within the radio area, for example, based on conditions such as the largest number of terminal positions that satisfy the required received power, radio The location of the base station and the orientation of the antenna are derived.

Therefore, for example, when the above-described multiple terminal positions, the number of wireless base stations installed in the wireless area, or the antenna orientation increases, the calculation required to compare and evaluate the calculation results of all the above combinations There is a problem that the time and memory amount become enormous.

The embodiment of the present invention has been made in view of the above problems, and is a station placement design device for designing the installation position of a wireless base station and the orientation of an antenna for constructing a wireless area. reduction in computation time and memory size.

In order to solve the above problems, a station placement design device according to an embodiment of the present invention is a station placement design device for designing installation positions of wireless base stations for constructing a wireless area, a dividing unit that divides a plurality of terminal positions, which are evaluation points, into clusters of the number of radio base stations installed within the radio area; a number of the terminal positions that satisfy required reception power for each cluster; based on the evaluation result including at least one of the satisfaction level of the required received power at all the terminal positions within An evaluation unit that prioritizes the displayed candidates for the installation location of the radio base station, and a determination unit that determines the installation location of the radio base station for each cluster based on the priority.

According to the embodiment of the present invention, it is possible to reduce the calculation time and the amount of memory required for design in a station placement design device for designing the installation position of a wireless base station and the direction of an antenna for constructing a wireless area. can.

It is a figure which shows the structural example of the station placement design apparatus which concerns on this embodiment. FIG. 10 is a diagram for explaining a problem; 5 is a flow chart showing an example of processing of the station placement design device according to the first embodiment; FIG. 10 is a diagram showing an example of propagation characteristic estimation results according to the first embodiment; FIG. 4 is a diagram for explaining division of clusters according to the first embodiment; FIG. 4 is a diagram for explaining priority according to the first embodiment; FIG. 7 is a flowchart (1) showing an example of determination processing according to the first embodiment; FIG. 10 is a diagram illustrating an example of processing when there is no competition according to the first embodiment; 7 is a flowchart (2) showing an example of determination processing according to the first embodiment; FIG. 10 is a diagram illustrating an example of processing when there is base station contention according to the first embodiment; 9 is a flowchart (3) showing an example of determination processing according to the first embodiment; FIG. 10 is a diagram showing an example of processing when there is cluster contention according to the first embodiment; 4 is a flowchart (4) showing an example of determination processing according to the first embodiment; FIG. 10 is a diagram showing an example of processing when there is base station contention and cluster contention according to the first embodiment; 10 is a flow chart showing an example of processing of the station placement design device according to the second embodiment; FIG. 10 is a diagram for explaining directions of existing wireless base stations according to the second embodiment; FIG. 10 is a flowchart showing an example of selection processing according to the second embodiment; FIG. FIG. 11 is a diagram (1) showing a specific example of selection processing according to the second embodiment; FIG. 11B is a diagram (2) showing a specific example of selection processing according to the second embodiment; FIG. 11 is a diagram illustrating an application example of selection processing according to the second embodiment; It is a figure which shows the example of the hardware configuration of the station placement design apparatus which concerns on this embodiment. It is a figure for demonstrating the precondition of comparison with the conventional method. FIG. 10 is a diagram showing an image of station placement design according to a conventional method; It is a figure which shows the image of the station placement design method which concerns on this embodiment.

An embodiment (this embodiment) of the present invention will be described below with reference to the drawings. The embodiments described below are merely examples, and embodiments to which the present invention is applied are not limited to the following embodiments.

<Configuration example of station placement design device>
FIG. 1 is a diagram showing a configuration example of a station placement design device according to this embodiment. The station placement design device 100 is an information processing device having a computer configuration or a system including a plurality of computers. The station placement design apparatus 100 performs station placement design for designing appropriate installation positions of wireless base stations for constructing wireless areas, for example, based on input design conditions.

The station placement design apparatus 100, for example, executes a program stored in a storage medium or the like by a computer provided in the station placement design apparatus 100, so that a design condition input unit 101, a division unit 102, an evaluation unit 103, a determination unit 104, and the selection unit 105 and the like. Also, the station placement design apparatus 100 implements a design condition storage unit 111, a propagation estimation result storage unit 112, and the like by using, for example, a storage device of a computer included in the station placement design apparatus 100. FIG.

The design condition input unit 101 receives input of design conditions for station placement design, and stores the received design conditions in the design condition storage unit 111 and the like. The design condition input unit 101 also receives an input of the propagation characteristic estimation result, and stores the received propagation characteristic estimation result in the propagation estimation result storage unit 112 or the like.

The design conditions received by the design condition input unit 101 include, for example, environmental information, station position candidates, multiple terminal positions, required received power, and the number of radio base stations installed within the radio area. The station position candidate is, for example, the position of the radio base station or the candidate of the installation position of the radio base station represented by a combination of the position of the radio base station and the orientation of the antenna. A plurality of terminal positions are evaluation points for evaluating received power and the like within a wireless area. The required received power is a reference value (or threshold) of received power for determining whether or not sufficient received power can be obtained at a plurality of terminal positions.

The propagation characteristics estimation result is, for example, a simulation result of estimating the reception power at a plurality of terminal positions for each station position candidate by radio wave propagation characteristics simulation. The propagation characteristics estimation result may be calculated by the station position design apparatus 100 by applying the conventional technique as disclosed in Patent Document 1, for example.

The design condition storage unit 111 stores the design conditions received by the design condition input unit 101. The propagation estimation result storage unit 112 stores the propagation characteristic estimation result received by the design condition input unit 101 (or calculated by the station position design apparatus 100).

The division unit 102 executes division processing for dividing a plurality of terminal positions, which are evaluation points within the radio area, into clusters corresponding to the number of radio base stations installed within the radio area. The dividing unit 102, for example, using a clustering method such as the k-means method, divides a plurality of terminal positions into clusters of the number N (N is an integer of 2 or more) of wireless base stations installed in the wireless area. Classify (divide). The clustering method is not limited to the k-means method, and other clustering methods may be used.

For each cluster divided by dividing section 102, evaluation section 103 determines the number of terminal positions that satisfy the required received power (hereinafter referred to as the number of terminals T) and the degree of satisfaction with the required received power at all terminal positions in the cluster ( An evaluation result including at least one of (hereinafter referred to as satisfaction level S) is obtained. In addition, based on the evaluation result, the evaluation unit 103 determines the position of the radio base station, or the candidate for the installation position of the radio base station represented by the combination of the position of the radio base station and the orientation of the antenna (hereinafter referred to as the position of the radio base station). perform an evaluation process that prioritizes candidate BSs).

For example, the evaluation unit 103 sorts the station position candidate BSs in descending order of the number of terminals T that satisfy the required received power (eg, −90 dBm, which may be different for each terminal position) for each cluster (first sort). In addition, evaluation section 103 selects station position candidate BSs in descending order of satisfaction level S of required received power (negative if required received power is not satisfied) represented by the following formula for calculating satisfaction level S for each cluster. (second sort).

In the formula for calculating the satisfaction level S, "UE" indicates the terminal position, which is the evaluation point within the wireless area.

Assume here that the evaluation unit 103 sorts the station position candidate BSs for each cluster in the order of the first sort and the second sort, and gives priority to the station position candidate BSs in the cluster. The following description is provided.

The determining unit 104 determines the installation positions of the wireless base stations for each cluster based on the priority given by the evaluating unit 103 . The installation position of the wireless position is as described above. It is represented by the position of the radio base station or a combination of the position of the radio base station and the orientation of the antenna. Preferably, the determination unit 104 determines the installation positions of the radio base stations in each cluster so that the positions of the radio base stations do not overlap between the clusters.

The selection unit 105 executes selection processing for selecting the direction of the existing radio base station when designing the station placement including the existing radio base station.

Note that the functional configuration of the station placement design device 100 shown in FIG. 1 is an example. For example, the design condition storage unit 111 or the propagation estimation result storage unit 112 may be realized by a storage server or a classed service that the station placement design device 100 can access via a communication network. Moreover, each of the functional configurations described above is not limited to a physical machine (computer), and may be implemented by, for example, a program executed by a virtual machine on a cloud. Furthermore, at least part of each of the functional configurations described above may be realized by hardware.

<About assignments>
FIG. 2 is a diagram for explaining the problem. In FIG. 2, BS1, BS2, . The station position candidate BS is represented by the position 202 of the radio base station or the combination of the position 202 of the radio base station and the orientation 202 of the antenna, as described above.

A plurality of terminal positions, which are evaluation points for evaluating received power and the like within the wireless area 200, are represented, for example, by dividing the wireless area 200 into a plurality of meshes and by center points 201 of the divided meshes.

In station placement design, for example, as shown in FIG. position. For example, the station placement design device uses the propagation characteristic estimation result 210 shown in FIG. 2 to determine the installation positions of the radio base stations so that the terminal positions that satisfy the required received power are the largest.

For example, when the number of wireless base stations installed in the wireless area 200 is two, the conventional station placement design method uses the propagation characteristics estimation result 210 to determine the required received power (eg, −70 dBm) for BS1 and BS2. Derive the combination of

In this method, for example, the number of terminal positions N _UE , the number of radio base station position candidates N _BS , the radio base station antenna direction candidates N _Ant , the number of radio base stations installed in the radio area M, etc. As the number increases, there arises a problem that the calculation time and the amount of memory required for station placement design become enormous.

For example, the number of reception power points required for station placement design is N _UE ×N _BS ×N _ant , and the number of combinations is _{N_BS} _CM × _{N_Ant} C ₁ ×M. Is required.

As a specific example, if N _UE =10,000 points, N _BS =500 points, N _Ant =20 directions, and M=30 points,
Number of received power points: 100000 x 500 x 20 = 20 ⁸
Number of combinations: ₅₀₀ C ₃₀ × ₂₀ C ₁ × 30 ≈ 8.6 × 10 ⁵⁰
Therefore, for station placement design, for example, 10 ⁸ ×8.6×10 ⁵⁰ =8.6×10 ⁵⁸ points of received power must be stored and processed.

Therefore, the station placement design apparatus 100 according to the present embodiment includes the division unit 102, the evaluation unit 103, and the It has a decision unit 104 and the like.

<Process flow>
Next, the processing flow of the station placement design method according to this embodiment will be described.

[Example 1]
(Processing of station placement design device)
FIG. 3 is a flowchart illustrating an example of processing of the station placement design device according to the first embodiment; This process represents an example of the station placement design process executed by the station placement design apparatus 100 described with reference to FIG. 1, for example. At the start of the processing shown in FIG. 3, the design condition input unit 101 has already stored the received design conditions in the design condition storage unit 111, and stores the received propagation characteristic estimation results in the propagation estimation result storage unit 112. shall have been completed.

In step S301, the station placement design device 100 reads design conditions and propagation characteristic estimation results. For example, the station placement design apparatus 100 reads design conditions such as station placement position candidates, multiple terminal positions, required received power, and the number of wireless base stations installed in the wireless area from the design condition storage unit 111 . Station position design apparatus 100 also reads the propagation characteristic estimation result from propagation estimation result storage section 112 .

FIG. 4 is a diagram showing an example of propagation characteristic estimation results according to the first embodiment. As shown in FIG. 4, it is assumed that there are a plurality of terminal positions and a plurality of station position candidate BS positions (BS1, BS2, BS3, . . . ) in a radio area 400 . Further, for example, as shown in FIG. 4, when BS1 has antenna orientation 1 and antenna orientation 2, the combination of BS1 and antenna orientation 1 is BS1-1, and BS1 and antenna orientation 2 are combined. are assumed to be BS1-2, and each of them is treated as a different station position candidate BS.

The propagation characteristics estimation result 410 stores simulation results of received power from each station position candidate BS for each of a plurality of terminal positions. For example, in the example of FIG. 4, at the terminal position UE (1), the received power from the station position candidate BS1-1 is -120 dBm, and the received power from the station position candidate BS1-2 is -110 dBm. Something is remembered.

Here, returning to FIG. 3, the explanation of the flowchart is continued. In step S302, the division unit 102 of the station placement design apparatus 100 divides a plurality of terminal positions within the radio area into clusters corresponding to the number of radio base stations installed within the radio area. For example, when three wireless base stations are installed in the wireless area, multiple terminal positions in the wireless area 400 are divided into three

clusters

1, 2, and 3, as shown in FIG.

For example, dividing section 102 uses a known clustering method such as the k-means method to classify a plurality of terminal positions into clusters of "3" wireless base stations installed in the wireless area.

In step S303, the station placement design device 100 initializes the variable n to "1" and executes the processes from step S304 onward.

In step S304, the evaluation unit 103 of the station placement design apparatus 100 calculates the number of terminals T satisfying the required received power (eg, −90 dBm) and the satisfaction level S for all BSs (station position candidates) of the cluster n. do. The satisfaction level S is calculated using, for example, the formula for calculating the satisfaction level S described above.

In step S305, the evaluation unit 103 prioritizes the BSs of cluster n using the calculation results.

FIG. 6 is a diagram for explaining the priority according to the first embodiment. In FIG. 6, terminal positions UE(1) and UE(2) are included in cluster 1, for example. It is assumed that the terminal position UE(M) is included in cluster 3.

For example, the evaluation unit 103 sorts in descending order of the number of terminals T in the cluster 1, so that the two terminal positions UE (1) and UE (12) are BSN priority that satisfies the required received power "-90 dBm" is set to "1". On the other hand, since each of BS1-1, BS3, and BS2 has one terminal position that satisfies the required received power of “−90 dBm”, evaluation section 103 sorts in descending order of satisfaction S, and sorts in descending order of satisfaction S, for example, , BS3 have a priority of "2", and BS2 has a priority of "3".

In addition, since BS2 is the only BS that satisfies the required received power (eg, -90 dBm) in cluster 3, evaluation section 103 sets the priority of BS2 to "1". On the other hand, since the other BSs do not satisfy the required received power, the evaluation unit 103 sorts the BSNs in descending order of the satisfaction level S, and sets the priority of the BSNs in descending order of the satisfaction level S, for example, "2". The priority of BS1-2 is set to "3".

Here, return to FIG. 3 again and continue the explanation of the flowchart. In steps S306 and S307, station placement design apparatus 100 adds 1 to variable n, and repeats steps S304 to S307 until the value of n exceeds the number N of clusters. Also, when the value of n exceeds the number N of clusters, station placement design apparatus 100 shifts the process to step S308.

After moving to step S308, the determination unit 104 of the station placement design device 100 executes determination processing for determining the installation positions of the wireless base stations for each cluster based on the priority assigned by the evaluation unit 103.

(Decision process 1)
7, 9, 11, and 13 are flowcharts illustrating examples of determination processing according to the first embodiment. This process shows an example of the determination process executed by the determination unit 104 in step S308 of FIG. 3, for example. First, the processing shown in FIG. 7 will be described. Here, as an example for explanation, it is assumed that the evaluation unit 103 has created an evaluation result 800 as shown in FIG.

In step S701, the determination unit 104 extracts the BS with the highest priority in each cluster from the evaluation result 800 by the evaluation unit 103. In the example of FIG. 8, the determining unit 104 extracts BS1 in cluster 1 and extracts BS3-2 in cluster 2. FIG. Further, the determining unit 104 extracts BS2 in cluster 3, and extracts BS5 in cluster 4. FIG.

In step S702, the determination unit 104 initializes the variable n to 1, and executes the processing from step S703 onwards.

In step S703, the determining unit 104 determines whether or not cluster conflict occurs in cluster n. Here, cluster contention means that a plurality of BSs with the highest priority exist within a cluster. In the example of FIG. 8, no cluster conflict occurs in any cluster.

If there is cluster conflict, the determining unit 104 shifts the process to step S706. On the other hand, if no cluster conflict has occurred, the determination unit 104 causes the process to proceed to step S704.

After moving to step S704, the determining unit 104 determines whether or not the BS with the highest priority in cluster n is in contention with the base station. Here, base station contention means that the position of the BS with the highest priority in cluster n and the position of the BS with the highest priority in another cluster are the same (conflict).

As a specific example, it is assumed that the BS with the highest priority in cluster 1 is BS3-1, and the BS with the highest priority in cluster 2 is BS3-2. In this case, since BS3-1 and BS3-2 have different antenna directions, they are different BSs (station position candidates). determine that it has occurred. In the example of FIG. 8, no base station contention occurs in any cluster.

If there is base station contention, the determining unit 104 shifts the process to step S706. On the other hand, if there is no base station contention, the determining unit 104 shifts the process to step S705.

When the process moves to step S705, the determination unit 104 selects the BS with the highest priority in cluster n and determines the installation position of the radio base station in cluster n.

In steps S706 and S707, the station design device 100 adds 1 to the variable n, and repeats the processing of steps S703 to S707 until the value of n exceeds the number N of clusters. Also, when the value of n exceeds the number N of clusters, station placement design apparatus 100 shifts the process to step S708.

In step S708, the determination unit 104 determines whether or not the installation positions of the radio base stations have been determined in all clusters. When the installation positions of the radio base stations have been determined in all clusters, the determination unit 104 terminates the determination process. On the other hand, when there is a cluster for which the installation position of the radio base station has not been determined, the determination unit 104 executes the processing of FIG.

As shown in FIG. 8, when neither cluster conflict nor base station conflict occurs, the installation positions of wireless base stations are determined in all clusters by the processing of FIG. For example, in the example of FIG. 8, the determining unit 104 determines the installation position of the base station of cluster 1 to be BS1, and the installation position of the base station of cluster 2 to be BS3-2. Further, the determining unit 104 determines the installation position of the base station of cluster 3 to be BS2, and the installation position of the base station of cluster 4 to be BS5.

(Decision process 2)
Next, the processing shown in FIG. 9 will be described. This processing shows an example of determination processing executed by the determination unit 104 when it is determined in step S708 in FIG. 7 that there is a cluster for which the installation positions of the radio base stations have not been determined. Here, as an example for explanation, it is assumed that the evaluation unit 103 has created an evaluation result 1000 as shown in FIG. Also, here, detailed descriptions of the same processing contents as those described with reference to FIG. 7 will be omitted.

In step S901, the determination unit 104 initializes the variable n to 1, and executes the processes from step S902 onward.

In step S902, the determination unit 104 determines whether or not the installation positions of the wireless base stations have been determined in cluster n. If the installation positions of the wireless base stations have been determined in cluster n, the determining unit 104 causes the process to proceed to step S910. On the other hand, if the installation positions of the wireless base stations have not been determined in cluster n, the determining unit 104 causes the process to proceed to step S903.

After moving to step S903, the determining unit 104 determines whether or not cluster conflict occurs in cluster n. If cluster conflict occurs, the determining unit 104 causes the process to proceed to step S910. On the other hand, if no cluster conflict has occurred, the determining unit 104 causes the process to proceed to step S904.

When the process moves to step S904, the determination unit 104 determines whether or not the BS with the highest priority in cluster n has base station contention. In the evaluation result 1000 shown in FIG. 10, base station contention has occurred between

clusters

2 and 4 .

When there is no base station contention, the determining unit 104 shifts the process to step S910. On the other hand, if there is base station contention, the determining unit 104 causes the process to proceed to step S905.

After shifting to step S905, the determining unit 104 determines whether or not there is another BS with the first priority in the competing cluster. If there is another BS with the first priority in the competing cluster, the determining unit 104 shifts the process to step S906. On the other hand, if there is no other BS with the first priority in the competing cluster, the determining unit 104 shifts the process to steps S907 and S908.

When the process moves to step S906, the determination unit 104 selects the BS with the highest priority in cluster n and determines the installation position of the radio base station in cluster n.

After moving to step S907, the determination unit 104 calculates the total score of BS set 1, which is a combination of the BS with the highest priority in cluster n and the BS with the next priority in the competing cluster. In step S908, the determining unit 104 calculates the total score of BS set 2, which is a combination of the next priority BS of cluster n and the priority 1 BS of the competing cluster.

In step S909, the determining unit 104 selects the BS set with the highest total score from the BS set 1 and the BS set 2.

FIG. 10 is a diagram illustrating an example of processing when there is base station contention according to the first embodiment. In the example of FIG. 10, base station contention occurs between

clusters

2 and 4 in which the position of the BS with the highest priority is in contention.

In this case, determining section 104 determines the total score of BS set 1 (the number of terminals T and the sum of satisfaction S).

In the example of FIG. 10, BS3-2, which has the second priority in cluster 4, competes with BS3-2, which has the first priority in cluster 2. Therefore, in cluster 4, the priority is 3. The BS4-2 with the highest priority is set as the BS with the next priority.

The determining unit 104 also calculates the total score 1001 of BS set 2, which is a combination of BS5, which has the second priority in cluster 2, and BS3-1, which has the first priority in cluster 4, which is the competitor. In the example of FIG. 10 , the total score 1001 is higher for BS set 2, so decision unit 104 selects BS set 2. As a result, determination section 104 determines the installation position of the radio base station in cluster 2 to be BS-5, and the installation position of the radio base station in cluster 4 to be BS3-1.

Here, returning to FIG. 9, the explanation of the flowchart is continued.

In steps S910 and S911, the station design apparatus 100 adds 1 to the variable n, and repeats the processing of steps S902 to S911 until the value of n exceeds the number N of clusters. Also, when the value of n exceeds the number N of clusters, station placement design apparatus 100 shifts the process to step S912.

After moving to step S912, the determination unit 104 determines whether or not the installation positions of the wireless base stations have been determined in all clusters. When the installation positions of the radio base stations have been determined in all clusters, the determination unit 104 terminates the determination process. On the other hand, when there is a cluster for which the installation position of the radio base station has not been determined, the determination unit 104 executes the processing of FIG. 11 .

(Decision process 3)
Next, the processing shown in FIG. 11 will be described. This process shows an example of the determination process performed by the determination unit 104 when it is determined in step S912 of FIG. 9 that there is a cluster for which the installation positions of the radio base stations have not been determined. Here, as an example for explanation, it is assumed that the evaluation unit 103 has created an evaluation result 1200 as shown in FIG. 12 . Also, here, detailed descriptions of the same processing contents as those described with reference to FIGS. 7 and 9 will be omitted.

In step S1101, the determination unit 104 initializes the variable n to 1, and executes the processes from step S1102 onward.

In step S1102, the determination unit 104 determines whether or not the installation positions of the wireless base stations have been determined in cluster n. If the installation positions of the wireless base stations have been determined in cluster n, the determining unit 104 causes the process to proceed to step S1106. On the other hand, if the installation positions of the wireless base stations have not been determined in cluster n, the determining unit 104 causes the process to proceed to step S1103.

Upon moving to step S1103, the determination unit 104 determines whether or not cluster conflict occurs in cluster n. If no cluster conflict has occurred, the determining unit 104 causes the process to proceed to step S1106. On the other hand, when cluster conflict occurs, the determining unit 104 causes the process to proceed to step S1104.

After moving to step S1104, the determining unit 104 determines whether or not there is a BS that is not in base station contention with other clusters among the BSs with the highest priority in cluster n. If there is no BS that satisfies the condition, the determining unit 104 causes the process to proceed to step S1106. On the other hand, if there is a BS that satisfies the condition, the determining unit 104 causes the process to proceed to step S1105.

At step S1105, the determination unit 104 selects the BS with the highest total score of all clusters among the BSs that have the highest priority in cluster n and are not in base station contention with other clusters.

For example, in the evaluation result 1200 shown in FIG. 12, BS3-2, BS4-2, and BS6 have the highest priority in cluster 2, and cluster conflict occurs. Also, none of the conflicting BS3-2, BS4-2, and BS6 have base station conflicts with other clusters. In this case, determination section 104 calculates total score 1201 of all clusters in BS3-2, BS4-2, and BS6. For example, the determining unit 104 sums the number of terminals T in clusters 1 to 4 of BS3-2, calculates the total score of the number of terminals T in BS3-2, and satisfies S in clusters 1 to 4 of BS3-2. to calculate the total score of satisfaction S in BS3-2.

Also, in the example of FIG. 12, the determination unit 104 selects BS4-2, which has the highest total score of all clusters, and determines it as the installation position of the wireless base station to be installed in cluster n.

In steps S1106 and S1107, the station position design apparatus 100 adds 1 to the variable n, and repeats the processing of steps S1102 to S1107 until the value of n exceeds the number N of clusters. Also, when the value of n exceeds the number N of clusters, station placement design apparatus 100 shifts the process to step S1108.

After moving to step S1108, the determining unit 104 determines whether or not the installation positions of the wireless base stations have been determined in all clusters. When the installation positions of the radio base stations have been determined in all clusters, the determination unit 104 terminates the determination process. On the other hand, when there is a cluster for which the installation position of the radio base station has not been determined, the determination unit 104 executes the processing of FIG. 13 .

(Decision process 4)
Next, the processing shown in FIG. 13 will be described. This process shows an example of the determination process performed by the determination unit 104 when it is determined in step S1108 of FIG. 11 that there is a cluster for which the installation positions of the wireless base stations have not been determined. Here, as an example for explanation, it is assumed that the evaluation unit 103 has created an evaluation result 1400 as shown in FIG. 14 . Further, here, detailed descriptions of the same processing contents as those described with reference to FIGS. 7, 9, and 11 are omitted.

In step S1301, the determination unit 104 initializes the variable n to 1, and executes the processing from step S1302.

In step S1302, the determining unit 104 determines whether or not the installation positions of the wireless base stations have been determined in cluster n. If the installation positions of the wireless base stations have been determined in cluster n, the determining unit 104 causes the process to proceed to step S1306. On the other hand, if the installation positions of the wireless base stations have not been determined in cluster n, the determining unit 104 causes the process to proceed to step S1303.

Upon moving to step S1303, the determination unit 104 determines whether or not cluster conflict occurs in cluster n. If cluster conflict has not occurred, the determining unit 104 causes the process to proceed to step S1306. On the other hand, when cluster conflict occurs, the determining unit 104 causes the process to proceed to step S1304.

After moving to step S1304, the determining unit 104 determines whether or not all the BSs with the highest priority that are in cluster conflict in cluster n are in base station conflict with other clusters. If there is no base station contention as described above, the determination unit 104 causes the process to proceed to step S1306. On the other hand, if the above base station contention is occurring, the determining unit 104 causes the process to proceed to step S1305.

After moving to step S1305, the determination unit 104 selects a BS set of combinations of BSs that do not conflict with each other in the cluster n and the competing cluster.

For example, in the evaluation result 1400 shown in FIG. 14, cluster competition occurs in

clusters

1, 3, and 4. Of these, in cluster 1, among the BSs with the highest priority, there are BS1 and BS4-2 that do not compete for base stations with other clusters. , to determine the installation positions of the radio stations in cluster 1 .

Also, in the evaluation result 1400 shown in FIG. 14, base station competition occurs between

clusters

2 and 6, and there is no other BS with the highest priority in the competing cluster. For example, the installation positions of the wireless stations in the

clusters

2 and 6 are determined by the processing of FIG. In cluster 5, BS5, which has the highest priority, has neither cluster conflict nor base station conflict.

Furthermore, in the evaluation result 1400 shown in FIG. 14, cluster conflict occurs in

clusters

3 and 4, and all the BSs with the highest priority that are in cluster conflict are base station conflicts with other clusters. ing. Therefore, the determination unit 104 determines the installation positions of the radio base stations in the

clusters

3 and 4 by the processing of FIG. For example, since there is no difference whether priority is given to

clusters

3 or 4, determination unit 104 determines BS2 as the wireless base station installation position in cluster 3 and BS6 as the wireless base station installation position in cluster 4 by ID ascending order or the like. Determine the installation position of the station. Note that the determination unit 104 may select BSs by any method such as score order, ID descending order, random, or the like, without being limited to the ID ascending order.

Here, returning to FIG. 13, the explanation of the flowchart is continued. In steps S1306 and S1307, station placement design apparatus 100 adds 1 to variable n, and repeats steps S1302 to S1307 until the value of n exceeds the number N of clusters. Also, when the value of n exceeds the number N of clusters, station placement design apparatus 100 terminates the determination process.

Through the above processes, the station placement design device 100 can determine the installation positions of the wireless base stations installed in each cluster with a smaller amount of calculation and memory than the conventional technique.

[Example 2]
The station placement design apparatus 100 can also perform station placement design to add a new radio base station within a radio area where an existing radio base station is located. In this case, station placement design apparatus 100 selects terminal positions excluding terminal positions that satisfy the required received power from existing radio base stations from a plurality of terminal positions within the radio area, It should be divided into clusters.

<Process flow>
(Station placement design process)
FIG. 15 is a flowchart illustrating an example of processing of the station placement design device according to the second embodiment. 15, steps S301 and S302 to S308 are the same as those of the station placement design apparatus according to the first embodiment described with reference to FIG. 3, so description thereof will be omitted here.

In step S1501, the station placement design device 100 determines whether or not to include existing wireless base stations in the station placement design. For example, the station placement design apparatus 100 refers to the read design conditions and the like, and determines whether or not to include the existing wireless base stations in the station placement design. When including an existing radio base station in the station placement design, the station placement design apparatus 100 shifts the process to step S1502. On the other hand, if the existing radio base station is not included in the station placement design, the station placement design apparatus 100 shifts the process to step S302.

After proceeding to step S1502, the station placement design apparatus 100 excludes terminal positions that satisfy the required received power from existing wireless base stations from the plurality of terminal positions included in the design conditions, and advances the process to step S302.

With the above processing, the station placement design apparatus 100 can perform station placement design in the same manner as in the first embodiment by the processing of step S1502 when the existing wireless base stations are included in the station placement design.

However, if the existing radio base station can change the direction of the antenna, it is desirable that the station placement design device 100 determines the direction of the existing radio base station used for station placement design.

FIG. 16 is a diagram for explaining directions of existing wireless base stations according to the second embodiment. For example, as shown in FIG. 16, there is an existing wireless base station 1601 in a wireless area 1600, and depending on the orientation of the antenna provided in the wireless base station 1601, the coverage range indicated by direction 1 or the coverage range indicated by direction 2 It is assumed that the required received power can be satisfied at the terminal position.

In this case, the coverage area represented by direction 2 (hereinafter simply referred to as "direction 2") covers more terminal positions than the coverage area represented by direction 1 (hereinafter simply referred to as "direction 1"). can be done.

On the other hand, when one new radio base station is added to the radio area 1600, two radio base stations can cover all terminal positions in the radio area 1600 in the direction 1, but in the direction 2 , a terminal position that cannot be covered occurs. Therefore, when designing a station including an existing radio base station whose antenna direction can be changed, it is desirable to appropriately select the direction of the existing radio base station in step S1502 of FIG.

(selection process)
FIG. 17 is a flowchart illustrating an example of selection processing according to the second embodiment. This process is an example of the selection process executed by station placement design apparatus 100 in step S1502 of FIG. showing.

In step S1701, the dividing unit 102 of the station placement design device 100 divides a plurality of terminal positions within the wireless area into clusters corresponding to the number of wireless base stations to be installed within the wireless area, including existing wireless base stations.

In step S1702, the evaluation unit 103 of the station placement design device 100 calculates the scores of the terminal position coverage U and the degree of satisfaction S in each direction in each cluster. Here, the terminal location coverage ratio U is defined as (the number of terminal locations satisfying the required received power in the cluster)/(the number of terminal locations in the cluster).

In step S1703, the selection unit 105 of the station placement design apparatus 100 extracts the maximum score in each direction (for example, direction 1 and direction 2 in FIG. 16) of existing wireless base stations.

In step S1704, the selection unit 105 determines whether the maximum scores in each direction calculated in step S1703 are the same value. If the maximum scores are the same value, the selection unit 105 causes the process to proceed to step S1706. On the other hand, if the maximum scores are not the same value, the selection unit 105 moves to processing step S1706.

After moving to step S1705, the selection unit 105 selects a direction with a higher maximum score.

On the other hand, when proceeding to step S1706, the selection unit 105 calculates the total score of all clusters in each direction.

In step S1707, the selection unit 105 determines whether or not the calculated total score in each direction is the same value. If the total score values are the same, the selection unit 105 causes the process to proceed to step S1709. On the other hand, if the total score values are not the same, the selection unit 105 causes the process to proceed to step S1708.

When the process moves to step S1708, the selection unit 105 selects a direction with a higher total score. On the other hand, after proceeding to step S1709, the selection unit 105 selects the direction by any method such as ascending ID order, descending ID order, or random.

FIG. 18 is a diagram (1) showing a specific example of selection processing executed by the station placement design device 100. FIG. For example, when installing a new radio base station in a radio area 1800 where existing radio base stations are installed, the station placement design apparatus 100 divides the radio area 1800 into two areas, for example, as shown in FIG. into two clusters (Cluster 1 and Cluster 2).

Further, station placement design apparatus 100 calculates score 1811 of coverage ratio U and degree of satisfaction S in each direction (direction 1 and direction 2) in each divided cluster, as shown in FIG. Extract the maximum score 1812 in the direction.

Here, since the maximum score for direction 1 is higher than the maximum score for direction 2, station placement design device 100 selects direction 1. As a result, for example, the direction 1 of the existing radio base station 1601 described with reference to FIG. 16 is selected.

FIG. 19 is a diagram (2) showing a specific example of selection processing executed by the station placement design device 100. FIG. For example, when installing two new radio base stations in a radio area 1900 in which an existing radio base station is installed, the station placement design apparatus 100 divides the radio area 1900 into three areas, for example, as shown in FIG. divided into two clusters (clusters 1-3).

19, the station placement design apparatus 100 calculates a score 1911 for each direction (direction 1 and direction 2) coverage U and satisfaction S for each divided cluster, and Extract the maximum score 1912 in .

Here, since the maximum score for direction 1 and the maximum score for direction 2 are the same score, the station position design device 100 further calculates the total value 1913 of the scores for each direction. In addition, in the example of FIG. 19, since the total score value for direction 2 is greater than the total score value for direction 1, station placement design apparatus 100 selects direction 2. FIG. As a result, for example, the direction 2 of the existing radio base station 1601 described with reference to FIG. 16 is selected.

(Application example)
In the above description, the case where the number of existing wireless base stations is one has been described, but the number of existing wireless base stations may be two as shown in FIG. 20, for example. For example, as shown in FIG. 20, when installing a new radio base station in a radio area 2000 in which two existing radio base stations BS1 and BS2 are installed, the station design apparatus 100: For example, as shown in FIG. 20, wireless area 2000 is divided into three clusters (clusters 1 to 3).

20, the station placement design apparatus 100 calculates the coverage ratio U and the degree of satisfaction S , and the maximum score 2012 in each direction of each BS is extracted.

Here, the maximum score in direction 1 of BS1 and the maximum score in direction 1 of BS2 are the maximum. However, when direction 1 of BS1 and direction 1 of BS2 are selected, there is a problem that the area covered by BS1 and the area covered by BS2 overlap as shown in FIG.

It is desirable that the station placement design device 100 selects the direction of BS1 and the direction of BS2 so that the coverage area of BS1 and the coverage area of BS2 do not overlap.

For example, when the area covered by BS1 and the area covered by BS2 overlap, station placement design apparatus 100 selects a combination of direction 1 with the highest priority of BS1 and direction 2 with the second highest priority of BS2. As combination 1, the total score of the coverage rate U and the satisfaction level S is calculated. In addition, the station placement design device 100 sets the combination 2 of the direction 1 in which BS2 has the highest priority and the direction 3 in which BS1 has the second highest priority, and sets the total score of the coverage ratio U and the satisfaction level S as combination 2. Calculate

Also, the station position design device 100 selects a combination with a higher total score (combination 2 in the example of FIG. 20) from the calculation result 2020 of the total score of combination 1 and the total score of combination 2. Thereby, station placement design apparatus 100 can select direction 2 of BS1 and direction 1 of BS2 so that the coverage area of BS1 and the coverage area of BS2 do not overlap.

For example, the station placement design apparatus 100 determines the direction of the existing radio base station by the selection process described in FIGS. 17 to 20, and then executes the process of step S1502 in FIG.

<Hardware configuration example>
(Hardware configuration of station placement design device)
FIG. 21 is a diagram showing an example of the hardware configuration of a station placement designing apparatus according to this embodiment. A station placement designing apparatus 100 has, for example, the configuration of a computer 2100 as shown in FIG. In the example of FIG. 21, computer 2100 has processor 2101, memory 2102, storage device 2103, communication device 2104, input device 2105, output device 2106, bus B, and the like.

The processor 2101 is, for example, an arithmetic device such as a CPU (Central Processing Unit) that implements various functions by executing a predetermined program. The memory 2102 is a storage medium readable by the computer 2100, and includes, for example, RAM (Random Access Memory), ROM (Read Only Memory), and the like. The storage device 2103 is a computer-readable storage medium, and may include, for example, HDDs (Hard Disk Drives), SSDs (Solid State Drives), various optical discs, magneto-optical discs, and the like.

The communication device 2104 includes one or more pieces of hardware (communication devices) for communicating with other devices via a wireless or wired network. The input device 2105 is an input device (for example, keyboard, mouse, microphone, switch, button, sensor, etc.) that receives input from the outside. The output device 2106 is an output device (for example, display, speaker, LED lamp, etc.) that outputs to the outside. Note that the input device 2105 and the output device 2106 may be integrated (for example, an input/output device such as a touch panel display).

A bus B is commonly connected to each of the components described above, and transmits, for example, address signals, data signals, and various control signals. Note that the processor 2101 is not limited to a CPU, and may be, for example, a DSP (Digital Signal Processor), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

(supplement)
The station placement design device 100 in this embodiment is not limited to being realized by a dedicated device, and may be realized by a general-purpose computer. In that case, a program for realizing this function may be recorded in a computer-readable recording medium, and the program recorded in this recording medium may be read into a computer system and executed. It should be noted that the "computer system" referred to here includes hardware such as an OS and peripheral devices.

In addition, "computer-readable recording medium" includes various storage devices such as portable media such as flexible disks, magneto-optical disks, ROMs and CD-ROMs, and hard disks built into computer systems. Furthermore, "computer-readable recording medium" refers to a program that dynamically retains programs for a short period of time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. It may also include something that holds the program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client in that case.

Further, the above program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in a computer system, It may be implemented using hardware such as PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

<Effects of Embodiment>
In a station placement design device for designing installation positions of wireless base stations and directions of antennas for constructing wireless areas, it is possible to reduce calculation time, memory size, etc. required for design.

<Comparison with conventional method>
Here, a conventional station position design method (hereinafter referred to as a conventional method) and a station position design method according to this embodiment will be compared.

(prerequisite)
FIG. 22 is a diagram for explaining preconditions for comparison with the conventional method. As a prerequisite, as shown in FIG. 22, 36 terminal positions (hereinafter referred to as UEs) were randomly set in an area 2201 of 100 m×100 m, and the number of BSs was set to 6 for comparative evaluation.

(conventional method)
The received power between each BS and UE is calculated using the propagation loss in free space, and a propagation characteristic estimation result 2301 is created in which the received power at 6BS×36 UE is calculated as shown in FIG.

In the station placement design of the conventional method, assuming that two radio base stations are installed in area 2201, for example, as shown in FIG. In this table, "BS12" indicates a combination of BS1 and BS2. "BS13" indicates a combination of BS1 and BS3. The same applies to other combinations.

In the station placement design of the conventional method, the number of UEs 2303 that satisfies the required received power (for example, -60 dBm) in each BS combination is obtained, and the optimal design that maximizes the number of UEs that satisfy the required received power is the combination of BS2 and BS5. , or the pair of BS3 and BS4.

(this embodiment)
For example, as shown in the right diagram of FIG. 22, the station placement design apparatus 100 according to the present embodiment clusters a plurality of UEs in an area 2201 with two BSs installed and divides them into two clusters. Also, similarly to the conventional method, for example, data 2401 is created by adding a cluster number to the propagation characteristics estimation result obtained by calculating the reception power between each BS and the UE.

24, station placement design apparatus 100 executes the processing of the station placement design apparatus as shown in FIG. Obtain the evaluation result 2403 of each BS in . As a result, station placement design apparatus 100 selects a combination of BS2, which has the highest priority in cluster 1, and BS5, which has the highest priority in cluster 2, as an optimal design that maximizes the number of UEs that satisfy the required received power. can be asked for.

In this way, the station placement design method according to the present embodiment can derive the same optimal design result as the conventional round-robin method with less calculation and memory than the conventional station placement design method.

<Summary of embodiment>
This specification discloses at least the following wireless communication methods and wireless communication systems.
(Section 1)
A station placement design device for designing the installation position of a wireless base station for building a wireless area,
a division unit configured to divide a plurality of terminal positions, which are evaluation points within the radio area, into clusters of the number of radio base stations installed within the radio area;
the radio base based on an evaluation result including at least one of the number of terminal positions that satisfy the required received power for each cluster and the level of satisfaction with the required received power at all the terminal positions in the cluster; an evaluation unit configured to prioritize candidate installation locations of said radio base station represented by a station location or a combination of said radio base station location and antenna orientation;
a determination unit configured to determine the installation position of the radio base station for each cluster based on the priority;
A station placement design device.
(Section 2)
2. The station placement design device according to claim 1, wherein the determination unit determines the installation positions of the radio base stations so that positions of the radio base stations do not overlap between the clusters.
(Section 3)
The decision unit
In the cluster, if the installation position of the radio base station is set in order from the candidate with the highest priority, and the position of the radio base station overlaps with another cluster,
determining installation positions of the radio base stations in the cluster and the other clusters based on at least one of the evaluation results in the cluster and the other clusters and the evaluation results in the plurality of clusters;
The station placement design device according to item 1.
(Section 4)
The decision unit
In the cluster, if there are multiple candidates with the highest priority,
Selecting one candidate from among the plurality of candidates based on the evaluation results in the plurality of clusters;
A station placement design device according to claim 3.
(Section 5)
When adding a new wireless base station in a wireless area where existing wireless base stations are located,
The division unit newly installs a terminal position within the radio area after excluding, from the terminal positions within the radio area, a terminal position that satisfies a required received power by the existing radio base station. into a number of clusters,
The station placement design device according to item 1.
(Section 6)
When the existing radio base station has a plurality of antennas,
dividing the plurality of terminal positions within the radio area into clusters of the number of radio base stations to be installed within the radio area including the existing radio base station;
calculating, for each cluster, the evaluation result including at least one of the proportion of the terminal positions that satisfy the required received power and the degree of satisfaction with the required received power at all terminal positions in the cluster;
selecting the direction of the antenna of the existing radio base station based on the evaluation result;
6. The station placement design device according to claim 5, having a selection unit configured as follows.
(Section 7)
A station placement design method for designing the installation position of a wireless base station for building a wireless area,
A division process for dividing a plurality of terminal positions, which are evaluation points within the radio area, into clusters of the number of radio base stations installed within the radio area;
the radio base based on an evaluation result including at least one of the number of terminal positions that satisfy the required received power for each cluster and the level of satisfaction with the required received power at all the terminal positions in the cluster; an evaluation process for prioritizing candidate installation positions of the radio base station represented by a station position or a combination of the position of the radio base station and the orientation of the antenna;
a determination process of determining the installation position of the radio base station for each cluster based on the priority;
A station design method in which a computer executes the
(Section 8)
A program that causes a computer to execute the station placement design method according to claim 7.

Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. is.

100 station placement design device 102 division unit 103 evaluation unit 104 determination unit 105 selection unit 2100 computer

Claims

A station placement design device for designing the installation position of a wireless base station for building a wireless area,
a division unit configured to divide a plurality of terminal positions, which are evaluation points within the radio area, into clusters of the number of radio base stations installed within the radio area;
the radio base based on an evaluation result including at least one of the number of terminal positions that satisfy the required received power for each cluster and the level of satisfaction with the required received power at all the terminal positions in the cluster; an evaluation unit configured to prioritize candidate installation locations of said radio base station represented by a station location or a combination of said radio base station location and antenna orientation;
a determination unit configured to determine the installation position of the radio base station for each cluster based on the priority;
A station placement design device.
The station placement design device according to claim 1, wherein the determining unit determines the installation positions of the radio base stations so that the positions of the radio base stations do not overlap between the clusters.
The decision unit
In the cluster, if the installation position of the radio base station is set in order from the candidate with the highest priority, and the position of the radio base station overlaps with another cluster,
determining installation positions of the radio base stations in the cluster and the other clusters based on at least one of the evaluation results in the cluster and the other clusters and the evaluation results in the plurality of clusters;
The station placement design device according to claim 1.
The decision unit
In the cluster, if there are multiple candidates with the highest priority,
Selecting one candidate from among the plurality of candidates based on the evaluation results in the plurality of clusters;
4. The station placement design device according to claim 3.
When adding a new wireless base station in a wireless area where existing wireless base stations are located,
The division unit newly installs a terminal position within the radio area after excluding, from the terminal positions within the radio area, a terminal position that satisfies a required received power by the existing radio base station. into a number of clusters,
The station placement design device according to claim 1.
When the existing radio base station has a plurality of antennas,
dividing the plurality of terminal positions within the radio area into clusters of the number of radio base stations to be installed within the radio area including the existing radio base station;
calculating, for each cluster, the evaluation result including at least one of the proportion of the terminal positions that satisfy the required received power and the degree of satisfaction with the required received power at all terminal positions in the cluster;
selecting the direction of the antenna of the existing radio base station based on the evaluation result;
6. The station placement design device according to claim 5, comprising a selection unit configured as follows.
A station placement design method for designing the installation position of a wireless base station for building a wireless area,
A division process for dividing a plurality of terminal positions, which are evaluation points within the radio area, into clusters of the number of radio base stations installed within the radio area;
the radio base based on an evaluation result including at least one of the number of terminal positions that satisfy the required received power for each cluster and the level of satisfaction with the required received power at all the terminal positions in the cluster; an evaluation process for prioritizing candidate installation positions of the radio base station represented by a station position or a combination of the position of the radio base station and the orientation of the antenna;
a determination process of determining the installation position of the radio base station for each cluster based on the priority;
A station design method in which a computer executes the
A program that causes a computer to execute the station placement design method according to claim 7.