Base station layout support device, base station layout support method and program

Abstract

This base station placement assistance device has: a clustering unit that divides position information for each of a plurality of wireless terminals into clusters so as to satisfy a limiting condition relating to the placement of wireless base stations; and a calculation unit that uses the number of clusters as the number of placements of the wireless base stations in relation to the wireless terminals, and calculates the placement positions of the wireless base stations on the basis of the position information belonging to each of the clusters. The efficiency of determination of the number of placements and the placement positions of the wireless base stations is thereby improved.

Description

[Technical field]

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

[0002] In recent years, with the rapid spread of wireless terminals such as smartphones and tablets, the number of users of large-volume content via wireless terminals is increasing, and the amount of traffic on wireless networks is rapidly increasing. In order to accommodate wireless traffic at low cost and easily, the IEEE802.11 wireless LAN standard, which is widely used as a high-speed wireless access system using radio waves in license-free bands, is often used. Wireless LAN networks are provided in various areas, such as private areas such as homes and offices, and public areas such as stores, stations, and airports.

[0003] When constructing a wireless LAN network, various elements must be considered, such as the construction of wireless base station equipment, the wireless LAN communication part such as parameter settings, the network part between wireless base station and switch and between switch and backhaul line, and the higher level service part such as user authentication and portal screen. Among them, this article focuses on the installation information of wireless base station equipment in the construction of wireless base station equipment.

[0004] In general, when wireless communication signals are attenuated due to propagation distance or obstructions, the quality and capacity of wireless communication declines. Therefore, it is desirable to keep the distance between wireless base stations and wireless terminals short and ensure visibility of the propagation path. On the other hand, the number of wireless base stations to be installed is restricted by the costs of equipment, installation, and operation, as well as radio interference, so it is important to install the required number of wireless base stations in appropriate locations for the area to be covered by wireless LAN. There are limitations on the distance radio waves can reach from a wireless base station and the number of users that one wireless base station can accommodate, so the number and locations of wireless base stations to be installed must be determined according to these conditions.

[0005] As a method for calculating the installation location of a radio base station, for example, Non-Patent Document 1 proposes a technology for dynamically changing the position of a radio base station according to the distribution of users within an area, and uses the k-means clustering method shown in Non-Patent Document 2 to calculate the installation location of a radio base station according to the user positions within an area. [Prior art documents] [Non-patent literature]

[0006] [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 Techniques, RCS2016-43, pp. 107-112, May. 2016. [Non-Patent Document 2] J. Macqueen, "SOME METHODS FOR CLASSIFICATION AND ANALYSIS OF MULTIVARIATE OBSERVATIONS", Proc. of 5th Berkeley Symposium on Mathematical Statistics and Probability, pp.281-297, 1967. Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the above conventional technology, the number of installed wireless base stations needs to be determined in advance. Therefore, when trying to calculate (optimize) including the number of installed wireless base stations, it is necessary to perform calculations multiple times with different numbers of installed wireless base stations and compare the results, which is a lot of work.

[0008] The present invention has been made in consideration of the above-mentioned points, and has an object to improve the efficiency of determining the number and locations of wireless base stations. [Means for solving the problem]

[0009] In order to solve the above problem, the base station deployment support device includes a clustering unit that divides location information of each of a plurality of wireless terminals into a number of clusters that satisfies a constraint on the deployment of wireless base stations, and a calculation unit that sets the number of clusters to the number of deployment of wireless base stations for the wireless terminals and calculates the deployment locations of the wireless base stations based on the location information belonging to each of the clusters. The clustering unit recursively repeats combining a pair of clusters having a minimum index value based on radio wave propagation attenuation between the clusters among the pairs of clusters that satisfy the constraint condition from a state in which the position information of each of the plurality of wireless terminals is classified into different clusters. . Effect of the Invention

[0010] This makes it possible to efficiently determine the number and locations of wireless base stations. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of a hardware configuration of a base station arrangement supporting device 10 according to an embodiment of the present invention. [Diagram 2] 1 is a diagram illustrating an example of a functional configuration of a base station arrangement supporting device 10 according to an embodiment of the present invention. [Diagram 3] 4 is a flowchart illustrating an example of a processing procedure executed by base station arrangement supporting device 10. [Figure 4] FIG. 11 is a diagram illustrating an example of terminal arrangement information. [Diagram 5] 13 is a flowchart illustrating an example of a processing procedure for generating terminal cluster information that satisfies a base station arrangement condition. [Figure 6] FIG. 13 is a diagram showing an example of a path for each cluster pair. [Figure 7] FIG. 11 is a diagram showing an example of a calculation result of radio wave propagation attenuation value in a path of each cluster pair. [Figure 8] FIG. 13 is a diagram illustrating an example of a calculation result of the wireless distance of each cluster pair. [Figure 9] FIG. 13 is a diagram showing an example of the calculation results of the placement information of the base station 30 when the "maximum communication distance" is set as the base station placement condition. [Figure 10]FIG. 13 is a diagram showing an example of the calculation results of the placement information of the base station 30 when the "number of terminals accommodated per base station" is set as the base station placement condition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a method for calculating placement information (placement number and placement location) of wireless communication base stations (hereinafter, referred to as "base stations 30") is disclosed.

[0013] First, a base station placement assistance device 10, which is a device (computer) that calculates placement information of base stations 30, will be described.

[0014] Fig. 1 is a diagram showing an example of a hardware configuration of a base station layout support device 10 according to an embodiment of the present invention. The base station layout support device 10 in Fig. 1 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.

[0015] A program for implementing the processing in base station placement assistance device 10 is provided by recording medium 101 such as a CD-ROM. When recording medium 101 storing the program is set in drive device 100, the program is installed from recording medium 101 via drive device 100 into auxiliary storage device 102. However, the program does not necessarily have to be installed from recording medium 101, but may be downloaded from another computer via a network. Auxiliary storage device 102 stores the installed program as well as necessary files, data, and the like.

[0016] 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 base station deployment support device 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.

[0017] Fig. 2 is a diagram showing an example of a functional configuration of a base station placement support device 10 in an embodiment of the present invention. In Fig. 2, the base station placement support device 10 has an information acquisition unit 11, a clustering unit 12, a placement information calculation unit 13, etc. Each of these units is realized by a process in which one or more programs installed in the base station placement support device 10 are executed by a CPU 104. The program may be distributed recorded on a recording medium, or may be distributed via a network.

[0018] The following describes a processing procedure executed by the base station placement supporting device 10. FIG.

[0019] In step S101, the information acquisition unit 11 acquires information (area information) about the area where the base station 30 is located, and information indicating the position of each of one or more wireless terminals (hereinafter simply referred to as "terminals 20") in the area (hereinafter referred to as "terminal location information"). Area information refers to information indicating the layout of the area. More specifically, area information refers to information indicating the size (shape) of the area, the location (position and shape of objects) of walls and objects (radio wave obstructions), material information, etc.

[0020] Fig. 4 is a diagram showing an example of terminal layout information. As shown in Fig. 4, the terminal layout information is information indicating the position of each terminal 20 in the area A1 indicated by the area information. The example of Fig. 4 shows that six terminals 20-A to 20-F are arranged in the area A1 at the positions shown in Fig. 4.

[0021] The area information is, for example, registered in advance in the auxiliary storage device 102 of the base station placement assistance device 10. The terminal placement information can be acquired using known technology. For example, if outdoors, location information may be acquired using a Global Positioning System (GPS). If indoors, location information may be acquired by positioning using a Bluetooth (registered trademark) beacon or the like or by positioning using geomagnetism. Furthermore, if the location of the terminal 20 is fixed, the location information of each terminal 20 may be registered in advance.

[0022] Next, the clustering unit 12 clusters (divides the terminals 20 into a plurality of clusters) so as to satisfy a constraint condition (hereinafter referred to as "base station arrangement condition") that is set in advance regarding the arrangement of the base station 30, and generates information indicating the clustering result (hereinafter referred to as "terminal cluster information") (S102). Details of the base station arrangement condition will be described later.

[0023] Next, the placement information calculation unit 13 calculates placement information (placement number and placement position) of the base stations 30 based on the terminal cluster information (S103). Specifically, the placement information calculation unit 13 calculates the number of clusters indicated by the terminal cluster information as the placement number of the base stations 30. The placement information calculation unit 13 also calculates the placement positions of the base stations 30 corresponding to each cluster based on the positions of the terminals 20 belonging to each cluster indicated by the terminal cluster information. For example, the placement information calculation unit 13 may calculate the center of gravity of the cluster as the placement position of the base station 30.

[0024] Next, details of step S102 will be described. Fig. 5 is a flowchart for explaining an example of a processing procedure for generating terminal cluster information that satisfies base station arrangement conditions.

[0025] In step S201, the clustering unit 12 sets all the terminals 20, whose locations are indicated in the terminal layout information, into individual clusters. Therefore, as many clusters as the number of terminals 20 are generated.

[0026] Next, the clustering unit 12 judges whether or not there is a cluster pair whose cluster coupling has not been judged among the currently existing clusters (S202). If there is no such cluster pair (No in S202), the process of FIG. 5 ends.

[0027] If the corresponding cluster pair exists (Yes in S202), Next, the clustering unit 12 calculates an estimate of the radio wave propagation attenuation of the path between clusters of each cluster pair for which cluster joining has not been determined (hereinafter referred to as the "radio wave propagation attenuation value") based on the area information and terminal placement information acquired in step S101 (S203).

[0028] Fig. 6 is a diagram showing an example of a path between each cluster pair. Fig. 6 shows an example of a path between clusters in each cluster pair in a state where step S102 is executed for the first time. Therefore, one terminal 20 corresponds to one cluster, and the dashed lines connecting the terminals 20 indicate the path (communication route) between the clusters. When the clusters are combined one or more times, for a cluster to which two or more terminals 20 belong, the center of gravity of the cluster may be set as the connection point of the path.

[0029] The radio wave propagation attenuation value can be calculated using various radio wave propagation models that consider ray tracing and shadowing, based on area information (area size, layout and material information of walls and objects, etc.) and terminal layout information. Figure 7 shows an example of the calculation results of radio wave propagation attenuation values ​​in the paths of each cluster pair. In Figure 7, one terminal 20 corresponds to one cluster.

[0030] Next, the clustering unit 12 calculates the wireless distance of the path between the clusters of each cluster pair based on the radio wave propagation attenuation value (S204). In this embodiment, the wireless distance refers to an index value indicating the "distance from the viewpoint of wireless communication" that takes into account the conditions of the wireless environment in addition to the physical distance (for example, increasing the distance when there is obstruction).

[0031] Figure 8 shows an example of the calculation result of the wireless distance for each cluster pair. The wireless distance can be calculated from the radio wave propagation attenuation value by, for example, assuming a constant transmission power and converting the radio wave propagation attenuation value into a distance assuming free space loss (square attenuation). Various attenuation models can also be used. This makes it possible to calculate the wireless distance taking into account area information (area size, arrangement and material information of walls and objects, etc.).

[0032] Note that calculating the radio wave propagation attenuation value and wireless distance for all cluster pairs whose cluster bonding has not yet been determined may result in an increased amount of calculations depending on the conditions. Therefore, it is possible to improve efficiency by calculating these values ​​for only one side, assuming that there is bidirectional communication, or by omitting the calculations for cluster pairs where the physical distance between the clusters is greater than a certain amount, and setting the wireless distance to infinity.

[0033] Next, the clustering unit 12 selects one cluster pair with the shortest wireless distance from among the cluster pairs for which cluster joining has not been determined, and sets the cluster joining determination as completed (S205). The selected cluster pair is hereinafter referred to as a "target cluster pair".

[0034] Next, the clustering unit 12 judges whether the target cluster pair satisfies the base station arrangement condition (S206). The base station arrangement condition is, for example, a condition including either or both of "maximum communication distance" and "number of terminals accommodated per base station".

[0035] The "maximum communication distance" is a threshold (maximum distance) for the distance from a terminal 20 belonging to a cluster to the location of a base station 30 for that cluster (for example, the center of gravity of that cluster). If the distances from the center of gravity of the cluster after the target cluster pair is combined to all of the terminals 20 belonging to the combined cluster are less than or equal to the "maximum communication distance", the condition for the "maximum communication distance" is satisfied.

[0036] The "number of terminals accommodated per base station" is a threshold for the number of terminals belonging to a cluster. If the number of terminals belonging to a cluster after the target cluster pair is combined is equal to or less than the "number of terminals accommodated per base station," the condition for the "number of terminals accommodated per base station" is met.

[0037] In addition, when both the "maximum communication distance" and the "number of terminals accommodated per base station" constitute a base station allocation condition, the base station allocation condition is satisfied only when both are satisfied.

[0038] If the target cluster pair does not satisfy the base station arrangement condition (No in S206), the process returns to step S202. If the target cluster pair satisfies the base station arrangement condition (Yes in S206), the clustering unit 12 combines the target cluster pair to form a new cluster (S207), and the process returns to step S202.

[0039] That is, the clustering unit 12 recursively repeats combining pairs of clusters having the shortest wireless distance among pairs of clusters that satisfy the base station arrangement conditions, from a state in which the location information of each of the multiple terminals 20 is classified into different clusters.

[0040] By proceeding with the combination of clusters when the base station deployment conditions are satisfied, it is possible to calculate deployment information of base station 30 (the number and locations of deployed wireless base stations) within a range in which the base station deployment conditions are satisfied.

[0041] For example, Fig. 9 is a diagram showing an example of the calculation result of the placement information of the base station 30 when the "maximum communication distance" is set as the base station placement condition. Fig. 9 shows an example where the "maximum communication distance" is X [m]. In the area A1 shown in Fig. 9, a plurality of terminals 20 in the area A1 are classified into three clusters, and as a result, three base stations 30-A, B, C are placed at the centers of gravity of the respective clusters.

[0042] Fig. 10 is a diagram showing an example of the calculation result of the placement information of the base station 30 when the "number of terminals accommodated per base station" is set as the base station placement condition. Fig. 10 shows an example where the "number of terminals accommodated per base station" is 4. In the area A1 shown in Fig. 10, a plurality of terminals 20 in the area A1 are classified into four clusters, and as a result, four base stations 30-A, B, C, and D are placed at the centers of gravity of the respective clusters.

[0043] As described above, according to the present embodiment, it is possible to easily calculate the number and locations of wireless base stations that satisfy constraints (e.g., communication distance and the number of terminals accommodated per base station) related to the placement of base stations 30 for terminals 20 distributed within an area. Therefore, it is possible to efficiently determine the number and locations of wireless base stations.

[0044] Therefore, in conventional technology, it was difficult to calculate the location of a radio base station taking into account the distance that radio waves can reach from the radio base station and the number of users that one radio base station can accommodate, but in this embodiment, such calculations can be easily performed.

[0045] In this embodiment, the arrangement information calculation unit 13 is an example of a calculation unit.

[0046] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to such specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0047] 10 Base station placement support equipment 11 Information acquisition department 12 Clustering Department 13 Placement information calculation unit 20 Terminals 30 base station 100 Drive device 101 Recording media 102 Auxiliary storage 103 Memory device 104 CPU 105 Interface device B Bus

Claims

1. a clustering unit that divides location information of each of a plurality of wireless terminals into a number of clusters that satisfies a constraint on the placement of wireless base stations; a calculation unit that sets the number of clusters as the number of radio base stations to be arranged with respect to the radio terminal, and calculates the arrangement positions of the radio base stations based on the location information belonging to each of the clusters; having the clustering unit, from a state in which the location information of each of the plurality of wireless terminals is classified into different clusters, recursively repeats combining a pair of clusters having a minimum index value based on radio wave propagation attenuation between the clusters among the pairs of clusters that satisfy the constraint condition. A base station arrangement support device comprising:

2. The constraint condition includes one or both of a maximum distance from a wireless base station to the wireless terminal and a number of terminals accommodated per wireless terminal.

2. The base station arrangement support device according to claim 1,

3. a clustering procedure for dividing location information of each of a plurality of wireless terminals into a number of clusters that satisfies a constraint on the placement of wireless base stations; a calculation step of setting the number of clusters as the number of radio base stations to be arranged with respect to the radio terminal, and calculating the arrangement positions of the radio base stations based on the location information belonging to each of the clusters; The computer executes the clustering step recursively repeats combining a pair of clusters having a minimum index value based on radio wave propagation attenuation between clusters among pairs of clusters that satisfy the constraint condition, from a state in which the location information of each of the plurality of wireless terminals is classified into different clusters; A base station arrangement support method comprising:

4. 3. A program for causing a computer to function as the base station arrangement support device according to claim 1.

Images