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

Abstract

This station placement design apparatus designs the placement of base stations and reflectors for constructing a wireless area and comprises: a placement unit that places multiple terminal locations, which are evaluation points, and multiple candidate locations, which are candidates for installation locations of the base stations or reflectors, within the wireless area including obstructions; a calculation unit that calculates the received power between a terminal location and a candidate location, and the received power between the candidate location and other candidate locations; a first selection unit that selects base station candidate locations for each of different numbers of base stations from among the multiple candidate locations; a second selection unit that, if there is a terminal location that cannot be accommodated by the base station candidate locations among the multiple terminal locations, selects such reflector candidate location and reflector orientation as to enable the unaccommodated terminal location to be accommodated, in combination with the base station candidate locations; and a determination unit that determines the base station and reflector placement that minimizes the cost of the wireless area from among base station candidate locations or combinations of the base station candidate locations, reflector candidate locations, and reflector orientations.

Description

[Technical Field]

[0001] The present invention relates to a station placement design device, a station placement design method, and a program. [Background technology]

[0002] A base station location design system is known that designs the appropriate installation locations of wireless base stations to build wireless coverage areas. As the use of high-frequency bands expands in wireless communication systems, the effects of attenuation and shielding become greater. Technological studies are being conducted on base station location design that utilizes reflectors.

[0003] For example, Non-Patent Document 1 discusses a method for converting a fluctuating NLoS area into a line-of-sight area without adding base stations by installing metal reflectors within the area that can control the reflection direction, as well as area shift technology that maximizes the number of terminals in an NLoS environment. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Shirasaka et al., "A Study on Improving Received Power in NLoS Environments for 28GHz Band Indoor Wireless Systems Using Metal Reflectors," IEICE Technical Report, vol. 121, no. 391, RCS2021-271, pp. 108-113, March 2022 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional technology, the placement design of reflectors for already deployed base stations has been considered, but it is not possible to combine base stations and reflectors to create a placement design that meets the necessary communication requirements at low cost.

[0006] The embodiments of the present invention have been made in consideration of the above problems, and enable a station placement design that meets necessary communication requirements at low cost by combining a base station and a reflector. [Means for solving the problem]

[0007] In order to solve the above problem, a station location design device according to an embodiment of the present invention is a station location design device that designs the location of base stations and reflectors to construct a wireless area, and includes: a location unit configured to locate a plurality of terminal positions that are evaluation points and a plurality of candidate positions that are candidates for installation positions of the base stations or the reflectors within the wireless area including obstructions; a calculation unit configured to calculate received power between the terminal positions and the candidate positions, and received power between the candidate positions and other candidate positions; a first selection unit configured to select, for each different number of base stations, candidate positions of base stations for the number of base stations from the plurality of candidate positions; a second selection unit configured, when there is a terminal position among the plurality of terminal positions that cannot be accommodated by the candidate positions of the base stations, to select, in combination with the candidate positions of the base stations, a candidate position of the reflector and an orientation of the reflector that can accommodate the terminal position that cannot be accommodated; and a determination unit configured to determine the location of the base stations and reflectors that minimizes the cost of the wireless area from the candidate positions of the base stations or combinations of the candidate positions of the base stations, the candidate positions of the reflectors, and the orientations of the reflectors. [Effects of the Invention]

[0008] According to the embodiment of the present invention, it becomes possible to perform a station placement design that meets necessary communication requirements at low cost by combining a base station and a reflector. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a station placement design apparatus according to an embodiment of the present invention. [Figure 2] 10 is a flowchart illustrating an example of a station placement design process according to the present embodiment. [Figure 3]FIG. 1 is a diagram (1) for explaining the station placement design process according to the present embodiment. [Figure 4] FIG. 10 is a diagram (2) for explaining the station placement design process according to the present embodiment. [Figure 5] FIG. 3 is a diagram (3) for explaining the station placement design process according to the present embodiment. [Figure 6] FIG. 10 is a diagram showing an example of an evaluation list according to the embodiment. [Figure 7] 10 is a flowchart illustrating an example of a second selection process according to the first embodiment. [Figure 8] 10 is a flowchart illustrating an example of a second selection process according to the second embodiment. [Figure 9] 10 is a flowchart showing an example of a first selection process according to the present embodiment. [Figure 10] 10 is a flowchart showing another example of the first selection process according to the embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a hardware configuration of a station placement design apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] <Configuration example of a station placement design device> FIG. 1 is a diagram showing an example of the configuration of a station location design device according to this embodiment. The station location design device 100 is an information processing device having a computer configuration, or a system including multiple computers. The station location design device 100 performs station location design, which designs the placement of base stations and reflectors to build a wireless coverage area. Here, the reflector is, for example, a reflector that alleviates the problem of radio waves not reaching places other than line of sight and enables direction control of reflected waves. Preferably, the reflector selectively reflects radio waves in a predetermined frequency band.

[0012] The station placement design device 100 realizes an area setting unit 101, an arrangement unit 102, a calculation unit 103, a first selection unit 104, a second selection unit 105, a determination unit 106, an input / output unit 107, etc., by, for example, a computer included in the station placement design device 100 executing a program stored in a storage medium or the like. Note that at least a part of the above functional configurations may be realized by hardware. Furthermore, the station placement design device 100 realizes a memory unit 108, for example, by a storage device or the like of the computer included in the station placement design device 100.

[0013] The area setting unit 101 sets a wireless area to be designed. The wireless area to be designed includes, for example, objects such as walls, desks, and shelves that act as shields. For example, the area setting unit 101 may set the wireless area to be designed based on a building database (DB) that represents the structure of a building, or a three-dimensional computer-aided design (CAD). Alternatively, the area setting unit 101 may set the wireless area to be designed based on three-dimensional data acquired by a three-dimensional sensor such as a LiDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging) or a depth camera.

[0014] The placement unit 102 executes placement processing to place, within the wireless area to be designed, a plurality of terminal positions which are evaluation points for evaluating received power and a plurality of candidate positions which are candidates for the installation positions of base stations or reflectors.

[0015] The calculation unit 103 executes a calculation process to calculate the received power between the terminal position placed by the placement unit 102 and a candidate position, and the received power between the candidate position and another candidate position. For example, the calculation unit 103 calculates the received power received from each candidate position at each terminal position using a radio wave propagation simulation technique such as ray tracing. In this embodiment, the calculation unit 103 further calculates the received power received from each other candidate position at each candidate position.

[0016] The first selection unit 104 executes a first selection process for selecting candidate positions of base stations of the number n of base stations from among a plurality of candidate positions for each different number n of base stations (for example, n=1 to N, where N is an integer equal to or greater than 2). For example, the first selection unit 104 divides the plurality of terminal positions arranged by the arrangement unit 102 into clusters of the number n of base stations, and selects, for each divided cluster, candidate positions of base stations for which more terminal positions satisfy a predetermined communication quality (for example, received power). Alternatively, the first selection unit 104 uses a greedy algorithm to select candidate positions of base stations in order from candidate positions of base stations for which more terminal positions satisfy the predetermined communication quality, until the number of base stations reaches n.

[0017] If there is a terminal position among the multiple terminal positions that cannot be accommodated by the candidate positions of the base station selected by the first selection unit 104, the second selection unit 105 selects a candidate position of a reflector that can accommodate the terminal position that cannot be accommodated, in combination with the candidate position of the base station, and an installation direction of the reflector. Note that the installation direction of the reflector is an example of the orientation of the reflector.

[0018] For example, based on the received power calculated by the calculation unit 103, the second selection unit 105 extracts a candidate position that can accommodate the terminal position that cannot be accommodated from among the multiple candidate positions, excluding the candidate position of the base station selected by the first selection unit 104. Furthermore, the second selection unit 105 calculates a reflector transmission power from the radio wave propagation attenuation from the candidate position of the base station to the extracted candidate position and the reflectivity of the reflector for the extracted candidate position. Furthermore, based on the calculated reflector transmission power, the second selection unit 105 sets, among the extracted candidate positions, a candidate position where the received power at the terminal position that cannot be accommodated is equal to or greater than a predetermined value as a candidate position of the reflector.

[0019] Further, the second selection unit 105 determines, for example, the installation direction of the reflector as the bisector direction of the angle between the radio wave arrival direction vector in which the power is maximum in the direction of the candidate position of the base station as viewed from the candidate position of the reflector and the radio wave arrival direction vector in which the power is maximum in the direction of the terminal position that cannot be accommodated. Alternatively, the second selection unit 105 may evaluate a plurality of installation directions of the reflector to be installed at the candidate position of the reflector, and determine the installation direction in which the received power from the reflector is maximum at the terminal position that cannot be accommodated as the installation direction of the reflector.

[0020] The determination unit 106 executes a determination process to determine the placement of the base station and the reflector that minimizes the cost of the wireless area from among the above-mentioned candidate positions of the base station or combinations of the candidate positions of the base station, the candidate positions of the reflector, and the installation direction of the reflector. For example, the determination unit 106 determines the installation position of the base station, the installation position of the reflector, and the installation direction of the reflector that minimizes the cost of the wireless area.

[0021] The input / output unit 107 performs, for example, an output process of outputting the installation method of the base station and reflector determined by the determination unit 106 to an external device, and an input process of receiving input of design conditions and the like from an external device.

[0022] The storage unit 108 stores, for example, data on the wireless area set by the area setting unit 101, data on the multiple terminal positions and multiple candidate positions placed by the placement unit 102, data on the received power calculated by the calculation unit 103, etc. The storage unit 108 also stores the candidate positions of the base station selected by the first selection unit 104, the candidate positions and installation directions of the reflectors selected by the second selection unit 105, etc.

[0023] 1 is an example. For example, the storage unit 108 may be realized by a storage server or a class service that the station placement design device 100 can access via a communication network. Furthermore, each functional component of the station placement design device 100 is not limited to a physical machine (computer) and may be realized by, for example, a program executed by a virtual machine on the cloud. Furthermore, each functional component of the station placement design device 100 may be distributed among multiple information processing devices.

[0024] <Processing flow> Next, the processing flow of the station placement design method according to this embodiment will be described.

[0025] (Channel placement design processing) 2 is a flowchart showing an example of the station placement design process according to this embodiment. This process shows an example of the station placement design process executed by the station placement design device 100 described with reference to FIG.

[0026] In step S201, the area setting unit 101 of the station design device 100 sets a wireless area to be designed. As an example, the area setting unit 101 sets a wireless area 300 indoors where a plurality of shielding objects 301 are arranged, as shown in Fig. 3. The wireless area 300 set by the area setting unit 101 has three-dimensional coordinates based on, for example, three-dimensional CAD data or three-dimensional data acquired by a three-dimensional sensor.

[0027] In step S202, the placement unit 102 of the station placement design device 100 places a plurality of terminal positions 302, which are evaluation points for evaluating wireless quality such as received power, within the wireless area 300 set by the area setting unit 101, as shown in Fig. 3, for example. Furthermore, the placement unit 102 places a plurality of candidate positions 303, which are candidates for installation positions of base stations or reflectors, within the wireless area 300, as shown in Fig. 3, for example.

[0028] In step S203, the calculation unit 103 of the station placement design device 100 calculates the received power between the terminal position 302 placed by the placement unit 102 and the candidate position 303, and the received power between the candidate position 303 and another candidate position 303. For example, as shown in FIG. 3, the calculation unit 103 calculates the received power between the terminal position 302 and the candidate position 303 by a radio wave propagation simulation such as ray tracing. In ray tracing, the way in which radio waves (rays) transmitted from a transmission point are reflected or diffracted by structures along the way and reach a reception point is traced as the trajectory of each ray, and the power of all rays that reach the reception point is added up to estimate the radio wave intensity at the reception point. Note that ray tracing is also called ray tracing. In the same manner, the calculation unit 103 calculates the received power for all combinations of the terminal position 302 and the candidate position 303, and the candidate position 303 and another candidate position 303.

[0029] In step S204, the station design device 100 initializes the number of base stations n to 1, and executes the processes from step S205 onwards.

[0030] In step S205, the first selection unit 104 of the station placement design device 100 selects candidate positions for n base stations from among the plurality of candidate positions 303. Fig. 4 shows an example in which the first selection unit 104 selects candidate positions 401a and 401b for two base stations from among the plurality of candidate positions 303 (when the number of base stations n=2). Note that a specific example of the first selection process in which the first selection unit 104 selects candidate positions for n base stations from among the plurality of candidate positions 303 will be described later.

[0031] In step S206, the second selection unit 105 of the station design device 100 determines whether there is a terminal position 302 that cannot be accommodated by the base station selected by the first selection unit 104. For example, in Fig. 4, it is assumed that the received power from candidate positions 401a and 401b of the base station selected by the first selection unit 104 is equal to or less than a predetermined value at terminal positions 402a and 402b. In this case, the second selection unit 105 determines that there is a terminal position 302 that cannot be accommodated by the base station selected by the first selection unit 104.

[0032] If there is a terminal position 302 that cannot be accommodated, the second selection unit 105 shifts the process to step S207. On the other hand, if there is no terminal position 302 that cannot be accommodated, the second selection unit 105 shifts the process to step S208.

[0033] When the process proceeds to step S207, the second selection unit 105 selects, in combination with the candidate positions of the base stations selected by the first selection unit 104, candidate positions of reflectors that can accommodate the terminal positions that cannot be accommodated, and the orientation (installation direction) of the reflectors.

[0034] For example, in FIG. 4, it is assumed that the candidate positions 401a and 401b of the base station selected by the first selection unit 104 cannot accommodate the terminal positions 402a and 402b (the received power is equal to or less than a predetermined value).

[0035] 5, the second selection unit 105 extracts a candidate location 501a that can accommodate the unaccommodable terminal location 402a from among the plurality of candidate locations 303, excluding base station candidate locations 401a and 401b. For example, based on the received power calculated by the calculation unit 103, the second selection unit 105 extracts a candidate location 501a from among the candidate locations 303, excluding base station candidate locations 401a and 401b, where the received power at the unaccommodable terminal location 402a is equal to or greater than a predetermined value. Furthermore, for the extracted candidate location 501a, the second selection unit 105 calculates a reflector transmission power from the radio wave propagation attenuation from the base station candidate locations 401a and 401b to the extracted candidate location 501a and the reflectivity of the reflector. Furthermore, based on the calculated reflector transmission power, the second selection unit 105 selects, from among the extracted candidate positions, a candidate position (e.g., candidate position 501a) where the received power at the terminal position 402a that cannot be accommodated is equal to or greater than a predetermined value, as the candidate position of the reflector corresponding to the terminal position 402a that cannot be accommodated.

[0036] Furthermore, the second selection unit 105 determines the installation direction of the reflector to be installed at the reflector candidate position 501a. For example, the second selection unit 105 obtains a radio wave arrival direction vector in which the power is maximum in the direction of the base station candidate position 401a and a radio wave arrival direction vector in which the power is maximum in the direction of the terminal position 402a that cannot be accommodated, as viewed from the reflector candidate position 501a. The second selection unit 105 determines the direction of the bisector of the angle between the radio wave arrival direction vector in which the power is maximum in the direction of the base station candidate position 401a and the radio wave arrival direction vector in which the power is maximum in the direction of the terminal position 402a that cannot be accommodated, as the installation direction of the reflector. Alternatively, the second selection unit 105 may evaluate multiple installation directions of the reflector to be installed at the reflector candidate position 501a, and determine the installation direction in which the received power from the reflector is maximum at the terminal position 402a that cannot be accommodated as the installation direction of the reflector.

[0037] The second selection unit 105 performs the same process for each of the terminal devices that cannot be accommodated. For example, based on the received power calculated by the calculation unit 103, the second selection unit 105 extracts candidate locations 501b and 501c from among candidate locations 303 excluding base station candidate locations 401a and 401b, where the received power at the terminal location 402b that cannot be accommodated is equal to or greater than a predetermined value. Furthermore, for the extracted candidate locations 501b and 501c, the second selection unit 105 calculates reflector transmission power from the radio wave propagation attenuation from the base station candidate locations 401a and 401b to the extracted candidate locations 501b and 501c and the reflectivity of the reflector. Furthermore, based on the calculated reflector transmission power, the second selection unit 105 sets, among the extracted candidate locations, a candidate location (e.g., candidate location 501b) where the received power at the terminal location 402b that cannot be accommodated is equal to or greater than a predetermined value as the candidate location of the reflector corresponding to the terminal location 402b that cannot be accommodated.

[0038] Furthermore, the second selecting unit 105 determines the installation direction of the reflector to be installed at the reflector candidate position 501b in the same manner as the installation direction of the reflector to be installed at the reflector candidate position 501a described above.

[0039] In step S208, the station placement design device 100 determines whether the value of n is equal to or greater than N, the maximum number of base stations that can be placed in the wireless area 300. If the value of n is equal to or greater than N, the station placement design device 100 moves the process to step S210. On the other hand, if the value of n is not equal to or greater than N, the station placement design device 100 moves the process to step S209. The value of N is set in advance in the station placement design device 100 by a designer or the like.

[0040] In step S209, the station design device 100 adds 1 to n and returns the process to step S205.

[0041] By the processing of steps S204 to S209, the station location design device 100 can select candidate positions of the base stations, or candidate positions of the base stations and candidate positions of the reflectors and installation directions of the reflectors, for each different number of base stations (number of base stations: 1, 2, 3, ..., N).

[0042] Proceeding to step S210, the determination unit 106 of the station placement design device 100 determines the placement of the base station and the reflector that minimizes the cost of the wireless area 300 from among the candidate positions of the base station, or from among combinations of the candidate positions of the base station, the candidate positions of the reflector, and the orientations (installation directions) of the reflectors.

[0043] For example, the determination unit 106 compiles the evaluation results of the candidate positions of the base stations and the candidate positions and installation directions of the reflectors selected for each different number of base stations in steps S204 to S209 into an evaluation list 600 as shown in Fig. 6. In the example of Fig. 6, the evaluation list 600 includes information such as the "number of base stations," "number of reflectors," "communication requirement achievement rate (%)," and "cost evaluation point" as items.

[0044] The "number of base stations" corresponds to the number n of base stations described above. The "number of reflectors" is, for example, the number of reflectors selected in step S207 of FIG. 2 for each "number of base stations." The "communication requirement achievement rate (%)" is, for example, the achievement rate of the communication requirement corresponding to the combination of the "number of base stations" and the "number of reflectors" (for example, the proportion of terminal positions 302 that satisfy the communication requirement among multiple terminal positions 302). The "cost evaluation point" is an evaluation point for evaluating the cost of constructing the wireless area 300. As an example, if the cost of a base station is five times the cost of a reflector, the determination unit 106 may calculate the cost evaluation point of the wireless area 300 using the following formula (1). Cost evaluation score = (number of base stations x 5) + number of reflectors ... (Equation 1)

[0045] Furthermore, the determination unit 106 determines, from the evaluation list 600, the placement of the base stations and reflectors that minimize the cost evaluation points of the wireless area 300 while satisfying the communication requirement achievement rate required for the wireless area 300. For example, in the evaluation list 600 shown in Fig. 6, if the communication requirement achievement rate required for the wireless area 300 is 100%, the determination unit 106 determines the candidate positions of the base stations and the candidate positions and installation directions of the reflectors when the number of base stations is two, as the placement of the base stations and reflectors.

[0046] Through the processing described with reference to FIGS. 2 to 6, the station placement design device 100 according to this embodiment can perform station placement design that combines base stations and reflectors to meet necessary communication requirements at low cost.

[0047] <Second selection process> Next, a specific example of the second selection process executed by second selection unit 105 will be described.

[0048] [Example 1] Fig. 7 is a flowchart illustrating an example of a second selection process according to the first embodiment. This process illustrates an example of the second selection process that the second selection unit 105 of the station placement design device 100 executes, for example, in step S207 of Fig. 2. For example, when there are terminal positions 302 that cannot be accommodated in the candidate positions of the base station selected by the first selection unit 104 in step S205 of Fig. 2, the second selection unit 105 executes the process illustrated in Fig. 7 for each of the terminal positions 302 that cannot be accommodated.

[0049] In step S701, the second selecting unit 105 extracts a candidate location 303 that can accommodate a terminal location that cannot be accommodated from among the plurality of candidate locations 303, excluding the candidate locations of the base station selected by the first selecting unit 104. For example, based on the received power calculated by the calculating unit 103, the second selecting unit 105 extracts a candidate location 303 that has a received power of a terminal location that cannot be accommodated that is equal to or greater than a predetermined value.

[0050] In step S702, the second selection unit 105 calculates the reflector transmission power for the extracted candidate position 303 from the radio wave propagation attenuation from the candidate position of the base station to the extracted candidate position 303 and the reflectance of the reflector.

[0051] In step S703, based on the calculated reflector transmission power, the second selection unit 105 selects, from among the extracted candidate positions 303, a candidate position 303 where the received power at a terminal position that cannot be accommodated is equal to or greater than a predetermined value as a candidate position of the reflector.

[0052] In step S704, the second selection unit 105 determines the installation direction of the reflector to be the bisector direction of the angle between the radio wave arrival direction vector in which the power is maximum in the direction of the candidate position of the base station, as viewed from the candidate position of the reflector, and the radio wave arrival direction vector in which the power is maximum in the direction of the terminal position that cannot be accommodated.

[0053] By the process of FIG. 7, the second selection unit 105 can select candidate positions and installation directions of reflectors that can accommodate the terminal positions that cannot be accommodated, in combination with candidate positions of base stations.

[0054] [Example 2] Fig. 8 is a flowchart illustrating an example of a second selection process according to the second embodiment. This process illustrates another example of the second selection process that the second selection unit 105 of the station placement design device 100 executes, for example, in step S207 of Fig. 2. For example, when there are terminal positions 302 that cannot be accommodated in the candidate positions of the base station selected by the first selection unit 104 in step S205 of Fig. 2, the second selection unit 105 executes the process illustrated in Fig. 8 for each of the terminal positions 302 that cannot be accommodated.

[0055] Among the processes shown in FIG. 8, the processes of steps S701 to S703 are the same as the second selection process according to the first embodiment described with reference to FIG. 7, and therefore will not be described here.

[0056] In step S801, the second selection unit 105 evaluates a plurality of installation directions of the reflector to be installed at the candidate position of the reflector, and determines the installation direction in which the received power from the reflector is maximum at the terminal position where the terminal cannot be accommodated as the installation direction of the reflector.

[0057] By the process of FIG. 8, the second selection unit 105 can select candidate positions and installation directions of reflectors that can accommodate the terminal positions that cannot be accommodated, in combination with candidate positions of base stations.

[0058] <First selection process> Next, a specific example of the first selection process executed by the first selection unit 104 will be described.

[0059] 9 is a flowchart showing an example of the first selection process according to this embodiment. This process shows an example of the first selection process that the first selection unit 104 of the station placement design device 100 executes, for example, in step S205 of FIG. 2.

[0060] In step S901, the first selection unit 104 selects, from among the candidate positions 303 where no base station is located, candidate positions of base stations where more terminal positions 302 satisfy a predetermined communication quality.

[0061] In step S902, the first selection unit 104 determines whether the number of candidate locations of the selected base stations has reached the number n of base stations. If the number of candidate locations of the base stations has not reached the number n of base stations, the first selection unit 104 returns the process to step S701. On the other hand, if the number of candidate locations of the base stations has reached the number n of base stations, the first selection unit 104 ends the process in FIG. 7.

[0062] In this way, the first selection unit 104 may select candidate positions of base stations number n by, for example, using a greedy method, selecting candidate positions 303 of base stations where more terminal positions 302 satisfy the required communication quality until the number of base stations reaches n.

[0063] 10 is a flowchart showing another example of the first selection process according to the present embodiment. This process shows another example of the first selection process executed by the first selection unit 104 of the station placement design device 100, for example, in step S205 of FIG. 2.

[0064] In step S1001, the first selection unit 104 divides the multiple terminal locations 302 into clusters with n base stations. As an example, the first selection unit 104 divides the multiple terminal locations 302 into clusters with n base stations using a known clustering method such as the k-means method. Note that the clustering method is not limited to the k-means method, and both non-hierarchical and hierarchical clustering methods can be applied.

[0065] In step S1002, the first selection unit 104 selects, for each divided cluster, base station candidate positions 303 for which more terminal positions 302 satisfy a predetermined communication quality.

[0066] In this way, the first selection unit 104 may, for example, divide multiple terminal positions 302 into clusters where n is the number of base stations, and select candidate positions 303 of base stations that satisfy the required communication quality at more terminal positions 302 for each cluster.

[0067] The station placement design device 100 and station placement design method according to this embodiment have been described above, but the station placement design device 100 and station placement design method according to the present invention can be modified and applied in various ways.

[0068] For example, in the above explanations, the multiple candidate positions 303 are described as the positions (coordinates) of a base station or a reflector, but the multiple candidate positions 303 may also be expressed as a combination of the position of the base station or a reflector and the installation direction (or the orientation of the antenna, etc.).

[0069] Although the above description assumes a single wireless communication system, a combination of multiple wireless communication systems may be used for each base station. In this case, since it is not possible to perform a fair evaluation across wireless communication systems using received power, the station location design device 100 may convert the received power into a comparable index such as an expected wireless transmission rate before evaluating the communication quality.

[0070] Furthermore, although the installation direction of the reflector has been described as being unchangeable after installation, this is not limiting, and for example, in step S207 of Fig. 2, when selecting a candidate position for the reflector, the second selection unit 105 may assume that the installation direction of the reflector can be controlled remotely, and may select the installation position for the reflector taking into consideration the control range.

[0071] Although the orientation of the reflector has been described so far as being the installation direction of the reflector, the orientation of the reflector may be the reflecting direction of the reflector, etc. For example, it is possible to use a reflector that can change the reflection direction of radio waves using metamaterial technology, etc. In this case, by selecting the reflection direction of the reflector so that radio waves are reflected and reach the base station and terminal, it is possible to achieve the same effect as when selecting the installation direction of the reflector. For example, in step S801 of FIG. 8, the second selection unit 105 may evaluate multiple reflection directions of the reflector to be installed at candidate reflector positions, and at a terminal position that cannot accommodate a terminal, select the reflection direction that maximizes the received power from the reflector as the orientation of the reflector. In this way, the orientation of the reflector may be the installation direction of the reflector or the reflecting direction of the reflector. Furthermore, the orientation of the reflector may be expressed by a combination of the installation direction of the reflector and the reflecting direction of the reflector, etc.

[0072] 2, the station placement design device 100 acquires a series of station placement design evaluation results while increasing the number of base stations within a predetermined range, and then performs station placement design from among these. However, the present invention is not limited to this, and the station placement design device 100 may acquire station placement design evaluation results each time while increasing the number of base stations, and if there is a station placement design evaluation result that satisfies all of the predetermined conditions, the station placement design result may be considered the final solution, and subsequent calculation processing may be terminated.

[0073] <Hardware configuration example> (Hardware configuration of station placement design device) Fig. 11 is a diagram showing an example of the hardware configuration of a station placement design device according to this embodiment. The station placement design device 100 has, for example, the hardware configuration of a computer 1100 as shown in Fig. 11. In the example of Fig. 11, the computer 1100 has a processor 1101, a memory 1102, a storage device 1103, a communication device 1104, an input device 1105, an output device 1106, a bus B, etc.

[0074] The processor 1101 is, for example, an arithmetic unit such as a CPU (Central Processing Unit) that executes predetermined programs to realize various functions. The memory 1102 is a storage medium readable by the computer 1100, and includes, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage device 1103 is a computer-readable storage medium, and may include, for example, a HDD (Hard Disk Drive), an SSD (Solid State Drive), various optical disks, and magneto-optical disks.

[0075] The communication device 1104 includes one or more pieces of hardware (communication devices) for communicating with other devices via a wireless or wired network. The input device 1105 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1106 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1105 and the output device 1106 may be integrated into one device (e.g., an input / output device such as a touch panel display).

[0076] The bus B is commonly connected to the above components and transmits, for example, address signals, data signals, and various control signals. The processor 1101 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).

[0077] (supplement) The station location design device 100 in this embodiment is not limited to being realized by a dedicated device, but may also be realized by a general-purpose computer. In this case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to realize the function. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0078] Additionally, "computer-readable recording media" includes various storage devices such as portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as hard disks built into computer systems. Furthermore, "computer-readable recording media" may also include devices that dynamically store programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and devices that store programs for a certain period of time, such as volatile memory within computer systems that serve as servers or clients in such cases.

[0079] Furthermore, the above program may be one that realizes part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in a computer system, or may be one that is realized using hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

[0080] <Effects of the embodiment> According to this embodiment, it becomes possible to perform a station placement design that satisfies necessary communication requirements at low cost by combining a base station and a reflector.

[0081] <Summary of the embodiment> This specification discloses at least the station placement design device, station placement design method, and program described in the following sections. (Section 1) A station placement design device that designs the placement of base stations and reflectors for constructing a wireless area, an arrangement unit configured to arrange a plurality of terminal positions as evaluation points and a plurality of candidate positions as candidates for the installation position of the base station or the reflector within the wireless area including the shielding object; a calculation unit configured to calculate a received power between the terminal position and the candidate position, and a received power between the candidate position and another candidate position; a first selection unit configured to select, for each different number of base stations, candidate locations of the base stations from among the plurality of candidate locations; a second selection unit configured to select, when there is a terminal position that cannot be accommodated by the candidate positions of the base station among the plurality of terminal positions, a candidate position of the reflector and an orientation of the reflector that can accommodate the terminal position that cannot be accommodated in combination with the candidate positions of the base station; a determination unit configured to determine an arrangement of the base station and the reflector that minimizes the cost of the wireless area from among the candidate positions of the base station or combinations of the candidate positions of the base station, the candidate positions of the reflector, and the orientations of the reflector; A station placement design device having the above. (Section 2) the orientation of the reflector includes an installation direction of the reflector; 2. The station location design device according to claim 1, wherein the second selection unit determines, as the installation direction of the reflector, the bisector direction of an angle between a radio wave arrival direction vector in which power is maximum in the direction of the candidate position of the base station and a radio wave arrival direction vector in which power is maximum in the direction of the terminal position that cannot be accommodated, as viewed from the candidate position of the reflector. (Section 3) The orientation of the reflector includes an installation direction or a reflection direction of the reflector, 2. The station location design device according to claim 1, wherein the second selection unit evaluates a plurality of installation directions or reflection directions of the reflector to be installed at the candidate position of the reflector, and determines the installation direction or reflection direction in which the received power from the reflector is maximum at the terminal position that cannot be accommodated as the orientation of the reflector. (Section 4) The second selection unit extracting a candidate position that can accommodate the terminal position that cannot be accommodated from among the plurality of candidate positions excluding the candidate position of the base station based on the reception power calculated by the calculation unit; calculating a reflector transmission power from the radio wave propagation attenuation from the base station candidate position to the extracted candidate position and the reflectivity of the reflector; Among the candidate positions extracted based on the reflector transmission power, a candidate position where the reception power at the terminal position that cannot be accommodated is equal to or greater than a predetermined value is determined as the candidate position of the reflector. 4. A station placement design device according to any one of items 1 to 3. (Section 5) 4. The station placement design device according to any one of claims 1 to 3, wherein the first selection unit divides the plurality of terminal positions into clusters of the number of base stations, and selects, for each cluster, candidate positions of the base stations that satisfy a predetermined communication quality for a greater number of the terminal positions. (Section 6) The station placement design device according to any one of paragraphs 1 to 3, wherein the first selection unit selects the candidate positions of the base stations in order from the candidate positions of the base stations that satisfy a predetermined communication quality with a larger number of the terminal positions, until the number of candidate positions of the base stations reaches the number of base stations. (Section 7) A station placement design device that designs the placement of base stations and reflectors for constructing a wireless area, A process of arranging a plurality of terminal positions as evaluation points and a plurality of candidate positions as candidates for the installation position of the base station or the reflector within the wireless area including the shielding object; A process of calculating a received power between the terminal position and the candidate position, and a received power between the candidate position and another candidate position; a process of selecting, for each different number of base stations, candidate locations for the number of base stations from the plurality of candidate locations; a process of selecting, when there is a terminal position that cannot be accommodated by the candidate positions of the base station among the plurality of terminal positions, a candidate position of the reflector and an orientation of the reflector that can accommodate the terminal position that cannot be accommodated in combination with the candidate positions of the base station; a process of determining an arrangement of the base station and the reflector that minimizes the cost of the wireless area from among the candidate positions of the base station or combinations of the candidate positions of the base station, the candidate positions of the reflector, and the orientations of the reflector; A station placement design method that performs the above. (Section 8) 8. A program that causes a computer to execute the station placement design method according to claim 7.

[0082] 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. [Explanation of symbols]

[0083] 100 Station location design device 102 Placement section 103 Calculation Unit 104 First Selection Section 105 Second Selection Section 106 Decision Section 300 wireless areas 301 Shield 302 Terminal Location 303 Candidate position 900 Computers

Claims

1. A station placement design device that designs the placement of base stations and reflectors for constructing a wireless area, an arrangement unit configured to arrange a plurality of terminal positions as evaluation points and a plurality of candidate positions as candidates for the installation position of the base station or the reflector within the wireless area including the shielding object; a calculation unit configured to calculate a received power between the terminal position and the candidate position, and a received power between the candidate position and another candidate position; a first selection unit configured to select, for each different number of base stations, candidate locations of the base stations from among the plurality of candidate locations; a second selection unit configured to select, when there is a terminal position that cannot be accommodated by the candidate positions of the base station among the plurality of terminal positions, a candidate position of the reflector and an orientation of the reflector that can accommodate the terminal position that cannot be accommodated in combination with the candidate positions of the base station; a determination unit configured to determine an arrangement of the base station and the reflector that minimizes the cost of the wireless area from among the candidate positions of the base station or combinations of the candidate positions of the base station, the candidate positions of the reflector, and the orientations of the reflector; A station placement design device having the above.

2. the orientation of the reflector includes an installation direction of the reflector; 2. The station location design device according to claim 1, wherein the second selection unit determines, as the installation direction of the reflector, the direction of the bisector of the angle between a radio wave arrival direction vector in which power is maximum in the direction of the candidate position of the base station and a radio wave arrival direction vector in which power is maximum in the direction of the terminal position that cannot be accommodated, as seen from the candidate position of the reflector.

3. The orientation of the reflector includes an installation direction or a reflection direction of the reflector, 2. The station location design device according to claim 1, wherein the second selection unit evaluates a plurality of installation directions or reflection directions of the reflector to be installed at the candidate position of the reflector, and determines the installation direction or reflection direction in which the received power from the reflector is maximized at the terminal position that cannot be accommodated as the orientation of the reflector.

4. The second selection unit extracting a candidate position that can accommodate the terminal position that cannot be accommodated from among the plurality of candidate positions excluding the candidate position of the base station based on the reception power calculated by the calculation unit; calculating a reflector transmission power from the radio wave propagation attenuation from the base station candidate position to the extracted candidate position and the reflectivity of the reflector; Among the candidate positions extracted based on the reflector transmission power, a candidate position where the reception power at the terminal position that cannot be accommodated is equal to or greater than a predetermined value is determined as the candidate position of the reflector. The station placement design device according to claim 1 .

5. 4. The station placement design device according to claim 1, wherein the first selection unit divides the plurality of terminal positions into clusters of the number of base stations, and selects, for each cluster, candidate positions of the base stations that satisfy a predetermined communication quality for a greater number of the terminal positions.

6. 4. The station location design device according to claim 1, wherein the first selection unit selects the candidate positions of the base stations in order from the candidate positions of the base stations at which a larger number of the terminal positions satisfy a predetermined communication quality, until the number of the candidate positions of the base stations reaches the number of the base stations.

7. A station placement design device that designs the placement of base stations and reflectors for constructing a wireless area, A process of arranging a plurality of terminal positions as evaluation points and a plurality of candidate positions as candidates for the installation position of the base station or the reflector within the wireless area including the shielding object; A process of calculating a received power between the terminal position and the candidate position, and a received power between the candidate position and another candidate position; a process of selecting, for each different number of base stations, candidate locations for the number of base stations from the plurality of candidate locations; a process of selecting, when there is a terminal position that cannot be accommodated by the candidate positions of the base station among the plurality of terminal positions, a candidate position of the reflector and an orientation of the reflector that can accommodate the terminal position that cannot be accommodated in combination with the candidate positions of the base station; a process of determining an arrangement of the base station and the reflector that minimizes the cost of the wireless area from among the candidate positions of the base station or combinations of the candidate positions of the base station, the candidate positions of the reflector, and the orientations of the reflector; A station placement design method that performs the above.

8. A program that causes a computer to execute the station placement design method according to claim 7.

Images