JP7615849B2 - Wireless access point arrangement method and wireless access point arrangement device - Google Patents

Description

The present invention relates to a wireless access point deployment method and a wireless access point deployment device.

When placing a wireless access point, a coverage area in which radio waves of a specified strength can propagate is set as a circle centered on the access point, and the position of the access point is determined so that the coverage area covers the target area without excess or deficiency (for example, see Patent Document 1).

JP 2020-167631 A

However, if the coverage area is calculated uniformly for the entire target deployment area, and the ease of radio wave propagation varies from place to place, there is a risk that the coverage area will be insufficient in places where radio waves propagate poorly, or that more access points than necessary will be deployed in places where radio waves propagate easily.

A wireless access point placement method for solving the above problem includes a first step of dividing a target placement area having at least walls around the area in which an access point is to be placed into a first area including the walls and a second area not including the walls, using a map of the target placement area; a second step of calculating a radius of a coverage area of the access point in each of the first area and the second area based on different radio wave propagation characteristics of the first area and the second area so that the radius of the coverage area in the first area is larger than the radius of the coverage area in the second area ; and a third step of placing the access point in accordance with the target placement area based on the radius of the coverage area.

This makes it possible to optimize the number of access points to be deployed in the deployment target area.
In the wireless access point arrangement method, in the first step, a range a predetermined distance from the wall surface may be defined as the first region, and the remaining range may be automatically divided into the second region.

A wireless access point placement device for solving the above problem comprises a memory unit that stores a map of a target placement area having at least walls around it in which an access point is to be placed, a division unit that divides the inside of the target placement area from the map into a first area that includes the wall and a second area that does not include the wall, a radius calculation unit that calculates a radius of a coverage area of an access point in each of the first area and the second area based on radio wave propagation characteristics that differ between the first area and the second area so that the radius of the coverage area in the first area is larger than the radius of the coverage area in the second area , and an access point placement unit that places an access point in accordance with the target placement area from the radius of the coverage area.

This makes it possible to optimize the number of access points to be deployed in the deployment target area.
In the wireless access point arrangement device, the dividing unit may automatically divide the area into a first area and a second area from the wall surface, the second area being within a predetermined distance from the wall surface.

According to the present invention, it is possible to optimize the number of access points to be deployed in a target deployment area.

FIG. 1 is a schematic configuration diagram of a wireless access point arrangement device according to an embodiment. Floor plan (floor plan). Radio wave propagation characteristics diagram. FIG. 1A is an explanatory diagram of a coverage area when there is a wall, and FIG. 1B is an explanatory diagram of a coverage area when there is no wall. FIG. FIG. 1 is an explanatory diagram of the calculation process of the coverage area. FIG. 2 is a diagram showing an example of the arrangement of access points. Another example floor plan (plan view). FIG. 11 is an explanatory diagram of another example of a coverage area calculation process. FIG. 11 is an explanatory diagram of another example of a coverage area calculation process. FIG. 11 is an explanatory diagram of another example of a coverage area calculation process.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1, the wireless access point deployment device 10 includes, for example, a control unit 20 and a storage unit 30. The control unit 20 is realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). In addition, some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware.

The storage unit 30 is realized, for example, by a storage device (a storage device with a non-transitory storage medium) such as a hard disk drive (HDD) or flash memory, or a removable storage medium such as a DVD or CD-ROM. In addition to a program that realizes the control unit 20, the storage unit 30 stores, for example, a map of a target area having at least walls around which an access point is to be placed.

The map of the target area for access point placement includes three-dimensional information (3D) of structures in the target area. Specifically, the three-dimensional information (3D) of structures in the target area includes information about structures such as walls and equipment, such as the area of the structure, the volume of the structure, the height of the structure, the height of the ceiling, etc.

The control unit 20 includes a dividing unit 21 , a radius calculation unit 22 , and an access point arrangement unit 23 .
An example of a map of the placement target area stored in the storage unit 30 is shown in FIG. 2. For example, FIG. 2 shows a factory floor (plan view), and equipment is placed in the factory. In FIG. 2, the placement target area for the access point has at least wall surfaces Sw1, Sw2, and Sw3 around it. In FIG. 2, the wall surfaces Sw1, Sw2, and Sw3 extend linearly. The wall surface Sw1 and the wall surface Sw3 are parallel. The wall surface Sw2 extends at a right angle to the wall surfaces Sw1 and Sw3 so as to connect one end of the wall surface Sw1 and one end of the wall surface Sw3. The area surrounded by the three wall surfaces Sw1, Sw2, and Sw3 is the area in which the access point is to be placed.

When placing a wireless access point, the coverage area is set as a circle centered on the access point, and the distance that radio waves of a certain strength can propagate is calculated from the radio wave propagation characteristics, and this distance is set as the radius of the coverage area. For this reason, the memory unit 30 in FIG. 1 stores information about the radio wave propagation characteristics shown in FIG. 3. Specifically, the radio wave propagation characteristics are stored as a propagation model formula. The propagation model formula is expressed by the following formula (1).

E=CN×log(L)…(1)
E: radio wave strength C: constant N: attenuation coefficient L: distance The horizontal axis of Fig. 3 represents distance L. The vertical axis of Fig. 3 represents radio wave strength E. In Fig. 3, the propagation characteristic line (propagation model The propagation characteristic line (propagation model equation) Lt1 is prepared in advance through experiments or the like.

Using this propagation characteristic line (propagation model formula) Lt1, the distance L can be calculated from a predetermined radio wave intensity E, which serves as a reference value. The distance L becomes the radius Rca1, Rca2 of the coverage area of the access point.

Figures 4(a) and 4(b) show conceptual diagrams of the coverage area. In Figures 4(a) and 4(b), terminal T is positioned with equipment Fa between them relative to the antenna of access point AP. In Figure 4(a), wall surface Sw is located on the opposite side of equipment Fa from the position of terminal T. On the other hand, in Figure 4(b), there is no wall surface on the opposite side of equipment Fa from the position of terminal T.

In the case of FIG. 4(a), radio waves output from the antenna of the access point AP can fly over the equipment Fa and head toward the wall Sw, where they are reflected and reach the terminal T. As a result, radio waves can be expected to be reflected by the wall, resulting in strong radio wave strength.

On the other hand, in the case of FIG. 4(b), the radio waves output from the antenna of the access point AP go over the equipment Fa and the terminal T and do not reach the terminal T. As a result, the radio waves cannot be reflected by the wall surface, and the radio wave strength is weak.

In FIG. 3, a reference value A of the radio wave strength when a wall is present as shown in FIG. 4A is compared with a reference value B of the radio wave strength when no wall is present as shown in FIG.
The reference value A of the radio wave strength when a wall is present as shown in FIG. 4A is smaller than the reference value B of the radio wave strength when no wall is present as shown in FIG. 4B.

Therefore, the distance L in the "case with wall" shown in FIG. 4(a) is greater than the distance L in the "case without wall" shown in FIG. 4(b). In other words, as shown in FIG. 5, the radius Rca1 of the coverage area in the "case with wall" shown in FIG. 4(a) is greater than the radius Rca2 of the coverage area in the "case without wall" shown in FIG. 4(b).

The target area for access point placement shown in Figure 2 is divided into a first area Z1 shown in Figure 4(a) where reflection from wall surface Sw can be expected, and a second area Z2 shown in Figure 4(b) where reflection from wall surface Sw cannot be expected. In Figure 2, in the target area for access point placement surrounded by three walls Sw1, Sw2, and Sw3, the area along the walls Sw1, Sw2, and Sw3 is the first area Z1 where reflection from the walls of radio waves can be expected. The area not along the walls Sw1, Sw2, and Sw3 is the second area Z2 shown in Figure 4(b) where reflection from the walls cannot be expected.

FIG. 6 is a diagram illustrating the process of coverage area calculation.
As shown in FIG. 6, the control unit 20 calculates the radius of the coverage area from the propagation model formula and the reference value of the radio wave intensity.

Explaining this using Figure 2, the target placement area surrounded by walls Sw1, Sw2, and Sw3 is divided into a first area Z1 with walls Sw1, Sw2, and Sw3 and a second area Z2 with no walls. The radius of the coverage area in the first area Z1 with walls Sw1, Sw2, and Sw3 is large. On the other hand, the radius of the coverage area in the second area Z2 with no walls is small. Therefore, access points can be placed depending on whether or not there are walls.

By dividing the coverage area into areas with walls and areas without walls depending on whether or not reflections from the building walls are expected, it is possible to efficiently place access points.
Next, the operation will be described.

A map of a target area having at least walls around it in which access points are to be placed is stored in the storage unit 30. The wireless access point placement method includes the following first, second, and third steps.

First, in the first step, as shown in Figure 2, a map of a target area having at least walls around which an access point is to be placed is used to divide the inside of the target area into a first area Z1 including the walls and a second area Z2 not including the walls. In more detail, in the first step, as shown in Figure 2, a range within a predetermined distance Dp from the walls Sw1, Sw2, and Sw3 is set as the first area Z1, and the rest is automatically divided into the second area Z2.

Specifically, the dividing unit 21 divides the inside of the target placement area from the map into a first region Z1 that includes walls and a second region Z2 that does not include walls. More specifically, as shown in FIG. 2, the dividing unit 21 automatically divides the area within a predetermined distance Dp from the walls Sw1, Sw2, and Sw3 into the first region Z1 and the rest into the second region Z2.

Then, in the second step, as shown in FIG. 3, the radii Rca1 and Rca2 of the coverage areas of the access points in the first and second regions are calculated based on the different radio wave propagation characteristics in the first and second regions Z1 and Z2.

Specifically, the radius calculation unit 22 calculates the radii Rca1 and Rca2 of the coverage area of the access point in each of the first and second regions Z1 and Z2 based on the different radio wave propagation characteristics in the first and second regions Z1 and Z2.

The explanation will be given using Figure 3. The radii Rca1 and Rca2 of the access point's coverage area are calculated from the propagation characteristic line Lt1 based on the radio wave propagation characteristics. In detail, the coverage area radii Rca1 and Rca2 are obtained at the reference values A and B in Figure 3. The reference value A is the value in the first region Z1 including the wall surfaces Sw1, Sw2, and Sw3, and the reference value B is the value in the second region Z2 that does not include the wall surfaces. The reference value A is smaller than the reference value B. Therefore, the radius Rca1 in the first region Z1 including the wall surfaces Sw1, Sw2, and Sw3 is larger than the radius Rca2 in the second region Z2 that does not include the wall surfaces.

The reference values A and B are determined based on the user's specifications (level of high quality or low quality) and are values for stable high-speed communication.
Furthermore, in the third step, the access points are arranged in accordance with the target area from the radii Rca1 and Rca2 of the cover areas as shown in Fig. 7. Specifically, the access point arrangement unit 23 arranges the access points AP1 to AP6 and the access points AP7 to AP9 in accordance with the target area from the radii Rca1 and Rca2 of the cover areas.

In FIG. 7, in the region along the walls Sw1, Sw2, and Sw3 of the target placement area, equipment Fa exists between the access point AP and the wall Sw, as shown in FIG. 4(a). If a terminal T is located between the equipment Fa and the wall Sw, the radio waves emitted by the access point AP are reflected by the wall Sw and reach the terminal T. Therefore, in the region along the wall Sw of the target placement area, the radius Rca1 of the coverage area of the access point AP is large.

On the other hand, in FIG. 7, in the area of the target placement area away from the walls Sw1, Sw2, and Sw3, if equipment Fa is present between the access point AP and the terminal T, as shown in FIG. 4(b), the radio waves emitted by the access point AP are blocked by the equipment Fa. Therefore, in the area of the target placement area away from the walls Sw1, Sw2, and Sw3, the radius Rca2 of the coverage area of the access point AP is small.

As shown in FIG. 7, a circle C1 is obtained from the radius Rca1 of the access point's coverage area, and a square cell S1 inscribed in the circle C1 is obtained. Then, the square cells S1 are arranged so that one side of each cell overlaps. In this way, the coverage areas Ac1, Ac2, Ac3, Ac4, Ac5, and Ac6 of the communication targets are determined. Also, as shown in FIG. 7, a circle C2 is obtained from the radius Rca2 of the access point's coverage area, and a square cell S2 inscribed in the circle C2 is obtained. Then, the square cells S2 are arranged so that one side of each cell overlaps. In this way, the coverage areas Ac7, Ac8, and Ac9 of the communication targets are determined. Coverage areas Ac1 to Ac6 are large, and coverage areas Ac7 to Ac9 are small.

According to the wireless access point deployment method and wireless access point deployment device of the above embodiment, the following effects can be obtained.
(1) The number of access points to be deployed in the target deployment area can be optimized. In addition, since there is no shortage of coverage, the labor required for installing access points can be reduced.

(2) The range of a predetermined distance Dp from the wall surface can be automatically divided into a first region Z1 and a second region Z2 outside the range.
The embodiment is not limited to the above, and may be embodied as follows, for example.

The cells used for arranging access points are not limited to squares, and may be polygonal, such as triangular or hexagonal.
The propagation model equation is not limited to the equation (1) shown above, and may be a formula standardized by the ITU or the like.

- Walls include not only the walls of a building, but also the walls of partitions used for dividing rooms.
Instead of automatically dividing the area into a first area Z1 within a predetermined distance from the wall and a second area Z2 outside of that, a person may manually input the area by looking at the map.

It is also possible to prepare multiple propagation characteristic lines (propagation model equations) according to the type (material) of the wall surface and calculate the radius of the coverage area according to the type of wall surface.
In the case of a floor plan (plan view) as shown in Fig. 8, when designing the layout of access points, the layout design is limited to the area where access points can be installed, as shown in Fig. 9 and Fig. 10. This makes it possible to install access points without worrying about whether they can actually be installed at the designed location. In addition, adjustment of the installation location is not required. In Fig. 10, the layout design is centered on the possible installation area, and the access point positions after the layout design are shown in the access point installation possible area in the target placement area.

Let me explain in detail.
As shown in Fig. 9, a structure St is placed in the target area for placement of an access point, and an access point installable area is input to the map information of this target area using the input device 100 shown by the virtual line in Fig. 1. In Fig. 10, the access point installable area is a desired position on the edge of the structure St. A placement determination is made for each point so that it can be placed in the installable area, and placement calculations are performed so as to cover the entire target area.

Figure 11 is an example of access point placement calculation. In the placement target area, the area where an access point can be installed becomes the placement location of the access point after placement design. At this time, it is confirmed whether the installation possible area should be covered in order. Specifically, a circle C10 is found from the radius Rca10 of the access point coverage area, and a square cell S10 inscribed in the circle C10 is found. Then, the square cells S10 are arranged so that one side of each square cell S10 overlaps.

In this way, the number of steps required for on-site access point installation can be reduced, and the need for on-site access point placement adjustments is eliminated.
In this case, the cells used for arranging the access points may be not only squares but also polygons such as triangles, hexagons, etc. Furthermore, the area in which the access points can be installed may be automatically set without the user's specification, for example, by using the edge of a structure St that is in advance in the map information.

10...wireless access point placement device, 21...division unit, 22...radius calculation unit, 23...access point placement unit, 30...storage unit, Ac1 to Ac9...coverage area, Dp...predetermined distance, Sw1, Sw2, Sw3...wall surface, Rca1, Rca2...radius, Z1...first region, Z2...second region.

Claims (4)

a first step of dividing an interior of a target area into a first region including the wall surface and a second region not including the wall surface, using a map of the target area having at least a wall surface around the periphery, in which an access point is to be placed;
a second step of calculating a radius of a cover area of an access point in each of the first and second areas based on radio wave propagation characteristics different from each other in the first and second areas, such that the radius of the cover area in the first area is larger than the radius of the cover area in the second area ;
and a third step of arranging access points in accordance with the target arrangement area from the radius of the cover area. The wireless access point arrangement method according to claim 1, characterized in that in the first step, a range a predetermined distance from the wall surface is defined as the first region, and the remaining range is automatically divided into the second region. a storage unit that stores a map of a target area having at least walls around which an access point is to be placed;
a dividing unit that divides an interior of a placement target area into a first region including the wall surface and a second region not including the wall surface based on the map;
a radius calculation unit that calculates a radius of a cover area of an access point in each of the first area and the second area based on radio wave propagation characteristics different in the first area and the second area, such that the radius of the cover area in the first area is larger than the radius of the cover area in the second area ;
an access point placement unit that places access points in accordance with the placement target area based on a radius of the cover area. The wireless access point arrangement device according to claim 3, characterized in that the dividing unit defines a range a predetermined distance from the wall surface as the first region and automatically divides the remaining range into the second region.