Information processing system, radio wave propagation simulation method, and program

1 . An information processing system comprising a processor configured to:

divide a target area into a plurality of meshes of a predetermined size, and acquire mesh data indicating an environment of the target area with height information about the plurality of meshes on a per-mesh basis;

determine a two-dimensional ray trace from a transmission point to a reception point on the basis of the mesh data, a radio wave being transmitted at the transmission point, the radio wave being received at the reception point;

determine a three-dimensional ray trace corresponding to the two-dimensional ray trace, on the basis of the mesh data, and height information about the transmission point and the reception point; and

calculate an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined,

when determining a diffracted ray with respect to the three-dimensional ray trace, determine the diffracted ray with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is not a line of sight in a route between the transmission point and the reception point.

2 . The information processing system according to claim 1 wherein

the processor is configured to:

divide the target area into a plurality of meshes of the predetermined size;

extract height information about the plurality of meshes on a per-mesh basis, using environment data indicating a position and a shape of an object present in the target area; and

create the mesh data indicating the height information about the plurality of meshes on a per-mesh basis.

3 . The information processing system according to claim 1 , wherein

the mesh data indicates a structural object present in a building and an inner side of the building, excluding a ceiling, as a plurality of planes, and

the processor is configured to:

determine the two-dimensional ray trace from the transmission point at which a radio wave is transmitted in the building to the reception point at which the radio wave is received in the building, on the basis of the mesh data,

determine the three-dimensional ray trace corresponding to the two-dimensional ray trace, on the basis of height information about the transmission point and the reception point, and the mesh data, and

add a reflected ray and a diffracted ray from a ceiling surface of the building to the three-dimensional ray trace, on the basis of data of the building.

4 . The information processing system according to claim 1 , wherein the processor is configured to determine the two-dimensional ray trace with limiting a route from the transmission point to the reception point via a structural object, to a route from the transmission point to the reception point via a structural object having a line of sight from the transmission point or the reception point.

5 . The information processing system according to claim 1 , wherein the processor is configured to, when determining one of a reflected ray or a diffracted ray, determine the one of the reflected ray or the diffracted ray with restricting a launch angle of ray launching.

6 . The information processing system according to claim 1 , wherein the processor is configured to, when there is a plurality of structural objects between the transmission point and the reception point, use a Bullington model, to determine the diffracted ray that is diffracted by the plurality of structural objects.

7 . The information processing system according to claim 1 , wherein the mesh data is generated in the GPU-readable image-data format that serves as an input dataset directly consumed by the GPU for ray-tracing computation, and store the mesh data in the GPU-readable data format.

8 . The information processing system according to claim 1 , wherein

the mesh data has a GPU-readable data format, and

the processor is configured to read the mesh data with a GPU.

9 . A radio wave propagation simulation method comprising:

dividing a target area into a plurality of meshes of a predetermined size, and acquiring mesh data indicating an environment of the target area with height information about the plurality of meshes on a per-mesh basis;

determining a two-dimensional ray trace from a transmission point to a reception point on the basis of the mesh data, a radio wave being transmitted at the transmission point, the radio wave being received at the reception point;

determining a three-dimensional ray trace corresponding to the two-dimensional ray trace, on the basis of the mesh data, and height information about the transmission point and the reception point; and

calculating an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined by the determining a second ray trace,

wherein the dividing, the acquiring, the determining a two-dimensional ray trace, the determining a three-dimensional ray trace, and the calculating are implemented by an information processing system, and

wherein the method further comprises, when determining a diffracted ray with respect to the three-dimensional ray trace, determining the diffracted ray with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is not a line of sight in a route between the transmission point and the reception point.

10 . A non-transitory computer-readable recording medium storing a program for causing an information processing system to:

divide a target area into a plurality of meshes of a predetermined size, and acquire mesh data indicating an environment of the target area with height information about the plurality of meshes on a per-mesh basis;

determine a two-dimensional ray trace from a transmission point to a reception point on the basis of the mesh data, a radio wave being transmitted at the transmission point, the radio wave being received at the reception point;

determine a three-dimensional ray trace corresponding to the two-dimensional ray trace, on the basis of the mesh data, and height information about the transmission point and the reception point; and

calculate an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined, and

when determining a diffracted ray with respect to the three-dimensional ray trace, determine the diffracted ray with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is not a line of sight in a route between the transmission point and the reception point.