# US 12,602,859 B2 · Information processing system, ray tracing method, and program for radio wave propagation simulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,602,859 B2 - Document ID: US12602859B2 - Status: Granted - Kind: B2 - Application number: 18/284,276 - Filed: 2021-04-05 - Published: 2024-05-16 - Granted: 2026-04-14 - Earliest claimed: 2021-04-05 - Assignees: NTT, Inc. - Applicants: NTT, Inc. - Inventors: Minoru Inomata; Wataru Yamada; Nobuaki Kuno; Motoharu Sasaki - Web page: https://patentgrep.com/patent/US12602859B2 ## CPC - G06T 15/06: Ray-tracing - H04W 16/18: Network planning tools - G06T 15/50: Lighting effects - H04B 17/3912: {Simulation models, e.g. distribution of spectral power density or received signal strength indicator [RSSI] for a given geographic region} - H04W 16/20: for indoor coverage or short range network deployment - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract An information processing system includes: a first ray tracing unit configured to determine a two-dimensional ray trace from a transmission point at which a radio wave is transmitted, to a reception point at which the radio wave is received; a second ray tracing unit configured to determine a three-dimensional ray trace corresponding to the two-dimensional ray trace, using height information about the transmission point and the reception point; and a radio field intensity calculation unit that calculates the intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined by the second ray tracing unit. ## Claims ### Claim 1 An information processing system comprising: a processor configured to determine a two-dimensional ray trace from a transmission point at which a radio wave is transmitted, to a reception point at which the radio wave is received; determine a three-dimensional ray trace corresponding to the two-dimensional ray trace, using height information about the transmission point and the reception point; calculate an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined, and determine a diffracted ray in the three-dimensional ray trace with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is no line of sight in a route between the transmission point and the reception point. ### Claim 2 (depends on 1) The information processing system according to claim 1, wherein the processor is further configured to determine the two-dimensional ray trace from the transmission point at which the radio wave is transmitted in a building to the reception point at which the radio wave is received in the building, using environment data indicating a structural object present in the building and the inside of the building, and determine the three-dimensional ray trace corresponding to the two-dimensional ray trace, using height information about the transmission point and the reception point, and the environment data. ### Claim 3 (depends on 1) The information processing system according to claim 1, wherein the processor is further configured to determine the two-dimensional ray trace within a range of a predetermined number of transmissions, a predetermined number of reflections, and a predetermined number of diffractions. ### Claim 4 (depends on 1) The information processing system according to claim 1, wherein the processor is further 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. ### Claim 5 (depends on 1) The information processing system according to claim 1, wherein the processor is further configured to, when determining one of a reflected ray or a diffracted ray in the three-dimensional ray trace, determine the one of the reflected ray or the diffracted ray with restricting a launch angle of ray launching. ### Claim 6 (depends on 1) The information processing system according to claim 1, wherein the processor is further configured to, when there is a plurality of objects between the transmission point and the reception point, determine the diffracted ray, using a Bullington model. ### Claim 7 (depends on 1) The information processing system according to claim 1, wherein the processor is further configured to determine the two-dimensional ray trace from the transmission point to the reception point in a vertical plane, when there is not a line of sight from the transmission point to the reception point in a two-dimensional ray trace from the transmission point to the reception point in a horizontal plane, and determine that there is not a line of sight in the route between the transmission point and the reception point, when there is not a line of sight from the transmission point to the reception point in the two-dimensional ray trace in the vertical plane. ### Claim 8 A ray trace method comprising: determining a two-dimensional ray trace from a transmission point at which a radio wave is transmitted, to a reception point at which the radio wave is received; determining a three-dimensional ray trace corresponding to the two-dimensional ray trace, using height information about the transmission point and the reception point; calculating an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined; and determine a diffracted ray in the three-dimensional ray trace with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is no line of sight in a route between the transmission point and the reception point, wherein the determining a two-dimensional ray trade, the determining a three-dimensional ray trance, and the calculating an intensity of the radio wave are performed by an information processing system. ### Claim 9 A computer-readable non-transitory recording medium storing a program for causing an information processing system to: determine a two-dimensional ray trace from a transmission point at which a radio wave is transmitted, to a reception point at which the radio wave is received; determine a three-dimensional ray trace corresponding to the two-dimensional ray trace, using height information about the transmission point and the reception point; calculate an intensity of the radio wave at the reception point, using one or more three-dimensional ray traces determined in the second ray tracing process, and determine a diffracted ray in the three-dimensional ray trace with replacing a structural object present between the transmission point and the reception point with a flat metal plate when there is no line of sight in a route between the transmission point and the reception point.