Patent Description:
In wireless communication systems, typically, a broad area is divided into wireless cells (small zones), and one wireless base station (base station) is placed for one or more wireless cells. Base stations placed outdoors have at least one antenna, and wireless communication with a wireless terminal is realized via the antenna. Because the environment of radio waves emitted from the antenna affects the communication quality at the wireless terminal, the base station needs to be placed in an area where the communication quality at the wireless terminal can be kept good, such as an area where line-of-sight communication with the wireless terminal is possible.

Patent Literature Document <NUM> discloses a system in which a candidate area including a service area for which radio wave propagation from a base station is desired is divided into grids, the coverage of the service area is digitalized based on the result of a radio wave propagation simulation conducted when the base station is placed at a central position of the grids, and a site candidate for base station placement is selected from among a plurality of sites that satisfy a predetermined coverage, with reference to predetermined conditions. Patent Literature Document <NUM> discloses a data processing device comprising: acquisition means for acquiring an aircraft image; and determination means for determining whether or not an area is a site appropriate for base station placement.

However, in the technique disclosed in Patent Literature Document <NUM>, the larger the number of wireless terminals or the number of areas where wireless communication is to be supported is, the larger the number of service areas (numerical information relating to degrees of latitude and longitude) to be input is. This arises the problem that the processing load for selecting a site candidate for base station placement increases.

The present invention was made to solve the above-described problem, and it is an object thereof to effectively determine a site appropriate for base station placement.

According to the present invention, it is possible to effectively determine a site appropriate for base station placement.

The object, aspects, and effects of the present invention described above, as well as objects, aspects, and effects of the present invention that are not described above can be understood by those skilled in the art from the embodiments of the present invention described below by referring to the accompanying drawings and the scope of the claims.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Out of the component elements described below, elements with the same functions have been assigned the same reference numerals, and description thereof is omitted. Note that the embodiments disclosed below are mere example implementations of the present invention, and it is possible to make changes and modifications as appropriate according to the configuration and/or various conditions of the apparatus to which the present invention is to be applied. Accordingly, the present invention is not limited to the embodiments described below. The combination of features described in these embodiments may include features that are not essential when implementing the present invention.

An information processing apparatus <NUM> according to the present embodiment estimates (predicts) an open area based on acquired satellite image data using a trained open area prediction model, and calculates the openness of the open area. Then, the information processing apparatus <NUM> determines, based on the openness, whether or not the open area is a site appropriate for base station placement.

<FIG> is a block diagram showing an example of a functional configuration of the information processing apparatus <NUM> according to the present embodiment.

The information processing apparatus <NUM> shown in <FIG> includes an image data acquisition unit <NUM>, an estimation unit <NUM>, a construction data acquisition unit <NUM>, an openness calculation unit <NUM>, a determination unit <NUM>, an output unit <NUM>, and a learning model storage unit <NUM>. The learning model storage unit <NUM> is configured to be able to store a trained open area prediction model <NUM>.

The image data acquisition unit <NUM> acquires satellite image data (hereinafter, referred to as a "satellite image") using a suitable service (such as website or database). The image data acquisition unit <NUM> may acquire the satellite image through input of a user via an input unit (input unit <NUM> shown in <FIG>). The satellite image can be acquired from various earth observation optical satellites and is acquired from, for example, the Sentinel-<NUM>, which is a European earth observation optical satellite. The satellite image from the Sentinel-<NUM> can be added (updated) on a daily basis when it is available. The satellite image can be downloaded from a predetermined website relating to the optical satellite.

The estimation unit <NUM> estimates an open area by applying the satellite image acquired by the image data acquisition unit <NUM> to the trained open area prediction model <NUM> stored in the learning model storage unit <NUM>. In the present embodiment, an open area refers to an area with a spatial extent where base station placement for wireless communication is possible, and a typical example thereof is an area (site) where obstacles or constructions are not closely spaced, such as a parking area or a building roof. The estimation unit <NUM> may divide the image of the area into a plurality of images to generate patch images, and may apply the patch images to the open area prediction model <NUM>. Estimation processing performed by the estimation unit <NUM> will be described later. The open area estimated by the estimation unit <NUM> serves as a candidate area for base station placement.

The construction data acquisition unit <NUM> acquires information (construction height data) relating to the height of a construction from an external database. Furthermore, the construction data acquisition unit <NUM> is configured to also acquire altitude data from the external database. The construction height data and the altitude data are associated with position information (e.g., latitude and longitude) with which a position on map data (geographical data) can be identified. Accordingly, it is possible to acquire data on the height of constructions in the surroundings of the open area estimated by the estimation unit <NUM> and the altitude of the constructions. The construction height data and the altitude data are used for calculation of the openness performed by the openness calculation unit <NUM>.

The openness calculation unit <NUM> calculates the openness of the open area estimated by the estimation unit <NUM>. Openness indicates an index of spatial openness of the surroundings of the open area intended for base station placement (a degree of openness). Processing of calculating openness performed by the openness calculation unit <NUM> will be described later.

The determination unit <NUM> determines, based on the openness of the open area calculated by the openness calculation unit <NUM>, whether or not the open area is a site appropriate for base station placement. When multiple openness of multiple open areas have been calculated, the determination unit <NUM> determines whether or not each of the open areas is a site appropriate for base station placement. Determination processing performed by the determination unit <NUM> will be described later.

The output unit <NUM> outputs the result of determination processing performed by the determination unit <NUM>. For example, the output unit <NUM> outputs information relating to a site (open area) that was determined by the determination unit <NUM> as a site appropriate for base station placement. This "output" may be any output processing, and may be an output to an external apparatus via a communication I/F (communication I/F <NUM> shown in <FIG>) or displaying on a display unit (display unit <NUM> shown in <FIG>).

<FIG> is a block diagram showing an example of the hardware configuration of the information processing apparatus <NUM> according to the present embodiment.

The information processing apparatus <NUM> according to the present embodiment can be implemented on a single or a plurality of any computers, mobile devices, or other processing platforms.

Although <FIG> shows an example in which the information processing apparatus <NUM> is implemented on a single computer, the information processing apparatus <NUM> of the present embodiment may be implemented on a computer system including a plurality of computers. The plurality of computers may be connected to each other via a wired or wireless network to enable communication between the computers.

As shown in <FIG>, the information processing apparatus <NUM> may include a CPU <NUM>, a ROM <NUM>, a RAM <NUM>, an HDD <NUM>, an input unit <NUM>, a display unit <NUM>, a communication I/F <NUM>, and a system bus <NUM>. The information processing apparatus <NUM> may also include an external memory.

The CPU (Central Processing Unit) <NUM> is adapted to perform overall control of operations of the information processing apparatus <NUM> and controls the constituent components (<NUM> to <NUM>) via the system bus <NUM>, which is a data transmission path.

The ROM (Read Only Memory) <NUM> is a nonvolatile memory that stores control programs and the like that the CPU <NUM> needs to execute processing. Note that the programs may also be stored in a nonvolatile memory, such as the HDD (Hard Disk Drive) <NUM>, an SSD (Solid State Drive), or an external memory, such as a removable storage medium (not shown).

The RAM (Random Access Memory) <NUM> is a volatile memory and functions as the main memory, work area, and the like of the CPU <NUM>. That is to say, when executing processing, the CPU <NUM> loads a required program or the like from the ROM <NUM> into the RAM <NUM> and executes the program or the like to implement various functional operations. The learning model storage unit <NUM> shown in <FIG> may be constituted by the RAM <NUM>.

The HDD <NUM> stores, for example, various data, various information, and the like that the CPU <NUM> needs to perform processing using a program. The HDD <NUM> also stores various data, various information, and the like obtained by the CPU <NUM> performing processing using a program or the like.

The input unit <NUM> is composed of a keyboard and/or a pointing device, such as a mouse.

The display unit <NUM> is composed of a monitor, such as a liquid crystal display (LCD). When configured in combination with the input unit <NUM>, the display unit <NUM> may also function as a GUI (Graphical User Interface).

The communication I/F <NUM> is an interface that controls communication between the information processing apparatus <NUM> and external apparatuses.

The communication I/F <NUM> provides an interface with the network and executes communication with external apparatuses via the network. Various data, various parameters, and the like are transmitted and received to and from external apparatuses via the communication I/F <NUM>. In the present embodiment, the communication I/F <NUM> may perform communication via a wired LAN (Local Area Network) or a dedicated line that complies with a communication standard, such as Ethernet (registered trademark). However, the network that can be used in the present embodiment is not limited to this and may be configured as a wireless network. This wireless network includes a wireless PAN (Personal Area Network) such as Bluetooth (registered trademark), ZigBee (registered trademark), and UWB (Ultra Wide Band). The wireless network also includes a wireless LAN (Local Area Network) such as Wi-Fi (Wireless Fidelity) (registered trademark), and a wireless MAN (Metropolitan Area Network) such as WiMAX (registered trademark). In addition, the wireless network includes a wireless WAN (Wide Area Network) such as LTE/<NUM>, <NUM>, and <NUM>. Note that it is sufficient for the network to connect devices to enable communication between them, and the communication standard, scale, and configuration are not limited to the above examples.

At least some functions of the elements of the information processing apparatus <NUM> shown in <FIG> can be realized by the CPU <NUM> executing a program. However, at least some of the functions of the elements of the information processing apparatus <NUM> shown in <FIG> may operate as dedicated hardware. In this case, the dedicated hardware operates under the control of the CPU <NUM>.

An open area estimation procedure will be described. The estimation unit <NUM> applies the trained open area prediction model <NUM> stored in the learning model storage unit <NUM> to a satellite image acquired by the image data acquisition unit <NUM> to estimate at least one open area in the satellite image.

The open area prediction model <NUM> is a learning model for machine learning that can predict, upon input of a satellite image, at least one open area in the satellite image. The open area prediction model <NUM> is, for example, a learning model subjected to transfer learning of an object detection model such as Mask-RCNN trained using COCO dataset. Note that the object detection model is not limited to Mask-RCNN and other deep learning models may also be used. "COCO" refers to Common Objects in Context data set of Microsoft. In the present embodiment, the open area estimated by the open area prediction model <NUM> is defined as a parking area. That is to say, the open area prediction model <NUM> is a learning model that has trained, upon input of a satellite image, a parking area in the satellite image as a ground true label. Note that an open area is not limited to a parking area and, typically, an open area need only be a site where obstacles or constructions are not closely spaced, such as a building roof.

The estimation unit <NUM> applies the satellite image acquired by the image data acquisition unit <NUM> to the open area prediction model <NUM>. In the present embodiment, the estimation unit <NUM> divides the satellite image into a plurality of image patches and applies the patch images to the open area prediction model <NUM>, in order to reduce the calculation amount. <FIG> is a conceptual diagram showing image patch generation. In the example of <FIG>, the estimation unit <NUM> divides the satellite image acquired by the image data acquisition unit <NUM> into image patches in <NUM> x <NUM> pixels to generate <NUM> patch images [<NUM>] to [<NUM>]. Note that the number of pixels of the image patches is not limited to a specific number.

<FIG> is a conceptual diagram illustrating an open area (a parking area in the present embodiment) estimated by applying image patches (satellite images) to the open area prediction model <NUM>. Upon input of a satellite image (image patch) <NUM>, the open area prediction model <NUM> outputs an image <NUM> including an estimated open area <NUM>. Note that when the open area is defined as a parking area, the open area prediction model <NUM> may be a learning model trained using, in addition to the combination of the satellite image and the ground true label (parking area), a dataset that includes road network information, in order to prevent roads from being estimated as open areas. Note that for open area estimation using machine learning, a human may confirm whether an estimated open area (the open area <NUM> in <FIG>) is an area used as a parking area instead of a park, for example. In this case, the open area confirmed by the human may be output as the output of the estimation unit <NUM>.

The open area estimated by the estimation unit <NUM> serves as a candidate area for base station placement. The open area estimated by the estimation unit <NUM> is converted into geographic coordinates on map data (geographical data), and the coordinates are output as information indicating the open area to the estimation unit <NUM>. For example, four coordinates of the bounding box of the estimated open area are output as information indicating the open area to the estimation unit <NUM>.

Note that although, in the present embodiment, the estimation unit <NUM> estimates an open area using machine learning, the estimation unit <NUM> may be configured to estimate an open area (e.g., a parking area or a building roof) from a satellite image using another known image processing technique.

After the open area (candidate area for base station placement) has been estimated by the estimation unit <NUM>, the openness calculation unit <NUM> calculates the openness of the candidate area. Openness indicates an index of spatial openness of the surroundings of the open area. The following will describe, with reference to <FIG>, an openness calculation procedure. <FIG> are conceptual diagrams illustrating an openness calculation procedure.

First, the openness calculation unit <NUM> sets, in the open area, a predetermined number of rays that are cast in a predetermined range from a candidate position for base station placement. The rays are pseudo/virtual and are used for simulation of openness calculation. The openness calculation unit <NUM> calculates, as openness, the ratio of the lengths of rays remaining without being blocked by an obstacle to the entire lengths of the predetermined number of rays.

<FIG> is a conceptual diagram showing rays cast from the candidate position for base station placement. In <FIG>, the position (white rectangle in the center) of a future base station <NUM> may be located at or near the center of the open area. Note that in <FIG>, the position of the base station <NUM> is indicated as a position having a certain region expressed by a rectangle, but the position of the base station <NUM> may be expressed by a point or another shape such as a circle. Also, in the present embodiment, the rays are cast from the position of the base station <NUM> over <NUM> meters in the horizontal direction at intervals of azimuthal angle of <NUM> degrees. Accordingly, <NUM> rays (= <NUM>/<NUM>) are set (at <NUM>, <NUM>, <NUM>,. , <NUM> degrees). A ray range <NUM> may be larger than the open area and may correspond to the range of cells for which services are provided. In the present embodiment, the rays are cast over <NUM> meters, but this is an example.

The openness calculation unit <NUM> calculates the height of a construction serving as an obstacle present in the ray range <NUM>, based on the construction height data and the altitude data acquired by the construction data acquisition unit <NUM>. Note that the height of a construction may be construction height data itself, but the value of the accurate height of the construction from the sea level can be obtained through calculation using the altitude data (by adding the value of the altitude data to the value of the construction height data).

<FIG> shows the positional relationship between the base station <NUM> and an obstacle. In the example of <FIG>, the rays are cast from the top of the base station <NUM> in a range of <NUM> meters in the horizontal direction. Note that the source from which the rays are cast is an end portion of the top of the base station <NUM> in <FIG>, but the source may be located at any position on the top of the base station <NUM>. In <FIG> shows a case where the construction <NUM> and a construction <NUM>, which serve as obstacles, are present within a range of <NUM> meters in the horizontal direction from the candidate position for placement of the base station <NUM>. In this case, the openness calculation unit <NUM> detects a cross point between a ray cast from the base station <NUM> at a set depression angle (downward angle with respect to the horizontal direction. Hereinafter, referred to as "casting angle") and an obstacle. Then, the openness calculation unit <NUM> deletes (slices) a portion of the ray having the cross point that is located further than the cross point (that is, portion of the ray between the cross point and an end of the ray opposite to the casting source). If a plurality of cross points between the rays and the obstacle are detected, the cross point closer to the position of the base station <NUM> is used.

The height of the base station <NUM> may be set to a suitable value. The height of the base station <NUM> may include the height of the antenna provided in the base station <NUM>. In the present embodiment, the open area is defined as a parking area, but if the open area is defined as a building roof, the height of the base station <NUM> includes the height of the building.

As shown in <FIG>, the cross point between a ray cast from the base station <NUM> and the obstacle varies according to the casting angle. In <FIG>, if the casting angle is <NUM> degrees, no cross point is detected between the ray and the construction <NUM> and between the ray and the construction <NUM>. If the casting angle is <NUM> degrees or <NUM> degrees, a cross point between the ray and the construction <NUM> is detected. If the casting angle is <NUM> degrees, a cross point between the ray and the construction <NUM> and a cross point between the ray and the construction <NUM> are detected. Accordingly, if the casting angle is <NUM> degrees, the cross point between the ray and the construction <NUM>, which is closer to the position of the base station <NUM>, is used. Thus, since the position of the cross point between the ray cast from the base station <NUM> and the obstacle varies depending on the radiation angle, it can be said that the calculated openness depends on the setting of the casting angle. The casting angle may be set in advance, or may be set to any value according to the performance of the antenna provided on a future base station and/or the size of the cell (cell design) for which the base station provides communication services.

<FIG> shows a conceptual diagram of rays that remain without being blocked by the obstacle. The openness calculation unit <NUM> calculates the ratio of the length of the rays that remain without being blocked by the obstacle (the final length of the rays) to the total length of the rays, as the openness. In other words, the openness calculation unit <NUM> calculates the openness by using the total length of rays when there is no obstacle (sum total of the lengths of all the rays shown in <FIG>) as the denominator and the total length of rays that remain without being blocked by the obstacle (sum total of the final lengths of the rays shown in <FIG>) as the numerator. As described above, since the calculated openness can depend on the setting of the casting angle, the openness calculation unit <NUM> may set a plurality of casting angles and calculate the openness for each of the casting angles.

The openness calculation unit <NUM> calculates the openness of the open area estimated by the estimation unit <NUM> and outputs the calculated openness to the determination unit <NUM>. If there are a plurality of open areas estimated by the estimation unit <NUM>, the openness calculation unit <NUM> calculates the openness of each of the open areas and outputs the calculated openness to the determination unit <NUM>.

The determination unit <NUM> determines, based on the openness of the open area calculated by the openness calculation unit <NUM>, whether or not the open area is a site appropriate for base station placement. The determination unit <NUM> may determine an open area whose openness is higher than a predetermined threshold as the site appropriate for base station placement. Alternatively, the determination unit <NUM> may set various conditions other than the openness and may determine an open area that satisfies the conditions as the site appropriate for base station placement. The conditions include, for example, the width of a road adjacent to the open area (large width, e.g., <NUM> meters or more or small width, e.g., <NUM> meters or more and less than <NUM> meters) and the distance (greater than or equal to a predetermined value or less than the value) between a future base station and an existing base station.

Also, the determination unit <NUM> may sort the open area into one of a plurality of categories based on the value of the openness. In this case, various conditions, such as the width of a road adjacent to the open area and the distance between a future base station and an existing base station, may be taken into consideration. For example, the determination unit <NUM> may sort an open area whose openness is <NUM> or more into an excellent candidate category, and an open area whose openness is <NUM> or more and less than <NUM> into a satisfied candidate category.

Note that, in the present embodiment, the open area estimated by the open area prediction model <NUM> is defined as a parking area, but if the estimated open area is defined as the roof of a building, different conditions for determination by the determination unit <NUM> may be used. For example, in addition to the determination conditions for the case of a parking area, the height of the building may be taken into consideration.

The following will describe a flow of overall processing performed by the information processing apparatus <NUM> according to the present embodiment. <FIG> is a flowchart of processing executed by the information processing apparatus <NUM>. Note that the flowchart shown in <FIG> can be realized by the CPU <NUM> of the information processing apparatus <NUM> executing a control program stored in the ROM <NUM> or the RAM <NUM> and executing operation and processing on information as well as control of the pieces of hardware.

In step S61, the image data acquisition unit <NUM> acquires a satellite image of an area where a base station is planned to be placed. For example, the image data acquisition unit <NUM> acquires the satellite image by downloading it from a predetermined website or accepting an input of the image by a user via the input unit <NUM>.

In step S62, the construction data acquisition unit <NUM> acquires information (construction height data) relating to the height of a construction in an area at least including the area of the satellite image acquired by the image data acquisition unit <NUM>, and altitude data. For example, the construction data acquisition unit <NUM> acquires the construction data from an external database. The construction height data and the altitude data are associated with position information (e.g., latitude and longitude) with which the position on map data (geographical data) can be identified.

In step S63, the estimation unit <NUM> applies the satellite image acquired by the image data acquisition unit <NUM> to the open area prediction model <NUM> to estimate at least one open area in the satellite image. The processing for estimating the open area is as described above with reference to <FIG> and <FIG>.

In step S64, the openness calculation unit <NUM> calculates the openness of the at least one open area estimated by the estimation unit <NUM>. The processing for calculating the openness is as described above with reference to <FIG>, and the calculated result is expressed as a numeric value of <NUM> to <NUM> or in percentage terms.

In step S65, the determination unit <NUM> determines, based on the openness of the open area calculated by the openness calculation unit <NUM>, whether or not the open area is a site appropriate for base station placement. As an example, the determination unit <NUM> determines an open area whose openness is higher than a predetermined threshold as the site appropriate for base station placement. Also, as described above, taking into consideration other conditions (for example, the width of a road adjacent to the open area and the distance between a future base station and an existing base station), the determination unit <NUM> may determine whether or not the open area is a site appropriate for base station placement.

In step S66, the output unit <NUM> outputs the result of determination by the determination unit <NUM>. For example, the output unit <NUM> generates information (hereinafter, referred to as "placement candidate information") based on the result of determination by the determination unit <NUM> and displays the information on the display unit <NUM>. <FIG> illustrates examples of placement candidate information displayed on the display unit <NUM>. In the examples of <FIG>, pieces of placement candidate information <NUM>, <NUM>, and <NUM> that correspond to the open areas <NUM>, <NUM>, and <NUM> estimated in a satellite image <NUM> and a satellite image <NUM> are shown. Also, in the present example, the predetermined threshold used by the determination unit <NUM> is defined as <NUM>% (<NUM>). That is to say, if the openness of an open area is greater than or equal to <NUM>%, the determination unit <NUM> can determine it is the openness for the site appropriate for base station placement.

In <FIG>, the openness of the open area <NUM> estimated in the satellite image <NUM> is <NUM>% (<NUM>), and thus the open area <NUM> is determined as being a site appropriate for base station placement. In this case, for example, the output unit <NUM> displays the placement candidate information <NUM>, together with the address and the openness of the open area <NUM>.

Also, the openness of the open area <NUM> estimated in the satellite image <NUM> is <NUM>% (<NUM>), and thus the open area <NUM> is determined as being a site appropriate for base station placement. In this case, for example, the output unit <NUM> displays the placement candidate information <NUM>, together with the address and the openness of the open area <NUM>.

Even if the openness of an open area is less than the predetermined threshold, the output unit <NUM> may also display the placement candidate information of this open area. The openness of the open area <NUM> estimated in the satellite image <NUM> is <NUM>% (<NUM>), and thus the open area <NUM> is determined as being a site inappropriate for base station placement. In this case, for example, the output unit <NUM> may also display the placement candidate information <NUM> of the open area <NUM>, in a mode different from the placement candidate information <NUM> and <NUM> of the open areas <NUM> and <NUM> whose openness are greater than the threshold.

As a result of such placement candidate information being provided, for example, a communication common carrier can take, with respect to a site that has a high openness and is determined as being appropriate for base station placement, a procedure for acquiring this site to place a base station, such as checking the owner of the site.

On the other hand, with respect to a site that has a low openness and is determined as being inappropriate for base station placement, the communication common carrier can proceed with preparations for improvement of the environment of the area in the surroundings of the site, in order to raise the openness, as needed.

Claim 1:
An information processing apparatus comprising:
acquisition means (<NUM>) for acquiring a satellite image;
estimation means (<NUM>) for estimating, in the satellite image, an open area with a spatial extent where base station placement for wireless communication is possible;
calculation means (<NUM>) for calculating openness of the open area using rays virtually cast from a predetermined position in the open area; and
determination means (<NUM>) for determining, based on the openness, whether or not the open area is a site appropriate for base station placement.